Department of Psychology, College of Life and Environmental Sciences, Washington Singer Laboratories, Streatham Campus, Exeter, EX4 4QG, United Kingdom.
Psychol Sci. 2013 Mar 1;24(3):352-62. doi: 10.1177/0956797612457390. Epub 2013 Feb 11.
The stop-signal paradigm is a popular method for examining response inhibition and impulse control in psychology, cognitive neuroscience, and clinical domains because it allows the estimation of the covert latency of the stop process: the stop-signal reaction time (SSRT). In three sets of simulations, we examined to what extent SSRTs that were estimated with the popular mean and integration methods were influenced by the skew of the reaction time distribution and the gradual slowing of the response latencies. We found that the mean method consistently overestimated SSRT. The integration method tended to underestimate SSRT when response latencies gradually increased. This underestimation bias was absent when SSRTs were estimated with the integration method for smaller blocks of trials. Thus, skewing and response slowing can lead to spurious inhibitory differences. We recommend that the mean method of estimating SSRT be abandoned in favor of the integration method.
停止信号范式是一种在心理学、认知神经科学和临床领域中用于检验反应抑制和冲动控制的流行方法，因为它可以估计停止过程的潜在潜伏期：停止信号反应时间（SSRT）。在三组模拟中，我们研究了使用流行的均值和积分方法估计的 SSRT 受到反应时间分布的偏度和响应潜伏期逐渐减慢的影响程度。我们发现均值方法一致地高估了 SSRT。当响应潜伏期逐渐增加时，积分方法往往会低估 SSRT。当 SSRT 用较小的试验块的积分方法估计时，这种低估偏差就不存在了。因此，偏度和响应速度减慢会导致虚假的抑制差异。我们建议放弃估计 SSRT 的均值方法，转而采用积分方法。
