TY - JOUR

T1 - Theory and method in the quantitative analysis of 'impulsive choice' behaviour

T2 - Implications for psychopharmacology

AU - Ho, M. Y.

AU - Mobini, S.

AU - Chiang, T. J.

AU - Bradshaw, C. M.

AU - Szabadi, E.

PY - 1999

Y1 - 1999

N2 - Impulsive choice refers to the selection of small immediate gains in preference to larger delayed gains, or the selection of large delayed penalties in preference to smaller immediate penalties. Current theoretical interpretations of impulsive choice are reviewed, and a synthesis of these ideas, the 'multiplicative hyperbolic model of choice', is presented. The model assumes that the value of a positive reinforcer increases as a hyperbolic function of its size, and decreases as a hyperbolic function of its delay and the odds against its occurrence. Each hyperbolic function contains a single discounting parameter which quantifies the organism's sensitivity to the variable in question. The hyperbolic discounting functions combine multiplicatively to determine the overall value of the reinforcer. Equivalent functions are postulated to govern the (negative) value of aversive events, the net value of an outcome reflecting the algebraic sum of the positive and negative values. The model gives rise to a quantitative methodology for studying impulsive choice, based on a family of linear indifference (null) equations, which describe performance under conditions of indifference, when the values of the reinforcers are assumed to be equal. This methodology may be used to identify individual differences in sensitivity to the magnitude, delay and probability of reinforcement. The methodology is also suitable for the quantitative evaluation of the effects of some pharmacological interventions on discounting parameters. Recent psychopharmacological studies of impulsive choice are reviewed, and the utility of indifference equations for extending this work, and developing a quantitative psychopharmacology of impulsive choice is discussed.

AB - Impulsive choice refers to the selection of small immediate gains in preference to larger delayed gains, or the selection of large delayed penalties in preference to smaller immediate penalties. Current theoretical interpretations of impulsive choice are reviewed, and a synthesis of these ideas, the 'multiplicative hyperbolic model of choice', is presented. The model assumes that the value of a positive reinforcer increases as a hyperbolic function of its size, and decreases as a hyperbolic function of its delay and the odds against its occurrence. Each hyperbolic function contains a single discounting parameter which quantifies the organism's sensitivity to the variable in question. The hyperbolic discounting functions combine multiplicatively to determine the overall value of the reinforcer. Equivalent functions are postulated to govern the (negative) value of aversive events, the net value of an outcome reflecting the algebraic sum of the positive and negative values. The model gives rise to a quantitative methodology for studying impulsive choice, based on a family of linear indifference (null) equations, which describe performance under conditions of indifference, when the values of the reinforcers are assumed to be equal. This methodology may be used to identify individual differences in sensitivity to the magnitude, delay and probability of reinforcement. The methodology is also suitable for the quantitative evaluation of the effects of some pharmacological interventions on discounting parameters. Recent psychopharmacological studies of impulsive choice are reviewed, and the utility of indifference equations for extending this work, and developing a quantitative psychopharmacology of impulsive choice is discussed.

KW - Delay of reinforcement

KW - Hyperbolic discounting functions

KW - Impulsive choice

KW - Indifference equations

KW - Probability of reinforcement

UR - http://www.scopus.com/inward/record.url?scp=0032693651&partnerID=8YFLogxK

U2 - 10.1007/PL00005482

DO - 10.1007/PL00005482

M3 - 文献综述

C2 - 10550487

AN - SCOPUS:0032693651

SN - 0033-3158

VL - 146

SP - 362

EP - 372

JO - Psychopharmacology

JF - Psychopharmacology

IS - 4

ER -