Impulsivity

Question 1

What is Impulsivity?


Answer 1

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

Question 2

Barratt Impulsiveness Scale (BIS-11; Patton et al. 1995) – measures 3 factors:

Answer 2

Attentional Impulsiveness (8 items)
Motor Impulsiveness (11 items)
Non-planning Impulsiveness (11 items)

Question 3

Limitations with self-report questionnaires

Answer 3

Can only measure trait impulsiveness and are insensitive to transient changes in impulsivity and they are subjective.

Question 4

Behavioural Laboratory Measures

Answer 4

• 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

Question 5

Attention Deficit Hyperactivity Disorder

Answer 5

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.

Question 6

Stanford Marshmallow Experiment

Answer 6

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.

Question 7

Is Impulsivity a Consequence of Stimulant Abuse?

Answer 7

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)

Question 8

Neural networks mediating Impulsivity

Answer 8

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