Psych 188B Exam 1

What is an EEG and how does it work?

-directly records electrical activity in neurons -via many electrode placed over the surface of the head -data in terms of ERPS (event-related potential), the change in neural activity due to a stimuli -some peaks are associated with specific kinds of processes -data can also be in terms of frequency analysis that gives you a power spectrum

Explain how sociality is central to the human mind and brain

-from birth, human are exceptionally interested in social stimuli -most of knowledge is learned from other people -human sociality likely drove human brain evolution -brains spend a great deal of time everyday processing information about others -most of human cortical region is specialized for social processing -most impressive feat of human are a result of cooperation -human social cognition and behavior dramatically distinguishes us from primate relatives

What is MRI and how does it work?

-measures BOLD signal -oxygenated blood has different magnetic properties than deoxygenated blood, distorts magnetic field inside scanner

How does animacy perception from motion cues work?

-mental state attribution to shapes based on motion of geometric animation, visual illusion of seeing mind where there is not -not something moving because of gravity or natural causes

What are the pros and cons of EEG?

-pros: millisecond time precision, direct measure of neural activity, inexpensive/portable -cons: spatial resolution, motion artifacts, depth of activity

What are the pros and cons of fNIRS?

-pros: non-invasive, allows participant motion, affordable/ portable -cons: surface cortex only, less spatial resolution than fMRI/PET, less temporal resolution than EEG, indirect measure of brain activity

What are the pros and cons of fMRI?

-pros: non-invasive, great spatial resolution -cons: expensive, limited temporal resolution, can't move in scanner, indirect measure of neural activity

What is a PET and how does is work?

-tracer injected into body, goes to locations of tissue metabolic activity -metabolic activity a consequence of brain activity -PET scanner identifies concentrations of tracer -can use FDG tracer or a ligand specific tracer to mimic certain neurotransmitters

How do human faces differ from houses?

1. Animacy 2. Overall global form

What is the 2 step process of mind perception?

1. animate form detection 2. mind perception

When was the term social neuroscience first coined?

1992

Describe animacy perception as a 2 step process

1: face detection, liberal face threshold, likely mediated by relatively early visual processing, any face-like object is attended to and subject to further visual processing 2: mind perception, much more stringent filter, likely mediated by relatively late visual processing (response patterns in FFA and STS, activity ~400 ms after stimulus onset)

What percent of our total energy expenditure does the brain account for each day?

20% of energy expenditure although it makes up only 2% of our body weight

What regions make up the core face processing network?

3 regions in the occipital and temporal lobes that responds strongly to face stimuli; inferior occipital gyrus (IOG), fusiform face area (FFA), superior temporal sulcus (STS)

What kind of data does fMRI produce?

BOLD response has a specific canonical shape: the hemodynamic response function (HDR); can model how well brain activity in one are matches the expected shape to indicate how well area is responding

What is the role of EBA in perceiving bodies?

EBA (Extra-striate body area) responds more to body parts and bodies than other objects in fMRI studies

T/F Brain responses cannot serve as useful implicit markers of thoughts and emotions that people may be unwilling to share or unable to share

False, Brain responses are useful implicit marker

T/F the strength of neuron firing is on a continuum

False, it is binary (either on or off), but number of firings per second varies; rate of responding (spiking rate) relates to the informational code carried by that neuron

T/F humans are not finely attuned to keys of animacy such as body movement

False, we are finely attuned even from early in development

What is a thought experiment that helps explain the difference between human and primate social cognition?

Hrdy's "Apes on a Plane" shows the tolerance of others; humans manage to sit through a crowded flight with others, but with apes one wrong look would cause violence to ensue

What is the difference between and MRI and an fMRI?

MRI studies anatomy while fMRI studies function

How is social neuroscience similar to evolutionary biology?

Mental phenomena might seem related, but neuroimaging suggests that the underlying neural mechanisms are entirely different processes; much like how dolphins and sharks may appear related but are actually genetically very distantly related

Is there a same animal specific preference with biological motion sensing?

No

What are the 2 paths of visual processing?

Route 1: occipital lobe -> ventral visual stream (what) -> temporal lobe Route 2: occipital lobe -> dorsal visual stream (where) -> parietal lobe

How can one influence brain activity?

TMS and tDCS use electromagnetic induction to temporarily influence brain function, amplify/disrupt activity in a particular area, can be very focal

What data suggests that there is a dissociation between covert and overt face recognition?

The fact that prosopagnosics elicit a SCR increase to familiar faces but cannot ID them

T/F faces are process distinctly from other forms of visual data

True

T/F facial recognition abilities fall on a continuum

True

T/F there is a triple dissociation of faces, bodies, and objects in extrastriate cortex

True, as found by using TMS to individually impair each of the regions: body perception was impaired only when TMS was applied to the EBA, face perception was impaired only when TMS was applies to the OFA, object perception was impaired only when TMS was applied to the LO

T/F the tendency for some mammals to form lasting monogamous romantic attachments (pair bonds) is determined by aspects of our brain chemistry

True, because child care requirements influences long term pair bonds

T/F animate motion is semi-rigid

True, partially constrained by rigid skeleton but more flexible than most example of inanimate movement

T/F when given a choice between looking ar a biological motion display or a non-biological motion display newborn infants spent ~2/3 of their time looking at the biological motion displays

True, this phenomena indicates an innate understanding of gravity, orientation of movement; there is also an innate preference for bipedal motion

What is the N170?

a rapid electrocortical signature of face processing in the occipitotemporal cortex that occurs approximately 170 ms after stimulus; associated with face perception

What is the Cambridge Face Memory Task?

a sensitive task for measuring face recognition across a wide range of abilities; inverted IDs are much harder and about the standard of prosopagnosic performance

How does pair bonding correlate with brain size?

across taxa, species that form long term monogamous pair bonds tend to have larger brains for their bodies

Using multi-voxel pattern analysis to organize data, what regions responded to face stimuli relative to the baseline?

areas of core face perception network all showed strong responses in all 4 categories relative to baseline

What is Dunbar's number?

as brain size increases, so does groups size: the theorized human social group size that's predicted from our neocortical ratio (abt 150)

What is the uncanny valley?

as faces get to be more human-like they are seen as off-putting and creepy as they are trying too hard to be hyper realistic

What is anthropomorphism?

attributing human traits to non human things; a process that is separate from memory/visual processes

What direction does the axon carry signals?

away from cell body

What composes the white matter?

axon tracts

What is Capgras syndrome?

can recognize faces, but lack emotional reaction of familiar people; visual system in tact but emotional tag missing; familiar people replaced by "imposters" or "body doubles"

What makes up the cortex?

cell bodies and synapses (grey matter layer)

What is the basic structure of a neuron?

cell body, dendrites, and axon

What is the role the STS in biological motion processing?

cells in the STS are sensitive to biological motion but not non-biological motion; distinct from the region that is responsible for visual motion perception in general (V5/MT)

What does "earlier" processing in the core face perception network seem to be based on?

centered on visual form

What does the latFG and FFA seem to encode?

distinguishing between stimuli based on both visual form and animacy; real human faces are encoded differently than other kinds of faces

What is an example of convergent evolution of large brains?

dolphins name each other and call each other by names; dolphins have the longest social memory

Are humans innately predisposed to detect and preferentially attend to biological motion?

evolutionary disposed to pick up on biological motion, as seen by point light displays of biological motion perception

What is a difficulty in measuring timing of face perception?

fMRI has poor temporal resolution and process of face recognition is really fast; use EEG to circumvent this difficulty

Does the brain care about shape or animacy more?

face is really marker of a living agent

Do familiar faces have an emotional signature?

familiar faces elicit higher SCR, indicating increased emotional arousal; happens even in prosopagnosics because it it an automatic and unconscious process

When does the brain perceive life in a face?

first it separates by face, then ~400 ms after stimulus onset it divides based on mind

Are humans innately predisposed to detect and preferentially attend to faces?

from within 1 hr of birth, human infants both detect faces and attend to them preferentially; measured by paddle held above infant and observing eyetracking; track things that are even coarsely resembling faces (high top density) as rooted in preference for similar visual characteristics to faces

What does the IOG appear to encode?

global visual form (eg is this a human face or a dog face)

What is the encephalization quotient?

how much bigger species general brain size is compared to what you would expect for their body size

How do chimps and humans compare in tests of brain capacity?

human brains a lot larger than chimps but humans don't have that much more skill in solving non-social ecological problems; chimps beat humans in working memory, spatial memory, quantity discrimination, and tool use; humans beat chimps at social learning, communication, and gaze following

What is Robin Dunbar's social brain hypothesis?

human's main evolutionary pressure is not the ability to be smarter but the ability to understand and predict complex social interactions, work together and outwit our peers

How does the STS organize information?

in terms of animacy, irrespective of overall visual form; cares about motion and movement

What is about long-term pair bonds that requires a large brain?

maintaining close relationships is hard work; partner choice crucial, must prevent/resolve conflict, must coordinate behavior

How does pressure to be socially smarter drive other changes?

may cause a change in brain size that leads to benefits such as non-social cognition

What is peripheral physiology?

measure function in peripheral rather than CNS, cortisol, HR monitoring, galvanic skin response, facial EMG

What is NIRS (and fNIRS) and how do they work?

measures BOLD signal but with light, project infrared light into brain and oxygenated blood reflects back differently than deoxygenated blood, measures on surface of the scalp not a 3D image

What are some challenges associated with inhabiting large social groups?

more self-control needed to avoid conflict; as group size increases need to track and encode increases exponentially; must be able to manipulate others; must be able to individuate and mentally track, must make a mental catalog of the people you have relationships with in order to inform your actions and predict their behavior

How was the uncanny valley discovered?

movie makers tried to make viewers forget they were watching animation but they came off as "lacking humanity"

What is regional functional specialization?

neurons responding to similar types of information tend to be grouped together

What is some evidence for hard-wired preferences for biological motion in other animals?

other animals without any previous visual experience preferentially attend to animate movement

What is developmental prosopagnosia?

present from birth (congenital), affects 2-2.5% of the US population

Are there other types of relationships outside of pair bonds?

primate social groups contain other intense, lasting relationships between individuals who are not kin or reproductive partners

What are the pros and cons of PET?

pros: meaningful biological units, can assess regional neurochemistry, whole brain spatial images limitations: low spatial and temporal resolution, radioactivity, can't move, costly

What is the advantage of large social groups (like dunbar's number)?

protection again predators (vigilence of others, evasion); finding food (coordination and communication); defend territory more effectively

What does the neocortex do?

recently evolved mammalian brain that supports 'higher' mental functions

How does Dunbar's number factor into social media and the modern age?

research shows that people only actively maintain 100-200 stable relationships on social media and internet communication platforms

What is the role of STS in face processing?

responds to faces and bodies; integrates multisensory information; encoding changeable aspects of faces (orientation. gaze direction, emotional expressions)

How does acquired prosopagnosia occur?

result of focal brain damage, very rare

What is interesting in the experiment about dissociating physical and identity face representations in the brain that has Margaret Thatcher and Marilyn Monroe?

seen as 2 categorical entities, not a change over time; varying how "same" is defined can reveal the properties and computational contributions of different brain regions

What does "later" processing steps seem to focus on?

separate stimuli based on whether they have minds (animacy)

What is the first step in social perception

simply detecting the presence of another mind

What is social neuroscience?

social neuroscience attempts to understand and explain, using the methods and theories of neuroscience, how individuals' thoughts, feelings and behaviors are influenced by the real or imagined presence of others

What is the difference between a sulcus and a gyrus?

sulcus is the crevice piece, gyrus is the part that is not the crevice, the outside

What test was made to examine super recognizers abilities?

the Before They Were Famous test

What structure has been implicated in animacy from motion and how?

the amygdala, in the geometric shapes video, people with amygdala lesions do not attribute animacy/narrative to the shapes

What is prosopagnosia?

the inability to recognize faces; have to rely on secondary cues; still have knowledge about the people, can see expressions and emotion but cannot ID

Why is it important for human to have an innate, crude tendency to look for signs of life?

the most important things for organisms are other organisms because they can be sources of danger, information and companionship

What is the neocortex ratio?

the ration of the size of the neocortex to the size of the rest of the brain

How does the brain constrain social processes?

the size and computational processing capacity of the human brain constrains the number of meaningful relationships the average human can maintain

How is Gore-Tex using Dunbar's number to increase productivity?

they cap the factories at 150 employees, because they found that after 150 the operations tend to run less smoothly

What direction do the dendrites carry signals?

they receive signals from other neurons and transmit them to the cell body

What is one suggested reason for why primate brains are so large?

to solve non-ecologically relevant problems for the individual in their environment

What are super-recognizers?

top ~2% of population in terms of facial recognition abilities, can recognize virtually any face they've ever encounters, can even ID face through the aging process

What are some cues to animacy?

voices (the auditory face), faces (more well established), motion; high prioritization of faces and voices

Approximately how many neurons are in the human brain?

~86 billion