Impulsivity Flashcards
What is Impulsivity?
A working definition of impulsivity refers to behavior that is performed with little or inadequate fore-thought.
Key sub-types of behavioural impulsivity:
Inability to inhibit actions
Inability to delay gratification
Inability to reflect before making a decision
Barratt Impulsiveness Scale (BIS-11; Patton et al. 1995) – measures 3 factors:
Attentional Impulsiveness (8 items) Motor Impulsiveness (11 items) Non-planning Impulsiveness (11 items)
Limitations with self-report questionnaires
Can only measure trait impulsiveness and are insensitive to transient changes in impulsivity and they are subjective.
Behavioural Laboratory Measures
- Temporal subtype – inability to delay gratification - measured with the Delay Discounting task.
- Motor inhibition subtype – inability to inhibit responding - measured with the Go/No Go test or Stop Signal task.
- Reflection subtype – inability to reflect (the tendency to gather and evaluate information) before making a decision
Attention Deficit Hyperactivity Disorder
ADHD is characterized by problems with attention, learning, impulse control, and hyperactivity.Stimulant drugs improve behavior and learning ability in 60-80% of children correctly diagnosed. The primary psychopharmacological agents are the CNS stimulants.
Stanford Marshmallow Experiment
Results - a minority ate the marshmallow immediately. Of those who attempted to delay, one third deferred gratification long enough to get the second marshmallow. Age was a major determinant of the ability to defer gratification.
Is Impulsivity a Consequence of Stimulant Abuse?
Acutely stimulants increase DA and 5-HT
Several studies show decreased impulsivity in behavioral laboratory studies in animals and humans.
Stimulants paradoxically decrease impulsive behaviour in ADHD and Conduct Disorder (CD)
Neural networks mediating Impulsivity
In highly impulsive individuals, regulatory structures including medial and lateral regions of the prefrontal cortex were found to be more isolated from sub-cortical structures associated with appetitive drive, whereas these brain areas were more functionally connected within the same module in less impulsive individuals