PSY605: Executive Control

  1. What controls the orientation of attention?
    • Source-Site Model
    • Posner and Peterson
    • Frontal-parietal control tells what attention should be doing at temporal, occipital, etc.
  2. Executive functions
    • Higher order cogntive operations that are subserved by the prefrontal cortex
    • Programming, regulating, monitoring, attention/inhibition, task management, contextual coding, planning
    • Ability to plan for a goal, be flexible, prioritize tasks, switch between tasks, evaluate efficacy
  3. Model of Cognitive Control
    • Schemata: Fully automatic processing (knowledge)
    • Contention Scheduling: Passive processing controlled (action sequence)
    • Supervisory Attentional System: Overriding action sequence
  4. Contention scheduling
    • Automatic organization of schemata together
    • Without conscious awareness
    • When routines clash, relative importance is used to determine which to perform
  5. Cortex associated with Executive Functioning
    • Lateral Prefrontal Cortex
    • Ventromedial Prefrontal Cortex

  6. Dysexecutive Syndrome
    Damage in the middle/superior/inferior frontal gyrus (MFG, SFG, IGF)
  7. Wisconsin Card Sorting Task
    • Strengths - Robust activator of executive functioning
    • Weaknesses - Doesn't distinguish types of executive functioning or inform how they are organized in the brain
  8. Poldrack Multi-tasking Study
    • Task: Sorting a deck of cards into groups
    • Condition A - Task , no distractions
    • Condition B - Task while hearing and counting sounds of various pitches

    • Hippocampal Activity - greater for A
    • Striatal Activity - greater for A

    Formation of long-term memories and motor functioning better for A!
  9. Tests of Prefrontal Functioning
    • Task Switching
    • Novely Detection
    • Initiation/Cessation of Action
    • Inhibition
    • Self-Monitoring
    • Sequencing
    • Abstract Thinking
  10. Task Switching
    Perform two tasks (i.e. report the letter if the card is green, and the number if it is red)

    Switch Cost = (RT on Switch from last card) - (RT on No-Switch from last card)

    • Switch - Longer for normal subjects
    • Takes even longer for PFL patients
  11. Novelty Detection
    • Oddball task (press button for gray circles (targets))
    • P3b - Parietal lobe - appears for response to targets
    • P3a - Frontal lobe - exhibited for task-irrelevant, rare (novel) items - doesn't show up for PFL patients
  12. Initiation/Cessation of Action
    • Psychological inertia: Difficult to initiate an action and difficult stopping it (perservation)
    • Perservation: Tendency to repeatedly perform the same behavioral response even when no longer appropriate

    Seen in Wisconsin Card Sorting
  13. Environmental Dependency Syndrome
    • Behavior is driven by environmental cues
    • Can't help but engage in schemas (can't override it)
  14. Inhibition
    • Tied with inferior frontal cortex
    • Go/No-Go Task -- either respond or withhold response
  15. Self-Monitoring
    • Evaluation of the appropriateness of one's actions and plans
    • Error-Related Negativity
  16. Error-Related Negativity
    • Tapping into brain-basis of self-monitoring, and hence indexes it
    • But may index an emotional, not just a cognitive, reaction
    • 100-150ms after a response
    • Tied to person thinking they made an error
    • Greater when accuracy is emphasized (as opposed to speed)
    • Greater the larger the error
    • Dipole Modeling - ERN generated in the Anterior Cingulate Cortex
  17. Sequencing
    • A very specific process that may be damaged with frontal damage
    • Damage patients - poor at determining which item appeared more recently
    • Difficulties even when patient determines the order
  18. Theory of Action Disorganization
    Behaviour of frontal patients reflects the functioning of contention scheduling in the absence of supervisory attention
Card Set
PSY605: Executive Control
Chapter 13: Cognitive Control