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Impulsivity. What is it?. Definition of Impulsive. 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
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Impulsivity What is it?
Definition of Impulsive • Acting or Done withoutForethought • 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 Impulsivity • 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. http://www.impulsivity.org/
Concept of Impulsivity • Actionsthat are • Poorly Conceived • Prematurely Expressed • Unduly Risky • Inappropriate to the Situation • Result in Undesirable Outcomes
Is impulsivity more than one thing? • Made up of • Several IndependentFactors • Integrated with • Qualitatively Different Aspects of Behavior Can we distinguish a • Functional Impulsivity From a • Dysfunctional Impulsivity
Is impulsivity more than one thing? • Facet of normal personality • Component of various Disorders: • ADHD, Substance Abuse, Bipolar Disorder, Antisocial Personality Disorder, Borderline Personality Disorder, OCD, Procrastination
Varieties of Impulsivity • Dysfunctional Impulsivity • Functional Impulsivity • Attentional • “Reflection-Impulsivity” • Disinhibition • Inhibitory Control • Decision Time • Lack of Persistence • Boredom/Sensation Seeking • Impulsiveness • Venturesomeness • Motor • Cognitive • Non-Planning • Ideomotor • Careful Planning • Coping Stability • Novelty Seeking • Harm Avoidance • Reward Dependence • Impulsiveness • Irritability • “Self-Control” • Time needed for Decision • Inattention • Hyperactivity • Impulsivity • Criterion 7 for Mania
Dysfunctional vs Functional Impulsivity • 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?
What differentiates socially acceptable impulsive behavior from unacceptable? • 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?
Class questions of Impulsivity • Must all Impulsive Actionsbe: • Poorly Conceived • Prematurely Expressed • Unduly Risky • Inappropriate to the Situation • Result in Undesirable Outcomes ? Must all Impulsive Actions • Include all of the above ?
The Impulsive Car Buy • For a Rich Man? • Poorly Conceived? • Prematurely Expressed? • Unduly Risky? • Inappropriate to the Situation? • Result in Undesirable Outcomes? Thoughtful/Rich/for fun purchase? Middle Class/Thoughtful/before finance? Poor?
Class conceptsof Impulsivity • 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
Do drug experiments strongly support the hypothesis that Impulsivity is multifactorial? • 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?
Two New Models of Impulsivity 5-choice serial reaction time task Transitional Bridge
5CSRTT • Poorly Conceived • Prematurely Expressed • Unduly Risky • Inappropriate to the Situation • confounded by issues related to learning • Result in Undesirable Outcomes • confounds include: • satiety issues • motivation
5CSRTT Explains 42% 10s 5s Explains 5% 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
Transitional Bridge • Motor Impulsivity • Go signal tone • one bridge used • rat on platform A • trained → platform B • food reward • tone after 1s A → B • if <2s reward • Testing • tone randomly • 2-3 or 3-4 s • Correct response: < 2s • Omission > 2 crossing • Premature response • cross before tone • Impulsivity
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 Transitional Bridge
Poorly Conceived • Prematurely Expressed • Unduly Risky • confounded by anxiety • Inappropriate to the Situation • confounded by issues related to learning • Result in Undesirable Outcomes • Affected by ETOH • confounds: • satiety issues • motivation T-Bridge: Motor Impulsivity
T- Bridge: Cognitive Impulsivity • Poorly Conceived • Prematurely Expressed • Unduly Risky • confounded by anxiety • Inappropriate to the Situation • confounded by issues related to learning • Result in Undesirable Outcomes • affected by alcohol • confounds include: • satiety issues • motivation
Toward Phenotypic Impulsivity The Next Step: • Models 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 } all individually variable