[UCSB] PSY 123: Cognitive Neuroscience
What are ERP's?
Aka Event related potential Stimuli like a tone creates electrical potential
how are epochs made possible?
EEG signals are recorded continuously but markers (mark the exact time when each stimulus was presented) segment EEG data in epochs
What brain regions are involved in cognitive control?
regions of the PFC:
How do proton precess?
Protons precess around the main magnetic axis (spinning top analogy).
memory bias,
the changing of memories over time so that they become consistent with current beliefs or attitudes
How is a TMS used?
applies a magnetic pulse to a certain brain region to temporarily modulate the function of that region.
Camillo Golgi (1843 - 1926)
developed the Golgi stain can visually see a neuron! (believed the brain was a physically connected network, the Reticular theory)
What is lateralization?
different parts of the brain have different functions, and that the left and right hemispheres of the brain, in particular, have their own specialization
Amygdala is not a homogenous structure, why?
different regions of the amygdala have different input/output anterograde and retrograde experiments to track input/output in amygdala areas higher resolution imaging/histology = show different neuronal subtypes
Beta wave is seen in ______region ?
frontal
effective connectivity
how easily activity can travel along a particular pathway between two structures
Is there functional specificity in PFC regions? why is this a hard problem?
it's very hard to give specific functions to regions in the frontal cortex BECAUSE the regions are highly connected!! but we still try to give specific functions to different frontal brain regions
Where did the false split brain ideas come from?
lateralization
reversal learning
learning that a previously rewarded stimulus or response is no longer rewarded vmPFC codes value OFC does not code stimulus value, but signals the amygdala when the value expectation is violated
What have gunshots in different hemispheres of the orbitofrontal cortex told us about laterality there? !skeptical
left = anxious depressive response right = character deficit / personality disorder !SKEPTICAL!!!
neocortex cell types and density !ask to explain this graphic
left = golgi stain (few full neurons) middle = Nissl stain (show cell body) right = weigert stain (axons) !ask yourself to add textbook info on the different layers
98% of right handed people have language in what hemisphere of the brain?
left hemisphere
Describe the asymmetry in visuo-spatial processing
left hemisphere does not have ability to put together higher order spatial relationships
Is there asymmetric control of attention?
lesions to left brain = mild attention impairments right brain = severe postulating right brain is allocating attention to both right and left visual field, but left is only to right hemisphere??? ^ not verified, but possibility
where is the precentral sulcus? what is it?
lies parallel to, and in front of, the central sulcus somato-motor cortex because it controls volitional movements of the contralateral side of the body.
What is maintenance and what is manipulation in working memory tasks?
n-back task: Maintenance: Hold information in mind (1-back task) - ventral PFC (keeping attentional set) Manipulation: Update information in mind (2-back task) - dorsal and superior prefrontal region + frontal and parietal interactions increase!
What cortical and subcortical computations in the sensorimotor network support the production of coordinated movement?
!add
What is the relationship between the ability to produce movement and the ability to understand the motor intentions of other individuals?
!add
What are some differences in selective attention between endogenous and exogenous spatial attention?
!add or remove
Why might you use a control group with a lesion in a different region when providing evidence causality of a different brain lesion's function?
!ask
Inhibition of BLA and CE's effect on fear conditioning
!ask I don't know how this works hopefully it's not too important
Organization of rods and cones in the fovea
!ask urself to add this/study
Locate these in the brain in a midsaggital plane: corpus callosum hypothalamus spinal cord cerebellum pons midbrain
!ask yourself to add cards from psy 106
What is the difference between static and functional brain imaging?
!ask, which are for what?
cool example of hemispatial neglect patient asked
+ burning house example + amygdala response to faces with left side showing fear/anger
human versus cat visual field
- 20 degree wider FoV - 1/6 amount of light required to see in the dark = larger rods and larger pupils - blue yellow tones not red - light is further reflected inside the eye
What is noise noise in EEG?
- background brain activity - random with respect to onset so averages to zero
What did Phineas Gage teach us about Social Cognition?
- became impatient, cursed a lot - less presitguous job - PFC does not impact IQ or fear learning but does affect impulsitivity and social behavior
What is a signal in EEG study?
- brain response evoked by stimulus - stimulus locked, repeatable, and the same activity on every trial of a certain type (ex. brain sees happy face will react in a certain way) - constant
Using an EEG, what part of the brain can you image? why?
- brain signals not traveling straight to EEG receptors, but are filtered out b biological tissue in the way (cortex and superficial layers of cortex can be imaged)
What parts of HM's brain were affected from surgery?
- entorhinal cortex (input from posterior parietal cortex via dorsal stream !ask urself to verify) - hippocampus (large part removed) - para-hippocampal gyrus - cerebellum impacted and lost part of amygdala
What are ventricles?
- fluid filled spaces in the brain that are lined with specialized endothelium = ependymal cells
What are pyramidal cells?
- large neurons - common in cortex - allow conscious control of precise, skilled, skeletal muscle movements - cell body has a pyramidal shape - lots of dendrites
What is signal to noise (SNR)?
- relative strength of the signal compared to noise - averaging increase SNR by decreasing the influence of random activity
What are the upsides of using an MRI?
- spatial resolution very good - Immediate imaging of lesions
Pop out search vs. conjunction search
- target defined by a single feature (pop out) vs. by a conjunction of features (conjunction) that are also shared by distracters - pop out search is fast and pre-attentive while conjunction search requires attention in a sequential manner (must attend to each individual object to detect targets)
Inside a magnetic field, how are hydrogen protons oriented?
Oriented with or against B0 NOTE: M= net magnetization
Mental state attribution theory
Originally called theory theory. A theory proposing that we acquire a commonsense "folk psychology" and use it, somewhat like a scientific theory, to infer the thoughts of others ("mind-read")
mental state attribution theory
Originally called theory theory. A theory proposing that we acquire a commonsense "folk psychology" and use it, somewhat like a scientific theory, to infer the thoughts of others ("mind-read")
Contents of consciousness
Our immediate environment and our current concerns.
What changes occur in the frontal lobes during late stages of life?
Over ~70, decreases in number of cells in prefrontal cortex but the cells that remain try harder so tasks that used to be automatic are no longer, and the frontal lobe is activated more instead
What are the Differences between the PET scan vs fMRI?
PET allows you to track multiple metabolic processes so long as the emitted photon can be detected - allows imaging of some neurotransmitters. PET is invasive - radioactive isotopes can only be administered (at experimental levels) every 4 - 5 years. fMRI has much greater spatial resolution (≈ mms). fMRI has greater temporal resolution - can detect activation to stimuli appearing for less than a second (PET is limited by the half life of the isotope used).
Difference between FMRI and the PET scan for using the subtraction method?
PET: is just a cartoon "average" brain overplayed with the information FMRI: uses the persons actual anatomical structure
What is the last region to develop phylogenetically and ontogenetically?
PFC especially mid-LPFC last region to fully myelinate in late teens or sometimes early twenties centrifugal pattern of development: 1. premotor cortex first 2. rostral medial PFC regions 3. further and further anterior
Godden and Baddeley (1975) asked scuba divers to learn a list of 36 words
The divers were separated in two groups: the first group learned the words on land, and the second group learned the words underwater. After this learning stage the scuba divers were asked to recall the words, both on land and in water. Figure 3 shows the results of this study: when the context for learning and recalling were the same, the scuba divers recalled more words.
Freq of theta waves?
4-7Hz
Freq of delta waves ?
4Hz
anterior and posterior commissures- where are they? what are they?
Additional connections between the hemispheres
What are we measuring in an emotion response? (according to Richard J Davidson from UW Madison)
Affective chronometry describes the time-course of an emotional response. • Emotional responses can be broken down into the "3 R's": •Reactivity •Recovery •Regulation
When do we experience conflict?
We experience conflict when a prepotent response should not be enacted!
attentional blink phenomenon
a manifestation of selective attention; when we focus on one event, it takes a moment or two to fully recover our information and shift it to a novel stimulus
Fast Fourier Transform (FFT)
a mathematical process used for analyzing and processing the Doppler signal to produce the spectral waveform
StereoElectroencephalography (sEEG)
a minimally invasive procedure. It uses electrodes placed directly in the brain to identify where epileptic seizures start. 2mm apart?
oddball effect
a perceptual phenomenon whereby novel or unexpected stimuli result in longer perceived time durations.
Repetition suppression (fMRI analysis technique):
a phenomenon that refers to the finding that if we process the same stimulus twice, BOLD is reduced (akin to "habituation"). Now we can look at "habituation" (or Repetition Suppression) of parietal and prefrontal cortex and compare whether they respond/habituate to outcomes (goals), movement, or both when u see something again, ur neurons dont respond as strongly as at first
power spectrum EEG
a plot of the power (energy per unit of time) of given frequencies of a sound
Cortical motor system (M1)
accessible! Extensively studied using Transcranial Magnetic Stimulation (TMS ~90 hz firing rate TMS single pulses to M1: produce visible (and easily quantifiable using EMG recordings) MEPs & muscle twitches
What happens when a patient suffers a lesion in V4?
achromotopsia- requires dramatic change in color for the patient to understand a color change has occured - a lack of cone vision processing
What is the difference between online and offline TMS protocol?
administered online - e.g., single pulses (1 sec) delivered during the task - can provoke motor movements, phosphenes, "disrupt" task processing at specific time points offline - prolonged administration of a repetitive protocol that lasts for 20-60 minutes; - one example is called "continuous theta burst/cTBS")
Subjective experience may or may not accompany a change in affect, (self report may not change), agree or disagree? why?
agree,
when is single cell recording used in humans?
are/clinical samples (e.g. epilepsy)
Where do motor and sensory pathways cross?
at the brain stem
Information in the peripheral of the visual field processed by fovea is processed where in the brain?
deep into calcarine sulcus
Different layers of the cortex
deep layers develop early superficial = last to mature (higher order cognition?) !ask yourself to add textbook info on the different layers
What did SM, who had a bilateral amygdala lesion teach us about fear conditioning?
does not sweat to conditioned stimulus BUT she knows shock is coming = double dissociation (next flashcard with WC) method: fear conditioned to sound/image and shock + measured skin conductance SCR + measured declarative knowledge, if they knew what stimuli presented the shock
hyperkinetic disorder
excessive motor movements damage to basal ganglia Huntington's disease In simplified form, there is either "too much" or "too little" excitation of the cortex (not enough "braking" by the output of the basal ganglia, internal Globus Pallidus), which may result in: • Hyperkinetic disorder (too much movement): Huntington's chorea • Hypokinetic disorder (too little movement): Parkinson's disease
how are ERPs obtained?
from averaging EEG epochs
prosopagnosia
inability to recognize faces = see a face and can describe features of the faces but cannot recognize who it is even if the person next to them is the same
How is the ERP evoked response changed by attention allocation?
increase in P1 magnitude (earliest visual evoked response, V2 V3 dependent most likely)
Describe the new methodology of the improved Macaque study to investigate more long term memory
increased delay time + select the opposite well (not the trained one) Monkey has to learn to pick the NEW object Monkey's were lesioned in either hippocampus (HP) or parahippocampal region (HPP)
Gamma motor neurons
innervate intrafusal muscle fibers - important for sense of where our body is in any moment = feedback on body position
In 150 primate species, a scientist found that how much of total brain matter was made up by PFC can be predicted by ______ (one major predictor)
Average size of species' social group
Faux pas test
Awkwardness/insult detection. Medial frontal lobe damage scored lowest on each question. Anne offended Janette but she was being sincere OFC patients have harder time with this compared to Dorso frontal lesioned and healthy patients
What is the difference between Broca's and Wenicke's Aphasia?
Broca - difficulty/inability to talk, speech comprehension intact Wernicke - can talk, but usually nonsense, difficulty understanding speech
How do case studies of patients with dense amnesia (Klein et al., 2002; Tulving, 1993) support that we should be able to maintain a sense of self even if we are robbed of our autobiographical memories?
DB retrograde amnesia (hypoxia) KC anterograde amnesia (motorcycle) Neither of these patients could recall a single thing they had done or experienced in their entire life, yet both could accurately describe their own personality = consistently with testimonials ALTHOUGH Db could not accurately recall personality traits of his daughter
What do patients with damage to the Inferior Temporal (IT) exhibit?
Damage to inferior temporal and inferior occipital brain areas • Developed visual agnosia (inability to recognize objects!) = can recall them (memory is intact), but cannot recognize them and recreate them can use their motor cortex to understand what they want to do with an object and can understand size of it but cannot recognize it visually (telephone and lock and clock examle)
Patient R.M.
Damage to occipital and parietal lobes Could draw accurate pictures of objects in front of him Could not draw accurate pictures of objects from memory (using imagery) extensive bilateral damage affecting his orbitofrontal cortex, temporal pole, and amygdala. compared his performance in two contexts: (a) social contract problems of the form "If you take the benefit B, then you must satisfy the requirement R," giving the example "If you borrow my car, then you have to fill up the tank with gas"; and (b) precautionary rules of the form "If you engage in hazardous activity H, then you must take precaution P," with the example "If you do a trapeze act, you must use a safety net." On the pre cautionary tasks, R.M. performed as well as control participants and two other patients with similar but nonoverlapping brain lesions—but he was 31 percent- age points worse than they were on social contract reasoning. supplies additional evidence that reasoning about social exchange is a specialized and separable compo- nent of human social intelligence
What are the most readily available atoms in the human body?
Hydrogen protons
What idea inspired fMRI machine to be made? How does it work/What does it rely on?
Idea before evidence: blood flow increase when you think = to supply more oxygen (to burn glucose and provide energy) Evidence: Fox and Raichle tried to show this, and found that oxygen consumption was constant thought changes in blood flow and glucose consumed fMRI relies on: if hemoglobin does not have much Oxygen attached = disrupts magnetic field EVIDENCE fmRI worked: see blood vessels in rats breathing room air versus no vessels breathing 100% oxygen Resulting Machine: "blood oxygen level dependent signal" to examine human acitvity in the brain
explicit attitudes vs implicit attitudes
Implicit -Unconscious associations -Experiential/fast system Explicit -Consciously accessible -Controllable and easy to report -Rational/slow system -Reported by an IAT, so it measures reaction times
Color "Blobs" in V1 - What are they? where are they?
In V1, each hypercolumn has one set of R/G and one set of Y/B for color processing
Brain areas involved in motor action
In addition, two major subcortical structures of the motor system are the cerebellum and the basal ganglia many neural structures of the motor system located in the brainstem basal ganglia similar to cerebellum: Input is restricted mainly to the two nuclei form- ing the striatum, and output is almost exclusively by way of the internal segment of the globus pallidus and part of the substantia nigra.
covert vs. overt attention
In addition, where you're looking doesn't always indicate what you are paying attention to; for example, it would be possible for you to turn your attention to the light on the stage curtain, even while continuing to fix your eyes on the friend next to you. This type of attention is called covert attention; when you are looking at and paying attention to the same location, that is overt attention.
vigilance of attention
In modern psychology, vigilance, also termed sustained concentration, is defined as the ability to maintain concentrated attention over prolonged periods of time. During this time, the person attempts to detect the appearance of a particular target stimulus
ipsilateral fibers
In the case of vision, those optic nerve fibers that project from one eye to the same side of the brain.
How does a DTI work?
In white matter, water preferentially travels along the direction of the axons (anisotropic diffusion) • In gray matter, water diffuses in all directions equally (isotropic) • By reconstructing the direction and amount of water diffusion for each voxel one can infer the most likely direction of the axons present in that voxel
Neural Pathways in Amygdala for fear conditioning
Inactivation of Basolateral Amygdala (BLA) prevents fear learning • Required for the actual association of CS+<->US -i.e. storage site! • Inactivation of Central Nucleus CeA also prevents alters fear learning • Required for the expression of the conditioned response
Locked-in syndrome
Individual is conscious, aware, and capable of thinking but is paralyzed and cannot communicate average lock down syndrome diagnosis = 78 days
What is a coup injury?
Injury directly below the point of impact brain goes back to front in car accident example and the brain may hit the ridges of the skull
Does your amygdala need conscious awareness to work? (what is the method to test this and results)
Intact response to 'invisible' untrustworthy faces NO same amygdala activity relationship whether u are conscious of those faces or not Living with affective blindsight: • Intact amygdala response to subjectively invisible emotional expressions • Preserved facial emotion discrimination (~60%correct) • Despite subjective blindness for squares & circles (45% correct • Fast & strong responses to non-conscious emotional stimuli • pupil dilates (measure of arousal with faster temporal resolution) = greater to fearful faces rather than happy faces even unconscious to what facial expression
What is intertemporal discounting?
Intertemporal choice involves deciding between smaller, sooner and larger, later rewards. People tend to prefer smaller rewards that are available earlier to larger rewards available later, a phenomenon referred to as temporal or delay discounting
Michael Gazzaniga's split brain experiment findings
Left FoV= Do not know what word they saw (right hemisphere can comprehend simple words of concrete objects, but cannot speak it) Right FoV = knew what word they saw (language abilities in left hemisphere) Hand matching visual field = found object mismatch = could not find or did not know what they were looking for-- (still a question why)
What provided evidence for the localization of motor function in the pre-central gyrus (and somatosensory function in the post-central gyrus)
Lesion and stimulation experiments !add from textbook or !ask to help clear this card
What are the differences of MRI vs fMRI?
MRI - High resolution - scans anatomical structures fMRI - low resolution - scans metabolic function !ask do they do the same thing with oxygen molecules in their magnetic field?
To image the amygdala of a live patient, what imaging technique would you use?
MRI T2 scan
What factor determines image contrast in an MRI?
MRI image acquisition time
What is a T1 scan? What is its acquisition time?
MRI: anatomical scans H20 relaxes at 2.5 seconds, so a T1 scan (acquisition time=0.5 sec) has little (no) water signal ventricles (which contain CSF) are dark
What is an MRI scan?
Magnetic Resonance Imaging [MRI],
How does positron emission tomography (PET) scan work?
Measures local changes in cerebral blood flow (CBF) by utilizing radioactive tracers that rapidly decay and emit positrons. When the positrons collide with electrons, two photons travel in opposite directions allowing the location of the collision to be determined.
Monism vs. Dualism
Monism is the belief that ultimately the mind and the brain are the same thing, whereas dualists believe that the mind and the brain are separate
What happens when a delay for holding information in short term memory is more than several seconds? what about long term memory? (results of improved macaque study)
Monkeys had selective lesions of hippocampus (HP) or parahippocampal region (HPP) green hippocampal + blue parahippocampal = impaired in performance from longer delays performed well in working memory task increased delay = medial temporal regions are recruited to maintain information for that long = HPP most impaired, then HP
in what ways are varying levels of awareness NOT correlated with wakefulness level
intermediate physiological state but quite drastic level of awareness conscious minimally conscious vegetative/unrepsonsive
What are the main types of brain imaging techniques?
intracranial EEG (ECoG, sEEG) , noninvasive EEG MEG MRI, fMRI DTI PET CAT !ask do we need to know about CAT/PET scans? it wasn't in lecture video
Define precess
is a change in the orientation of the rotational axis of a rotating body.
Experience sharing
it involves the desire and skills to be a good reciprocal playmate, to value others' points of view, to develop friendships, and to conduct emotion-based interactions automatic empathy less conscious than competing theory
Who's controlling the control? Who told the goal directing region what the role is?
likely mechanisms of midbrain dopaminergic reinforcement learning is used to determine what rule or set is currently use to influence behavior these neurons are sensitive to... - reward when you don't expect it - stimulus that predicts a reward - lack of reward when a reward was predicted = dopamine reward prediction error - timing of reward then they project dopamine WIDELY throughout the brain DA Prediction signals (positive and negative) acts like an "error signal" telling the rest of the brain something went wrong (or right)
three common tasks to asses hemispatial neglect (hemineglect)
line cancellation test line bisection task copy the model and redraw it
where is the intraparietal fissure?
located on the lateral surface of the parietal lobe
When Protons are pushed out of alignment with the magnetic field _________________ refers to the time it takes for them to come back into alignment with the magnetic field.
longitudinal relaxation
If you want to affect a deeper region of the brain with TMS, what strategy is there?
look for associated networks to have a network level impact! Like make the study's task to learn an object along with it's spatial location so that when you use TMS on the spatial location area in the parietal lobe, you also affect the hippocampus?? association of anatomy and function example: hippocampus is not reachable, but you can find the portion of the inferior parietal cortex which is strongly associated with the hippocampus and use TMS there to indirectly inhibit the hippocampus
Images in the upper visual field are processed by which area in the occipital lobe? and vice versa
lower
Santiago Ramon y Cajal (1852-1934)
neurons: - postulated that neurons are discrete entities! - first to note info travels one way from the dendrites to the axon and not the reverse beautiful cell drawings: - purkinje cell and pyramidal cells - Shared the 1906 Nobel Prize with Golgi
What two types of brain damage occur most commonly from accelerative forces?
orbitofrontal cortex and diffuse axonal injury
If experiences trauma to the head, what brain area is most likely to be damaged? why?
orbitofrontal cortex due to bad skull design the ethmoid and sphenoid ridge are sharp and will damage the brain tissue in rapid acceleration and stop
What part of the frontal love is very susceptible to damage from a traumatic head injury? Why?
orbitofrontal lobe because of the anatomy of the bones makes it likely to get bruised
(contextual) fear conditioning paradigm
rat learns to associate tone and shock In contextual fear conditioning, rat learns to associate the room with a shock, without any tone Function of the amygdalar nuclei are critical for emotional memory formation!
What is the BOLD signal?
ratio of oxygenated/deoxygenated blood oxygen level dependent signal (FMRI) indirect measure of neural activity (correlation, not causaton) change in is correlated with brain activity
Electroencephalography (EEG)
recording of the oscillatory electrical activity of the brain measures voltage changes that vary ms-by-ms when ions flow into and out of brain cells in the cortex
Measuring levels of consciousness across three patients with TMS-EEG probe
recovered: resembled healthy awake patients wave travels through many brain regions for a long period of time
What types of cones do we have?
red, green, blue
Insula
regions of cortex located at the junction of the frontal and temporal lobes • Primary gustatory cortex • Reliable association with disgust behaviors! • But also a site of projection (possibly rerepresentation) and convergence across various senses • Some believe the insula allows for interception: "knowing how you feel" (physiologically ) = may be critical to understand how we feel in terms of how our body feels Experiments: - monkeys eating and disgust from stimulating insula - ability to detect whether music was in sync heart beat pulse correlated with greater insula activity
Week 8 False memory ZAPS conclusions
reminds us that the certainty with which someone states a claim cannot be used as a gauge for how truthful that claim is. Researchers find that participants generally ver confidently recall seeing the critical lure with just as high a frequency as words that actually appear on the original list.
Habitual behavior
repetitive behavior that no longer is under the control of reward learning mechanisms and is a Major issue in addiction
When you selectively attend to something, how much information do you withdraw from?
retain SOME level of processing of other things going on so you can turn your attention to whatever is needed example: cocktail party
The primary visual pathway is best described as
retina → optic nerve → optic chiasm → thalamus → occipital lobe
rods and cones
rods- slow black and white, low threshold(dark) cones- fast color, high threshold(light)
conjunction search
search for a target defined by the presence of two or more attributes
David Hubel and Torsten Wiesel won the Nobel prize for discovering the functional organization and basic physiology of neurons in V1. They discovered three different types of neurons that can be distinguished based on how they respond to visual stimuli that they called:
simple cells, complex cells, and hypercomplex cells.
Hebbian learning
simultaneous activation of cells leads to pronounced increases in synaptic strength between those cells
What is localization of function?
specific functions are served by specific areas of the brain
What do patients with lesions to the fusiform gyrus experience?
suffer from prosopagnosia effect is more severe if lesion is on right compared to left
sentinel hypothesis
the brain at rest is always broadly monitoring sensory inputs from our surroundings the default network is there to ensure that we always have some idea of what is going on around us
endogenous cuing
the control of attention by internal stimuli under voluntary control
What is the Stroop effect?
the difficulty of naming the colors in which words are written instead of reading the words themselves (not necessarily text and color, works as well for orientation) measuring response time differences to measure competing processes (understanding meaning versus seeing color of word)
Motor Evoked Potential (MEP)
the electrical response of the central nervous system produced by an external stimulus
functional connectivity
the extent to which multiple brain regions function at the same time, which improves during adolescence
xenomelia
the feeling that one or more limbs do not belong to one's body, and the lifelong desire to amputate them observers noted that the offending limb was most often the left leg (similar to how hemineglect most often presents on the left side; see Chapter 7) and that the condition most often affected males (90 % of people with this syndrome are men) problem was neurological rather than psychological Compared to touch on accepted body parts and in controls, touch on the undesired limb elicited no cortical response in one particular brain area: the right superior parietal lobule (SPL) (Figure 13.10). neuroarchi- tectural abnormalities in exactly those cortical areas impli- cated by Ramachandran's group: decreased cortical surface area in the right anterior insular cortex and decreased cortical thickness in the SPL
What is the fovea?
the fovea is the region of the retina with a high density of cones and highest visual "acuity" = clearest
graph theory
the geometry of networks
encoding specificity principle
the idea that cues and contexts specific to a particular memory will be most effective in helping us recall it 1) information must first be stored, or encoded in memory, before it can be retrieved, and 2) the helpfulness of a cue in assisting retrieval depends on how your brain encoded the information to begin with.
agnosia
the inability to recognize familiar objects.
True or false: Our attentional systems cope with the overwhelming amount of information that we encounter on a daily basis by engaging in selective attention, and by extension, the attentional blink
true
Alpha wave
type of relatively low frequency, relatively high amplitude brain wave that becomes synchronized; characteristic of the beginning of stage 1 sleep 8-12 Hz,
Patient GY
unilateral damage to primary visual cortex • Left occipital (V1) lesion at age 8 • Right field blindness! • Fails at simple visual stimulus discrimination tasks • But can detect motion & emotion confuses negative facial expressions more so than happy emotions dynamic fast motions he can see well and replicate with pointing (superior colliculus and thalamus rather than in LGN)
How do unilateral lesions compare to bilateral lesions
unilaterally lesioned patients usually do just fine, it's bilateral lesion that is problematic and function cannot take over
Akinetic mutism
unresponsiveness to the environment; the patient makes no movement or sound but sometimes opens the eyes (no action, no talking) will not talk unless you prompt them to able to perform actions only if they are assigned to them = no self made goals?
How reversal learning changes with OFC lesions
unstable preferences and value assignment even though they can perceive information correctly = no perceptual deficit only preference deficit
homotopic fibers
connect corresponding sections of the two hemispheres
Sir Charles Sherrington
inferred the existence of synapses
How long can a neuron survive without oxygen
~ 5 minutes
How does William James define attention?
"Everyone knows what attention is. It is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought. Focalization, concentration of consciousness are of its essence. It implies withdrawal from some things in order to deal effectively with others, and is a condition which has a real opposite in the confused, dazed, scatterbrain state" (James, 1890).
What evidence did Hughlings Jackson (1835-1911) provide in favor of localization? How? (Localization of function vs. aggregate field theory)
"Jacksonian March": Studied seizures, abnormal brain electrical activity Observed predictable manner of some seizures starting in the hand moving up the arm to the body inferred: perhaps they are organized close to each other in the brain = fundamental organizational principle of the motor system: somatotopy (map of the body in the brain)
What is the "idea" of right versus left brain people in the media? what is factually different?
"right brain" dominates the thinking of people who are particularly artistic or imaginative, and that the "left brain" dominates the thinking of people who are inclined toward math or logic left hemisphere of the brain is dominant for language, and the right hemisphere is dominant for global spatial information
action plan evidence
(1) picture from above 2 competiting spaces for cues, parallel activated, then fires a bunch before selection (2) During competition for action selection: cross talk between hemispheres; we force our hemispheres to decide on one goal • Callosotomy: reduced competition better performance (less interference) while executing two distinct actions simultaneously (drawing two images at once)
P1
(earliest visual evoked response, V2 V3 dependent most likely) starts around 80 ms, but peeks around 100 The P1 component is a positive ERP component that occurs approximately 100 ms after stimulus presentation. The P1 component appears to be sensitive to faces, as the amplitude for this component is significantly larger for face stimuli than most other types of stimuli (Itier & Taylor, 2004d).
Topoplot
(think place field) The topoplot shows you where power for a particular frequency is strongest • Here they are plotting Alpha (10-15Hz) for the first 100-300ms after a visual stimulus was shown
difference between the Electroencephalogram (EEG) and the ERP's (and VEP's)
-EEG tends to record global brain activity. - ERPs (and VEPs) are a special case of EEG. average EEG trace from a large number of trials. align signal to onset of a stimulus or response - hence event-related potential (ERP).
What Functional neuroimaging techniques are all all derivative from electroencephalogram (EEG)?
-ERP (event related potentials) - VEP (visual evoked potentials) !ask do we need to know VEP?
Who is Clive Wearing (Patient C.W.)?
-Good memory for generic information -Love for his wife (only recognizes) -Unable to remember events -Disrupted episodic memory but intact semantic memory - can play piano, form words, but understanding of the world resets every 30 seconds - Herpes virus = focal damage in inferior posterior parietal cortex (angular gyrus, thick arrows), extending into the subcortical white matter of the right hemisphere (dashed arrows).
What are the Pros of ERP's?
-Good temporal resolution. -Good at linking specific physiological markers to cognitive processes.
How does an Electroencephalogram (EEG) collect data?
-Large populations of neurons firing produce electrical potentials that can be measured at the scalp. -ALSO: Brain, skull and scalp passively conduct signals that can be amplified and measured.
What are the cons of ERP's?
-Poor spatial resolution. -Difficult to get at some brain regions (e.g. temporal cortex).
What are the downsides to CAT/CT scans?
-Spatial resolution not so good. -Lesions often take some time (hours) to become evident on CT.
Alpha wave occurrence ?
-Wakefulness -Relaxation -Mind wandering -Eye closed
What are some rules for Magnet safety?
-even large and heavy objects can 'fly' into the magnet bore. - be sure to Screen subjects carefully. - Develop strategies for screening yourself every time you enter the magnet. - Man the torpedoes. (Aka shooting oxygen tanks)
heterotopic fibers
connect different areas of the two hemispheres
Describe visual processing in the LGN
1 .6 layers. 2. Cells have monocular input. 3. Layers alternate inputs from each of the two eyes. Parallel Pathways: 4. The top four are parvocellular layers, two layers from each eye. Parvo (small - cones) LGN cells receive inputs from (small) midget ganglion cells. 5. The bottom two are magnocellular layers, one layer from each eye. Magno (large - rods) LGN cells receive inputs from (large) parasol ganglion cells.
What is phrenology?
1. "Faculties" (such as "destructiveness", "compassion") are localized to different parts of the brain 2. The bigger a brain area is that is responsible for one of the faculties, the better the person is at that faculty 3. Having part of your brain be big will cause the skull around it to "stick out" 4. Therefore, the shape of one's skull can be used to determine how much a specific faculty is expressed in a person.
5 pieces of evidence for localization of function
1. Jacksonian March Seizures 2. Somatotopy Lesion and stimulation experiments 3 . Stroke Brain Damage 4. "tan" and broca's aphasia (wernicke's too) 5. Brodman's cytoarchitectonics
What first pass three broad regions does Robert T. Knight like to break up the frontal lobe into?
1. Orbitofrontal Cortex (control of social behavior, and emotion interactions) 2. Lateral Frontal Cortex (executive control of cognitive activities) 3. Medial Part between hemisphere (motor cortex, parts of ACC: motor planning/control/sequencing)
What evidence did Jean Pierre Flourens provide against phrenology?
1. Showed that lesions to the cerebellum caused uncoordinated movement (not vital magnetism, as phrenology predicted!) 2. Lesions to different cortical areas had little or no specific effect - they all generally impaired the animal's behavior 3. Moreover the animal recovered some or all of the function after a cortical lesion = he called it equipotentiality
Explain the progression of MRI use in studies:
1990- 1st paper using MRI technology 2001- 746 papers 2018- 36,600 papers
Wisconsin Card Sorting Test (WCST)
1. Sort the cards however you like (one by one) 2. Experimenter has a rule in mind (shape, color or number) 3. Feedback after each card gives the subject information about the rule Once the subject gets 10 correct trials, experimenter switches the rule Dependent variable: do participants update their sorting strategy after feedback that the rule has changed? If you continue to sort according to the old rule - you perseverate! An assessment instrument that requires an individual to sort cards into four piles; each card has a specific shape on it and a specific number of these shapes, and each card is printed in a specific color; thus, the cards could be sorted by shape, number, or color. The sort criteria are changed throughout the test. The purpose of the test is to measure the person's ability to adjust to changes in sorting criteria
Why is vision in the fovea clearer than the periphery?
1. high density of cones 2. more cortical tissue processing this area of vision compared to peripheral vision processing
How do we establish causal inference?
1. lesion method 2. TMS 3. Deep Brain Stimulation 4. Optogenetics
What evidence was presented in class for separate memory circuits?
1. patient HM, patient CW, patient K.C 2. fMRI - skill learning task evokes different representations than episodic memory task 3. basal ganglia damage in Parkinson's - habit learning and procedural learning difficulty 4. entorhinal cortex affected in Alzheimer's - memory & navigation deficit
What is different in the frontal lobe between the hemispheres?
1. right handed = language in left hemisphere 2. attention capacity (right hemisphere) like an Operating System (NOT that strong of a lateralization like not strongly one sided)
Three common confounds confused for short term memory in early memory studies
1. short term memory 2. internal attention to a representation 3. intended movement plan
What are some possible causes of brain lesions?
1. stroke 2. tumors 3. degenerative neurological disorders 4. trauma
beta wave frequency
18-30Hz
explicit and implicit memory
2 types of long term memory: explicit is declarative (semantic, episodic) implicit is non-declarative (procedural, priming, conditioning, habituation)
For each probe on a sEEG/ECoG how many neurons can u image?
200-500k from one electrode = local field potential (sum activity)
What experimental approach can we use to study Global Workspace Theory?
30 ms for words (shorter for images) sandwich masking paradigm with a visible distractor word at the end goal: identify middle target stimuli if you give participants 50-100ms between the target word and the masks, even if u present the word for 30ms, then the participant can register the word non-conscious processing trails: show participants perform at chance levels for detection trials participants respond faster when the same word is presented in between the masks than if it is a different word suggesting that the target word we do not process fully (to the semantic level) or distribute it widely enough in our cortices, but seeing it again allows for that = quicker reaction time for detection this is a semantic priming effect
Freq of gamma waves ?
30-80Hz
How many regions provide a seminal cortical map of different cell types in the brain?
52 regions with areas that are functionally distinct under the microscope
What happens to patients with lesions to the LPFC? What did Lhermitte (1986) find? What about kids whose LPFC has not developed much?
<2 yo may imitate experiment healthy patient over 3 yo = laugh/watch LPFC lesion = Patient cannot help but mimic the Dr's behavior = example of utilization behavior
hypercolumn
A 1-millimeter block of striate cortex containing two sets of columns, each covering every possible orientation (0-180 degrees), with one set preferring input from the left eye and one set preferring input from the right eye.
Implicit Association Test (IAT).
A computer-driven assessment of implicit attitudes. The test uses reaction times to measure people's automatic associations between attitude objects and evaluative words. Easier pairings (and faster responses) are taken to indicate stronger unconscious associations.
What is First Order Theory?
A first-order representational (FOR) theory of consciousness is one that attempts to explain and reduce conscious experience primarily in terms of world-directed (or first-order) intentional states. The core idea of first-order representationalism is that any conscious state is a representation, and what it's like to be in a conscious state is wholly determined by the content of that representation
ultimatum game
A game in which a proposer is given a sum of money and makes an offer to a responder as to how this money should be split between them. The responder must choose to accept the offer or reject it. This game has been used to study people's decision-making strategies. one player (P1) must split a sum of money with another player (P2). P1 offers a portion of the sum to P2, and P2 must either accept or reject the offer. The offer may be fair (e.g., very close to 50% for each person) or unfair (e.g., 80% for P1 and 20% for P2). If P2 rejects the offer, however, then nei- ther player gets any money. consider- ation of unfair offers was associated with activity in the dorsolateral prefrontal cortex and the insula
What is a gyrus or (pl. pyri) ?
A gyrus (plural: gyri) is a ridge on the surface of the brain. Each ridge is surrounded by fissures known as sulci (singular: sulcus). Gyri are unique structures that have an important evolutionary function; they increase the surface area of the brain up to an impressive 2000 centimeters squared hills in fold of cortex
Who is Patient K.C.?
A patient who sustained damage to the cortex that renders him unable to form and retrieve new episodic memories. • Head injury due to a motorcycle accident at age 30. • College graduate; quality control for an engineering plant. • No effect on his intelligence, but he had severe retrograde and anterograde amnesia. • Only impacted his episodic memory • Great Digit Span the late Kent Cochrane, a patient who sustained damage to the cortex that rendered him unable to form and retrieve episodic memories
akinetopsia
A rare neuropsychological disorder in which the affected individual has no perception of motion.
What does the amygdala do?
Amygdala: detection of emotionally salient stimuli, fear and appetitive learning, modulation of attention and bodily responses be careful it is often in the press and represented incorrectly
error-related negativity (ERN)
An electrophysiological marker that occurs when participants make errors in cognitive tasks. localized to the anterior cingulate cortex.
The mind-body problem
Are mind and body separate and distinct, or is the mind simply the physical brain's subjective experience?
pre motor and supplementary motor cortex regions (area 6)
Area 6 : Pre Motor Cortex (PMC): reciprocal parietal cortex projections. • May contain "abstract" action maps regardless of effector used (e.g. grasp action) • PMC intracranial stimulation: complex movement without awareness or intention (surprised patient that they performed that movement) • Supplementary Motor Area (SMA): interconnected with medial PFC- input into motor system likely governed goals, preferences. • Important for sequential, complex plans, and goal—> hand assignment • SMA Lesions: • can't use 2 hands together for two step action • Alien Hand syndrome (near corpus colusm = interaction between hemispheres, that needs to be inhibtied sometimes for complex actions to occur)
What is the magnetic field of an MRI machine?
B0 to line up spins of H20 protons B1 radio frequency sent to temporarily change proton's spins
Why do people reject the offer in the ultimatum game?
By rejecting the offer and incurring a small loss, how- ever, you can punish the other player for violating the social contract. From a rational economic perspective, participants should not let negative emotional reactions lead them to reject the unfair offer. Even if it is unfair, they will still gain some money instead of no money. From a broader perspective, however, the negative emotional reaction leads participants to reject unfair offers that might oth- erwise compromise their reputation. If you continually accept less than your share, word gets around and you lose social status, with the loss in status entailing other consequences, including negative effects on economic, physical, and mental health. For example, men who lose social status are four times more likely to suffer depres- sion (Tiffin et al., 2005).
Classical Conditioning
CS = condition stimulus (bell) US = unconditioned stimulus (food) UR = unconditioned response (natural salivation from US) CR = conditioned response (salivating)
What is the optic nerve?
Carries impulses from the retinal ganglion cells to the thalamus (mostly LGN)
What two structures of emotions did we discuss?
Categorical and Dimensional
Do prefrontal cortex (PFC) vs. parietal neurons care about the action outcome (goal) or the required movement to reach the goal?
Clever Strategy: short movies where a particular movement (A) could reach goal 1 or 2; conversely, goal (1) may be reached via movement A or B. • sensistive to goal not movement - so when the goal stayed the same but the movement of how to open the box changed, then neurons fired less strongly with more repetition - when goal changed, neuronal firing was less susceptible to changes from habituation scott Grafton ^ UCSB Inferior Parietal Lobe: responds to action outcomes Inferior Frontal Gyrus: responds to action movement (kinematics)
What are the Two broad organizational schemes of neurons together? What are their differences?
Cortex and Nuclei cortex - continuous folded sheet-like structure (sulci=valleys & gyri=hills) nuclei - collection of cell bodies (chaotic and disorganized, but common function)
Treatment of Parkinson's:
Deep brain stimulation targettting output of basal ganglia (inernal globus paladus) or subthalamic nucleus
Social Behavioral Deficits in Acquired and Neurodevelopmental Disorders
Deficits in social cognition are observed in people with some neurodevelopmental disorders and with acquired damage to the orbitofrontal cortex. Social deficits seen in autism spectrum disorder and schizophrenia may be the result of deficits in the ability to understand that others have mental states. Some social deficits seen in antisocial personality dis- order are associated with deficits in cognitive control and a lack of empathy.
How is the CAT scan image formed?
Different tissues (brain, CSF, white and grey matter) have different densities - therefore a different proportion of the X-ray is absorbed and an image can be formed.
What is a DTI?
Diffusion Tensor Imaging - images white matter pathways (thru water movement) - used to observe connections between regions -The DTI tractography is performed in an MRI scanner, which is a large tube surrounded by a circular magnet that creates a magnetic field around you.
What is coded in the motor cortex?
Direction of movement • Force of movement (# of action potentials going into fibers) • Entire posture?? consistent return of the body to a certain posture
Dorso-dorsal and ventro-dorsal streams for motor actions ^ subdvision of dorsal stream versus ventral stream
Dorsal (Where) Dorso-dorsal = reaching and simple grasp • Lesion: Optic Ataxia (cannot reach object whilst still recognizing it); you've seen the video of a patient w/ this condition in the Vision lecture ventro-dorsal = complex grasps and interactions with objects + tool/conceptual knowledge of objects Lesion left supramarginal gyrus in inferior parietal lobe: Ideomotor Apraxia (loss of knowledge of how to use an object) ventral stream = Objects, object properties (what)
Describe the two networks in Attention
Dorsal top down attentional shifts to spatial, feature, & object properties Ventral novelty + salience detector exogenous (loud noises, may do a lot of automatic filtering, and impacted from hemispatial neglect Hemineglect,)
coup-contrecoup injury
Dual impacting of the brain into the skull; coup injury occurs at the point of impact; contrecoup injury occurs on the opposite side of impact, as the brain rebounds.
event-related potential (ERP)
Electrical changes in the brain that correspond to the brain's response to a specific event; measured with EEG.
What's an emotion? A functionalist view
Emotion - from latin movere - to move • Emotions are valenced: i.e. pleasant or unpleasant: "good, bad, or somewhere in between... never indifferent" (Damasio & Damasio) • Emotions (or affective states) are for something • A thermostat of your current environment often accompanied by an action tendency • The action tendency associated with a particular affective state is often functional (and adaptive) • In their simplest form, approach and avoidance action tendencies towards desirable vs. unwanted stimuli are observed in species as rudimentary as the amoeba and bacteria
Give properties of emotions
Emotions are: • Valenced: pleasant vs unpleasant • Scalable: an affective state can scale in intensity (arousal) • Persistent: emotional states outlast their eliciting stimulus- influencing information integration and cognition over time. Emotions are temporally dynamic and features of those temporal dynamics may be key in understanding risk for psychopathology. • Generalizable: the same affective state may occur for different stimuli • Global: an affective state often mobilizes multiple response channels in the brain and in the body • Automatic: Emotions have priority on behavioral control • Social: Emotions often elicit by signals that can be read by conspecifics
What is an ERF?
Event Related Field, similar to ERP but made with MEG
Why is fMRI so popular?
Excellent spatial resolution! current scan protocols easily get functional signals from 2x2x2 mm voxels and 3d brain map with MRI + get brain activity thru fMRI
Two prominent theories of theory of mind
Experience sharing: akin to automatic emotion & action contagion • Proposed network: mirror neuron (ventral premotor areas), insula • Mental state attribution theory (once called theory-theory): we use accumulated knowledge and folk theory to infer others' states; inference based • Proposed network: mPFC, STS, TPJ (do not have to have gone thru the same experience to empathize) - medial prefrontal cortex, super temporal sulcus, temporal parietal junction
Describe area of the brain that are specific to visually recognizing certain things
FFA (fusiform gyrus) = faces EBA = bodies PPA = places VWFA = words lateral occipital lobe = general objects BUT the information represented in these modules travel up the visual stream to other areas (not exclusively contained to these regions) and it brings important feedback to lower order visual areas
Describe movement of Parkinson's patients
FIGURE 8.1 Parkinson's disease disrupts posture, as well as the production and flexibility of voluntary movement. (a) This man has had Parkinson's disease for many years and is no longer able to maintain an upright posture. (b) These people developed symptoms of Parkinson's disease in their 20s and 30s, after ingesting the drug MPTP (sold as heroin). Facial expression, including blinking, is frequently absent, giving people with Parkinson's disease the appearance of being frozen.
What is the pathway in which abstract intentions + goals become motor actions? (Motor Pathways hierarchy)
FIGURE 8.2 Overview of the motor pathways. All connections to the arms and legs originate in the spinal cord. The spinal signals are influenced by inputs from the brainstem and various cortical regions, whose activity in turn is modulated by the cerebellum and basal ganglia. Thus, control is distributed across various levels of a control hierarchy. Sensory information from the muscles (not shown) is transmitted back to the brainstem, cerebellum, and cortex.
How muscles work
FIGURE 8.3 Muscles are activated by the alpha motor neurons. An electromyogram (EMG) is recorded from electrodes placed on the skin over the muscle to measure electrical activity produced by the firing of alpha motor neurons. The input from the alpha motor neurons causes the muscle fibers to contract. Antagonist pairs of muscles span many of our joints. Activation of the triceps produces extension of the elbow (a); activation of the biceps produces flexion of the elbow (b). activated by alpha motor neurons that release acetylcholine so that they contract they are organized in pairs: Thus, to produce movement, we need: • Excitatory signal to target muscle • Inhibitory signal to antagonist muscle (via interneuron) ex: biceps and triceps
Basal Ganglia in Motor Actions
FIGURE 8.6 The basal ganglia and the cerebellum are two prominent subcortical components of the motor pathways. The basal ganglia proper include the caudate, putamen, and globus pallidus, three nuclei that surround the thalamus. Functionally, however, the subthalamic nucleus and substantia nigra are also considered part of the basal ganglia. The cerebellum sits below the posterior portion of the cerebral cortex. All cerebellar output originates in the deep cerebellar nuclei. Highly interconnected with prefrontal cortex - forming "corticostriatal loops", thought to be essential for instrumental learning (get reward/avoid punishment) • Caudate+Putamen: receive input from cortex • Internal Globus Pallidus: sends output • Basal ganglia dysfunction implicated in various motor disorders
more motor areas of the cerebral cortex
FIGURE 8.7 Motor areas of the cerebral cortex. Brodmann area 4 is the primary motor cortex (M1). Area 6 encompasses the supplementary motor area (SMA) on the medial surface, as well as premotor cortex (PMC) on the lateral surface. Area 8 includes the frontal eye fields. Inferior frontal regions (area 44/45) are involved in speech. Regions of parietal cortex associ- ated with the planning and control of coordinated movement include primary (S1) and secondary somatosensory areas, and posterior and inferior parietal regions. M1 includes two anatomical subdivisions: an evo- lutionarily older rostral region and a more recently evolved caudal region Corticospinal neurons that originate in the rostral region of M1 terminate on spinal inter- neurons.
Jan Evangelista Purkinje
First person to describe a nerve cell in the nervous system electric current in cell = not by product of cellular activity but medium of carrying information
What is Cerebrospinal fluid?
Fluid in the space between the meninges that acts as a shock absorber that protects the central nervous system. The brain floats in it
Describe the process of light hitting the eye and being sent to the primary visual cortex. What is the distinction in left and right visual fields?
FoV flash of light 1. eyes focus light onto photoreceptors 2. light hits retina (nasal or temporal retinal fibers) 3. signal travels along optic nerve 4. passes in optic chiasm (nasal = cross, temporal = stay in that hemisphere) 5. in the thalamus LGN it synapses 5a. subset goes to superior colliculus 5b. subset goes to pulvinar nucleus 6. arrives in primary visual cortex retinogeniculate and geniculocortical
Where are all the lobes and what do they do roughly?
Frontal Lobe: motor control, reasoning, language production, inhibitory control, working memory. Temporal Lobe: auditory processing, language comprehension, object recognition. Parietal Lobe: somatosensory, spatial attention. Occipital Lobe: visual processing.
Frontotemporal dementia (how to test + what is it + how they perform socially)
Frontal and temporal regions degenerate, resulting in badly impaired emotional stability, decision-making and language use engage ventromedial / OFC region Frontotemporal dementia = atrophy of this brain area = deficit in evaluating social violations in negative light
What is a T2 scan? What is its acquisition time?
H20 relaxes at 2.5 seconds, so a T2 scan (acquisition time=2.5 sec) has a prominent water signal ventricles (which contain CSF) are white
Who discovered EEG?
Hans Berger
Does anyone still believe in dualism? What is a modern argument for dualism?
Hard problem Objective analysis (e.g., science) gives us descriptions of things in terms of causal mechanisms and dynamics. Even once we know all the physical mechanisms ("easy problem"), the question still persists Why does it feel like something, why does it feel that particular way and not some other way? Why does burning our hand feel like pain and not itching?
Why is the sensory motor system useful?
Helps maintain posture and Preserves stability following unexpected perturbations
What does the hippocampus do?
Hippocampus: episodic learning, associative learning, memory consolidation, long term memory
How do LFPC lesion patients do on WCST? What control groups did Brenda Milner studies this against?
Lesion to parietal cortex, occipital lobe, and orbitofrontal cortex = no change in perseveration LFPC lesion = double in perseveration (verbalize what they should have done and what the correct response was BUT NOT BEING ABLE TO EXECUTE IT)
hemiplegia
Lesions of the primary motor cortex usually result in hemiplegia, the loss of voluntary movements on the contralateral side of the body. Hemiplegia most frequently results from a hemorrhage in the middle cerebral artery; perhaps the most telling symptom of a stroke, hemiplegia leaves the patient unable to move the affected limb. The problem is not a matter of will or awareness; a patient with hemiplegia may exert great effort, but the limb will not move. Reflexes are absent immediately after a stroke that produces hemiplegia. Within a couple of weeks, though, the reflexes return and are frequently hyperactive or even spastic (resistant to stretch).
tractography
Method that builds on diffusion tensor information (DTI) to ascertain information about probable white-matter tracts in the brain.
What is alien hand syndrome?
Motor control disorder featuring involuntary, yet purposeful movements example: corpus callosum cut + stroke in anterior commissure = little to no connection between hands
negative deflections versus positive deflections (EEG, ERP)
N1, N2, N400 P1, P3, P300
Is neglect (like hemispatial neglect) a sensory problem? Give an example
NO also manifests in imagining mental objects and redrawing them example= patient asked to recount things in this place they have been to from two different perpsectives and in both cases together recounted all the locations but ONLY on one side
Is the Amygdala the 'fear center'?
NO that's Too simple, just been a useful paradigm for understanding emotional memories
When participants view Color and motion do they activate the same area of the brain?
NOPE.
Recording neurons in the Inferior Temporal (IT) cortex displayed what about object recognition?
Neuron really responds to monkey faces, whether without some features like eyes, but prefers full face and even responds to cartoon human faces BUT not hands control: scrambled pictures of faces to test if neurons liked pattern/contrast/lines or some other features of the image than the face
What is the difference between neurons and glia cells?
Neurons an aerobic cell that is highly specialized to transmit electro/chemical signals Glia cells that maintain proper function of neurons such as schwann and astrocytes
forward versus feedback projection
Neurons that send their axons from lower to higher areas of the hierarchy are referred to as "feedforward" (FF) neurons, whereas those projecting in the opposite direction are called "feedback" (FB) neurons.
If disrupting Broca's area and conducting stroop test, what happens?
No change in response? Because understanding language is largely in tact with Broca's area disrupted so color processing and word processing are still competing (if not responding verbally)
What is the difference between Noetic (knowing) retrieval and Auto-noetic (self-knowing) retrieval coined by Tulving (1985)?
Noetic (knowing) retrieval familiarity • Knowing facts/semantics • Semantic • Faster • Experienced as "recognizing" or "knowing" ex: familiar face Auto-noetic (self-knowing) retrieval Recollection • Knowing something but with an associated re-experience of the original learning episode ("mental time travel") • Related to contextual reinstatement - the idea that you reinstate the original context of a memory when you recall it • Episodic-like (auto-noetic) • Slower to occur • Experienced as "remembering"
How are other brain areas outside the amygdala emotionally regulated?
Occipital (visual) cortical regions increased responses to emotional faces. • In monkeys (direct neuronal recordings) • In humans (fMRI) • These effects remain after amygdala damage! spatial attention and stimulus processing: stimulus actively attended to get LGN and primary visual cortex enhancement of activity (V1) ~emotionally latent content = information grabbing
Where is the angular gyrus located?
On the parietal lobe posterior and superior to the temporal lobe
Posterior Parietal Cortex (Area 5 and 7)
Parietal areas: reciprocal PFC projections. • Conceptual knowledge of actions; multi sensory control of actions • Parietal stimulation: intention of movement (sometimes belief in having performed a particular action in the absence of action performance)
Alpha wave most marked in which area ?
Parietoocipital area
William Kelley and his colleagues at Dartmouth College (2002) studying what brain regions are activated when people encode memories in relation to themself, others, or just syntactically
Participants judged personality adjectives in one of three experimental con- ditions: in relation to the self ("Does this trait describe you?"), in relation to another person ("Does this trait describe George Bush?"—the president at the time the study was conducted), or in relation to its printed format ("Is this word presented in uppercase letters?"). most likely to remember self condition The medial prefrontal cortex (MPFC) was differentially activated in the self condition compared to the other two conditions Later studies found that the level of activity in the MPFC predicted which items would be remembered on a surprise memory test (Macrae et al., 2004). The relation between the MPFC and self- reference also extends to instances in which participants have to view themselves through another person's eyes.
environmental dependency syndrome
Patient cannot help but interact with objects in the world in a stimulus-driven manner irrespective of context LPFC lesion Environmental dependency syndrome, also called Zelig syndrome or Zelig-like syndrome from the name of the protagonist of Woody Allen's Zelig, is a syndrome where the affected individual relies on environmental cues in order to accomplish goals or tasks
subtypes of consciousness content
Phenomenal awareness - am I experiencing the same red as others? Access Awareness - do people have access to a specific experiences? are you subjectively aware of having an experience? Meta Awareness - reflecting on having the perception of seeing a color red
How did Stroke Brain damage provide evidence for localization of function?
Phineas Gage (frontal cortex/lobe) Tan - Broca's Aphasia (inferior frontal gyrus) Wernicke's Aphasia ^All case were patients with focal lesions those specific areas of damage = loss of specific functions
What is Wernicke's aphasia?
Posterior temporal lobe lesion • Intact ability to talk - but speech is usually non-sensical (actual words, but no semantics or pragmatics) • Marked difficulty understanding speech
Area 6 (premotor cortex + Supplementary Motor Area ) versus posterior parietal cortex
Pre Motor Cortex (PMC) stimulation: complex movement performance (without awareness or intention) • Parietal stimulation: intention of movement (sometimes belief in having performed a particular action in the absence of action performance)
How does self referential processing benefit encoding?
Processing information as "self relevant": subsequent improvement in memory • Side note: if information is self relevant and negative, even greater performance benefit in individuals with depression compared to healthy controls
What are the pros and cons of TMS?
Pros -Good temporal resolution (with single pulse at specific moments of task) -Can presumably disrupt individual processes within a task. -Potential combination with other imaging techniques. - can have a within subjects design that is not available with brain lesions - used on healthy individuals - clinical applications (depression) Cons -Poor spatial localization (~1 cm) = Can't stimulate certain areas (e.g., temporal lobe - orbitofrontal cortex) and can only stimulate cortical surface. -Distance effects - changed interactions due to stimulation. Can induce seizures (particularly rTMS). - individual differences (not everyone responds to same degree) - network level effects! can't be sure TMS target per se because we're observing behavior/neural and the brain is highly interconnected
In a "field free" space how are hydrogen protons oriented?
Randomly
Huntington's chorea
Rare autossomal dominant disease (onset: 40 y) • Characterized by: • Involuntary movements • Dementia • Depression (prefrontal cortex connection lacking) ventricle is enlarged, no caudate nucleus? = no interconnectedness to prefrontal cortex hands/toes shake someitmes can't swallow (throat spasm) oral forental corea/axial chorea lots lose balance neurodegenerative disease that is mostly inherited. The earliest symptoms are often subtle problems with mood or mental abilities. A general lack of coordination and an unsteady gait often follow
Neural mechanisms of emotion regulation
Reappraisal (Reappraise > Maintain)- asking to change emotional response (imaging car accident had an okay outcome) = bilateral PFC (dorsolateral, interior insula, frontal parietal network) = holding a goal in mind, to do top down control = hypothesis Uncinate Fasciculus - synapse is connected to 90% of PFC - better down-regulate emotions = better coupling with prefrontal regions - connects PFC to hippocampus/amygdala amygdala and hippocampal activity decreases when asked to down-regulate emotions, but PFC activity increases https://docs.google.com/document/d/1z6gZKuyQaFLTtgTqBhcWxy-sbFgBbzTEtJlQZ_65wh0/edit search "Re-appraisal" ^
What emotional intensity (arousal) metrics do psychologists use to study emotion in a non-obtrusive way? (peripheral-physiology)
SCR= skin conductance response (sweat) higher intensity (negative or positive) = stronger SCR Heart Rate (negative = deceleration of heart)
What are the names of brain planes/sections?
Sagittal Axial/transverse/horizontal coronal
What are the sections/planes of direction in neuroscience?
Sagittal Axial/transverse/horizontal coronal
autoscopic hallucination
Seeing an image of oneself in external space In this case, people do not feel as if they have left their body, but they see a double of themselves in extra- personal space.
What are different sources of selective attention?
Source of attentional control: Exogenous: external source ("bottom up") = you get distracted by your phone buzzing and you feel compelled to check it Endogenous: internal source: "goal oriented"/"top down" =
What is the thalamus? What important area does it include?
Sensory "relay station." Sensory info. such as visual/auditory information evaluated here A set of diverse nuclei including the Lateral Geniculate Nucleus (LGN)
Where is the central sulcus?
Separates frontal lobe from parietal lobe Lateral view: Major gyri in the brain pre and post central gyrus next to it
Where is the Sylvian fissure ?
Separates the temporal from the frontal lobe, and the temporal from the parietal lobe (Also called lateral sulcus.)
T1 versus T2 imaging
T1 dark ventricles 0.5 T2 light ventricles 2.5
What are different modalities of selective attention?
Spatial attention: Attending to different regions of space without moving your eyes can enhance processing at the attended location (at the cost of decreased processing at the unattended location) Feature-based attention: Attending to all red objects, for example. Feature-specific visual cortex (e.g. V4) shows enhancement. Object-based attention: Attending to a face, for example. Object specific cortex (e.g. FFA) shows attentional enhancement even if the face itself is not the focus of attention (e.g. if face movement is the focus).
sterotype
Stereotypes are mental shortcuts that allow for easy, fast processing of information about groups of people. Like attitudes, stereotypes often are automatic.
n-back task
Task in which items (e.g., letters) are presented one at a time and participants must identify each item that repeats relative to the item that occurred "n" items before its onset. 1-back: press button if the stimulus is a repeat of the stimulus prior to it (only maintain last stimulus) 2-back: press button if same as the stimulus 2 stimuli back from the one currently presented
How did scientists use the Central Target Identification Task to investigate what function being consciously aware give us?
Task: identify stimulus in the center Arrows: distracting motion that was either below the threshold (5% coherence) for consciousness (subliminal) or above (supraliminal) black line = behavior performance, subliminal detection = worse performance Motion Detection module in dorsal visual stream activity = increases at 5% coherence when motion is subliminal LPFC = only engages when motion coherence is conscious a function may be not to just perceive things to a greater depth but to ignore irrelevant stimuli Function of consciousness: If we are aware of distractors in environment, than we can deploy resources necessary to tune it out Participants in brain imaging scanner had to identify stimulus in the center with a bunch of distracting stimuli (moving arrows around it) Could manipulate motion of arrows so it's processed consciously (supraliminal) or subliminally (patients had know idea they saw arrows moving) Participant's dprime - higher # = better at detecting center stimulus Results Behaviorally: No MT+ coherence = do successfully 5% coherence of MT+ = patients do not recognize motion and do not consciously see the distracting stimuli Brain: 5% Mt = increase activation in motor area ? LPFC (lateral PFC) ramps up activity at 10% coherence when movement is conscious, but is not very engaged when movement is not consciously detectable Task- irrelevant signals around the threshold level may be sufficient strong to be processed in visual system but not strong enough for the LPFC to notice = LFPC has effective inhibitory control on the signals !ask urself to summarize
tectospinal vs reticulospinal tract
Tectospinal The origin of the Tectospinal tract is in the superior colliculus of the midbrain. As this area recieves information regarding visual input, this tract is primarily responsible for mediating reflex responses to visual stimuli. - The Tectospinal tract receives information from the retina and cortical visual association areas. In response to visual stimuli, the tectospinal tract mediates reflex movements.It is able to orientate the head/trunk towards auditory stimulus (inferior colliculus) or visual stimuli (superior colliculus). - Efferent fibres are also sent to the reticular formation that trigger saccades and also spinal regions innervating the neck. Reticulospinal The Reticulospinal tract is responsible primarily for locomotion and postural control. The Reticulospinal tract is comprised of the medial (pontine) tract and the lateral (medullary) tract. Involved in the control of alpha and gamma motor neurons; helps to control breathing; regulating posture
How motor actions travel in the brain pt 2 - brain stem emphasis
The 12 cranial nerves, essential for critical reflexes associated with breathing, eating, eye movements, and facial expressions, originate in the brainstem. Many nuclei within the brainstem, including the vestibular nuclei, the reticular formation nuclei, and the substantia nigra (which figures prominently in Parkinson's disease), send direct projections down the spinal cord. These motor pathways are referred to collectively as the extrapyramidal tracts, meaning that they are not part of the pyramidal tract (extra- means "outside" or "beyond"), the axons that travel directly from the cor- tex to the spinal segments (Figure 8.5). Extrapyramidal tracts are a primary source of indirect control over spi- nal activity modulating posture, muscle tone, and move- ment speed; they receive input from subcortical and cortical structures. Pyramidal tract (pyramidal tract because the mass of axons resembles a pyramid as it passes through the medulla oblongata) - Corticospinal - fine control! Extrapyramidal tracts - Brain stem origin Rubrospinal - stance/gait Tectospinal -> superior colliculus (attention orientation) Vestibulospinal - balance Reticulospinal - startle/adrenaline
False belief task
The Sally-Anne False-Belief Task for investigating theory of mind • This task is used with children to determine whether they can interpret what Sally is thinking about the location of the marble • Because Sally does not see Anne move the marble from the basket to the drawer, Sally should look for the marble in the basket
Time-frequency spectrum
The Time-Frequency plot is rich with information about when and what • You can see that power in the Alpha band (y axis; red=greater power) increases between 200-300ms • Can be used to study distant cortico-cortical communication (cross-frequency coupling) inter-region communication
how do visual cues influence attention and what effect this has on visual perception (week 9 zaps)?
The arrow was usually a "valid cue": on 80% of the trials, the arrow correctly told you where the target would be; on the other 20% of trials it was an "invalid cue," meaning that it did not point in the direction of the red square. The plus sign was a "neutral cue" that did not provide any information about where the target would be. very powerful paradigm because, in addition to demonstrating selective attention, it allows us to compare the effects of different kinds of cues, to measure how quickly attention shifts, and to observe many other properties of selective attention. Neuroscience research has shown that attention works by strengthening brain responses to attended things and reducing responses to un-attended things (Desimone & Duncan, 1995). Neurons that respond to an attended location respond more strongly than neurons that respond to other locations. This also works for directing attention to a particular color or type of object. For example, if you are looking for a red square, red-selective neurons will respond more strongly than neurons that respond to other colors. This means that attention is not limited to a particular level of processing; instead, it can affect many different levels of processing, from the earliest stages of visual perception to higher-level conceptual processing. real-world consequences: talking hands free on the phone while driving is still problematic: problem is often framed in terms of keeping the driver's eyes on the road by, for example, requiring the use of a hands-free device to talk on the phone. However, as the covert attention research shows, attention is not identical to visual fixation. If the driver is visually fixating the road but their attention is on their phone, then even the lowest levels of visual perception will have weaker responses to hazards, leading to slower responses and possibly contributing to a crash (see Strayer & Johnston, 2001; Strayer et al., 2003). !ask urself to summarize
What are some problems with the term "the limbic system"
The brain did not evolve separately for "emotion" vs. "cognition"
How motor actions travel in the brain pt 1
The brain innervates the spinal cord via the pyramidal and extrapyramidal tracts. The pyramidal (corticospinal) tract originates in the cortex and terminates in the spinal cord. Almost all of these fibers cross over to the contralateral side at the medullary pyramids. The extrapyramidal tracts originate in various subcortical nuclei and terminate in both contralateral and ipsilateral regions of the spinal cord. CST axons terminate either on spinal interneurons or directly (monosynaptically) on alpha motor neurons. most cross 80% at junction of the medulla and the spinal cord 10% cross when they exit the spinal cord
What is the CNS and PNS composed of?
The central nervous system is made up of the brain and spinal cord. The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body.
binocular rivalry
The competition between the two eyes for control of visual perception, which is evident when completely different stimuli are presented to the two eyes con: little control in the how long people perceive each stimulus
Explain the radioactive glucose experiment conducted to understand retinotopy
The figure below shows the results of an experiment in which an anaesthetized monkey viewed a flickering bulls-eye pattern, and was injected with radioactively labeled glucose. The glucose was taken up by active neurons. The animal was then sacrificed, and V1 was surgically removed and flattened. The flattened V1 was then used to expose radioactively sensitive film. The result is a picture of regions of activity evoked by the bulls-eye. As you can see, V1 maintains a retinotopic map.
What is the Jennifer Aniston neuron?
The grandmother cell, sometimes called the "Jennifer Aniston neuron", is a hypothetical neuron that represents a complex but specific concept or object. It activates when a person "sees, hears, or otherwise sensibly discriminates" a specific entity, such as their grandmother or Jennifer Aniston Quiroga's team's finding was phrased more scientifically as "various pictures of Jennifer Aniston elicited a response in a single neuron inside the medial temporal lobe
What is aggregate field theory? Who proposed it? Why?
The idea that cerebral functions are distributed throughout the brain that functions as a whole Proposed by Jean Pierre Flourens - animals following cerebral lesions recovered some or all of the function that was lost
Homonymous Hemianopsia hemianopia?
The loss of the right or left half of the field of vision in both eyes due to damage on visual fibers from LGN to V1 = aware they are missing one field of vision and frequently turn their head to receive visual input from that side
How do parallel pathways travel from the LGN to the primary visual cortex (V1)?
The magno and parvo layers project separately in the input layers of V1, but then these parallel pathways (that originated in the retina) get pretty much completely merged in subsequent areas.
modal model of memory
The model proposed by Atkinson and Shiffrin that describes memory as a mechanism that involves processing information through a series of stages, including short-term memory and long-term memory. It is called the modal model because of the great influence it has had on memory research.
Adolescence and the effects of social isolation and stress in social cognitive areas of the brain
The prefrontal cortex continues to develop through adolescence. Social isolation and lack of social play during childhood and adolescence have negative impacts on the neuronal development of areas that support social behavior, resulting in social behavioral deficits that last into adulthood. Social stress during childhood affects the neuronal development of the brain. Social stress in adults contributes to neural degeneration.
Feedforward sweep
The propagation of visual information from the primary visual cortex down the "what" and "where" pathways. (to cortical higher order pathways)
Describe retinotopy in the LGN
The retinal (hereafter called "retinotopic") map is preserved. Axons from the retina preserve their order. There is an entire map of a visual hemi-field in each layer of the LGN. The maps are in register in each layer. The retinotopic map is laid out across the folded cortical surface in the gray matter of the Calcarine sulcus. The central (foveal) part of the visual field is represented at the very back and more peripheral regions of the visual field are represented further forward (anterior). The retinotopic map is lateralized so that the left hemisphere V1 represents the right half of the visual field and vice versa.
How is the retinotopic map preserved or not in V1?
The retinotopic map in V1 is distorted so that the central 10 degrees of the visual field occupies roughly half of V1 (orange regions in the above diagram). This makes sense because of the poor acuity in the periphery (recall that peripheral ganglion cells have large dendritic trees and pool over many photoreceptors). The distortion is called cortical magnification.
simulation theory aka experience sharing theory
The theory that we come to understand others (their emotions, actions, mental states) by vicariously producing their current state in ourselves
Dual streams hypothesis
The two-streams hypothesis is a model of the neural processing of vision as well as hearing. The hypothesis, given its initial characterisation in a paper by David Milner and Melvyn A. Goodale in 1992, argues that humans possess two distinct visual systems. Dorsal (where) and Ventral (what) lesion studies helped identify this !add
What are the ventricles of the brain?
The ventricular system is composed of 2 lateral ventricles, the third ventricle, the cerebral aqueduct, and the fourth ventricle
What is the "Jacksonian March" ?
The wave-like movement of a seizure from a point of focus to other areas of the brain coined by Huglings Jackson
Theory of Mind
Theory of mind is the ability to impute mental states to oneself and other people. Theory of mind is important for social developmentand interactions. It underlies the capacity to cooperate, empathize, and accurately anticipate the behavior of others. Theory of mind appears to be innate and automatic. Two theories have been proposed regarding how we read the thoughts and intentions of others: experience shar- ing theory (simulation theory) and mental state attribu- tion theory (theory theory). picture false belief task: whether kid thought experimenter knew ball was behind the screen improved reaction time to pressing a button in response to detecting the ball
Chronic Hemispatial Neglect
There is often substantial recovery from acute hemispatial negelct over the first few weeks to months • BUT: the patient is left with parietal lobe deficits and extinction, the failure to perceive two stimuli when simultaneously presented (begin to see left visual field, but will not see two objects simultaneously) • Extinction can be seen in all modalities, typically visual > somatic > auditory
Describe the difference between working memory versus short term memory
They both do not hold information for very long but short term memory simply stores information no longer in the environment, while working memory retains the information in order to manipulate it. Short term memory is part of working memory, but that doesn't make it the same thing • E.g. repeating a phone number vs. the phone number multiplied by 2
What is MRI acquisition time?
Time in the MR pulse sequence during which the MR signal is recorded. The duration can be denoted TAD (for "time of analog to digital conversion").
What is Tonic skin conductance
Tonic skin conductance is generally considered to be the level of skin conductance in the absence of any particular discrete environmental event or external stimuli.
describe neuroanatomy of neglect
Typically: lesion in Posterior Parietal Cortex: but can also occur in ventral prefrontal and posterior parietal network like: - Temporal-Parietal Junction (TPJ) - Inferior Parietal Lobe (IPL) But also can occur following lesions to the highly interconnected ventral attention network and thalamic nuclei
What is the primary visual cortex (V1)? Why is it named that? Where is it located?
V1 is "primary" because the LGN sends most of its axons there, so V1 is the "first" visual processing area in the cortex. V1 processes the information coming from the LGN (as described below) and then passes its output to the other visual cortical areas which are (creatively) named V2, V3, V4, etc. V1 is located in the Calcarine sulcus in the medial occipital lobe of the brain (near the back of the head, just to the left and right of the middle).
Describe the V4 visual cortex. What evidence gives this function of V4?
V4: specialized color module - detecting color changes and color constancy and object/shape perception taking difference of colorful and black and white region ends up in seeing activity of the V4 region
What are VEP's?
Visual Evoked potential Visual stimuli creates electrical potential
parvocellular pathway
Visual pathway specialized for color and detail cones that "flows" along bottom of cortex
magnocellular pathway
Visual pathway specialized for motion and localization rods, "flows" along top part of cortex
!ask how is the EEG recording this?
When enough cells are co-active and co-aligned the changes (LFPs) sum and can be recorded at the surface of the head
The stretch reflex
When the doctor taps your knee, the quadriceps is stretched. This stretch triggers receptors in the muscle spindle to fire. The sensory signal is transmitted through the dorsal root of the spinal cord and, via an interneuron, activates an alpha motor neuron to contract the quadriceps. In this manner, the stretch reflex helps maintain the stability of the limb following an unexpected perturbation the contraction of a muscle in response to stretch of that muscle 1. quadriceps stretch 2. sensory stretch receptor (muscle spindle) senses the quadricep muscle was stretched 3. receptor sends signal thru dorsal pathway to interneuron in the spinal cord 4. interneuron engages alpha motor neuron via ventral pathway == contracts quadriceps
What is the difference between white and gray matter?
White matter: Axons - white from myelin - bundles or cables Gray matter: Cell bodies of neurons
In the Principles of Psychology by William James, what was a big early question that intrigued people to make neuroimaging techniques?
Why the brain pulsates (can feel in soft spot of infants) some speculation on blood circulation
What is diffuse axonal injury?
Widespread microscopic damage, primarily to the axons. Depending on severity can lead to persistent vegetative state.
Who mapped the homunculus (somatotopic map)?
Wilder Penfield
In 1790 what progress was made on identifying brain regions?
Willis had begun to draw & name brain regions Franz Joseph Gall founded phrenology No idea what neurons are • Limited understanding of neuroanatomy • No understanding of brain function!
How does a CAT scan work?
X-rays pass through the head at many different angles.
out of body experience
You feel that you are not residing in your own body (abnormal sense of spatial unity between self and body); you feel as if you are inhabiting another body, usually hovering above the physical body (abnormal self-location); and you see your own body and a view of the world from that location (abnormal egocentric visuospatial perspective; Blanke et al., 2005). strong right angular gyrus stimulation of patient undergoing brain surgery to prevent seizures (light stimulation = falling/sinking feeling)
visual heuristic
a "rule of thumb," such as size constancy) that is usually so reliable that the brain can't help but trust it.
What is optogenetics?
a biological technique which involves the use of light to control cells in living tissue, typically neurons, that have been genetically modified to express light-sensitive ion channels.
attentional blink
a brief period after perceiving a stimulus, during which it is difficult to attend to another stimulus
backward masking
a brief visual stimulus after another brief visual stimulus that leads to failure to remember the first second stimulus = called as mask sometimes sandwich masking is used
schema /script
a cognitive structure that helps us perceive, organize, process, and use information
Give an example of "spatial cueing"
a cue (the spotlight) tells you where (spatial location) to focus your attention. from week 9 ZAPS: It is Saturday night and you and your friends have decided to go to a play. You take your seat and chat with your friends while you wait for the show to begin. Suddenly, a spotlight turns on and a moment later an actor appears from behind the curtain, precisely where the light had hit. The actor gives an introduction to the show and wishes everyone an amusing evening. Imagine that no spotlight had been used. Chances are you would not have noticed the actor as quickly. The spotlight served as a cue that something was going to happen onstage, which prompted you to focus your attention on the stage. Attention is "selective" in the sense that it allows us to focus on one input or task while ignoring others. Focusing on your chat with friends makes you slower to notice the actor, while focusing on the stage would make you less likely to understand what your friends are saying.
What is a Tachistoscope?
a device designed to present stimuli for precisely controlled amounts of time sometimes exclusively to the right or left visual field !ask does it have to have left/right split to be a tachistoscope?
Parkinson's disease
a progressive disease that destroys of neurons in the substantial nigra and is identified by muscular tremors, slowing of movement, and partial facial paralysis substantial nigra (midbrain) = critical for projection to basal ganglia (caudate/putamen striatum reduced dopamine) impaired Purinergic input !! First described by James Parkinson (1817) as the shaking palsy • Primary pathology identified as a loss of pigmented cells in the substantia nigra • ~70 years later reduced dopamine (DA) in striatum identified • Characterized by: • Akinesia (loss of ability to produce volitional movements) • Bradykinesia (slowness of movement; decreased blinking, decreased facial expressions) • Resting tremor (increases with movements)
What is the pulvinar nucleus?
a prototypic association nucleus that participates in reciprocal cortico-cortical interactions and promotes synchronized oscillatory activity in functionally related areas of the cortex.
What is a continuous theta burst (cTBS)?
a repetitive transcranial magnetic stimulation paradigm reported to decrease the excitability of the stimulated cortical area and which is thought to reflect a form of inhibitory synaptic plasticity
prepotent response
a response that has been "primed" to occur through reinforcement, repeated use, habit, or reflex
parallel search
a search in which multiple stimuli are processed at the same time
describe pop-out search
a single distinguishing feature that was salient differentiated the targets from distractors
inhibition of return
a slowing of reaction time associated with going back to a previously attended location occurs when returning attention to a previously viewed object or when the location is suppressed
Bistable figures
a stimulus that produces two alternating perceptions
What is the superior colliculus?
a structure in the midbrain that is important in initiating and guiding eye movements
dichotic listening
a task in which people wearing headphones hear different messages presented to each ear
Single Cell Recording - rasterplot and peristimulus histogram
a technique by which the firing rate and pattern of a single receptor cell can be measured in response to varying sensory input firing with stimulus - no firing when no stimulus = depression in firing - extra cellular Quantification: Rasterplot: 1 point per action potential; trials * time (summarized in a peristimulus histogram) • Superb temporal resolution in pic!
center-surround receptive fields
a visual receptive field with a circular center region and a surround region forming a ring around the center; stimulation of the center produces a response opposite that generated by stimulation of the surround
Monkey Lesion study to support Dual Streams Hypothesis: Lesions to what brain identified what function? What skill was tested?
a) object discrimination (temporal lobe lesion: cannot identity objects but can identify relative spatial locations) b) landmark discrimination (parietal lobe lesion: cannot identify relative spatial locations but can identify object type associated with reward)
the cocktail party effect
ability to attend to only one voice among many
What do patients with lesions to V5 experience?
akinetopsia
What is equipotentiality?
all parts of the cortex contribute equally to complex behaviors such as learning, and any part of the cortex can substitute for any other (memory is distributed)
What is the DTI used for?
allows us to measure microscopic movement of water in the brain. This makes it possible to visualize the location, orientation, and direction of the brain's white matter tracts.
Who is Henry Molaison (Patient HM)?
an American memory disorder patient who had his hippocampus surgically removed in an attempt to cure his epilepsy surgery = lifted frontal lobe and vacuumed medial aspect of temporal lobe bilaterally
Abulia
an absence of willpower or an inability to act decisively / the loss or impairment of the ability to make decisions
How is visual processing is a network problem? Describe some of the interconnectedness in the visual cortex
as you move along visual cortical hierarchy - preferences for visual features changes (orientation direction -> faces) it gets more complex as you move along hierarchy and receptive field increases and it branches into the dorsal and ventral pathway
How does measuring levels of consciousness with fMRI work?
ask questions and see brain activity
How did Hans Berge in Jena discover electroencephalography (EEG)?
asked individuals to perform hard arithmetic problem then rest (open/close eyes) dramatic oscillations at rest short sharp ripples when thinking/eyes open picture = alpha wave
Describe how Jason Samaha UCSC and Tommy Sprague UCSB investigate how we enhance our attention to respond and process particular stimuli
asked patients to fixate on center point and attend to location in space according to color of diamond when not attending to particular spatial location = see increase in alpha when attending to particular location = reduction in alpha in anticipation of visual cue = cortical excitability increases to intended location in order to respond to cues better in that region only with alpha band did ML classifier accurately classify where participants were attending to
Explain the Intracranial EEG: verb generation example
asked to listen to the word then a few seconds later to repeat the word Listening: Wernicke's planning: cortex about to produce word: broca's producing: motor cortex
Compare brain waves with Fourier transform applied when asleep versus awake and active
asleep = greater power in delta band thinking hard = greater power in gamma wave
What brain area(s) processes selective attention?
attention impacts visual processing even earlier than the 80-100ms P1 response! enhancement of BOLD response in LGN and visual cortex enhanced response in contralateral field to whatever they were responding to TRN (thalamic reticular nucleus) inhibits or excites LGN which may be key for selective attention processing ^all recent work, shown in non-human primates, may or may not be the case
What is a common strategy to get an event-related potential (ERP)?
average the EEG signal across trials, thus increasing the signal-to-noise (SNR) ratio = sum repetitive events time locked to a stimulus or response because background EEG can be assumed to be random - # of trials are dependent on amplitude of ERP of interest
What are EEG epochs?
average time-locked to an event across many trials resulting in event related potentials
why is it important to average trials?
bc each indv epoch is rlly noisy so its important to average many trials to obtain clean ERPs
What is the fusiform gyrus' function?
brain area of the inferior temporal cortex that recognizes faces
Where is the nuclei organizational scheme of neurons found in the brain?
brainstem, thalamus, basal ganglia, etc !ask basal ganglia = action selection? https://gauchocast.hosted.panopto.com/Panopto/Pages/Viewer.aspx?id=2683f7f0-523c-4642-8077-aca50036f017 13:00
What changes occur in the frontal lobes during development?
bursts of development in frontal love with normal development related to neuronal pruning thickness of frontal lobe decreases over certain stages of development (like ages 4-7 and in early teenage period) and increase in white matter connectivity = competition for neuronal connectivity
Just like retinal ganglion cells, cells in the LGN, have what kind of receptive fields?
center-surround receptive fields
Where is the majority of neurons in the brain?
cerebellum (69 billion in cerebellum!!! 3-4x cerebral cortex)
What is the medial view / limbic system of the brain? label the parts
cingulate gyrus corpus callosum thalamus hippocampus amygdala
What is an oddball task?
commonly used task for cognitive and attention measurement in ERP studies - evoke a large positivity
In what ways is cognitive control a distributed process? How can we use graph theory to model whole brain connectivity?
compute network affiliation at rest compared to 10 minute finger tapping block compared to 10 minute complicated working memory task cognitive control network is much more pronounced and connected in n-back task finger tapping task does not require cognitive control, only get provincial hub increases (motor network, connectivity increases within a network) cognitive control working memory n-back task = increase in connector hubs (between network connectivity) , makes sense cannot just use PFC network but must interact with occipital and temporal cortices to send this goal directed behavior to = suggests connectivity between frontal and posterior sites are more connected when exerting cognitive control
What does CAT /CT stand for?
computerized axial tomography
corticospinal tract (corticomotoneurons)
connections between brain and spine crossed firing (right side of body = left hemisphere affected) 1. terminate at interneurons in spinal cord or 2. CST fibers end monosynaptically at alpha motor neurons (i.e. corticomotor (CM) fibers) OR at interneurons (most of them) • Corticomotor (CM) fibers promote greater dexterity: unique to human+ higher order primates
pros and cons of MEG
cons - only picks up a few cm into the brain (poor spatial resolution) - does not image the brain anatomy, just the activity, so often used with MRI - expensive - picks up mostly sulci activity (no gyri due to perpendicular imaging) pros - non invasive, no radiation - superb temporal resolution - takes pictures more often than MRI
Levels of consciousness
conscious, preconscious, unconscious !varying levels of awareness is correlated with wakefulness level for the most part
Global Workspace Theory
consciousness is achieved when information is distributed to much of the cortex
three different ways to map the same space along the visual heirarchy
convoluted brain flat map flattened again
corpus callosotomy
corpus callosum severed to stop epileptic seizures -> brain has more difficulty sending messages between hemispheres -Allows study of each hemisphere independently
when do gamma waves occur?
correlated with large scale brain network activity and cognitive phenomena such as working memory, attention, and perceptual grouping, and can be increased in amplitude via meditation[2] or neurostimulation.[1][3] Altered gamma activity has been observed in many mood and cognitive disorders such as Alzheimer's disease,[4] epilepsy,[5] and schizophrenia.[6]
corticomotoneurons or Corticomotor (CM) fibers
corticomotoneurons or CM neurons, include promi- nent projections to muscles of the upper limb, and they support the dexterous control of our fingers and hands CM neurons are preferentially active during pinch compared to power grip. Recordings are from a single CM neuron in the primary motor cortex of a monkey that projects to a finger muscle. Peri-event histograms for precision grip with light and heavy resistance for a CM neuron (a) and power grip (b) show that the CM neuron fired more strongly for the precision grip tasks. The EMGs of the finger muscle show that muscle activity was stronger for the power grip. While the muscle was active in both tasks, activation during the power grip came largely from non-CM corticospinal and extrapyramidal neurons, suggesting that CM neurons specialize in fine motor control.
How did Lebdev et al 2004 deconfounded the delay experiment
covert attention process to remember position without moving their eyes + the dots going to move and they have to covertly attend to new location while keeping in mind previous location target then dims (current attended location) or brightens (previous location) expect to find PFC neurons firing to first memory, if firing to attention they would fire at attended location • Lebedev et al., Plos Biology, 2004 showed Majority of PFC neurons (61%) tracked the attended location, only 16% tracked the remembered location did not address movement confound
Korbinian Brodmann
cytoarchitectural areas of human brain 52 different areas of the brain
Which of the following is NOT thought to be an evolutionary pressure that gave rise to access-consciousness? Select one: a.cost of time b.cost of resources c.cost of space d.cost of prey
d. cost of prey
Anosognosia
denial of illness shown in Acute Hemispatial Neglect
peri-threshold stimuli
depending on excitability of your visual cortex (depends on amount of alpha waves currently there) = you may or may not see this stimulus, sometimes you see it sometimes you don't
capacity of working memory with Braddley's model (ZAPS module)
depending on how you use workspace = how much you remember phonological loop (broadly used for sound-based or linguistic information) visuospatial sketchpad (broadly used for visual or spatial information) central executive (directs attention and coordinates information) TESTED ON: short words long words similar sounding letters different letters numbers
What did Flourens find when seeking evidence for/against phrenology
destroyed parts of brains of pigeons and rabbits found cerebral hemispheres = no perception, motor ability, judgement cerebellum = uncordinated, lost equilibrium thought memory and cognition are diffusely scattered throughout brain aggregate field theory > localization
Posner cueing task
determined that the fastest responses are generated for valid targets since they appear at the location that is being attended to most closely https://en.wikipedia.org/wiki/Posner_cueing_task valid: arrow points to where object will appear invalid: arrow points to different area neutral: arrow pointing both ways measured: how long it took patients to indicate where the cue appeared cost of inattention = reaction times slowed down = attention can be voluntarily guided to regions of space without moving one's eyes
What is Baddeley and Hitch's model of working memory?
dominant theory in the field of working memory. Consists of the central executive mechanism which acts as supervisory system and controls the flow of information from and to its slave systems: the phonological loop, visuospatial sketchpad, and the episodic buffer
What are the two kinds of Intracranial EEG for surgical processes? What is their main difference?
electrocorticography (eCoG) brain exposed with surface electrodes Stereo Electroencephalography (sEEG) depth electrode probes
What are some methods to study Instructed emotion regulation (to study neural mechanisms)
electrodermal activity (skin conductance SCR) told to decrease/increase response record a muscle (smiling/frowning muscle) better regulators = most inverse relationship between amygdala time course and all prefrontal brain areas
What valence metrics do psychologists use to study emotion in a non-obtrusive way? (peripheral-physiology)
electrodes attached to valence dependent muscle groups smiling muscle - Zygomaticus frowning muscle - Corrugator Supercili
How does an MRI scan work?
employs powerful magnets which produce a strong magnetic field that forces protons in the body to align with that field. When a radiofrequency current is then pulsed through the patient, the protons are stimulated, and spin out of equilibrium, straining against the pull of the magnetic field. = this movement is captured by the MRI machine https://www.youtube.com/watch?v=nFkBhUYynUw
What are the stages of memory?
encoding -> storage -> retrieval another stage not on slide: consolidation
Describe more in depth how the dorsal network works for ___endogenous or exogenous___ attention modulation?
endogenous = the brain areas that are specified functionally for whatever we are selectively attending to activate even before the stimulus is presented If paying attention to stimulus in left or right visual field = BOLD change occurs in contralateral hemisphere brain area
What did Jean Pierre Flourens argue for ?
equipotentiality and aggregate field theory
the cerebellum's role in motor actions
error detector = compares our movements to our intended movements
What is an artifact in EEG?
ex. eye blinks, muscle movement, heart beat, etc
What is Apraxia?
inability to perform particular purposive actions, as a result of brain damage.
How does one conduct retinotopic eccentricity mapping with fMRI?
expanding circle of checkerboard to see how information processed in fovea (occipital pole) differs from periphery (sulcus)
What experiment covered in lecture investigated object-based attention? What were the outcomes?
expect: reaction times faster in area in which people were asked to attend to and slower when cue appeared in an incongruent area BUT when attending to A, you are slower to respond to C than the B, but still fastest responding to A hypothesized this is because you are attending to the whole blue bar despite C and B being equidistant from A
Explain the pathways visual information takes in the brain
eyes to V1: parvocellular (cones, 2 from each eye) or magnocellular (rods, 1 from each eye) Dorsal: (where and how to interact with objects) from V1 to V2 then to V5/MT then MST neighbor then posterior parietal cortex Ventral: (recognizing identity of objects) V1 to V2 then V4 (VLA) color then inferior temporal cortex (processing objects and details about visual world) Notes: - every stage has feedback - input loops to the thalamus at every stage - is there functional significance to separating this processing? dual streams hypothesis
What is the role of feedback in visual heirarchy?
feedback on every level and this helps us infer what things are
embodiment
feeling of body ownership, complete with all its parts, and the feeling of spatial unity between the "self" and the body, referred to as embodiment lateral occipitotemporal cortex,
What is a visual field?
field of view that can be seen without moving the head
Aprosodic
flat affect, impaired emotional perception shown in Acute Hemispatial Neglect
How does one conduct retinotopic visual angle mapping with fMRI?
flickering high contrast checkerboard image to see where different orientations are processed in your brain across left and right visual fields blue = upper visual field red = lower visual field
affective spillover
following an emotion provocation (fearful face) then that emotion can influence your subsequent behavior
How and Why does the ACC correlate w/ "conflict" & produce "error signals"....? is ACC function required for cognitive control (for stroop for example) ?
following an error (ERP is flipped, neg ontop), activity is heightend and generates activity in mPFC? no difference in ACC lesion to healthy paitent performance on stroop task!
How did HM's memory perform post surgery? What does this tell us about memory?
following surgery memory is impaired = anterograde amnesia and cannot make new ones + very little retrograde amnesia (can remember past events, but had temporary 1-2 year retrograde amnesia: temporally grade retrograde amnesia NOT dependent on MTL: - short term memory (short conversations) - procedural / non-declarative memory (writing mirrored) = neural substrates for learning skills (basal ganglia) are different from facts - cognition (no in IQ or language abilities) - retrieval of old consolidated memories (episodic, emotional memories are better further back you go from the surgery)
What evidence did Paul Broca (1824-1880) contribute to localization of function argument?
found that Frontal brain region subserves language "Tan" suffered from what we now call Broca's aphasia
materialism /monism
only one substance - material in nature one body
Using Global Workspace Theory, what brain activity differentiates stimuli that is consciously attended to versus non-consciously processeD?
fronto-parietal ignition for visible words: increased activation in frontal and parietal cortex for sounds: auditory cortical engagement even for sounds they cannot consciously report 1. Sensory activation: insufficient for access consciousness (i.e. reportable subjective experience) 2. Access seems to occur concurrent with frontoparietal engagement, believed to require long-range connectivity, and provide recurrent top-down feedback to sensory areas 3. Closely related to attentional mechanisms (but note: not synonymous) !ask urself to add this to doc
electrocorticography (ECoG)
graded potentials recorded with electrodes placed directly on the brain's surface
Describe how Hermann von Helmholtz (1894) investigated covert spatial attention
he had patients focus on a point but pay attention to a certain part of their visual field without moving their eyes a light would flash and the patient would be asked to report the letter briefly illuminated = patient could better report letters in areas they were paying attention to and less so in other areas
How would people with (frontotemporal lobar degeneration (FTLD)) rate scenarios with positive and negative contingencies on their acceptability? (Grossman et al., 2010)
healthy controls vs vmPFC degeneration (frontotemporal lobar degeneration (FTLD)) judged 20 social situations (run red light at 2am) scale of 1 to 5 for social acceptability given positive (sick child in the car) or negative (cop car nearby) contingencies judge according to two randomly presented instructions: "Should everyone do this all of the time?" (rule-based condition) or "Is this generally okay?" (similarity-based condition). The FTLD patients judged negative scenarios to be more acceptable than the healthy adults judged them to be significantly greater activation was observed in their vmPFC (the very region of cortical atrophy in FTLD patients) than when they judged the positive social scenarios (Figure 13.32)
In 1790 in ancient Egypt, what was believed to be the organ of thought?
heart, the brain was discarded in the mummification process
What brain condition did Egyptian Papyrus contain? Where else was this described?
hemiplegia (paralysis of one side of the body) from brain injury (2500-3000BC) Also in/by Hippocrates (400 BC)
What brain areas does selective visual attention have the strongest impact on?
higher order visual areas bar graph in picture: attending to the difference between green, blue, and turquoise has the greatest impact to V4
!ask urself to make a question
https://gauchocast.hosted.panopto.com/Panopto/Pages/Viewer.aspx?id=1f2fb92c-f004-4c84-8145-ae190179b916 44:00 is this even important?
So how is the LPFC allowing us to make goal congruent decisions and exercise cognitive control? What hypotheses are out there?
hypotheses: 1. LPFC promotes the overriding of prepotent responses - but is it really inhibitory? 2. inhibition as a consequence/byproduct of biased competition example: if someone asks you about the color of the golden gate bridge then you will think of the shape of the bridge, it's location, and color, all different properties of it BUT the temporo-occipital activity may be engaged more so because you were asked about color specifically and similarily the other areas are inhibited
System consolidation theory
idea that the hippocampus consolidates new memories, a process that makes them permanent then stores them in a new location, in the neocortex
How do we map subjective value: describe how Scott Grafton investigated Approach vs. avoidance decisions
identified brain regions for patient's easy acceptance or easy rejection of electric shock for money = OFC and vmPFC increased engagement (higher social or monetary rewards = higher engagement)
How does feature based attention affect what brain areas encode selective attention?
if attending to only motion: V5 activates mostly if attending to only color: V4 activates mostly
Utilization behavior
impulsively acting on irrelevant objects in the environment - answer the phone in their doctor's office or use their friend's toothbrush when they see it at their friend's house or they see a bed and immediately undress and get into bed
Information in center of visual field processed by fovea is processed where in the brain?
in the occipital pole
ataxia
inability to perform coordinated movements results from Damage to the cerebellum from stroke, tumor, or degenerative processes
Wilder Penfield (1891-1976)
mapped somatosensory and motor cortex using electrical brain stimulation developed "montreal procedure" to stop seizures by removing the source tissue of the siezure TEST the area before removal: - record behavioral response to brain parts stimulated with electrical currents = discovered homunculus (somatotopic map)
What criticism is there for masking tasks to investigate consciousness? What is a potential solution?
masking really decreases stimulus strength, so are you studying the neural correlates of conscious awareness or the neural correlates of greater stimulus strength? Is the amount of sensory information a confound? sol = mask does not cover stimulus, but instead is a contour inside the stimulus that is compatible with both stimulus = stimulus does not disappear but results in 2 types of subjective experiences and controls for simtulus intensity 1. 33 ms later mask = 2. 100 ms later mask = = in both conditions, participants are able to identify prepositional target (diamond or square) with no significant difference in performance ~70% accuracy IF YOU ASK if they saw it or if they are guessing= 1. guessing 2. saw it with confidence ^ significantly different WE SHOULD MATCH ACCURACY IN STIMULUS DETECTION, BUT MISMATCH CONFIDENCE IN CONSCIOUSLY PERCEIVING STIMULUS TO ACTUALLY STUDY CONSCIOUSNESS AND NOT NEURAL CORRELATES OF STIMULUS STRENGTH
What impact does stimulating a V5 MT cell in a monkey detecting direction of motion ?
maximally bias perception of motion when stimulation occurs while monkey is perceiving dots in random direction and minimally bias when dots are strongly moving in one direction !ask what does this mean, does the monkey think they are moving in a certain direction because you are stimulating that cell?
How did Arielle Tambini UCI measure awake consolidation in humans? What did she find?
measured similarity in hippocampal activity during learning and during resting found that people who had more similar activity during resting performed better in the memory task
source misattribution
memory distortion that occurs when people misremember the time, place, person, or circumstances involved with a memory
How might we Measure levels of consciousness
metabolic measures: PET scan or EEG are not sensitive or sufficiently specific TMS/EEG probe approach works well!! deliver one TMS pulse (usually to somatosensory cortex) then examine the spatial temporal features of the EEG to measure effective connectivity if done awake: probing goes to cortices quickly and has a long lasting effect if done in NREM sleep: probing does not go to cortices but stays in local circuitry and lasts very short time period
What are the two sagittal sections of the brain?
midsagittal and lateral sagittal mid = middle lateral = anywhere but middle
dualism
mind and body are separate
Methods used to study theory of mind
mind in the eyes task Participants view pictures of eyes cropped out of a face and decide what emotion the person is feeling brain areas engaged: - temporal cortex meets parietal cortex (close to occipital lobe) - inferior frontal regions social animations test - silent animation - attest moods and personalities to triangles and circles - apply ToM to triangle being bullied Jamil Zaki developed method to test tracking other's feelings false belief task
solution to spinal cord damage
monkey using robotic arm: 100-Unit electrode array in a monkey motor cortex • Record activity • Connect signals to a robot arm • Have the brain learn how to control the robot arm
What is V5 responsible for? What are MT cells sensitive to?
motion MT cells sensitive to: • Position in space • Direction of motion • Motion speed !ask why is V5 cells called MT cells?
What is somatotopy?
muscles of body mapped to area on primary motor cortex in CNS
Who is Patient S.M?
no amygdala since early childhood = no fear shown to regularly fear/threat inducing situations - SM: altered subjective emotional intensity for fearful & surprised faces - freely gazes at human faces, not fixating on eyes - when instructed to look at eyes, S.M. could identify fear, but not before - cannot draw emotional expressions from memory super well - trusts everyone A LOT, comfortable standing very close to people (twice as close)
What's wrong with Phrenology?
no construct validity (what is amativeness? does it exist?) why those locations? why would there be a relationship? If someone learns a new skill, they should get a new bump but they don't no evidence, psuedoscience confirmation bias: published paper says "anyone can demonstrate the truthfulness of the above by mere observation"
Are we conscious of activity in our visual cortex?
no, evidence: blindsight- patient reports not consciously seeing anything but is still able to navigate a hallway littered with obstacles to not run into so primary visual cortex may be necessary for conscious sight but is not sufficient
If you shine the word "knight" to the left visual field, what would a patient with a normal brain say that they saw? What about partial split? Full corpus callosum split brain patient?
normal: knight partial: description until there is access to the information full: no idea
What did Joseph Fourier discover? How does it apply to EEG?
noted that any complex sound can be broken down into a series of component pure tones (fourier transform) complex EEG form can be broken down into simple waves
posner cueing task
often used to assess attention, also known as the Posner effect, its about an individual's ability to perform an attention shift
V1 neurons transform information (unlike LGN cells whose receptive fields look just like those of ganglion cells) so that they are selective for what?
orientation selective and direction selective. Most V1 neurons are orientation selective meaning that they respond strongly to lines, bars, or edges of a particular orientation (e.g., vertical) but not to the orthogonal orientation (e.g., horizontal). each cell maximally fires at their preferred orientation
extra cellular
outside the cell
What are different strategies of selective attention?
overt (e.g. using eyes) = redirect your body or eyes to whatever you are paying attention to vs. covert = not moving your body
In children, theta waves normally occur in____&_____regions.
parietal temporal
How do we study long term memory? (subsequent memory paradigm)
participants are presented with items they have to remember. memory is assessed later. heightened lateral prefrontal + medial temporal activity for words that were remembered
The "line cancellation test" is used to assess ___ + what is it?
participants asked to bisect all lines on sheet of paper, if they have unilateral visual neglect they will only bisect lines on one half of paper assess hemispatial neglect / hemineglect
Jamil Zaki developed method to test tracking other's feelings
participants tell either sad or happy story (differing valence and arousal levels) post story: asked OTHER participants to watch back story and asked to rate how they felt at each moment of the story track correlation between target feeling and perceived feeling empathy brain areas engaged: Distributed network including "mirror neuron" (simulation), mPFC and STS (superior temporal sulcus) regions
How did Amnesiacs differ in processes a sad movie compared to healthy participants? What does this tell us about emotional vs episodic memory?
participants: healthy or amnesic watched sad movie for 20 minutes, asked how they were feeling (three times) and what they watched how sad amnesiacs were compared to healthy patients right after watching were not significantly different BUT amnesic's negative effect lingered longer in the absence of being able to declare what they watched emotional and episodic memory use different memory systems because amnesiacs who have impaired episodic memory had a stronger emotional memory than the healthy participants
corticostriatal motor loop
pathway = Excitatory (glutamateric) projections from deep layers of the cerebral cortex to the striatum. Projections are organized topographically with distinct cortical areas projecting to distinct divisions of the striatum.
Describe how LPFC lesion patients compared to healthy patients hold a sound in memory while listening to distractor sounds
patients had to indicate if sound heard in beginning is same as sound heard at the end with task irrelevant tones played in the middle (should be ignored to maintain the original sound representation) parietal lesion - processed delay sounds same as healthy control patients frontal lesion - amplified processing of task irrelevant delay sound attend to some sounds and not other sounds: healthy patients: greater n1 ERP when they attend to a sound vs. when they don't right prefrontal lesions: do not have greater ERP for contralateral sound = only show for sounds played ipsilaterally to lesion (right ear tones) left prefrontal lesion: no attention modulation (no difference between attending to sounds when not attending to sounds)
How does the visual cortex affect object/shape perception?
patients with lesions to V4 region have a problem with complex shapes and sharp edges so V4 struggles to see face in Monet but not picasso !ask to clarify
Describe Nancy Kanwisher's experiment with object-based attention
paying attention to man opposed to house = increase in BOLD in FFA (face processing area) house = increase BOLD in PPA attention to moving cue = MT/V5/MST enhanced BOLD , experiment 2 displayed FFA/PPA do not enhance much if only paying attention to movement despite the cue being a face/house
How is BOLD a sluggish signal?
peak BOLD change happens ~7 seconds after neuronal firing (6-10 seconds) = poor temporal resolution!
describe the fMRI study investigating role of LPFC in cognitive control in selecting foods with diet in mind
people on a diet make a food decision in the fMRI scanner (chocolate or apple?) choose at random one of the decisions the participants made to give the food at the end of the session OFC and vmPFC sites engaged more for foods the participant's really liked (tracks subjective value) LPFC engagement in trials when patients were able to say no to chocolate bar and yes to apple (making a goal directed decision)
color constancy> give an example
perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object The retina detects different colors from these chairs because of the light and shade. V4 determines they are all the same color
What is the general approach to content consciousness studies?
peri-threshold stimuli
What is baseline in an EEG?
period before stimulus onset
continuous flash suppression
present a static stimulus to one eye, present 'flashes' of ever changing stimuli to the other eye, most people report not seeing the static stimulus low contrast stimulus to one eye, high contrast stimuli to another eye = better control and timing
What is the encoding specificity principle?
phenomenon of remembering something better when the conditions under which we retrieve information are similar to the conditions under which we encoded it
Anatomical personology
phrenology, created by Gall, character could be divined through palpating the skull dubbed phrenology by Spurzheim
How does Crick and Koch define the neural correlates of consciousness (NCC)
placing constraints on what biological mechanisms may be! "the minimal neuronal mechanisms jointly sufficient for any one specific conscious percept" purpose for defining this: Leaving philosophical issues aside for now to revisit later
Why do some figures have EEG positive stimulus responses in the negative direction?
positive waveforms used to be plotted in the negative direction, now it is the other way around
occipital pole
posterior end of occipital lobe; primary visual area; visual cortex; actual sight is here and in the occipital lobe
If disrupting Wernicke's area and conducting stroop test, what happens?
quicker response time because speech comprehension and understanding is inhibited so there is less entropy/competition when perceiving the color of the text
mood-congruency effect
presenting words as word pairs has created the context. Other experiments have found that being in the same mood at encoding and retrieval leads to better memory.
Lapate's investigations into affective spillover using an emotional distribution task
priming with emotionally valent images of faces then shown a neutral face and asking patients to evaluate emotion of neutral face (ex: how much do you like or trust this person on a scale 1-10?) inhibitory TMS protocol (parts of brain inhbited before undergoing affective spillover task) inhibited LPFC (experimental) and somatosensory cortex (control) LPFC inhibition = larger affective spillover 2-3 seconds somatosensory = no statistically significant difference in likability ratings of neutral faces following positive/negative priming images EMOTIONALLY BIASED FIRST IMPRESSION WERE STILL DETECTABLE 3 DAYS LATER-- WHAT?!
Korsakoff's syndrome + evidence patients have some social cognition memory
profound inability to recall events shown two pictures of men and were told a biographical story of each. One man's story described him as a "good guy"; the other man's story described him as a "bad guy." One month later, most of the patients preferred the picture of the man whose story had revealed him to be a good guy, although they did not recall any of the biographical information about him (M. K. Johnson et al., 1985).
Line bisection task
shows a shift towards the right (ignoring the left)
Stanley Klein and his colleagues at UC Santa Barbara (1992) asked whether self-descriptive judgments rely on recall of specific auto- biographical episodes
self-judgment condition- word "describe" flashed followed by a personality trait adjective, after which participants were to decide whether the adjective was self- descriptive (e.g., "Are you generous?"). autobiographical condition, the word "remember" was flashed, followed by a trait adjective. Here participants were asked to recall a particular instance from their lives when they exhibited that personality characteristic (e.g., "Give an example of when you were stubborn"). definition condition, the word "define" was flashed, followed by a personality adjective that participants were to define (e.g., "What does lazy mean?"). 2 weeks later REPEATED half of the adjectives were traits that they had seen in the previous session, and the other half were traits that they had not been asked about before If self-descriptions rely on searching episodic memory for examples, then participants should answer faster when asked about a personality characteristic that they had lately considered in relation to themselves findings suggest that our judgments about self-descriptions are not linked to recall of specific past behaviors.
Multiple Traces Memory Model
semantic memory = outside of hippocampus contextually rich episodic memories = hippocampus invoked - brain regions supporting retrieval differ depending on type of memory - semantic memories = less hippocampus, more so other areas - episodic = hippocampal activity
calcarine sulcus
separates the occipital lobe into superior and inferior halves and processes peripheral vision
How does varying durations of inter-stimulus interview interval affect exogenous (bottom up) selective attention processing?
short = benefit in reaction time and increased P1 reaction magnitude long = reduced reaction time and decreased P1 reaction magnitude
Michael Gazzaniga
split-brain research; understanding of functional lateralization in the brain; how the cerebral hemispheres communicate
What is Magnetoencephalography (MEG)?
squids detect tiny magnetic fields generated by the brain, but operate at very cool temperatures picks up perpendicular magnetic signals
How Insula brain area was tied to disgust in an experiment
stimulate insula while monkey is about to eat = will reject food, if already ate food = will spit out food
describe the intertemporal discounting experiment investigating the role of the vmPFC and OFC
suffer OFC lesion = discount value steeply (so after 2 weeks they are not willing to wait no matter the reward)
What are pros and cons of the lesion method for determining causality?
strong causal evidence with good control group (ex: lesion in a different region) cons: - variable brain lesions across participants - impacted white matter in addition to gray matter (hard to localize function= is it due to region or it's connectivity?) - Adaptation may occur (compensatory strategies) to make sure the loss of function is due to the loss of brain matter and not swelling/impact, but person's brain may have adapted to take over the function to it's best ability
How do we test cognitive control?
stroop task - incongruent condition requires cognitive control
Does the ACC/ mPFC keep the LPFC in check? What experiment was used to test this idea?
stroop task: told participants whether they would read out the color of the word or reading out the text of the word Instruction phase: told what to pay attention to ACC does not care about rule LPFC engages more for color rule > reading text During stroop trials: ACC engages more for incongruent trials LPFC does not care if trials are congruent or incongruent conclusions: • LPFC is sensitive to goal/instruction difficulty • ACC is sensitive to stimulus conflict (congruent vs incongruent color-word) • LPFC activity is predicted trial-wise by prior ACC engagement! if the ACC experienced an incongruent trial then activity for the next trial would be higher!
How do we connect with others? (experiment) In what ways are we wired together?
studied cohort for first year students (sampled friendship network) highly connected popular people and some less connected people can we predict friendship based on neuronal responses to social stimuli? movies with different emotional and social scenarios + recorded neural engagement for each person = YES, similar brain activity among friends!!!!
What is the lesion method?
studying brain damaged patients to understand the function of an area
what provided early evidence for monism?
studying patients with brain lesions and later from scientific investigations
cortical magnification
the amount of cortical area devoted to a specific region in the visual field
What did WC, who had a bilateral hippocampal lesion teach us about fear conditioning?
sweats to conditioned stimulus (emotional learning) BUT cannot declare what stimulus predicted the shock = double dissociation (previous flashcard with SM) method: fear conditioned to sound/image and shock + measured skin conductance SCR + measured declarative knowledge, if they knew what stimuli presented the shock
What is the delayed nonmatching sample task?
task in which an animal sees an object and then after a delay must choose an object that does not match the sample
self-reference effect
tendency to better remember information relevant to ourselves
fissure versus sulcus
terms fissure and sulcus as they are classically de- fined are: a fissure separates one lobe from another, while a sulcus is within a lobe and delimits gyri.
What are magnet strengths of MRI measured in? What is the strength of a 3T scan?
teslas! 1.5, 3.0. 4.0, 7.0. ("3T scan" = 3 Tesla) 1 Tesla ~ 20,000 times earth magnetic field
What is the "listener" in an MRI machine?
the MRI coil, it picks up synchronized rebounding of the protons when the radio waves turn off
affective blindsight
the ability of a person who cannot see objects in his or her blind field to accurately identify facial expressions of emotion while remaining unconscious of perceiving them; caused by damage to the visual cortex
What is the Lateral Geniculate Nucleus (LGN)?
the nucleus within the thalamus that receives input from the optic tracts -receives 90% of input sends it to the primary v1 cortex
where is the postcentral sulcus? what is it?
the parietal lobe lies parallel to, and behind, the central sulcus in the human brain. corresponds to the primary somatosensory cortex
phonological loop
the part of working memory that holds and processes verbal and auditory information
What is a receptive field?
the region of the sensory surface that, when stimulated, causes a change in the firing rate of that neuron
Hemineglect (Hemispatial Neglect)
the result of certain right parietal lobe lesions that leave a patient inattentive to stimuli to her left, including the left side of her own body causes: stroke, trauma, alzheimers lesioned/impaired brain area: right parietal, and interconnectedness of parietal cortex and ventral prefrontal cortex
What is The frequency of protons precession is dependent on?
the strength of the magnet.
suggestibility
the tendency to incorporate misleading information from external sources into personal recollections The words in this experiment were all meaningfully related to a relevant schema. The schema activation you experienced enabled you to create false memories by giving you enough information to make you believe that the lure word was also present. This type of memory distortion is referred to as suggestibility, which is defined as the development of false memories from misleading information
Retinotopy
the topographic organization of visual pathways in which neighboring cells on the retina send information to neighboring cells in a target structure
What did a patient report when stimulating their mPFC?
the will and motivation to persevere the was present\ feeling that there is some conflict/challenge ! but they are going to find a way through, some physiological response to example: your tire is half flat and you're halfway to where you need to be, how am I gonna get there? am I gonna get through it? more of a thrill, positive feeling heart rate feeling that something out of their control will/did happen but there was inclination to remain motivated, to fight, not give up stroop may be too minor of a problem to capture this feeling
depth-of-processing effect
thinking about meaning at the time of encoding provides an advantage, compared to thinking about rhyming at encoding
who first brought up biology could affect behavior?
thomas willis then franz joseph gall expanded on it a century later
What is A Radio Frequency (RF) pulse is used in MRI for?
to push protons out of alignment with the magnetic field.
Eyeblink conditioning paradigm
tone + airpuff = Depends on the cerebellum (if delay = depends on hippocampus too) even if you distract them a bunch (movies) = still blink in preparation of air puff = easy to learn, even with amnesia (although they do not pick trace conditioning task: instead of tone terminates with puff, there is a delay for the puff (hippocampal dependent and less straight forward!) = amnesic patients cannot learn!!!! (even separated with 1 second)
How does viewing positive / negative pictures affects the vmPFC and OFC activity?
tracking participants trial to trial activation of corrugator supercilli muscle group (eyebrow) and see activation with the brain positive picture viewing trials = deactivation of corrugator supercilli = increased vmPFC and OFC engagement negative picture viewing trials = increased activation of corrugator supercilli = visual cortex engagement = decreased vmPFC and OFC engagement
What is a TMS?
transcranial magnetic stimulation
Describe/List briefly the brain areas which play a role in attention
ventral prefrontal / posterior parietal cortex (source and intimately interconnected network) temporoparietal junction pulvinar nucleus in thalamus (really coordinates what brain regions talk to each other) superior colliculus superior frontal cortex (some LGN axons travel here)
will patients with OFC damage keep reward in mind when making a decision?
ventral striatum reduced in volume and function "value network" deficit with consequences for social learning no- they'll go for the more immediate reward if a better one is only offered in a long time (~more than a week)
If you take an electrode and place it vertically or horizontally into V1, what organization do you find?
vertical = cells similar orientation horiztonal - neatly organized rotational differences in cells ALSO left and right inputs are kept separate in V1 (ocular dominance columns) picture: Organizational Principles of V1 in respect to direction and orientation selective maximal firing
Jennifer Beer (2006) whether patients' behavior was inappropriate because they lacked insight into their own behavior or because they were unaware of the social norms. + what brain area was damaged?
videotaped healthy control participants, patients who had damage to the orbitofrontal cortex, and lateral PFC damage patients tranger made conversation with the participants by asking them a series of questions. Unlike the other two groups, patients with orbitofrontal damage tended to bring up impolite con- versation topics. participants rated how appro- priate their answers had been, considering that they had been talking to a stranger. orbitofrontal damage = very well rating but shame and embarrassment when rewatching behavior
What do patients with damage to the posterior parietal cortex exhibit?
visual agnosia where the patient can recognize and name objects well but part of the dorsal stream is damaged and they cannot locate where it is, and coordinate movements to grab it
autoscopic phenomena (APs) (what is it + causes)
visual body illusions that affect the entire body (as opposed to body part illusions, such as phantom limbs) 3 types: - Out-of-body experiences - autoscopic hallucination - heautoscopy CAUSES: - The different APs are associated with damage to dif- ferent regions of the temporoparietal cortex. - two disintegrations: fail- ure of two or more sources of tactile, proprioceptive, kinesthetic, and visual information to match up. - conflicting visual and vestibular information, such as when your vestibular system senses that you are moving in one direction but your visual information doesn't correspond
unresponsive wakefulness syndrome (UWS)
when people appear to have emerged from coma yet do not respond to external stimuli for more than a month - have wake/sleep cycle from ARAS - grimace/smile - simple reflexes - no response to external stimuli = ARAS activation is not sufficient for conscious function and interaction with environment
How do we decide should we stay or should we go? Suppose you are trying to maximize your yield of berry picking • As a patch thins out, when do you decide to move to another patch? Describe the experiment that investigated this question
whenever firing rate of ACC doubled from before = less berries in the patch = quicker for ACC firing rate increases, but same threshold firing rate in ACC for monkeys to choose to leave the patch to another one
mPFC intercranial stimulation patients paper
will to persevere region: - • "Getting up" impulses! (e.g. wanted to get up from bed and walk away) - Body directed actions- particularly protecting face/ mouth region (patient: astonished) = super connected with motor regions and dorsal PFC • Laughter (patient astonished; didn't know why) • Interoceptive sensations (stomach emptiness) • Autonomic sensations (cold sweats, tachycardia, often reported as fear and anxiety) = not too many differences in stimulation sites so they combined the region and called it affective
Describe apraxia of the left hand with corpus callosum disconnection
with the right hand the patient is able to make the gestures the interviewer asks, and then copy them with their left hand but if asked to do it in her left hand first the patient fails and if asked to copy the right hand with the eyes closed (gesture command in left hand now), gesture is wrong
Describe the study: Endel Tulving and Donald Thomson (1973) strong and weak cue word pairings
word pair table and chair in the learning stage, it is true that seeing table again in the recognition stage would provide a strong retrieval cue for chair. If you'd seen the pair glue and CHAIR in the recognition stage, however, it would not be as useful because a) the new cue glue provides a different context for chair from when you encoded the information in the learning stage, and b) glue is a weak retrieval cue for chair. - SETTING - CUE ASSOCIATION - MOOD CONGRUENCY
Localizationist findings raise the question: Do different brain regions look different under the microscope, i.e., at the cellular level?
yes
heautoscopy
you see a double but aren't sure if you feel disembodied
How many neurons do you have? What about glia cells?
~86 billion • Glia are Just as numerous as neurons!
Brenda Milner
• According to Nobel laureate Eric Kandel, Brenda Milner is the founder of Cognitive Neuroscience • She discovered the existence of multiple memory systems by careful experimentation. She studied patient H.M., who, after hippocampal ablation to treat epilepsy, was seemingly unable to form new memories • Brenda discovered that he was able to learn new procedural skills in the absence of any awareness or memory of having done the task before (i.e. a memory dissociation) • She's 102 and still going to the lab!
What parts of the brain are involved in memory? What are their functions?
• Amygdala - involved in processing emotionally salient events • Hippocampus - thought to be responsible for H.M.'s memory problems • Entorhinal cortex - main input into the HC from cortex • Parahippocampal cortex - input into EC from dorsal visual stream (PPC) • Perirhinal cortex - input into EC from ventral stream (IT)
prefrontal cortical action:
• At any one moment, opportunities for action — and their associated action plans— emerge in parallel • Action selection ("what") and action specification ("how") compete for selection in an interactive manner • Utility of action is continually assessed • Eventually one action wins and gets selected (others are inhibited)
What is Cytoarchitectonics
• Cellular architecture the way in which cells differ between brain regions
What's right with Phrenology?
• Despite the pseudoscience behind the theory and the appalling ways in which it was applied, this is one of the earliest theories to introduce the idea that different parts of the brain have different functions • birth of the idea of localization of function
Give examples of things that are not emotions
• Emotions are not reflexes • Emotions are not inflexible • Emotions are not bad • Emotions are not noise in the system (most systems are slaves to your emotional state? argument?)
Acute Hemispatial Neglect
• Eyes, head and body turned to right • Failure to orient to left sided stimuli • Failure to search the left hemispace • Anosognosia: denial of illness • Aprosodic: flat affect typically improves in a few weeks to months or becomes chronic
Retrieval memory paradigm for testing memory recall rather than memory recognition
• Have people study a list of e.g. words (or faces) • Wait... • Now scan while you test with a mix of old and new items • The more active the hippocampus during retrieval, the more likely they are to be correctly remembering the item recollection rather than familiarity = greater hippocampal reactivation
How are Inferior Temporal (IT) cortex neurons different from V1 neurons?
• Large bilateral receptive fields (both sides of visual field) • 20-30 times larger than V1's • Highly dependent on stimulus but not location (i.e., location-invariant) • Highly feature selective • Many are also size invariant • Huge receptive fields (~10 to 30 degrees) • Very different from V1! V1: tiny receptive fields & location variant
What is Broca's aphasia?
• Left inferior frontal lesion • Difficulty or inability to produce speech • Speech comprehension largely intact
What is the function of cognitive control?
• Overcome automatic, stimulus-driven, habitual behavior • Behave flexibly according to current context & goals (like preventing yourself from eating 2 donuts because you started a diet) • In other words, it promotes goal-oriented behavior
Why does dopamine agonists (DA) signaling matter for PFC function?
• PFC has one of the highest density of dopamine receptors • In PFC, dopamine basically acts like a clamp • Turning PFC on and lock in a pattern of activity (up state) • Turning PFC off and allowing it to form a new pattern (update) • When a stimulus is rewarding, PFC "locks in" to that pattern of activity - acts like a reward-based switch for behavior = promotes adaptive behavior over time
What happened to Phineas Gage
• Rod goes through skull and lands 25 feet away • Gage is dazed but does not loose consciousness • Gage is taken 3/4 mile to Dr. John Harlow • Harlow shaves Gage's head, removes bone fragments • Treats the wound with magnesium sulfate, calomel and rhubarb; • Note no antibiotics in 1848 !! • Developed "hernia cerebri", brain swelling through skull • Treated with silver nitrate a caustic agent and ice water packs to the head: Gage improves • 2 weeks post-injury: chills, rigor, increased pulse, pain in head, lapsed into a coma • Harlow incises Gage's forehead and removes eight ounces of purulent material • Amazingly, Gage survives • Gage dies 12 years later from uncontrolled grand mal seizures; buried in San Francisco
Gustav Fritsch and Eduard Hitzig
• discovered the motor cortex by electrically stimulating parts of an animal's cortex (dog) = led to brain cell differentiation research
What emotional response systems do we measure for emotion studies?
• peripheral-physiological - autonomic nervous system (sympathetic and parasympathetic) - endocrine system (hormones: cortisol example) - skin conduction • motor behavior (facial-expressive, freezing) - situations of threat = freezing • subjective experience - asking people how they feel - however caveat: not every emotion has a change in subjective experience or change in self report
The recurrent processing framework
• proposed by victor Lamme and colleagues • Feedforward sweep not sufficient for conscious access or experience even if it reaches PFC • Local recurrent processing: sufficient for some conscious experience: possibly 'phenomenal' consciousness (synchronizing local networks = may pick up some information subliminally like priming) • Recurrent widespread connectivity (from fronto-parietal circuitry) required for access consciousness
Describe Habit learning (probabilistic)
•Subject has to guess the weather based on a stimulus. This is done by reinforcement learning in the basal ganglia •Parkinson's disease patients can't learn this 4 different cues predict varying amounts of sunshine or rain = participants predict whether it will rain or not because of the differing probabilities in cues and non-clear boundaries = takes a long time to learn, procedural medial temporal memory
What things are associated w/ low freq of alpha waves ?
▪ Low blood glc ▪ low body temp ▪ low adrenal glucocoritcoids ▪*High* PCO2
