The role of response processes in the formation of cross-modality assimilation effects

A unimanual, two-digit choice-reaction-time task was used in conjunction with visual signals presented in the extreme peripheral field. The position of the signal on the retina, the eye stimulated, the hand used in responding, and the operating digits were all controlled for their effects. Stimulus-response compatibility was maintained throughout. It was found that RT to ipsilateral S-R pathways was consistently faster than when the pathways involved transcommissural connections. Subsidiary findings related to differences between the operating digits and the side of signal occurrence. These effects are discussed in connection with known interhemispheric phenomena and other CRT findings.