Ivan Victorita E, Banks Parker J, Goodfellow Kris, Gruber Aaron J
Canadian Centre for Behavioral Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, AB, Canada.
Front Integr Neurosci. 2018 Mar 8;12:9. doi: 10.3389/fnint.2018.00009. eCollection 2018.
The propensity of animals to shift choices immediately after unexpectedly poor reinforcement outcomes is a pervasive strategy across species and tasks. We report here on the memory supporting such lose-shift responding in humans, assessed using a binary choice task in which random responding is the optimal strategy. Participants exhibited little lose-shift responding when fully attending to the task, but this increased by 30%-40% in participants that performed with additional cognitive load that is known to tax executive systems. Lose-shift responding in the cognitively loaded adults persisted throughout the testing session, despite being a sub-optimal strategy, but was less likely as the time increased between reinforcement and the subsequent choice. Furthermore, children (5-9 years old) without load performed similarly to the cognitively loaded adults. This effect disappeared in older children aged 11-13 years old. These data provide evidence supporting our hypothesis that lose-shift responding is a default and reflexive strategy in the mammalian brain, likely mediated by a decaying memory trace, and is normally suppressed by executive systems. Reducing the efficacy of executive control by cognitive load (adults) or underdevelopment (children) increases its prevalence. It may therefore be an important component to consider when interpreting choice data, and may serve as an objective behavioral assay of executive function in humans that is easy to measure.
动物在意外获得较差强化结果后立即改变选择的倾向是跨物种和任务的一种普遍策略。我们在此报告关于支持人类这种输后转换反应的记忆，该记忆通过一个二元选择任务进行评估，在这个任务中随机反应是最优策略。参与者在全神贯注于任务时几乎没有输后转换反应，但在执行任务时额外承受已知会消耗执行系统的认知负荷的参与者中，这种反应增加了30%-40%。尽管输后转换反应是一种次优策略，但在有认知负荷的成年人中，这种反应在整个测试过程中持续存在，不过随着强化与后续选择之间的时间增加，其可能性降低。此外，没有负荷的儿童（5-9岁）的表现与有认知负荷的成年人相似。这种效应在11-13岁的大龄儿童中消失。这些数据为支持我们的假设提供了证据，即输后转换反应是哺乳动物大脑中的一种默认和反射性策略，可能由逐渐衰退的记忆痕迹介导，并且通常由执行系统抑制。通过认知负荷（成年人）或发育不全（儿童）降低执行控制的效力会增加其发生率。因此，在解释选择数据时，它可能是一个需要考虑的重要因素，并且可能作为一种易于测量的人类执行功能的客观行为测定方法。
