What is it?
• Acting or Done without Forethought•Latin Root: impulsivus = Driven Onward• Actuated or swayed by emotional or involuntary impulses• Proceeding from natural feeling or impulse without external stimulus• Doing things or tending to do things suddenly
Definition of Impulsive
What is Impulsivity?
Impulsivity has been variously defined as behavior without adequate thought, the tendency to act with less forethought than do most individuals of equal ability and knowledge, or a predisposition toward rapid, unplanned reactions to internal or external stimuli without regard to the negative consequences of these reactions.
Impulsivity is implicated in a number of psychiatric disorders including Mania, Personality Disorders, and Substance Use Disorders;
yet, there is significant disagreement among researchers and clinicians regarding the
exact definition of impulsivity and how it should be measured.
Definition of Impulsivity
http://www.impulsivity.org/
Actions that are • Poorly Conceived• Prematurely Expressed• Unduly Risky• Inappropriate to the Situation• Result in Undesirable Outcomes
• Dysfunctional: maladaptive•Act with less forethought, which produces difficulty
• Functional: Adaptive?• Act with little forethought when it is optimal
Impulsivity vs Risky Behavior
Are they the same?
Impulsivity vs Risky Behavior
Are they the same?
Impulsivity vs Risky Behavior
Risky?
Does Training matter for Impulsivity?
Impulsive?
• Not all impulsive behavior is disadvantageous• Impulsive individuals say they act with less forethought•But they often respond more slowly in experimental Tasks than non-impulsive individuals• Are decision time, persistence, boredom, and sensation seeking important aspects?
• Phenotypic Impulsivity• Negative consequences• Risky Behavior• Repetitive* • Not able to discern want from need• Underdeveloped PFC• less feedback from PFC to limbic• impatience• make choices even recognizing the negative consequences for that choice
Why don’t drugs work consistently?
• Drugs were delivered systemically –• Complex Behavioral Outputs• Such as Impulsivity• Require Complex Circuitry• Suggests multiple Transmitter modulation
• Is the Definition of Impulsivity Good Enough to determine multifactorial causation?
Do drug experiments strongly support the hypothesis that Impulsivity is multifactorial?
Transitional Bridge 5-choice serial reaction time task
Two New Models of Impulsivity
5CSRTT
5CSRTT
5CSRTT
Strong negative correlation r2=0.42 of premature responding with accuracy for Long ITI (5-10s)
Variable ITI (2-15s) – low correlation of premature responding and accuracy
Explains 42%
Explains 5%
5s
10s
Transitional Bridge
Transitional Bridge• COGNITIVE IMPULSIVITY• 2 bridges/remove panel 4• on platform A or C• trained → B or D• tone + food reward• √ bridge preference
•TESTING• A → B• immediate reward• C → D• 2X reward•5 s delay (3 days)
•7s delay (days 4-6)
• 10 s delay (7-9)
• Impulsivity =• choosing A → B• ↓ crossing latency
T-Bridge: Motor Impulsivity
T- Bridge: Cognitive Impulsivity
Toward Phenotypic ImpulsivityModels must include/consider • Behaviors meaningful to the animal used• Poor Conception is impossible to measure in animals and humans• Undue Risk•Situation Inappropriateness•Undesirable Outcomes• All affected by • Emotional state & Stress responsivity• Habitual, Learned and Not yet Learned behavior
The Next Step:
all individually variable}