midterm 3 Flashcards
behaviour that is involved in perpetuating cravings linked to addiction
habitual and involuntary attention cues that signal the reward that the thing we are addicted to brings
what is addiction driven by
seeking
emotions of seeking/approach and addiction
desire
hope
anticipation
what is the action tendency in addiction
approach
what is stimulus bound appetitive behaviour
a form of working toward the thing that makes you feel good
what does stimulus bound appetitive behaviour harness
the dopamine system in search and goal directed behaviour to achieve a range of appetitive goals
what is dopamine
a neurochemical that is all about wanting but NOT about getting. its about motivation
incentive salience
a cue stands out because of its association with reward. associations with the cue trigger cravings.
what are the steps of incentive salience
cue
craving
automatic action.
the cue makes you crave, and then you automatically reach for the cigarettes, drugs, etc.
what did crimes against dopamine blog say about calling the DA system the reward system?
there are associations with pleasure.
it should be called the “reward prediction error system” or just the prediction error system.
nucleus accumbens
region of the ventral striatum
key node in the mesolimbic DA system (seeking system).
plays role in motivation and addiction
3 regions that are involved in making decisions, motivation, motor control
nucleus accumbens, caudate nucleus, putamen
tail of the caudate nucleus has been implicated in
motivational influences on attention
2 brain nuclei where DA is produced
substantia nigra and ventral tegmental area
tonic dopamine
motivates you to get up and get out of bed and work to get rewards in general.
wanting/seeking
phasic dopamine
fast busts of dopamine, all about prediction errors.
also signals reward expectation
dopamine and incentive salience
when a cue acquires an association with reward.
this triggers wanting or craving and gets our seeking system going.
if a cue predicts reward, it is
habit forming
when expectations are met you have a
habit
when unexpected things happen it leads to
learning
what was the big picture question of andersons paper
what is the role of dopamine in attentional biases to cues signalling reward
background of andersons paper
dopamine is important for learning that certain cues predict reward.
cues signalling reward capture attention, even when not relevant to the “top-down” goals
what is the specific question of the Andersons paper
what is the role of dopamine in maintaining the attentional salience of reward cues even when they no longer predict reward
who were the participants in the anderson paper
20 healthy young adults
methods of the anderson paper: building an attention bias
day 1: training
* creates incentive salience for certain colours
* report orientation of bar in red or green circle
* specific colour predicts probability of either a high or low reward
day 2: test attention bias
* inject with tracer
* put in PET scanner
* task is to report orientation of unique shape
* scan A - distractors present (60 mins)
* break (75 mins)
* scan B - distractors absent (60 mins)
info on scan A anderson paper
high reward distractor (25% of time)
low reward distractors (25% of time)
no distractor (50% of time)
based on orientation of bar in the unique shape, you raise right hand if horizontal and left hand if vertical
scan B anderson paper info
no distractors.
what is the orientation of the bar in the unque shape, raise right in horizontal and left if vertical
basics of PET scans
radioactive tracers used look at neurotransmitter activity
often used in clinical studies
very expensive and invasive
what were the independent and dependent variables in the Anderson paper
independent:
training (the IV was different levels of reward associated with a specific colour)
test: distractor present and no distractors present. distractor present: rewarding, distractor absent: high reward, distractor present: low reward,
region of interest (focused on putamen and anterior and posterior caudate)
dependent variables: reaction time indicating the bar orientation.
PET measures of DA availability
what is value driven attentional capture (VDAC)
a form of reward-biased attention.
measure of incentive salience.
its attentional capture because it is NOT relevant to your task goals, but you cant help but pay attention to it
anderson training chart summary
they learned to be faster for high value targets, which is an index of appetitive conditioning.
anderson testing chart summary
in the first block of trails (before the learned that there was really no reward related to the distractors, aka extinction), they were slower to find the target when there was a high value distractor than when there was no distractor.
it captured attention away from the location of what they were supposed to be looking for. it acquired incentive salience.
in the anderson paper what was the difference between high value and distractor absent
the measure of value driven attentional capture (VDAC)
anderson differences in DA release
high bias group showed more DA release for distractors and more attentional capture (aka reaction time slowing) in the presence of distractors.
low bias group showed no evidence of attentional capture, DA release was lower on distractor present scans.
dissociation between groups: strong value driven attentional capture is associated with significantly elevated levels of DA, but ability to ignore previously reward associated stimuli is associated with less od DA release in the same regions.
what has the caudate been implicated in
the shifting of covert attention
what does the caudate tail communicate with
visual cortex
caudate modulates
reward (bc of its roles in habits)
in anderson paper, what is attention captured by
objects that previously predicted reward, even when they no longer do
in anderson paper, what do people who are more captured by cues of past reward show
more DA in the dorsal striatum in the presence of reward cues
in anderson paper, what do those who are not captured by cues of past reward show
less DA, maybe they supress??
what is the habit in the anderson paper
DA signalling in the dorsal striatum is imp for involuntary motivated attention linked to addictive behaviour
results of anderon type study with depressed vs control people
there is no reaction time difference in the presence of a high value distractor in the depressed group. they show no VDAC.
researchers conclude that attentional capture is decreased in depression
what is DA circuitry important for
acquiring incentive salience leading to attentional biases for reward
what are indiv differences in DA availability related to
differencesin reward based attention
what is reward based attention a marker for
both addictive behaviour (more attention), and depression (less attention)
what did endel tulving suggest
that we have multiple memory systems
implicit (unconscious) memory
- procedural memory: performance of skilled action
- conditioning: memory for emotional relevance revealed by actions
explicit (conscious) memory
- semantic memory: facts
- episodic memory: events (mental time travel)
- autobiographical memory: memories of events in your own life
- prospective memory: performance of future action
what does the hippocampus do
form and recollect episodic memories, and to imagine future experiences
hippocampus regions that play a role in navigation in rats
medial temporal lobe
what do grid cells do
organize space into a grid like map that is used in any environment.
cognitive map hypothesis
the brain builds a representation, or mental map, of the spatial environment to support memory and guide future action
what are cognitive maps
mental representations of physical locations
what are schemas
mental scripts of how certain situations tend to go
seen as organizing memories as they are laid down
2 functions of cognitive maps
landmarks (link mental map to sensory info): where you are in relation to something in the world you can perceive
planning a route to destination: hippocampus
taxi driver study basics
20 london taxi drivers
used fMRI and a realistic VR of London
had to navigate to a destination in response to customer requests
after the scan, they watched a vid of the route and reported what they were thinking
what happened during fMRI scanning during taxi driver study
navigation was tested in blocks. subject responded to customers requests heard via headphone. customer would ask for one destination, then part way through pick a different one.
in the taxi driver study, where was hippocampal activation seen
customer driven planning
when was hippocampal activation biggest and smallest in taxi study?
biggest: initial request and customer switch
smallest: customer stating irrelevant statements
who was TT
taxi driver who had enciphilitis (Severe memory loss). was asked to drive a route and TT showed vast impairment compared to 10 control drivers.
retrograde amnesia
people cannot recall events in their lives that occur prior to some critical event that affected their brain
anterograde amnesia
cant form new memories after the incident that lead to their impairment
stages of memory
encoding
consolidation
retreival
what is encoding memory
initial perception of an event (attention, perception)
what is consolidating a memory
stregthening and making more enduring over time.
synaptic level
system level
what is retreival of memory
calling it back up later
autonoetic consciousness
the ability to time travel. to place ourselves in the past or future (or hypothetical situations)
what is semantic memory
facts
standard consolidation theory
memories intially depend on the hippocampus
later become consolidated across other brain regions
multiple trace theory
episodic memories always require the hippocampus
system wide consolidation is accompanied by changes in the nature of the memory (semanticization)
what is semanticization
when general knowledge is pulled from rehearsed events and stored separately
reinstatement
when the brain helps consolidate a memory by playing the pattern of brain activation that represented the event during encoding offline later on.
schema
mental concept that informs a person about what to expect from a variety of experiences and situations
schemas are scripts
big picture question of the bird paper
what roles do active rehersal and prior knowledge (schemas) play in episodic memory consolidation
research question of bird paper
- does active rehearsal influence memory durability
- do stronger patterns of neural similarity between encoding and rehearsal (reinstatement) in episodic memory nodes lead to more detailed memory
goal of experiment 1 - bird paper
investigate effect of active rehearsal on durability of memories
goal of experiment 2 (fMRI) bird paper
- identify whether they see reinstatement of BOLD activity when remembering unique videos
- does the strength of this reinstatement when the memories are being actively rehearsed predict how well the video will be remembered later
experiment 1 in the bird paper
within subject. each participant saw 7 videos in each of the 3 conditions on the first day and had to recall different combinations of videos on a second and third day.
particpants, IV, DV, experiment 1 bird paper
13 young adults
IV: days (1, 8, 18) and condition (recall at all times, skip day 1 recall, skip day 18 recall)
DV: number of details recalled
experiment 1 bird paper results
rehearsal shortly after encoding boosts details remembered
bird paper experiment 2
on days 1 and 26 videos were watched. 20 of them were silently rehearsed in an fMRI. were asked to rate how well they remembered the vid from 1-5. one week later all 26 vids were recalled with a researcher.
experiment 2 bird paper participants, IV, DV
16 young adults
IV: day (1 or 7) encoding vs retrieval, rehearsed or not
DV: BOLD response, vividness of rehearsal memory, pattern of BOLD response, memory detail when recall 1 week later
what was associated with active rehearsal
reinstatement of BOLD patterns in episodic memory nodes
crucial role in active memory consolidation
posterior cingulate cortex
