Boulinguez Philippe, Jaffard Magali, Granjon Lionel, Benraiss Abdelrhani
Centre de Recherches sur la Cognition et l'Apprentissage, Equipe Attention and Contrôle, CNRS UMR 6234, Universite de Poitiers, 99 Avenue du Recteur Pineau, Poitiers, France.
J Neurophysiol. 2008 Mar;99(3):1572-8. doi: 10.1152/jn.01198.2007. Epub 2008 Jan 2.
Typical simple reaction-time (RT) paradigms usually include a warning signal followed by a variable foreperiod before the presentation of a reaction stimulus. Most current interpretations suggest that the warning stimulus alerts the organism and so results in faster processing of either the sensory or motor components of the task. In this study, electromyography (EMG) was used to detect both covert and overt motor errors in a simple warned RT task. Results show that warning signals may trigger automatic motor activations that are likely to cause false alarms. Distribution analysis reveals that 77% of all errors detected with EMG are erroneous responses to the warning signal. Accordingly, we propose that movement triggering needs to be temporarily inhibited before the stimulus to prevent premature responses during the foreperiod. This proactive inhibition would be responsible for a paradoxical increase in RT for conditions with short foreperiods compared with control conditions in which no warning signal is presented. These results call for a reassessment of the theoretical framework used to interpret the effects of warning signals.
典型的简单反应时（RT）范式通常包括一个警告信号，在反应刺激呈现之前有一个可变的前间隔。目前大多数解释认为，警告刺激会使机体警觉，从而导致对任务的感觉或运动成分进行更快的处理。在本研究中，肌电图（EMG）被用于在一个简单的有警告的RT任务中检测隐蔽和明显的运动错误。结果表明，警告信号可能会触发自动的运动激活，这很可能导致误报。分布分析显示，用EMG检测到的所有错误中有77%是对警告信号的错误反应。因此，我们提出在刺激之前需要暂时抑制运动触发，以防止在前间隔期间出现过早反应。与没有呈现警告信号的对照条件相比，这种主动抑制将导致前间隔较短的条件下RT出现反常增加。这些结果要求对用于解释警告信号效应的理论框架进行重新评估。
