Concurrent right–left and amplitude spatial congruency effects in a visual discrimination task

ABSTRACTDuring a perceptual task, the presentation of a visual stimulus is known to automatically activate a spatially congruent manual response, which influences the speed of the motor response provided depending on the non-spatial stimulus feature (e.g., colour). Such effect was found to depend on the congruency between either the (1) right–left stimulus location and lateralized manual response (Simon effect), or (2) near–far stimulus location and manual response amplitude (Amplitude Congruency effect). In the present study, we conjointly manipulated Simon and Amplitude Congruency effects in a stimulus colour discrimination task. It was found that stimulus location potentiated concurrent but independent Simon and Amplitude Congruency effects: the more the to-be-executed response was congruent with the response activated by these effects, the faster was its execution. Moreover, our results suggest that the magnitude of Amplitude Congruency effect on response latency and execution time reflects the tempor...