Effects of stimulus set arrangements on the response interference effect

With two-choice reaction time tasks, a reaction time advantage for two responses from different hands, rather than from the same hand, has been attributed to the response interference within the same-hand finger pairing (Kornblum, 1965). The purpose of this study was to determine whether the degree of spatial compatibility between the stimulus and response sets influences the magnitude of the response interference effect. Individuals (N=36) participated in four two-choice reaction time sessions, which differed in terms of finger placement (two or four fingers), degree of stimulus set arrangement (more or less compatible) and finger pairing (same-hand or different-hand finger pairings). The finger placement and finger pairing manipulations were the same as those used in previous studies of the response interference effect (Alain et al, 1993). The manipulation of the stimulus set arrangement used either the same central stimulus location (less compatible) for all finger pairings or a direct stimulus location, spatially aligned with each finger pairing (more compatible). The interactions of finger pairing with finger placement and with stimulus set were significant. As the pattern of reaction times for the finger pairing varied with the different degree of spatial compatibility between stimulus set arrangements, the magnitude of the response interference effect may be influenced by the specific arrangement used for the stimulus display.