School of Psychology, University of Auckland, Auckland, New Zealand.
Department of Psychology, University of North Carolina at Greensboro, Greensboro, NC, USA.
Psychon Bull Rev. 2019 Aug;26(4):1400-1410. doi: 10.3758/s13423-019-01576-y.
Previous research has indicated that two components of reaching behavior, initiation time and reach curvature, exhibit distinct patterns of trial sequence effects in congruency tasks. The observed patterns have been proposed to reflect two dissociable processes underlying decision behavior, with initiation times capturing the functioning of a threshold adjustment process involving the temporary inhibition of motor output, and reach curvatures reflecting a controlled selection process that supports goal-driven stimulus-response translation. The tasks used in previous studies, however, did not control for a range of associative-priming confounds commonly featured in congruency tasks. Consequently, the extent to which the observed patterns reflected the proposed processes or associative-priming confounds remained unclear. We therefore presented 45 adult participants with a reach-tracking version of the Stroop task that featured both confound-minimized and confound-laden trials. Initiation times revealed main effects of previous and current congruency on both confound-minimized and confound-laden trials, consistent with the claim that initiation times can be used to target the functioning of the threshold adjustment process. Conversely, reach curvatures exhibited a clear sensitivity to associative-priming effects, revealing a congruency sequence effect on confound-laden but not on confound-minimized trials. This finding is consistent with the claim that reach curvatures can be used to target the functioning of the controlled selection process. Thus, by directly evaluating the influence of associative-priming confounds, the present study revealed the strongest evidence to date that decision behavior in tasks involving conflict is fundamentally structured by the functioning of two dissociable processes.
先前的研究表明，在符合任务中，伸手行为的两个组成部分，即起始时间和伸手曲率，表现出明显的试验序列效应模式。所观察到的模式被提出反映了决策行为背后的两个可分离的过程，其中起始时间捕捉到了一个涉及暂时抑制运动输出的阈值调整过程的功能，而伸手曲率反映了一个支持目标驱动刺激-反应转换的受控选择过程。然而，先前研究中使用的任务并没有控制在符合任务中常见的一系列联想启动混淆因素。因此，所观察到的模式在多大程度上反映了所提出的过程或联想启动混淆因素仍然不清楚。因此，我们向 45 名成年参与者展示了一种具有最小和最大混淆试验的 Stroop 任务的伸手跟踪版本。起始时间在最小和最大混淆试验中都显示了先前和当前一致性的主要影响，这与启动时间可用于目标阈值调整过程的功能的说法一致。相反，伸手曲率对联想启动效应具有明显的敏感性，在最大混淆试验中显示出一致性序列效应，但在最小混淆试验中则没有。这一发现与伸手曲率可用于目标受控选择过程的功能的说法一致。因此，通过直接评估联想启动混淆因素的影响，本研究提供了迄今为止最有力的证据，表明涉及冲突的任务中的决策行为是由两个可分离的过程的功能所构成的。
