Cog Neuro

dorsal stream (or subsystem) of visual system:

"where" system, includes the posterior parietal lobe. also known as the occipitoparietal pathway, specialized for spatial perception. Sends information from V1 to the parietal lobe

ossicles

(teensy teensy) tiny tiny bones in the ear - three of them! responsible for impedance!

dual process theory of memory

- John Wixted - memory for past events can be based on: retrieval accompanied by specific contextual details (recollection) or on the feeling that on event is old or new, without the recovery of contextual details (familiarity)

Area A1

- Located in temporal lobes, primary processing center for auditory information. A1's receptive field is very precise (small), and is most reactive to "pure" frequencies. Information flow is NOT unidirectional here (up and down processing), allows for feedback such that the brain can adapt to meet new demands (plasticity)

McGaugh, James

- compared memory for boring vs. exciting stories. the outcome was as expected - memory was better for exciting stories. McGaugh then administered propanolol (a beta-receptor blocker) before the story. This blocks epinephrine & the exciting story works like boring one. Beta blocker inhibits excitement and epinephrine

fear conditioning paradigm

- fear is learned it is not an innate behavior - mice experiment with the shock and the light

sensory representation

- image of kangaroo, or the sound of a can being opened

isomerization (photoisomerization)

- isomer converted to another isomer. in vision it triggers a cascade of intracellular events. Every isomerization after state of 1000s of molecules in rod/cone cytoplasm.

internal representations (sensory, verbal, motor)

- learning/memory imply an internal representation of some kind. after the stimulus is gone its impact persists.

verbal representation

- lyrics to the national anthem

entorhinal cortex (including major inputs and outputs)

- major input to the hippocampus - receives input from all sense. sends output to hippocampus, site of "place" cells

impedance matching, in ear

- the ossicles ((hammer, stirrup and anvil) amplify the signal sent down the canal - after traveling these three ossicles the signal is amplified

motor representation

- touch typing - like entering a PIN for an ATM

inner ear:

1. Sound vibrations strike the eardrum 2. The auditory ossicles vibrate and the footplate of the stapes moves at the oval 3. Movement of the oval window causes the fluid inside the scala vestibuli and scala tympani to move 4. Fluid movement against the cochlear duct sets off nerve impulses, which are carried to the brain via the cochlear nerve

cochlear implant:

= hair cells can be damaged by rapid and loud sounds, and at the moment we cannot regrow them, but we can bypass the whole thing with a cochlear implant= little microphone that catches the acoustic disturbance and sends an electrical (magnetic) signal through the skull and into a transmitter on the outside, which sends the signals to the responder inside the skull which then send it, by very thin wires, the to VIIIth (auditory cranial nerve) nerve fibers.= if you put it in when children are young, then the system will develop more normally, develop new paths

blindsight

= paradoxical phenomenon; patient DB was shown a stimulus in his scotoma, (A region in external space in which a person or animal fails to perceive a stimulus following neural damage. Following lesions of primary visual cortex or partial lesions of ascending visual pathways) and after a sound was told to look at where the stimulus had been. was also shown control trials with no stimulus. to DB, these both appeared the same; he saw neither in either trial, thus didn't know where to look. But when encouraged to guess, DB guessed far better than chance in trials when a stimulus was actually shown in his scotoma than could have happened with chance.= patient acts and feels as if he is blind yet shows a residual ability to localize stimuli-blindsight is the effect shown when a scotoma is present

belt areas (a.k.a secondary auditory cortex?)

Another processing center for auditory information, located inferior to the area A1. Its receptive field is more diffuse as well as more reactive towards complex frequencies (amplitude modulation such as a wailing siren), less precise in tonotopic organization

Eye Witness-

Beth Loftus is a scientist who is often brought into court cases to discredit eye witness testimony. She says its unreliable because the misinformation effect of eye witness encounter. For example, if one shows a group of subjects a video of a car crashing into a stop sign and ask them how fast the car was going, subjects on average gave a much higher estimate when the experimenter used the word "crash"

light-gated channel (light-gated receptor)

Cellular channels that are activated by light. Proteins involved in these channels are called "opsins", an example of which is rhodopsin, found in rod cells in the eye. Main gated membrane channel in visual sensory pathways.

achromatopsia:

Deficit in color perception. Disturbance of the CNS. Without hue. These patients see the world without color. The shading reflects variations in brightness rather than hue. Shape and texture perception are still in tact so someone who achromatopsia can recognize objects. Achromatopsia has consistently been associated with lesions that encompass V4 and the region anterior to V4, but the lesions typically extend to neighboring regions of the visual cortex. Color-sensitive neurons are also orientation selective; as such, many achromatic patients have difficulty with form perception. There is an experiment that tests this form perception hypothesis in the textbook: pg. 191

acoustic disturbance:

Distribution in air pressure of sufficient strength and frequency contents. Some people call it sound. An event initiates this acoustic disturbance- intensity and time-scale are two possibilities for these disturbances

agnosia (including topographical agnosia):

Failures of perception can happen even when processes such as the analysis of color, shape, and motion are intact. A failure to acknowledge or recognize. Visual Agnosia specifically:% Cannot develop a coherent percept, inability to access knowledge of the concept of perceived objects and use this knowledge to identify them. Patient G.S. was shown a picture of a combination lock: He taught us that perception and recognition do not appear to be single, distinct phenomena but are manifest in many guises - he used the circling of his fingers while looking at the picture to figure out that it was a combination lock and not a telephone or clock! Recognition from other sensory modalities may be just fine. After touching the object, a patient with agnosia may report seeing the object clearly. Other subtypes: Apperceptive agnosia--> failures in object recognition linked to problems in perceptual processing and is a ventral-stream disorder. Associate agnosia--> cannot use normal visual perception to recognize things.

-opsin (see light-gated channels)

Family of proteins responsible for light-gated channels

Sacks, Oliver

He has agnosia which is a disorder where you can't recognize/remember specific things. He couldn't recognize faces (prosopagnosia), but he could tell people by using voices or other cues. Because of his agnosia he now avoids social situations.

hemianopia:

If the lesion in the primary visual cortex is restricted to one half of the visual field, the loss of perception will be restricted to the contralateral side of space

Fusiform Face Area (FFA)

It is important to understand the importance of being able to recognizing faces, which is one of the most useful functions of human beings in general. When one cannot recognize faces, this is called Prosopagnosia and there is an article in which Oliver Sacks talk about this. In fMRI scans, compared to a passive viewing of random patterns, faces led to a stronger BOLD response along the ventral surface of the temporal lobe of the fusiform gyrus. The region where this fusiform gyrus lies is called the Fusiform Face Area: an area of the brain related to the visual system that is best attuned for face recognition. Activation in the fusiform cortex is much greater when they are presented with something in which they have expertise. FFA may be dominant specifically to neurons attuned to recognize faces.

LOC, and short term memory

LOC is the lateral occipital complex: the lateral prefrontal cortex is the primary repository for the interaction between current perceptual information and stored knowledge.

consolidation:

Memories are solidified in long term stores over days, weeks, months, and years. In most current models, the idea is that consolidation has different phases: an initial rapid consolidation process, followed by a slower permanent consolidation process. creates a stronger representation over time after initial acquisition . the medial temporal lobe and the hippocampi are essential for the rapid consolidation and storage for episodic and semantic memories. The neocortex is considered crucial for fully consolidated long term memories.

medial temporal lobe (and memory) - MTC

NOT a single structure, but a collection of diverse structures, In the temporal lobe all aspects are involved in memory. Forms and consolidates new episodic and perhaps semantic memories and is involved in binding together the relationships among different types of info about an episode.

Area V1 -

One of many integrating centers for visual information. Located medial in the brain. General pathway: sensory information from receptive fields of each eye activate rods/cones → fibers cross at optic chiasm → pulvinar nucleus → lateral geninucleate nucleus → superior colliculus → V1. Information is processed contralaterally (right side of brain process visual information from the left visual field in each eye)

PTSD

Post traumatic stress disorder, one of the downsides of the fact that stress tends to increase emotional memory, taking away fear conditioning experiments have been done in order to reduce symptoms of PTSD

perception-action cycle:

Reflected light to the eye which presents an image- in this case a cat in the eye and then neural activity occurs. Then the action occurs where the person reaches for the cat and the cat moves which causes a new image and this cycle is continuous

Area V5 -

Specialized visual processing center for motion (especially speed) ; it is directionally selective and located anterior to the occipital cortex. Unlike V1, the receptive field for V5 is much larger/ broad (similar relationship as A1 to belt areas).- electrical stimulation of V5 creates phosphenes; phosphene will move in a particular direction given which neuron in V5 is stimulated (very specialized)-Patient LM had an intact V1 and dysfunctional V5. As a result, could see, but could not perceive moving objects.

rapid serial visual presentation (RSVP task)

The RSVP task is the rapid serial visual processing task. So in this task is utilized to assess visual object recognition. It consists of subject staring at a fixation cross on a screen.for 2 seconds followed by a series of images (about 50) presented at a particular frequency (100ms/image) and the subject is asked to identify when the target is seen. time of delay of object recognition from this can be measured.

Law of Specific Nerve Energies (formulated by Johannes P. Muller)

Theory that suggests sensory perception is dependent upon the particular neural pathways in which stimuli is processed. Differences in sensory information *(like hearing and seeing) is NOT caused by the difference in stimuli, but rather the differences in the neural pathways that said stimuli activate.

basilar membrane:

Within the cochlea. Hair cells sit on this and on fibers that make up the 8th cranial nerve (vestibulocochlear nerve). Stiffness and thickness change systematically from one end to the other. High frequency acoustic disturbance will cause deformation in basilar membrane. There are tiny hair cells location on the surface of the basilar membrane. Hair cells are primary auditory receptors. Oscillations of the basilar membrane prompt hair cells to generate action potentials. Mechanical signal is converted to neural signal. The basilar membrane is located within the cochlea.

cortical column:

a group of neurons in the brain cortex which can be successively penetrated by a probe inserted perpendicularly to the cortical surface, and which have nearly identical receptive fields

partial report procedure; sperling test:

a high-, medium- or low- pitched tone is produced at the same time as the presentation is over and the task given to the subject is to reproduce the first, second or third line according to the pitch of the tone. A performance in the order of three correct responses was obtained under these conditions. Since the subject was unable to know what line he would be asked for to report, it must be so the information necessary to recall the letters had to be available somewhere. Iconic memory

L.M ( called LM in lecture, but MP in book).

akinetopsia, 43 years old, symptom - headache. patient L.M. could see slow movements but could not see fast movements. akinetopsia - failure to see motion. Damage to V5, but V1 intact

re-consolidation

already explained in a previous vocab term

eyeblink conditioning:

article with mice, specifically play a tone and then shoot a puff of air into the mouse's eye, the mouse will eventually learn that once the tone comes he should blink to avoid getting an uncomfortable puff of air in his eye. To make the task harder, extend the tone so that the mouse has to think harder to time his blink correctly (it saves more neurons)

Kraus, Nina -

auditory brain plasticity. focuses on music's impact on hearing. Interesting model for studying plasticity in humans. Regular engagement with music influences various non-musician brain and perceptual function. Psychophysics and auditory brainstem response.

brain's bouncer - basal ganglia:

basal ganglia acts as a bouncer because of action selection, filters out irrelevant information (riff-raff)

propranolol

beta blocker for stressed people

D.F.

bilateral lesions in ventral "what" pathway encompassing lateral occipital cortex, severe object recognition deficit, not anomia because once she touched the object she could name it. Couldn't do the explicit matching test (orient card to put in slot) but could do the action task. She also did not have a memory problem. apperceptive agnosia

basal ganglia -

collection of subcortical nuclei: the caudate, putamen, globus pallidus, subthalamic nucleus, and substantia nigra. the basal ganglia are involved in motor control and learning. Reciprocal neuronal loops project from cortical areas to the basal ganglia and back to the cortex. Two prominent basal ganglia disorders are Parkinson's and Huntington's. Plays a role in procedural memory (specifically motor control tasks)

cone photoreceptors (S- M- and L-types)

cones are the photoreceptors for color vision. short = "blue," medium = "green" and long = "red." there are many more rods than cones. cones are very dense in the fovea centralis.

declarative vs. procedural memory:

declarative memory is memory that you have conscious knowledge of, including personal and world knowledge. This can be broken up into episodic memory (includes events in our personal history: personal and autobiographical memory) and semantic memory (knowing things such as how to tell time. It is world knowledge that we remember in the absence of any recollection of the specific circumstances surrounding its learning) procedural memory is memory that resists being put into words and can operate outside of conscious knowledge. it is also is related to implicit knowledge which is learning without awareness.

auditory brainstem response - (ABR) -

electrical responses from ascending auditory pathways in the brainstem recorded from electrodes on the human scalp using signal averaging to extract the small signals from the ongoing background EEG. A more thorough explanation: Electrical recordings of human auditory processing from scalp electrodes can pick up sensory activity as early as the brainstem relays, and even the compound action potential of the auditory nerve itself. This activity is called the ABR and is manifest as voltage deflections in the auditory ERP's with latencies between 1 and 10 ms after stimulus onset.

occlusion, visual (including self-occlusion)

experimental method where the experimenter conceals body parts or movements during a particular task and assesses how this concealment affects the subject's ability to visually anticipate the next best course of action for a response

face recognition, challenges of:

face recognition happens in the FFA, challenges include Prosopagnosia (failure to recognize faces physically NOT familiarity)

sensory register, sensory store

has a lifetime measurable in milliseconds to seconds, as when we recover what someone said to us a moment ago even though we are not paying close attention to them

Loftus, Elizabeth

has done most work demonstrating the fragility of long-term memory. She is the expert on the fragility of memory in court cases. she looked at eyewitness and wondered if the way questions were worded had an effect on the witnesses memory. She developed the "misinformation effect" that describes that misinformation that is presented between the encoding and recall can cause impairment in memory.

phonological loop

hypothesized mechanism for acoustically coding information in working memory (modality specific )

Gnostic Unit:

idea that cells can signal unknown stimuli. The type of neuron that can recognize a complex object has been called a gnostic unit- there is an example with "Grandmother cells" where these cells specifically become excited when a grandmother comes into view.

posterior parietal cortex & STM

important for planned movements; output to frontal motor cortex (specifically, dorsolateral prefrontal cortex, secondary motor cortex); damage causes perception and memory of spatial relationship complications, apraxia, hemispatial neglect

Interaural time:

important in locating a sound (it's the the difference of arrival time of sound between two ears). specifically in Barn Owls- Barn owls rely on 2 cues to localize sounds: the difference in when a sound reaches each of the 2 ears- interaural cues and the difference in the sounds intensity at the 2 ears.

lateralized difference wave (or potential):

ipsi - contralateral activation difference, used by the ears to get more information about where a sound is coming from (uses differnces in time, volume, and phase between the two for information not sure which one LDW refers to)

learning -

is the process of acquiring new information

optic chiasm:

located posterior to thalamus; part of the brain where optic nerves partially cross; shows lateralization (described below)

post-central gyrus

location of primary somatosensory cortex (main sensory receptive area for the sense of touch)

LTP (long term potentiation)

long-lasting enhancement in signal transduction between two neurons that results from stimulating them synchronously; underlies synaptic plasticity (the ability of synapses to change their strength); as memories are thought to be encoded by modification of synaptic strength, LTP is widely considered one of the major cellular mechanisms underlying learning and memory

P.M. (from article about cellist) -

lost his memory (essentially all of his past, and couldn't remember layout for new apartment so retro and anterograde) due to a virus that hit his medial temporal lobes but retained fairly good musical memory (familiarity with pieces played when had a memory, and was able to learn new music as well) before memory loss was part of a German orchestra

globus pallidus (and basal ganglia)

major component of the brain bouncing and action selection

retinotopic

map of the retina in the visual system that corresponds to locations of receptive fields on the retina

Parkinson's disease

neurodegenerative disorder of the central nervous system characterized by cell death of dopamine releasing neurons. Symptoms include abnormally low levels of dopamine and severely impaired motor skills. Also, slowness of movement, poorly anticipated speech, and in some cases, resting tremor. Pathology results from the loss of dopaminergic cells in the substantia nigra (part of the basal ganglia)

cornea

outside layer of the eye through which light passes through

echoic store

part of sensory memory, auditory verbal information just presented to you seems to persist as an "echo" in your head and if you try to retrieve it quickly enough, its still there and you are able to repeat it aloud. This also relates to the phonological loop.

Corticofugal -

pathway where activity in top-down pathway selectively strengthens ascending sensory pathway

optic ataxia:

patients can recognize objects but can't use this information to guide their actions. Problems with the "where/dorsal" pathway(opposite from what Patient DF experienced)

agnosia:

patients with visual agnosia have difficulty recognizing visually presented objects. Key word= VISUAL. The deficit is restricted to the visual domain; recognition through other sensory modalities (eg. touch) may be just fine. Only after touching the object may the patient with visual agnosia see the object clearly. This knowledge is directly linked to visual perception or an inability for the product of visual perception to access modality independent knowledge stores. *There are different kinds of agnosia: Apperceptive = failure in object recognition linked to problems in perceptual processing, Associative = derive normal visual representations but cannot use this information to recognize objects.

memory -

persistence of learning in a state that can be revealed later

biomotion:

point light display; object recognition from minimal information [he skipped the slides in class]

neurogenesis -

process by which neurons are generated from neural stem and progenitor cells. Article by Shors: The growth of new neurons, that until recently, neurologists believed stopped happening in adulthood; however, new research shows that when the mind is active and engaged (working hard at tasks) your brain can build new neuron cells. Thousands of new cells are generated in hippocampus and associated with memory and learning, but unless the brain is challenged to learn something new and difficult, the new neurons will die. By enhancing neurogenesis, the brain can stay healthy/fit and help slow cognitive decline.

Rhodopsin

protein (opsin) involved in vision. depolarizes photoreceptors. involved in light-gated channels that are activated by light

mechanoreceptors

receptors that respond to mechanical pressure --hair cells in the cochlea are the most sensitive (transducing air pressure waves into nerve signals sent to the brain)

false memory:

see "confabulation;" a type of "honest lying," person is unaware their information is false or doesn't have intent to deceive; caused by traumatic and acquired brain damage, psychological/psychiatric disorders, underlies anosognosia -hippocampus is involved in the retrieval of semantic information whereas the parahippocampal gyrus is involved in the retrieval of sensory information (see page 350 and 351)

Area MT (of cerebral cortex)

see area v5. A region in the visual cortex containing cells that are highly responsive to motion. Area MT is part of the dorsal pathway, thought to play a role not only in motion perception but also in representing spatial information. Lies in the middle temporal lobe region of the macaque monkey. Also known as visual area 5

akinetopsia:

selective loss of motion perception, connected to damage in MT, which is also known as area V5. One views the world as a series of snapshots. Rather than seeing things move continuously in space, LM. saw moving objects appear in one position and then another. When pouring a cup of tea, LM. would see the liquid frozen in air. She would fail to notice the cup overflowing. The loss of motion perception also made LM. hesitant about crossing the street. Her ability to judge direction and speed of moving objects was severely impaired. kind of like a flip book. CT scans revealed large, bilateral lesions involving the temporoparietal cortices. On each side, the lesions included posterior and lateral portions of the middle temporal gyrus. These areas roughly correspond to areas that participate in motion perception and lateral and superior to human V4, including V5, the human equivalent of MT-The application of TMS over human V5 can produce deficits in motion perception

olfaction

sense of smell (activated by ligand-gated channels)Pathway:1. Odor molecules, called odorants enter the nasal cavity through normal breathing or sniffing 2. Odorans then attach to receptors embedded in the mucous membrane of the roof of the nasal cavity, called the olfactory epithelium3. Signal is sent to the neurons in the olfactory bulb, called the glomeruli 4. The axons from the glomeruli exit the olfactory bulb laterally, forming the olfactory nerve, and travel to the primary olfactory cortex, which is located at the ventral junction of the frontal and temporal cortices 5. Neurons from this area connect to the orbitofrontal cortex, which is considered a secondary olfactory processing center (may play a role in identifying the smell itself)

amygdala:

structure anterior to the hippocampus and about the size of an almond. It is very small but has a very big role because it communicates with many different areas of the brain. It has a role in learning of emotions, especially the learning of fear. Sensory information goes into the amygdala in two ways: from the thalamus (fast route - no extra processing) or from the sensory cortex (slow route). It also gets contextual information from the hippocampus.

LeDoux, Joseph:

studied the amygdala's role in learning of fear. mapped out the neural circuits of fear learning from stimulus perception to emotional response. it has become clear that the amygdala serves as a convergence area for information from multiple brain regions, allowing for the formation of associations underlying fear conditioning.

hippocampus (vs. peririhinal cortex):

surrounds thalamus and is responsible for working and short term memory. The hippocampus also helps solidify memory into other areas of the brain (LTM)

beta blocker:

target beta receptors, block action of endogenous catecholamines epinephrine (adrenaline) and norepinephrin (noradrenaline) -- decrease in fight or flight response (anxiety) → McGaugh: gave people B-blocker (Inderal) before he showed them a scary movie and saw that b-blocker made story less scary (people could recall what happened but had decreased emotional content/fear response) - binding of ligand triggers sympathetic NS respontses. They inhibit fear response

Corkin, Suzanne:

tested H.M-- mirror imaging drawings. She discovered that his procedural memory was intact, but his episodic was not

lateral geniculate nucleus - LGN -

thalamic nucleus that is the main target of axons of the optic tract. output from the LGN is directed primarily to the primary visual cortex.

receptive field

the area from which a sensory cell collects information. the nerves project from that cell to the area in its receptive field and then receive information from that area. many maps in the brain correspond to the locations of cells' receptive fields (ex: tonotopic maps, retinotopic maps, somatosensory maps, etc)

pre-form (pre-shape) grip

the idea that when we reach for an object, before we touch it we pre-form our hands to be able to grasp it, indicating a knowledge of the shape and weight from the visual appearance (and our prior knowledge)

Grandmother Cell-

the term has been coined to convey the notion that there might be gnostic units that become excited only when one's grandmother comes into view. There are 3 problems with the Grandmother Cell hypothesis: 1. The idea of gma cells rests on the assumption that the final percept of an object is coded by a single cell. Because cells are constantly firing and refractory, a coding scheme of this nature would be highly susceptible to error. If a gnostic unit were to die, we would expect to experience a sudden loss for an object. 2. The gma cell hypothesis cannot adequately account for the fact that we perceive novel objects- a perception whose mechanism is unexplained 3. the gnostic theory does not account for how the gma cell would have to adapt as the gma changed over time (plasticity due to aging)

change detection task (for measuring short term visual memory) -

two stimuli are presented to a subject. did something change from S1 to S2.

procedural memory

type of memory that remained intact in HM. oftentimes involves an action that is more difficult to put into words than it is perform. memory for DOING something. ex: riding a bike, mirror drawing test, tying shoes etc

prosopagnosia

unable to recognize faces (may also generalize to difficulty recognizing familiar places, according to oliver sacks' article)

Blaser, E & Kaldy, Z (infants' iconic memory):

used the preferential looking technique to test if infants have iconic memory (they used the fact that infants tend to look at novel objects or stimuli). They found that infants performed very close to adult level. (this experiment was similar to George Sperling's experiment and his partial report technique).

H.M. (Henry Mollaison)

used to have a lot of seizures, but his surgeon was very aggressive and took out too much of his temporal lobe. As a result of this, H.M. lost his ability for form new (declarative) memories. He would do a task one day, then the next day have no recollection of the task at all, but when he actually had to do the task, he was just as good as someone who had done and improved on the task - so he obviously did have some level of procedural memory.

Areav V4 -

visual area in the brain specialized in processing color

-cross-over in vision:

what is perceived in the left visual field via the nasal branch is processed in the right primary visual cortex- the nerve fibers from each eye rearrange themselves. The fibers from each nasal retina cross over into the opposite hemisphere of the brain, and fibers from the temporal retina do not cross but remain on their same side of the brain.-The right hemisphere receives information from nasal retina of the left eye, and the left hemisphere receives information from the right eye. The end, and very efficient, result is that the portions of each eye that look at the same part of the visual field send their fibers to the same region of the brain i.e. the right hemisphere gets info about the right side of the left eye and the right side of the right eye. The left hemisphere gets info about the left side of the right eye and the left side of the left eye.

Anton's syndrome:

when a person is blind but denies it. They are not aware that they cannot see.

reconsolidation:

when you recall a memory that has already been consolidated (when you're done with the memory) it must then go through the consolidation process again (re-consolidation). When this happens, it is susceptible to change.

Capgras syndrome:

you are convinced that one you know is an imposter and a stranger trying to convince you that they actually know you or are related to you.

mirror tracing -

you can see the lines that you are supposed to trace but you cannot see your hand that is actually doing the tracing, was used to test the procedural memory of HM by Suzanne Corkin, saw that despite his deficits in episodic memory, there was some improvement in his procedural memory, even though he wasn't aware of it