L10 - Decisions, metacognition and modelling

Question 1

Do patients with MDD have slower RT?

Answer 1

• Yes
• Slower response selection

Question 2

Why are mental processes slower and more variable in some people in others

Answer 2

• Biological perspective: bio system is different than a normal person, bio systems are complex and involves a cascade of processes, some psych elements can be reduced to cellular and atomic level
• Metacognitive perspective: Process of thinking about one’s own thinking e.g attention focus, motivation and confidence
• Bio perspective falls under cog neuroscience and Metacognitive perspective is amenable to behavioural psych

Question 3

Why does mean RT increase with depression?

Answer 3

• H1: caused by distraction from task unrelated thoughts and rumination (focus passively and repetitively one symptoms of depression)
• Can use questionnaires or do a task and do interruption/attention checks
• EX: give ppts boring repetitive task, and then randomly, use a slide that asked what they are thinking (experience sampling)
• EX: Used Beck Depression Inventory 21-term questionnaire: ppts were split into high or low scorers on BDI, and then tried t induce either a negative or positive mood e.g listening to upbeat music whilst answering the questionnaire with slightly happier questions and vice versa for the negative mood = neg mood induction is effective on depressed people, but pos induction does not reduced rumination, neither induction made difference to non-depressed people

Question 4

What are brain dynamics in healthy people?

Answer 4

• Diff brain networks activated at diff times, and some networks devoted for specific things
• Balance between Default Mode Network (bored/thinking about past/future) and Central Executive Network in the Salience Network
• Depressed brain = more Default mode network at expense of CE network

Question 5

What are ways to maintain sustained attention?

Answer 5

• Go/nogo task, interrupt their experiment, ask if they focused on task: yes/no, if no: awareness of paying attention to the task
• People with depression do things without paying attention

Question 6

What types of mind-wandering do people with ADHD do?

Answer 6

• Spontaneous
• Deliberate
• People with ADHD have higher spontaneous mind-wandering, less related to motivation
• Found Psych Undergrad students with ADHD engage in more spontaneous MW than other students
• All ppt use the ASRS: adult adhd self-report scale, control ppts with high ADHD tendencies engage more in spontaneous MW than ppts with low ADHD tendencies

Question 7

ADHD and performance variability?

Answer 7

• Can relate to decreased performance in task and high variability in their scores
• Comparing patients with controls in a 0-back (click only when you see E) and 1-back (more cognitively loaded, if letter appears twice in a row). In both conditions, variability is higher in ADD condition

Question 8

How does what is on your mind relate to your task performance (exp)

Answer 8

• Use metronome task: press button in synchrony with a tone
• Allows to measure continuous measure of performance inc variability, and can interrupt people and ask how on-task they feel
• When people report being off-task = poorer performance = robust but weak

Question 9

What are the stages for each trial to make the decision?

Answer 9

Detection, decision, execution, time

Question 10

What is the drift-diffusion model?

Answer 10

• Brain will accumulate evidence over time = determines the choice and RT on each trial
• Fast/slow depends on boundary separation: distance between yes/no threshold, large = lots of confidence needed = slower RT = Is a speed-accuracy trade-off
• Drift rate: how fast does evidence accumulate = quicker accumulation = faster RT = depends on quality of evidence = also depends on efficiency of processing
• Non-decision time = before decision: includes detection and execution = other processing stages
• RT = Decision time + Non-decision time

Question 11

How do parameter differ between people with ADHD and controls?

Answer 11

• Metanalysis found that slower drift rate in ADHD = some studies suggest faster non-decision time in ADHD
• Reduced processing/decision efficiency
• Less cautious boundary separation
• Faster sensory/motor processes

Question 12

How to study Within subject manipulations with decision modelling?

Answer 12

• To have a causal interpretation, not just correlational
• Decision models allow to infer invisible parameters from observed behaviour
• Infer effect of empirical manipulations like effect of instruction or alcohol consumption

Question 13

What are the effects of alcohol consumption?

Answer 13

• Placebo or alcohol and if that is moderate or high level of intoxication
• Alcohol decreases processing efficiency and sensory/motor delay