Sequential effects in two-choice reaction time tasks: decomposition and synthesis of mechanisms.
Sequential effects in two-choice reaction time tasks: decomposition and synthesis of mechanisms.
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DOI：
10.1162/neco.2009.09-08-866
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发表时间：
2009-09
影响因子：
2.9
通讯作者：
Cohen JD
中科院分区：
文献类型：
--
作者：
Gao J;Wong-Lin K;Holmes P;Simen P;Cohen JD
串行任务的性能分别受到一阶和高阶顺序效应的影响，这是由于之前的试验和更早的试验。随着反应-刺激间隔（RSI）的增加，反应时间模式从传统上归因于自动促进（AF）的纯收益模式转变为由于战略期望（SE）的成本-收益模式。为了阐明这种效应的来源，我们开发了一个由两个相互抑制的神经决策单元组成的连接主义网络，该网络受先前试验反馈的影响。一项独立偏倚机制的研究表明，剩余决策单元活动只能导致一阶AF，但高阶AF可能是由冲突监测介导的策略启动导致的，我们实例化了两个不同的版本。另一种机制介导了预期相关的偏差，这种偏差在RSI过程中向饱和水平增长，由加权重复（或交替）序列长度决定。有了这些机制，该网络与已知的神经生理学一致，可以解释大范围rsi的几组行为数据。结果还表明，练习加速了所有机制，而不是调整它们的相对优势。
Performance on serial tasks is influenced by first- and higher-order sequential effects, respectively due to the immediately previous and earlier trials. As response-to-stimulus interval (RSI) increases, the pattern of reaction times transits from a benefit-only mode, traditionally ascribed to automatic facilitation (AF), to a cost-benefit mode, due to strategic expectancy (SE). To illuminate the sources of such effects, we develop a connectionist network of two mutually-inhibiting neural decision units subject to feedback from previous trials. A study of separate biasing mechanisms shows that residual decision unit activity can lead only to first-order AF, but higher-order AF can result from strategic priming mediated by conflict-monitoring, which we instantiate in two distinct versions. A further mechanism mediates expectation-related biases that grow during RSI toward saturation levels determined by weighted repetition (or alternation) sequence lengths. Equipped with these mechanisms, the network, consistent with known neurophysiology, accounts for several sets of behavioral data over a wide range of RSIs. The results also suggest that practice speeds up all the mechanisms rather than adjusting their relative strengths.