奖惩对行为抑制能力和自主生理活动影响的时效性

Timeliness of Impact of Reward/punishment Stimulations on Behavioral Inhibition Ability and Automatic Physiological Responses

将45名被试随机分配为奖励组、惩罚组和对照组,实验进程按时间发展过程被分为五阶段,采用停止信号任务探讨奖惩刺激对行为抑制能力和自主生理活动影响的时效性。结果显示:奖惩刺激对行为反应时和抑制失败率影响仅在第二、三阶段差异显著,对心率影响的显著差异在第三阶段结束、而对皮电和指温影响的显著差异仍持续到第五阶段。结果表明:奖惩刺激对行为的抑制作用具有时效性,有效时间内表现为仅奖励能提高行为抑制能力;奖惩刺激对心率的影响具有时效性,但对其它生理指标的影响则未显示出时效性。

Reward and punishment play an important role in clinical education. A series of studies have indicated that the clinical effect of reward and punishment can be affected by the frequency, individual sensitivity and the expectation of reward and punishment. However, little is known about the timeliness of the role of reward and punishment. In the present study, we investigated the length of time for which the emotion triggered by cumulative reward/punishment could act on inhibition ability. This was investigated using a psycho-physiological methodology which used the stop-signal task to explore the timeliness of reward and punishment. The experiment comprised a 3 （group： reward group, punishment group, and control group） × 5 （periodicity： stage 1, stage 2, stage 3, stage 4, and stage 5） mixed factorial design, in which stimulus condition varied between subjects, and periodicity varied within subjects. Forty-five college students were allocated to the reward group, punishment group, or control group at random. The experimental process was divided into five latent stages. The experiment used the Super Lab system to present the stimuli, and to record the response time and rate of error inhibition made by participants in the stop-signal task during each stage. Automatic physiological responses were collected continuously by a 16-channel physiological recording system during each stage. The results showed that （1） differences in behavioral response time and error inhibition rate only occurred in Stages 2 and 3. Specifically, the response time of the reward group in Stage 2 was much higher than that in the control group; the response time of the reward group in Stage 3 was much higher than those observed in the punishment or control group; and the error inhibition rate of the reward group in Stages 2 and 3 was much lower than in the punishment or control group; （2） For automatic physiological responses, the impact of reward/punishment stimulations differed in almost all stages for skin conductance responses and finger temperature, but not heart rate. In conclusion, the present study demonstrated that the effects of reward/punishment stimulations on behavioral inhibition ability differed across time. At the critical time periods, only the reward condition improved behavioral inhibition ability; and the punishment condition increased the inhibition response. The effects of reward stimulations across time differed for heart rate, but not skin conductance responses or finger temperature activities.