Executive functions modulate the activity of other cognitive functions in a flexible and goal-directed manner. They perform a supervisory or regulatory role.
- Flexible: depending on the current context
- Goal-directed: to achieve the current goal
Taxonomy of executive functions:
Intelligence:
- Charles Spearman: central intelligence factor ‘g’
- Cattell: division between
- Fluid intelligence: ability to solve abstract reasoning problems
- Crystallized intelligence: learned procedures and knowledge
Fluid intelligence correlates highly with measures of executive functions
Executive functions in the brain are mostly regulated in the prefrontal cortex.
The anterior cingulate cortex and the parietal cortex are also important.
The caudate nucleus and putamen (basal ganglia) are also important for executive functions.
Frontal-cortex-basal ganglia loops:
Damage to the PFC: cognitive function appears to be normal and unimpaired.
But there is impairment in forming, updating and implementing rules for appropriate or effective behavior. This can lead to profound difficulties carrying out simple activities. Damage can lead to:
- Dysexecutive syndrome: lack of initiation, socially quiet.
- Disinhibition syndrome: lack of inhibition, socially too expressive
- Environmental dependency syndrome: actions not based on goals but on surrounding environment. Used imitation and utilization.
Miller & Cohen model: cognitive control stems from the active maintenance of patterns of activity in the prefrontal cortex that represent goals and the means to achieve them.
Switching between rules
- Wisconsin Card Sorting Test
- The orbitofrontal cortex: shifting between rules for behavior
- Reversal learning: rules mapping of stimuli to rewards switch unexpectedly
- Damage to OFC: trouble switching between rules.
Relating rules: reasoning.
- Deduction: truth of a conclusion must be deduced solely from a set of premises that is already at hand
- Induction: likely truth of a conclusion determined from a set of probabilistic, often imperfect premises.
vlPFC: deduction. dlPFC: induction.
You can test relating rules (higher-order integration) with the Raven’s Progressive Matrices test.
Frontal pole: integration of abstract information from multiple sources to form a more general rule. Also involved in mental simulation and implementing higher-order goals.
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