Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Psyc 443 > MARCH 27 > Flashcards

MARCH 27 Flashcards

1
Q

developmental trajectories of fear learning (non-linear) likely reflect what?

A

developmental trajectories of underlying mechanisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

paper: “________ ______ integrity is related to early life adversity and _____ ______”

A

ACCUMBOFRONTAL TRACT integrity is related to early life adversity and FEEDBACK LEARNING

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

ELA is recognized risk factor for…

A

range of negative outcomes

  • depression
  • anxiety
  • substance use disorder
  • poor educational achievement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

majority of work on ELA has focused on what?

A

threat processing

ELA is linked to altered threat processing reported structural/functional changes in HIPPOCAMPUS and AMYGDALA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

ELA has also been associated with what?

A

altered REWARD PROCESSING

but the neural mechanisms haven’t been explored

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

deficits in reward processing and learning about reward could be related to…

A

other consequences of early life stress

ie. learning, social functioning, risk for psychopathology

(understanding how neural circuits underlying reward processing are shaped by ELA could have wide reaching implications for addressing negative effects of ELA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

corticostriatal circuit

A

plays key role in MOTIVATION, REWARD RESPONSES and REWARD LEARNING

involves ventral striatum (VS aka nucleus accumbens), VTA, vmPFC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

corticostriatal circuit = enriched in what type of receptors?

A

dopamine

(recall: it’s implicated in motivation, reward responses and reward learning)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

effects of ELA on mPFC and VS…

A

have been reported

(and these are part of the corticostriatal circuit)

ELA = associated with reduced mPFC volume and changes in VS activity

what if ELA alters the CONNECTIVITY BETWEEN mPFC and VS?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

paper uses specialized MRI techniques..

A

that make it possible to VISUALIZE and QUANTIFY the WHITE MATTER TRACTS that CONNECT BRAIN REGIONS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

white matter

A

primarily made of axons (neuronal projections)

fatty myelin sheath of axons give white matter its colour

white matter pathways = organized into tracts (bundles of myelinated axons that form connections between diff brain areas)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

accumbofrontal tract

A

(part of the corticostriatal circuit)

WHITE MATTER TRACT BETWEEN THE mPFC AND VS

individual diffs in structure/functional connectivity of mPFC and VS = related to diffs in IMPULSIVITY, REWARD LEARNING and FEEDBACK SENSITIVITY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

feedback sensitivity

A

indicates how much information about reward or punishment (or loss, absence of reward) impacts future choice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

DWI

A

diffusion weighted imaging

type of MRI allowing for DIRECT ANALYSIS OF MICRO-STRUCTURAL DIFFS IN WHITE MATTER

measures movement of WATER MOLECULES in brain to map CONNECTIVITY between diff brain regions

sensitive to diffs in AXONAL DENSITY and MYELINATION - properties collectively interpreted as ‘WHITE MATTER INTEGRITY’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

white matter integrity

A

axonal density and myelination

DWI can measure this

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how does DWI create maps of brain’s white matter pathways?

A

uses water

in brain, water molecules move more easily along the DIRECTION OF AXONS

series of magnetic pulses cause water molecules to move in particular direction

measure movement of the water molecules in diff directions, to infer how movement is restricted by surrounding tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

DWI derives measure of what type of connectivity?

A

structural

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

present study

A

we know ELA = associated with ALTERED REWARD PROCESSING and that ACCUMBOFRONTAL TRACT is implicated in reward processing

present study wanted to see if THESE TWO THINGS WERE CONNECTED

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how did study investigate if accumbofrontal tract and altered reward processing were both affected by ELA?

A

used validated MEASURE OF CHILDHOOD ADVERSITY (quantified individual differences in ELA)

and ‘state-of-the-science’ technique for QUANTIFYING WHITE MATTER INTEGRITY (quantitative anisotropy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

quantitative anisotropy (QA)

A

measure used in diffusor tensor imaging (DTI)

(DTI = similar to DWI but more complex and detailed)

QA provides sensitive measure of structural integrity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

lower values of QA indicate what?

A

DECREASED WHITE MATTER STRUCTURAL INTEGRITY

(high axonal density and myelination)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

higher values of QA indicate what?

A

higher white matter structural integrity

23
Q

study’s primary hypothesis

A

higher ELA will be related to lower white matter integrity in accumbofrontal tracts

24
Q

study’s secondary hypothesis

A

lower white matter integrity will be related to MALADAPTIVE DECISION MAKING

as measured by ALTERATIONS IN POSITIVE and NEGATIVE FEEDBACK SENSITIVITY

25
study methods - participants
equal split M & F reasonable racial and ethnic diversity sufficient socioeconomic variation mean age = 15
26
methods - assessment of adversity
lifetime adversity section of Youth Life Stress Interview (YLSI)
27
YLSI
Youth Life Stress Interview structured interview used to assess stressful life events asks about range of adversities (family, school, traumatic events, major life transitions) rating system has high reliability and validity
28
methods - reinforcement learning paradigm
Ps completed PROBABILISTIC REINFORCEMENT LEARNING (RL) task during scanning session Ps presented with drawings of 2 diff stimuli (bell and ball) instructed to choose one after choice, Ps got positive feedback or negative feedback each P did two diff versions of the task with diff stimulus pairs that were probabilistically reinforced
29
two diff versions of the task with diff stimulus pairs that were probabilistically reinforced
AB: stimulus A led to positive feedback on 80% of trials, B led to positive feedback on 20% of trials CD: stimulus C led to positive feedback on 70% of trials, D led to positive feedback on 30% of trials
30
methods - mathematical modelling of reinforcement learning
data from reinforcement task = used to fit REINFORCEMENT LEARNING MODEL
31
by fitting a RL model to each Ps behavioural data, it's possible to...
derive MODEL PARAMETERS that CAPTURE DIFFERENCES in how INDIVIDUALS RESPOND to feedback to optimize decision making parameters: learning rate, and exploring parameter
32
positive prediction error
when feedback is better than expected this INCREASES the DECISION WEIGHT of the stimulus (ie. higher expected probability of reward)
33
negative prediction error
when feedback is worse than expected DECREASES the DECISION WEIGHT of the stimulus
34
learning rate parameter
the impact of the PREDICTION ERROR ON UPDATING DECISION WEIGHTS is scaled by a LEARNING RATE parameter ("feedback sensitivity" parameter) separate ones for both positive feedback and negative feedback
35
what does a high sensitivity to positive feedback indicate?
indicates that positive feedback has a HIGH IMPACT ON FUTURE CHOICE (low sensitivity for positive feedback indicates it would hardly change future choice)
36
what did they do as a control to assess any effects on reward learning?
measured general cognition using spatial working memory task
37
methods - youth behavioural problems
used the CBCL (child behaviour checklist) to assess child behavioural problems asks Qs about anxiety, depression, social withdrawal, conflict, violation of social norms
38
methods - MRI scanning
DWI in MRI scnaner analyses to extract the accumbofrontal tract separately for each hemisphere to calculate values for each P also examined a 'CONTROL' tract to assess if ELA = associated with WIDESPREAD effects on white matter (chose middle longitudinal fasiculus as it's not involved in reward learning)
39
what control tract did they select?
middle longitudinal fasiculus as it's not involved in reward learning
40
results for ELA from the sample
sample included modest amount of ELA (mean adversity was 3.78) (score of 3 = associated with serious marital conflict in household, parental separation, parental unemployment)
41
results: association between ELA and QA
it was significant in both the LEFT and RIGHT hemispheres high QA = low ELA high ELA = low QA SUPPORTS PRIMARY HYPOTHESIS
42
greater ELA predicted what in both hemispheres?
predicted lower QA (lower tract integrity) results held when controlling for general cognitive ability
43
when accounting for cognitive functioning, was there a sig relationship between ELA and QA in the middle longitudinal fasiculus (control pathway)
no, not when accounting for general cognitive ability (but there was a marginally sig relationship in only the right hemisphere when not accounting for cog ability) this suggests that ELA may have general effect on cognitive function (in addition to specific effect on accumbofrontal white matter integrity)
44
white matter tract integrity and feedback sensitivity
LOWER white matter integrity was related to NEGATIVE FEEDBACK SENSITIVITY for both left and right hemispheres (this remained significant when controlling for general cognitive ability) NO ASSOCIATIONS for white matter integrity and POSITIVE FEEDBACK
45
white matter tract integrity and negative feedback sensitivity
lower white matter tract integrity = higher negative feedback sensitivity
46
white matter tract integrity and positive feedback sensitivity
no association
47
what's the relationship between ELA, accumbofrontal tract integrity and negative feedback sensitivity?
performed a MEDIATION ANALYSIS to get at this NO DIRECT RELATIONSHIP between ELA and negative feedback sensitivity but there is an INDIRECT RELATIONSHIP: ELA > accumbofrontal tract integrity (QA) > negative feedback sensitivity
48
is there a direct relationship between ELA and negative feedback sensitivity?
no
49
is there an indirect relationship between ELA and negative feedback sensitivity?
yes mediated via effect on accumbofrontal tract integrity (supports their hypothesis)
50
discussion
1. adolescents who experienced high ELA had lower accumbofrontal tract integrity 2. accumbofrontal tract integrity predicted negative feedback sensitivity in RL task (but not related to positive feedback sensitivity) 3. chicken or egg? do structural and functional alterations in mPFC and VS cause diffs in connectivity in accumbofrontal tract, or does reduced connectivity lead to structural and functional changes?
51
specific effects of ELA on negative feedback sensitivity may be especially relevant to understanding what?
understanding how ELA shapes behaviour and risk for disorders (like depression) that are linked with increased negative feedback sensitivity increased negative feedback sensitivity can shape how individuals respond to challenges/stressful situations in the future
52
limitations
small sample size - good chance of missing real effects (lack of power) in behavioural task, many factors influence choices (impulsivity, risk assessment, exploration/exploitation strats) and these also may be influenced by ELA - could complicate interpretations of effects/lack of effects
53
understanding how ELA shapes connectivity in reward circuits could ultimately help to develop...
more targeted strategies for prevention or intervention to ameliorate negative consequences of ELA across development ie. disciplinary measures may not be adaptive - call for less intense negative feedback

Psyc 443 (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions