Cognitive Neuroscience

Card Set Information

Cognitive Neuroscience
2011-03-31 02:09:42
Executive Control

Exam #2
Show Answers:

  1. What controls the orienting of attention?
    frontal -parietal control
  2. Executive Functions
    Higher order cognitive operations that are subserved by the prefrontal cortex
  3. types of exec functions
    programming, regulating, monitoring, attention/inhibition, task managemetn, contextual coding, planning, monitoring
  4. Goal -Directed behavior
    • Choose goal
    • plan-subgoals
    • execute-sequencing
    • monitor progress
    • interweaving planning and executing
    • flexibility
  5. Executive Functions include
    • The ability to plan for a goal and take concrete stepts to reach goal
    • The ability to be flexible and deal with novel situations
    • The ability to prioritize tasks and to switch between them
    • The ability to assess or evaluate the efficacy of actions
  6. Models of Cognitive Control
    • Norman and Shallice
    • 1. Fully automatic processing controlled by SCHEMATA
    • 2. Passive processing controlled by Contention Scheduling
    • 3. Supervisory Attentional System (SAS)
  7. Fully automatic processing controlled by SCHEMATA
    • knowledge-restaurant- picking up the phone.
    • schema need to be developed before they are automatic
  8. Passive processing controlled by Contention Scheduling
    • action-sequence: coming to class and taking notes
    • -Gear changing when driving is performed "automatically" (without conscious awareness)
    • -When routines clash, relative importance is used to determine which to perform (contention scheduling) (left foot on brake or clutch)
  9. SAS Model
    • override action sequence via voluntary control
    • -Driving in England - inhibit look right, activate look left
    • SAS overides habitual actions
  10. SAS is active when in
    dancer, choice of response, novelty
  11. Attentional Slips and Lapses
    Habitual actions become automatic (overactive CS)

    SAS does not inhibit a habit (underactive CS)
  12. SAS Box Model
    perceptual system ->trigger database ->contention scheduling (passive, prevents simultaneous activation of multiple schema) SAS overlay (flexible behavior, learning novel stimuli, overcoming habits, error correction etc) -> effector system
  13. Brain regions of executive system
    • Lateral prefrontal cortex
    • ventromedial prefrontal cortex
  14. Frontal lobe lesions- damage in the
    • Medial frontal gyrus
    • Superior FG
    • Inferior FG
  15. phineas gage
    damage to left frontal cortex
  16. W.R. patient
    • seizure left him with lack of motivation
    • frontal astrocytoma
    • passive detachment
  17. these patients have normal IQ but...
    • but lack ability to function in every day life
    • (example with errands)
  18. What cognitive operations are necessary to perform task with Wisconsin Card Sorting Task
    • sensory processing of stimuli
    • understanding task instructions
    • selecting a response
    • executing a response
    • understanding feedback
    • planning next response
    • mainintaing correct rule
    • manipulating response based on new rule
    • switching strategy based on a new rule
  19. Possible reasons for failure on WCST
    • 1. tendency to focus on one stimulus dimension at the expense of others
    • 2. inability to ignore a dimension hat was reinforced previously
  20. strengths/weaknessess of WCST
    • robust activator and engager in executive control
    • but so broad - is maintaining a rule separate from retaining a rule?
    • doesn't fractionate aspects of control into difference subprocesses
  21. Poldrack Multi-tasking Study
    • Condition A: card task alone, no distraction
    • Condition B: task while hearing high and low pitched sounds, keeping count of sounds
  22. In poldrack multi-tasking study, describe active brain regions
    • Hippocampal activity greater for condition A than B
    • Striatal activity greater for Condition B than A
    • Memory for cards better in condition A
    • flexibility to extrapolate categories better in A
  23. Myth of multitasking
    executive attention is INDIVISIBLE. you are actually rapidly switching between tasks!

    activate pathways, inactivate pathways, switch
  24. Switch tasks
    remember the number for trail 1 and trial 2, then remember the letter for trial 3 and trial 4
  25. Do normal subjects/frontal lobe damage pts have switch cost?
    yes, switch task trial takes longer for normal subjects, and even longer for frontal lobe pts
  26. Switch cost
    RT on switch-RT on no-switch trials
  27. Novelty Detection
    Show oddball target and get the P3b response in both normal and pre-frontal region damage pts.

    Show oddball and task-irrelevant (novel) stimuli, get the P3a to novel, task-irrelevant stimuli, don't get this for pts wtih prefrontal damage.
  28. Novelty and response to target
    -corresponding brain region and ERP
    • Parietal regions important for response to targets- P3b for targets,
    • Frontal regions important for response to novel stimuli P3a for novel stimuli