Exploring the effect of stimulus characteristics on location-based inhibition of return using abrupt and ramped stimulus presentation

A recent study illustrating the importance of sensory influences on inhibition of return (IOR) found stimuli biased towards the parvocellular (P) pathway produced greater IOR while stimuli biased towards the magnocellular (M) pathway produced less IOR (Brown, 2009; Guenther & Brown, 2007). The present study used a different sensory manipulation (temporal onset/offset) to further explore this relationship. Greater M activity was expected when stimuli were presented abruptly (M-biased) compared to when stimuli were ramped on and off (P-biased). Consistent with our recent findings, greater location-based IOR was found under ramped vs. abrupt conditions. The results showed location-based IOR is influenced by the nature of stimulus presentation (ramped vs. abrupt) providing convergent evidence of an IOR mechanism sensitive to M- and P-biased stimuli.