The Simon effect is a stimulus-response compatibility effect in which the spatial dimension of the stimulus is task-irrelevant. This effect is often larger in reaction time (RT) for the stimulus located on the dominant-hand side of participants, for most of which it is the right hand, due to dominant-hand keypress responses being faster than non-dominant-hand responses. Experiment 1 demonstrated that pedal-press responses with the left and right feet show a similar asymmetry, favoring the right response for right-footed persons. The asymmetric pattern for keypress responses was absent in results of Wallace (Journal of Experimental Psychology, 93, 163–168, 1972) when participants were not permitted to see the response keys or their hands placed on the keys at any time during the experiment, whereas we found the asymmetric pattern in a recent study when participants placed their hands on the keys prior to their being covered up. Experiments 2 and 3 showed that the Simon effect asymmetry for RT was evident even when participants were prevented from seeing the response device and their responding hands or feet. Although both hands and feet showed a Simon effect asymmetry in RT, consideration of incorrect responses suggested that whereas the asymmetry for hands is not due to a response bias, that for the feet may be due at least in part to such bias. Regardless, our results suggest that the Simon effect asymmetry is mainly an artifact of comparing conditions for which one response is made by the faster dominant right effector and the other with the slower non-dominant left effector.

西蒙效应是一种刺激-反应相容性效应，其中刺激的空间尺寸与任务无关。对于参与者的主导手侧的刺激，此效果的反应时间（RT）通常较大，这在大多数情况下是右手，因为主导手的按键响应要快于非主导手的响应。实验1表明，左右脚的踏板踩踏响应显示出相似的不对称性，有利于右脚人的右响应。Wallace的结果中不存在按键响应的不对称模式（实验心理学杂志，93（163-168，1972）时，实验期间的任何时候都不允许参与者看到响应键或将他们的手放在键上，而在最近的一项研究中，当参与者事先将他们的手放在键上时，我们发现了不对称模式被他们掩盖。实验2和3表明，即使阻止参与者看到响应设备及其响应的手或脚，RT的西蒙效应也不对称。尽管手和脚在RT中均表现出西蒙效应的不对称性，但对不正确响应的考虑表明，尽管手的不对称性不是由于响应偏差引起的，但脚的不对称性可能至少部分是由于这种偏差引起的。而不管，