Lec 4 Flashcards
1
Q
Cog control
- aka
- Definition
- Cog C vs SC
- how Cog C is related to SC
A
Cognitive control (executive function/ control)
- strive for a goal when there’s conflicts that grab your attention
- Cog control vs SC:
- Cog control requires us to flexibly direct attention when there is temptation
- SC is not specifically about attention (but relies on attention)
- Cog control vs SC:
- SC is similar to inhibition; inhibition is a facet of cog control
2
Q
Exploring cognitive control tasks – Stroop
- compatible
- incompatible
- Emotional stroop task
- kids version
- how is cog C used in stroop task
- Stroop effect calculation
- indicator of better control
- Murphy et al 2012
A
Exploring cognitive control tasks – Stroop
- Normal stroop task
- Compatible: color of word = word
- Incompatible: color of word diff than word
- Emotional stroop task
- Emotion condition: there is emotional word that may affect us
- Ex. aunt just died of cancer and that emotionally delays you in the task
- Neutral condition: the words have no emotional meaning
- Stroop variant – kids version
- Name the animal of the picture vs the label of an animal name
- Stroop task: b/c reading is over-learned, to complete Stroop one needs to inhibit/suppress reading response & focus on (colour) naming response
- Stroop effect = incongruent RT – congruent RT
- Smaller Stroop effect = better control
- Murphy et al 2012
- Brought in drug addicts
- Have them do emo stroop
- A: emo condition (words are more meaningful to them)
- B: control condition
- Results: Addicts spend more time in A compared to non-addicts
3
Q
Exploring cognitive control tasks - Stop signal task
- Common stop signal task in daily life
- Stop signal task in the lab
- Circle vs X
- SSD
- Longer SSD = ?
- Stop signal task variant – for animals
- Go trial
- Stop trial
- Result
A
- Stop signal task: Can you stop once you’ve already decided to go?
- Common stop signal task in daily life
- driver decides to go on a yellow light
- Sees police in the intersection
* If the driver crosses the intersection and the light turns red while he is crossing, he will get a ticket
- Sees police in the intersection
- Qs: can the driver stop his car when he wants to cross during the yellow light
- Stop signal task in the lab
- Circle = go
- When you see circle, you press the button
- X = stop signal delay (SSD)
- When you see X, you do NOT press button
- 90% of the trials = go trials
- 10% of trials = stop trials (see circle then X)
- Stop signal comes after GO signal
- SSD is calibrated for 50% error rate (where most ppl will have 50% error)
- Longer SSD = better inhibitory control
- SSD = time b/w seeing circle and X
- If there is a long SSD time, and ppl can refrain from pressing the button, they have higher inhibitory control
- Circle = go
- Stop signal task variant – for animals
- Rat goes in the chamber
* 2/3 trials = go trial
* 1/3 trials = stop trial
* Go trial- Hear a sound
- Need to run as quickly as they can to the other side of the port
- If they reach the port in less than ½ a sec, they have water; if they take longer = no water
- Stop trials
- If they reach the port in less than ½ a sec, they have water; if they take longer = no water
- Hear a sound
- There’s a delay (SSD), and they see a light
* The light = stop
- There’s a delay (SSD), and they see a light
- Opp to go trials
* If you get to the port in less than ½ sec = no water
* Take longer = hv water
- Opp to go trials
- Rat goes in the chamber
- Same as humans: the longer the SSD/ delay the rats can overcome, they have strong inhibitory control
4
Q
Exploring cognitive control tasks - Operation Span task
- Describe the task
- Result
- How is it a task of inhibitory control
- How to calculate WMC
A
Exploring cognitive control tasks - Operation Span task (OSPAN)
- primary task: Told to remember letters (ex. SAHBK)
- interfering secondary processing task: Then do a few math qs (ex. 5 x 5 = 25)
- What are the letters?
- Demo result: can recall up to 5 letters
- Corresponds to Miller’s WM capacity: 5 +/- 2
- This is also a task of inhibitory control
- You need to maintain the item in WM (letters)
- And suppress the distraction (math problems)
- WMC = # of trial items correctly recalled, weighted by trial length
- OSPAN performance predict performance on cog abilities
5
Q
Exploring cognitive control tasks - Task Switching paradigm
- high voice decision
- low voice decision
- Results
- repeat trials
- switch trials
- Switch cost
- child’s version
A
Exploring cognitive control tasks - Task Switching paradigm
- When you hear high/low voice, you need to make diff types of decisions
- High voice = odd/even judgment (8 = even) pink = high voice
- Low voice = high/low judgment (3 = low) blue = low voice
- Results
- Repeat trials: When ppl are doing only one type of task (ex. blue #s/ low voice = high/low judgement), the rx time is fast
- Switch trials: When ppl have switch to another task (ex. from high/low judgements to odd/even judgements), the rx time is slower when there is a switch
- Rs look at the repeat and switch trials
- Switch costs = switch RT – non-switch RT
- Larger switch costs = Less cognitive flexibility (but perhaps more stability)
- There is a child’s version
- Sometimes they name the color
- Sometimes they name the shape of animal
6
Q
Miyake & Friedman, 2012 - The unity & diversity of cognitive control
- M & F’s view on whether diff cog control tasks measure the same construct
- unity
- diversity
- 3 types of cog control**
- how does updating and shifting contain inhibition?
- Is there a genetic component?
- Is cog control and 3 facets related to IQ?
*
A
Miyake & Friedman, 2012 - The unity & diversity of cognitive control
- Since there are so many tasks assessing cognitive control, do they all assess the same latent construct?
- Miyake & Freeman think: These tasks are united, yet diverse
- Unity: All correlate with one another
- Diversity: Not perfectly correlated, thus separable
- i.e. Stroop task and stop task are correlated but not perfectly correlated
- 3 types of cog control (**influential model)
- Updating (ex. what are the letters mentioned)
* Maintaining task goals in memory
- Updating (ex. what are the letters mentioned)
- Shifting (ex. task switch – odd/even & high/low; color & animal)
* Flexibly adapting to new task
- Shifting (ex. task switch – odd/even & high/low; color & animal)
- Inhibition (ex. stroop task, stop signal task)
* self-stopping based on task goals
- Inhibition (ex. stroop task, stop signal task)
- All types have a bit of inhibition in it
- Ex. updating – keep updated on the new letters, while inhibiting the other task
- Ex. Shifting – need to inhibit that other set of instructions
- Strong genetic component to control (.75 = correlation from MZ twin studies)
- Recent studies show that cog control and all 3 facets are related to IQ
7
Q
Friedman et al., 2011 -“don’t touch toy” task
- Methods
- Results
- self restraint overall
- self restraint
- inhibition
- updating
- switching
A
Friedman et al., 2011 -“don’t touch toy” task
- At early age (14 mo), rs put nice in front of kids and tell them “don’t touch toy”
- examined whether self-restraint in early childhood predicted 3 executive fx (EFs; inhibiting, updating working memory, and shifting task) later on among twins.
- 3 executive fx = common EF factor
- Gps w/ poor self-restraint = touch the toy
- Gps w/ better self-restraint = didn’t touch
- Rs followed the kids
- Results:
- Overall, all kids get better at self-restraint as they grow older
- Kids who could self-restrain, at age 17
- Had better inhibition
- No difference in updating
- Those who can self-restraint had worse shifting
- IOW: Good restraint might work against readily switching
- Higher IQ, but mediated by EF factors
8
Q
Dual mechanisms of cog control
- the 2 mechanisms
A
Braver et al 2012
- Proactive control: (proactive = b4)
* = constant reminding themselves of the goal; where a conflict arises, turn down one of the event (‘early selection’)
* anticipatory maintenance of goal-relevant information before demanding event
* IOW: you hv a goal, act on the goal, even b4 you face conflict
- Proactive control: (proactive = b4)
- Reactive control
* = after the fact; ‘late correction’
* Transient, recruited as needed in a just-in-time manner after demanding event detected
* IOW: you show control only when it is needed in the situation
- Reactive control
Examples
- Reactive control:
- At 9AM, she gets a msg to get groceries afterwork, so she tells herself to go shopping after work
- 5PM, someone asks for a meeting, person goes for the meeting instead
- At 6PM, realizes she’s late, and goes to get groceries
- Proactive:
- At 4:30PM, she gets msg to get groceries afterwork
- at 5PM, someone asks for a meeting, person refuses the meeting as she has to go shopping after work
- At 5:30PM, she goes to get groceries
9
Q
Reactive & proactive control on Stroop - Conflict adaptation
- reactive control during stroop task
- proactive control during stroop task
- Results
- Conflict adaptation
A
Reactive control during stroop task (goal: say the color):
- See blue word in blue color → says blue
- See red word in green color → says red, then reminds herself “attend color”, so she then says green
Proactive control
- Keeps the goal in mind “I need to attend to color”
- See blue word in blue color says blue
- Keeps the goal in mind “I need to attend to color”
- See red word in green color says green
- Results
- Orange = incongruent trial
- White = congruent trial
- X-axis: the trial type b4 the current trial (congruent or incongruent)
- If trial b4 is congruent, and current trial is incongruent → slowest RT
- If trial b4 is congruent, and current trial is congruent → fastest RT
- If trial b4 is incongruent, and current trial = congruent → slower RT
- If trial b4 is incongruent, and current trial is incongruent → faster RT
Conflict adaptation: if prev trials are all incongruent, you have the mindset of “need to attend to color”; in subsequent trials, the RT decreases as you adapt to the conflict
10
Q
Dual process model of self-control - Thinking fast and slow (Kahneman, 2011)
- 2 systems
A
Dual process theory: 2 systems
- automatic, unconscious/implicit/impulsive process
- controlled, conscious/explicit/reflective process.
- influenced by situational, dispositional conditions
- This leads to SC outcome
11
Q
Neuroscience of control - situational threats to control
- control equation
- 2 ways to cause SC failure
- brain regions in stop system
- brain regions in go system
- Heatherton & Wagner, 2011 - model
- 2 threats to self regulation & brain region affected
- Main reason for SR failure
- Is the model still used?
A
Control = executive/reflective system – impulsive/emotional (dopaminergic) system
- IOW: control is controlled by 2 opposing systems (hence the “-“)
- Point: Anything that decreases the power of the executive system or strengthens the impulsive system → self-control failure
- And, there are brain regions that correspond to each of these two systems
- Red = stop system
- Green = go system
- Red: PFC, anterior cingulate
- Green: ventral striatum (nucleus accumbens), ventromedial PFC (vmPFC), amygdala
- Heatherton & Wagner, 2011
- 2 threats to SR
- impulse system amplified → impulses overwhelm PFC
- exec system is impaired → impair PFC fx
- 2 threats to SR
- SR failure is caused by PF subcortical circuit is broken
- Model not really accepted anymore
12
Q
brain on cocaine (films) - Cocaine users inhibiting vs. not-inhibiting cravings
Nora Volklow et al, 2010
- Methods
- Findings
- NAcc & vmpfc
- R IFG
*
A
Nora Volklow et al, 2010
- Methods
- Did fMRI scans of cocaine addicts
- Showed addicts images related to cocaine
- Addicts were told to inhibit responses or just look at the images
- Results
- Decreased activation in Nacc (nucleus accumbens) & VMPFC for those inhibiting cravings
- The larger decreases in Nacc activation (during inhibition) related to larger increases in right IFG activation
- right IFG activation is thought to represent the exec system
13
Q
Brain as predictor - IFG activation in lab and real-world smoking
- Berkman, Falk, & Lieberman, 2011
- Methods
- Part 1
- Part 2
- Results
- low, avg, high r IFG activation
- What does this suggest
- Methods
A
Berkman, Falk, & Lieberman, 2011
- Recuit real smokers and followed them
- 31 heavy smokers (>10 cigarettes per day, 7 days/week) who wanted to quit
- NOTE: This is Underpowered
- Methods
- Completed Go/no-go task in lab while being scanned with fMRI
* Press the button when you see any letter, except when you see “x”
* Since there are way more other letters presented compared to “x”, the pressing button becomes a habit
- Completed Go/no-go task in lab while being scanned with fMRI
- Called smokers and they had to report cravings & smoking in the past 15 min
* Avg: 8 times/day for 21 days
- Called smokers and they had to report cravings & smoking in the past 15 min
- Hypothesis: IFG activation in go/no-go will moderate craving-smoking link
- Will not necessarily predict fewer desires (though perhaps fewer cigarettes smoked)
- IOW, this doesn’t mean that those have stronger IFG activation during the go/no-go task will have fewer desires;
- It is less about system 1 (ppl exposed to desires), and more about system 2 (regulate desires, break the link b/w craving and smoking)
- Results:
- X-axis; +2 = strong cravings; -2 = no cravings
- Among those w/ avg rIFG activation
- The more they crave, the more they smoke
- For those w/ low avg rIFG activation
- Super strong link
- Whenever I crave system → very strong motivation to smoke
- For those w/ high avg rIFG activation
- You have craving, but it does not mean you will smoke
- This suggests that IFG is the link b/w craving and smoking
- IFG also predicted less smoking (at least for those with strong cravings)
14
Q
Conflict monitoring theory - botvinick, Cohen, & Carter, 2004
- When is control recruited?
- Define Conflict
- 3 types of conflict - define
- Incongruent trial
- Under-determined choices
- Errors
- Kerns et al, 2004 finding
A
Q: Cohen asked: How is control recruited? How do we know when to control?
- The answer is not that WE consciously decide to—humuncular thinking!
- A: Control recruited when there is conflict in information processing
- Conflict: competition between inconsistent mental representations
- Incongruent trial: competition between correct response and habitual response
- E.g., incongruent stroop trial
- Under-determined choices: Conflict among multiple permissible, desirable responses
- E.g., Do you want $1 today or $3 in one week
- Errors: Conflict between erroneous response and correct/goal-directed response
- E.g., playing wrong note on guitar
- Incongruent trial: competition between correct response and habitual response
2 hypotheses
- Deanna Barch et al, 2001 - Conflict detected in dACC
- Kerns et al, 2004 - Conflict triggers subsequent control
- When there is an incongruent control, you messed up
- You were told to pay attention
- So in subsequent incongruent trials, you exert more control
- Images: ACC (left) and DLPFC (R image)
- X = ACC activity on prev trial
- Results: the higher the ACC activity on prev trial, the more activity you see in the PFC during the current trial
- IOW: errors or conflicts → brain tells you to pay attention → lead to more control activity subsequent trial
15
Q
Errors: Ultimate conflict - The error-related negativity (ERN)
- EEG Pro over fMRI
- ERP
- ERN
- When does the peak occur
A
- EEG: can measure brain activity on the scalp
- Pro over fMRI: can precisely see when it happens (50-100ms)
- ERP: use EEG and lock it to an event
- ERN: a class of ERP
- Ex. ppl do stroop task
- You lock the EEG (aka cut it to repeat itself)
- Here = repeated mistakes on the stroop task
- When they make a mistake, you see a strong spike to -ve polarity (grey) in ACC
- NOTE: y axis – the top = -ve
- Measured with EEG, precise timing
- Generated by the ACC
- Very fast: Peaks by 50-100ms post-error
- Sometimes starts before error!
