Gordi Vera Michaela, Drueke Barbara, Gauggel Siegfried, Antons Stephanie, Loevenich Rebecca, Mols Paul, Boecker Maren
Institute of Medical Psychology and Medical Sociology, University Hospital of RWTH Aachen University, Aachen, Germany.
Department of General Psychology: Cognition and Center for Behavioral Addiction Research, University of Duisburg-Essen, Duisburg, Germany.
Front Psychol. 2019 Feb 28;10:279. doi: 10.3389/fpsyg.2019.00279. eCollection 2019.
Previous research comparing the speed of inhibiting a motor response in no-foreknowledge vs. foreknowledge conditions revealed inconsistent findings. While some studies found stopping to be faster in the no-foreknowledge condition, others reported that it was faster in the foreknowledge condition. One possible explanation for the heterogeneous results might be differences in experimental design between those studies. Given this, we wanted to scrutinize whether it makes any difference if foreknowledge and no-foreknowledge are investigated in a context in which both conditions are presented separated from each other (block design) vs. in a context in which both conditions occur intermingled (event-related design). To address this question a modified stop-change task was used. In Experiment 1 no-foreknowledge and foreknowledge trials were imbedded in a block design, while Experiment 2 made use of an event-related design. We found that inhibition speed as measured with the stop signal reaction time (SSRT) was faster in the foreknowledge as compared to the no-foreknowledge condition of the event-related study, whereas no differences in SSRT between both conditions were revealed in the block design study. Analyses of reaction times to the go stimulus reflect that participants tended to slow down their go responses in both experimental contexts. However, in the foreknowledge condition of the event-related study, this strategic slowing was especially pronounced, a finding we refer to as strategic delay effect (SDE), and significantly correlated with SSRT. In sum our results suggest that inhibition speed is susceptible to strategic bias resulting from differences in experimental setup.
先前比较无预知条件和预知条件下抑制运动反应速度的研究结果并不一致。虽然一些研究发现无预知条件下的停止速度更快，但其他研究报告称预知条件下更快。这些不同结果的一个可能解释可能是这些研究之间实验设计的差异。鉴于此，我们想仔细研究一下，如果在预知条件和无预知条件相互分开呈现的情境（组块设计）与两种条件混合出现的情境（事件相关设计）中对它们进行研究，是否会有任何不同。为了解决这个问题，我们使用了一种改良的停止 - 改变任务。在实验1中，无预知和预知试验被嵌入组块设计中，而实验2则采用了事件相关设计。我们发现，与事件相关研究的无预知条件相比，在预知条件下，用停止信号反应时间（SSRT）衡量的抑制速度更快，而在组块设计研究中，两种条件下的SSRT没有差异。对启动刺激的反应时间分析表明，在两种实验情境中，参与者都倾向于减慢他们的启动反应。然而，在事件相关研究的预知条件下，这种策略性减慢尤为明显，我们将这一发现称为策略性延迟效应（SDE），并且与SSRT显著相关。总之，我们的结果表明，抑制速度容易受到实验设置差异导致的策略性偏差的影响。
