ISSN 1671-3710
CN 11-4766/R

心理科学进展 ›› 2021, Vol. 29 ›› Issue (1): 140-149.doi: 10.3724/SP.J.1042.2021.00140

• 研究前沿 • 上一篇    下一篇


杨玲, 刘文鑫, 张炀, 张建勋(), 牛禄霖   

  1. 甘肃省行为与心理健康重点实验室; 西北师范大学心理学院物质成瘾与康复研究所, 兰州 730070
  • 收稿日期:2020-05-13 出版日期:2021-01-15 发布日期:2020-11-23
  • 通讯作者: 张建勋
  • 基金资助:
    * 国家自然科学基金项目(31660276);国家自然科学基金项目(31960185)

The external validity of delay discounting in the field of substance addiction

YANG Ling, LIU Wenxin, ZHANG Yang, ZHANG Jianxun(), NIU Lulin   

  1. Key Laboratory of Behavioral and Mental Health of Gansu Province; Institute of Substance Addiction and Rehabilitation, School of Psychology, Northwest Normal University, Lanzhou 730070, China
  • Received:2020-05-13 Online:2021-01-15 Published:2020-11-23
  • Contact: ZHANG Jianxun


物质成瘾者的跨期决策缺陷已被大量使用金钱延迟折扣任务的研究所证实。然而近年来, 来自金钱延迟折扣任务变式(成瘾物质延迟折扣任务、性延迟折扣任务和跨类别延迟折扣任务)的发现表明, 在物质成瘾领域的延迟折扣研究中单一使用金钱延迟折扣任务存在一定的局限性。首先, 物质成瘾者对金钱的延迟折扣水平可能并不能完全代表其对成瘾物质、性和其它自然奖赏的延迟折扣水平; 其次, 仅使用单一延迟折扣任务可能存在对物质成瘾者跨期决策过程的过度简化; 最后, 金钱延迟折扣任务较其变式对物质成瘾者的一些临床特征不够敏感。未来研究应进一步丰富、拓展物质成瘾领域的跨类别延迟折扣研究, 并对可能影响跨期决策的时间因素进行深入探索。

关键词: 物质成瘾, 延迟折扣, 跨期决策, 外部效度


Deficiency in inter-temporal decision making of substance addicts has been consistently confirmed by a vast array of studies using monetary Delay Discounting Task. Substance addicts showed a myopia tendency towards the immediate reward during the process of inter-temporal decision making. This myopia tendency corresponds well with the substance-use behavior in their real life. However, the recently emerging evidence from new variants of the monetary Delay Discounting Task (the addictive substance Delay Discounting Task, the Sexual Delay Discounting Task, and the Cross-Commodity Delay Discounting Task) highlighted some limitations in the single use of this paradigm in the delay discounting study of substance addiction, which need to be considered in terms of external validity.
First of all, the results from monetary Delay Discounting Task may not fully reflect and represent the overall patterns of delay discounting in substance addictive population, the delay discounting level of addictive substance as cigarette, alcohol and heroin, of sex and of other natural rewards were significantly different from the delay discounting level of money. This further confirmed the hypothesis that delay discounting has domain specificity. That is to say, there may not be a general level of delay discounting despite different types of rewards. We need to be cautious when explain the results from monetary Delay Discounting Task in the study of substance addiction, and the additional employing of addictive substance Delay Discounting Task may improve the external validity of studies in this area.
Secondly, by employing Single Delay Discounting task alone may over simplify the intertemporal decision-making process of substance addicts. The intertemporal decision-making process faced by this group in real life may be more complex than the one simulated by Single Delay Discounting Task. In real life, substance addicts often face intertemporal choices between different types of rewards including but not limited to money, for example, choice between immediate drug using VS. delayed financial benefits in future. According to the specific position of reward in intertemporal decision-making (the immediate one or the delayed one), the relative value between different types of rewards may change. It is of great significance for the purpose of description, explanation, prediction and intervention in the study of intertemporal decision-making in substance addicts to employ the Cross-Commodity Delay Discounting Task more frequently in future studies.
Finally, compared with its variants, the monetary Delay Discounting Task was not sensitive to the withdrawal status, addiction severity and clinical characteristics related to risky sexual behaviors of substance addicts, hence the monetary Delay Discounting Task showed poor ecological validity compared with Cross-Commodity Delay Discounting Task and Sexual Delay Discounting Task. Whether the monetary Delay Discounting Task is the most ideal task to capture the dynamic changes of intertemporal decision-making in substance addicts after withdrawal and intervention remains to be determined. And here is reason to suspect the results from monetary Delay Discounting Task in the perspective of external validity.
Considering the external validity of studies on intertemporal decision-making of substance addicts, future research should further enrich and expand the research which employs the Cross-Commodity Delay Discounting Task in the field of substance addiction. Besides, there emerged some evidence which have showed that the authenticity of waiting time between immediate choice and delayed choice would also affect the process of intertemporal decision-making, and the subjective time perception of the waiting duration may also play a nonnegligible role in intertemporal decision-making of substance addicts. So it may be valuable to further elucidate the time factors that may affect intertemporal decision-making. At the same time, researchers also need to consider the question of how to equate non-material rewards with money. The development of effective quantitative methods for non-material rewards such as health, sex and freedom is necessary. In addition, questionnaires and interviews can be introduced to future studies of delay discounting to explore the real motivation of substance addicts to obtain money reward in Delay Discounting Tasks.

Key words: substance addiction, delay discounting, inter-temporal decision making, external validity