Swearingen Joshua E, Buhusi Catalin V
Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA.
J Exp Psychol Anim Behav Process. 2010 Oct;36(4):443-55. doi: 10.1037/a0019485.
Humans and lower animals time as if using a stopwatch that can be "stopped" or "reset" on command. This view is challenged by data from the peak-interval procedure with gaps: Unexpected retention intervals (gaps) delay the response function in a seemingly continuous fashion, from stop to reset. We evaluated whether these results are an artifact of averaging over trials, or whether subjects use discrete alternatives or a continuum of alternatives in individual-trials: A Probability-of-Reset hypothesis proposes that in individual gap trials subjects stochastically use discrete alternatives (stop/reset), such that when averaged over trials, the response distribution in gap trials falls in between "stop" and "reset." Alternatively, a Resource Allocation hypothesis proposes that during individual gap trials working memory for the pregap duration decays, such that the response function in individual gap trials is shifted rightward in a continuous fashion. Both hypotheses provided very good fits with the observed individual-trial distributions, although the Resource Allocation hypothesis generated reliably better fits. Results provide support for the usefulness of individual-trial analyses in dissociating theoretical alternatives in interval timing tasks.
人类和低等动物计时时，就好像使用了一个可以根据指令“停止”或“重置”的秒表。来自带有间隔的峰值间隔程序的数据对这一观点提出了挑战：意外的保留间隔（间隔）以一种看似连续的方式延迟反应函数，从停止到重置。我们评估了这些结果是试验平均的人为产物，还是受试者在单次试验中使用离散的选择或连续的选择：重置概率假设提出，在单个间隔试验中，受试者随机使用离散的选择（停止/重置），这样在试验平均时，间隔试验中的反应分布落在“停止”和“重置”之间。或者，资源分配假设提出，在单个间隔试验期间，对间隔前持续时间的工作记忆会衰退，这样单个间隔试验中的反应函数就会以连续的方式向右移动。尽管资源分配假设产生的拟合效果可靠地更好，但这两个假设都与观察到的单次试验分布非常吻合。结果为单次试验分析在区分间隔计时任务中的理论选择方面的有用性提供了支持。
