Neuroscience Exam 4

Medial Prefrontal Cortex

involved in thinking about ourselves, self referential processing, and forming impressions of others

Kelley et al mpfc study

presented with an adjective, you have to decide:

1. describes yourself?

2. describes Bush?

3. uppercase or lowercase? control condition

#1 had the strongest response in the mpfc

Mitchell et al mpfc study

looked at brain activity when

1. making impressions of others

2. memorizing sequence of quality

3. intimate objects control condition

#1 had the strongest response in the mpfc

Temporo Parietal Junction

involved in theory of mind (cognitive capacity to understand and attribute mental states to oneself and others), and understanding others thoughts, feelings, and behaviors

Saxe and Kanwisher TPJ study

Had people read stories and looked at TPJ activity

1. theory of mind stories

2. mechanical interference stories

3. human action stories

#1 showed Strongest response in the TPJ

Superior Temporal Sulcus

visual and auditory information are combined to interpret the behavior, intentions, and emotions of other people

Allison et al STS Study

Showed that the Superior Temporal Sulcus is active during

1. gaze direction

2. facial expression change

3. intentional movements

4. biological motion (lights taped to joints)

Amygdala

performs rapid social evaluation of face, is this personal threatening? is this person socially significant?

Winston et al Amygdala Study

put people in an MRI and had them look at faces

1. non-threatening - trustworthy

2. threatening - untrustworthy

#2 had the strongest response in the amygdala

Bateson et al honesty study

asked the question do we behave more honestly when being watched? put money in the honesty box when you take coffee or other drinks, they put eyes/flowers above the honesty box to see who paid more often.

People paid more often when the picture of eyes was up above honesty box than when there was flowers or nothing.

Humans are especially sensitive to social cues that indicate we are being observed

Nucleus Acumbens

reward pathway and pleasure (in basal ganglia)

Meshi et al Nucelus Acumbens Facebook Study

1. participants recorded video of themselves

2. Facebook intensity scale on usage

3. mRI recording

a. read positive feedback about their own video

b. read positive feedback about another person’s video

c. gambling task that results in them winning $

A had the strongest response in nucleus acumbens, and that was strongest in individuals who scored highest on the Facebook intensity scale.

Vogel et al Social Comparison Study

1. measured self esteem

2. measure social media use

3. measured amount of upward comparisons

-increased social media use = decreased self esteem

-increased social media use = increase upward social comparison = decreased self esteem

Atkinson-Shiffrin Model

Human memory is 3 separate sequential stages:

sensory information → short term memory → long term memory

Sensory Memory

where all incoming sensory information is stored for a few seconds

Short- term/ working Memory

active but time limited, workspace that allows us to temporarily hold on to and manipulate information, continuous

Long-term memory

limitless, long term storage for your knowledge and experiences

consolidation

the brain’s way of making a permanent representation of an event, short term to long term, a fresh unstable memory is converted into a durable, permanent long term storage

retrieval

pulling information out of long term memory

Declarative/explicit memory

dependent on hippocampus, conscious recollection of the facts we know and personal experiences, includes episodic and semantic

episodic memory

type of declarative/explicit memory, personal episodes, for example your first kiss

semantic memory

type of declarative/explicit memory, knowledge and facts, for example who is the first president

Nondeclerative/Implicit Memory

unconscious memories that influence our actions, behaviors, and automatic responses, like muscle memory, skills, priming, example riding a bike

anterograde amnesia

inability to make new memories

retrograde amnesia

loss of memory of events before the trauma

Hebb Rule

When 2 neurons fire together, the synapse between them strengthens.

stimulate presynaptic neuron with electric current → resulted in increased response of postsynaptic neuron, strengthening the connection

Long Term Potentiation

simultaneous activity of a presyantpic and postsynaptic = synapse between them becomes stronger overtime, it’s how you make memories

How you make memories

1. presynaptic neuron releases glutamate

2. glutamate binds to AMPA receptors

3. postsynaptic neuron becomes depolarized

4. Mg ions become dislodged

5. glutamate binds to NMDA receptors

6. influx of sodium and CALCIUM

7. calcium activates enzyme CAMKII which causes…

8. increased glutamate release, increasing AMPA receptors, and an increase in dendritic spines

Long term depression

when activity of the presynaptic neuron is no longer sufficient to activate the postsynaptic neuron neighbor, which equals a weak synapse, modifies, cleans up, and deletes memories

Associative Long Term Potentiation

simultaneous activity of a weak and strong synapse, as a result the weak synapse becomes stronger, like conditioning memories, (shock/tone, strong/weak) strengthening of a weak synapse after being paired with a strong one

Neocortical areas

all the lobes, examples, visual cortex, wernicke’s area, motor cortexm ventral stream, involved in original experiences of an event

remote long ago memories

increased activity in neocortical areas

recent memory

increased activity in hippocampus

Hippocampus

it’s job is to do the connecting and linking, it links and connects the neocortical areas, at some point, the neocortical areas become independent of this, every time you reactive and retrieve a memory, you consolidate it

Nader et al Reconsolidation Theory

fear conditioning with rodents

1. day 1, tone + shock = fear response (classic fear conditioning)

2. day 2, anisomysin → tone = no fear response (doesn’t develop for memory)

3. day 3, anisomysin during reactivation → wipes out memory

Findings showed that previously consolidating memories are not stable, but return to a temporary, unstable state when recalled and require a protein-synthesis dependent process called reconsolidation to be stabilized

Evidence for strength of emotional memories

-memory is more accurate for emotional information

-strength of amygdala during activation during encoding predicts later recall

-always see an increase in amygdala activity during exposure to emotional information

amygdala and hippocampus

extra brain area involved, modulates hippocampus activity in a way that strengthens encoding and consolidation

flashbulb memory

vivid, detailed, and long-lasting autobiographical memory of the moment a person learns about a surprising, shocking, or emotionally significant event

everyday event

accuracy overtime declines and confidence overtime declines

flashbulb event

accuracy overtime declines, but confidence stays high

Frontal Lobe Syndromes (disturbances of motor function)

-fine movement, speed, and strength issues, if your left area is damaged it impairs the fine motor skills of your right hand

-movement and programming issues, it impairs speed/strength of movements of hands and limbs

-voluntary gaze issues

-speech issues, Brocas aphasia, supplementary speech area damage, aggrammatism

Broca’s Aphasia

impaired ability to produce speech/talk

Aggrammatism

inability to produce correct grammar

Frontal Lobe Syndromes (Loss of divergent thinking)

-loss of divergent thinking, can’t come up with multiple solutions and answers

-lack behavioral spontaneity, decreased verbal fluency, perseveration, decrease in nonverbal fluency, have a hard time getting up in the morning

-lack strategy formation, can’t come up with a plan for the day

perserveration

keep doing the same thing even when told not to

Frontal Lobe Syndromes (environmental control of behavior)

-environmental dependency syndrome

-response inhibition

-risk taking and rule breaking, gambles all money away, even when gambling is rigged and they know it they keep picking risky deck

-self regulation, someone has to tell them to do things

environmental dependency syndrome

environmental cues automatically trigger behavior (ex sees dirty dishes in someone else’s home, immediately starts washing them)

response inhibition

once you learn a rule, you can’t shift to a new rule, even though they know it, they can’t stop following the first rule

Frontal Lobe Syndromes (social, sexual, and personality changes)

-personality changes, ex Phineas gage

-Pseudodepression

-creates bizzarre sexual behavior

-pseudopsychopathy

pseudodepression

on the surface there’s symptoms of depression, but it’s not actual depression, just frontal lobe damage. decreased energy, motivation, and emotional expression

pseduopsychopathy

on the surface, they have symptoms of psychopathic and antisocial disorder, they’re rash, disrespectful, and inappropriate

Temporal Lobe Syndromes

-disorders of auditory and speech perception, wernicke’s aphasia

-disorders of music perception, receptive amusia

-disorders of visual perception, visual agnosia, prosopagnosia

-memory impairment, anterograde and retrograde amnesia

-altered affect and personality, extreme emotional bluntness, increase in anger and emotional outburst, personality issues and pedantic speech

Wernickie’s Aphasia

speech doesn’t make any sense, but they’re happy

Receptive Amusia

can still hear sound, but music sounds like nonsense, decreased ability to perceive music

visual agnosia

inability to identify objects, can’t name them

Prosopagnosia

inability to identify faces

Retrograde Amnesia

cannot remember any memories from before the trauma

Anterograde Amnesia

inability to make and form new memories

pedantic speech

overly concerned with petty, trivial details, extreme paranoia, preoccupation with religion

Parietal Lobe Syndromes (Somatoperceputal Disorders)

-asetreognosis

-simultaneous extinction

-numb touch

-somatosensory agnosias

-alien hand syndrome

astereognosis

inability to express objects by touch

simultaneous extinction

inability to perceive a stimulus if it is presented simultaneously with another stimulus

numb touch

report no perception of touch, but they can localize the place of the touch (like blindsight but with touch)

somatosensory agnosias

loss of knowledge of one’s own body

Alien Hand Syndrome

perception that one hand is being controlled by someone else

Posterior Parietal Lobe Syndromes

-Balint Syndrome

-Optic Ataxia

-Contralateral Neglect, egocentric neglect, allocentric neglect

-object recognition

-Gerstmann Syndrome, agraphia, acalculia

-ideomotor Apraxia

-Constructional Apraxia

-Drawing Impairment

Balint Syndrome

inability to perceive more than one at a time, includes object apraxia

object apraxia

if you hold up spoon, they can see it, if you hold up comb, they can see it, If you hold up both they can only see one of them not both

egocentric neglect

neglecting everything left of the body’s midline

allocentric neglect

neglecting left half of all objects

Objection recognition

impairment in identifying objects when they’re not in their stereotypical views

Gerstmann Syndrome

left and right confusion, finger agnosia, agraphia, and acalculia

Agraphia

inability to write

acalculia

inability to do math

ideomotor apraxia

inability to copy movements or make gestures

constructional apraxia

inability to accurately build, assemble, or draw two or three dimensional objects

drawing impairments

issues drawing spatial layouts and copying them

Occipital Lobe Syndromes

-V1 damage and a scotoma

-V1 damage and blindspot

-V4 damage and loss of color vision

-V5 damage (MT) and the perception of movement

scotoma

v1 damage, blindspot depending on where the damage occurs

blindspot

V4 damage, reacting to visual stimuli without conscious experience of seeing

V4 damage

loss of color vision (what area is damaged)

perception of movement

V5 (MT) damage, the world looks like snapshots, not fluid movements

Disconnection Syndromes

caused by surgery, last resort treatment to severe epilepsy, cuts the corpus callous, so the 2 hempisheres can’t communicate with each other, they always report what is presented in the right visual field, never left

verbal

left hemisphere job (cut)

spatial processing

right hemisphere, it’s mute

Standard Model of Consolidation

explains how the brain transforms fragile, short-term memories into permanent, long-term ones by shifting where they are stored over time. When you first learn something, a brain region called the hippocampus acts as a temporary hub that binds together all the different sights, sounds, and feelings of the experience. Over weeks, months, or even years—especially while you sleep—the hippocampus repeatedly replays that memory to the neocortex, the brain's outer layer. Eventually, the connections within the neocortex become strong enough to hold the memory on their own, allowing the hippocampus to step back completely so the memory remains safe even if the hippocampus is later damaged.