An investigation of the applicability of a multiplicative impulsive behavioral model in human participants

• Main Authors: LIANG CHUN-HAN, 梁君涵
• Other Authors: 何孟洋
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/91634200880491716383

碩士 === 長庚大學 === 臨床行為科學研究所 === 93 === ‘Impulsivity’ constitutes the predominant feature of many clinical disorders, and there is also full of homely examples of impulsive behaviors in everyday life. In literature, the definition of impulsivity adopted by the behavioral approach appears to be more uniform, most of the existing models tend to define impulsivity as ‘inability to tolerate delayed gratification’. That is, when an organism is confronted with two choice alternatives differing in reinforcer size and delay, the preference to the immediate small reinforcer may be regarded as being impulsive, whereas the preference to the bigger reinforcer but with longer delay may be coined as being more ‘self-control’. The models thus provide theoretical bases for examining the behavioral processes of impulsivity in animals. However, relatively few empirical studies based on these models have been applied to humans. Therefore, the major aims of the present study were to investigate whether a multiplicative behavioral model proposed by Ho, Mobini, Chiang, Bradshaw, & Szabadi (1999) can be applied to human participants, in order to provide a methodological basis for future clinical studies. The model proposes that choice behaviors are determined by the product of reinforcer size, delay and its probability of occurrences. Thus, it is essential to examine the effects of the interplay between these variables on impulsive choice. The present study consists of two experiments. The purposes of Experiment 1 were to examine the psychometric properties of the translated versions of two self-reported questionnaires (Eysenck Personality Questionnaire-Revised & Impulsiveness Questionnaire 7); and to test the applicability of a behvioral choice task in humans (by manipulating the reinforcer size and delays). Experiment 2 was based on a within-participant design. All participants had to undergo two behavioral choice tasks: one was related to reinforcer size and delays, and the other was associated with reinforcer probability and delays. The results showed that the relabilities and validities of the two translated questionnaires were compatible with the original ones. The data obtained from the behavioral choice tasks indicated that humans’ choice behaviors appeared to be modulated by the reinforcer size, probability and delay. In addition, the inter-correlation analyses of all impulsivity measures did not reveal significant correlations between most measures. The present study suggests Ho et al.’s (1999) model is applicable to human participants; and that impulsivity is a highly diverse construct.