Spatial compatibility effects in the writing page: A comparison of left-handed inverters and noninverters

In recent contribution, Moscovitch and Smith (1979) and Smith and Moscovitch (1979) reported that left-handed inverters responded faster, using one hand, to target stimuli presented in the contralateral, rather than ipsilateral, visual field. Moscovitch and Smith attributed this finding to an anomaly in the visual or visuomotor neurological organization of inverters. The present experiment was an attempt to replicate the Moscovitch and Smith result with the purpose of questioning the validity of their neurological account. Therefore quite a similar visual RT paradigm was used in left-handed inverters and noninverters, but the form of the response was changed. The subjects responded to the stimuli with a stylus contact, made with their left dominant hand, on an A4-format sheet of metal, in well-contrasted conditions of inverted and noninverted writing posture. Both groups, in either condition, displayed faster RTs for stimuli presented in the visual field ipsilateral to their responding hand. In addition, this visual field effect strongly interacted with the lateral position of the response-stylus on the page, despite the fact that this position was varied between trials. The present experiment shows that the Moscovitch and Smith result is not reliable. It also demonstrates that spatial S-R compatibility effects may arise in tasks not involving a choice between concurrent response locations.