Tryptophan depletion disrupts the motivational guidance of goal-directed behavior as a function of trait impulsivity.
Neuropsychopharmacology
; 30(7): 1362-73, 2005 Jul.
Article
en En
| MEDLINE
| ID: mdl-15770237
ABSTRACT
Serotonin (5-HT) is well known to affect the motivational properties of stimuli predictive of rewards as well as the inhibitory control of behavior. Here, central 5-HT depletion was induced by the acute tryptophan (TRP) depletion (ATD) procedure in young healthy volunteers to examine the role of 5-HT in motivated action and prepotent response inhibition. A novel reaction-time task, tailored to individual differences in general cognitive speed, was employed to measure the guidance of behavior by motivationally relevant signals predictive of reinforcement likelihood, while the stop-signal reaction-time task was used to measure response inhibition. Following the TRP-balancing control drink, cues predictive of high-reinforcement certainty induced faster, but less accurate responses compared with cues predictive of lower reinforcement certainty. Depletion of central 5-HT modulated this coupling between motivation and action by slowing responses and increasing accuracy as a function of incentive certainty. These effects of ATD on motivated action correlated highly with individual differences in the personality trait of Nonplanning Impulsiveness (Barratt Impulsivity Scale (BIS-11)), so that strongest effects on motivated action were observed in high-impulsive individuals. By contrast, ATD left unaltered the ability to inhibit prepotent responses. Our findings may have implications for a variety of neuropsychiatric disorders including impulsive aggressive disorders and depression.
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Banco de datos:
MEDLINE
Asunto principal:
Tiempo de Reacción
/
Triptófano
/
Serotonina
/
Objetivos
/
Conducta Impulsiva
/
Motivación
Tipo de estudio:
Guideline
/
Prognostic_studies
Límite:
Adult
/
Humans
/
Male
Idioma:
En
Año:
2005
Tipo del documento:
Article