Influences of abrupt vs. ramped stimulus presentation on location-based inhibition of return

Abstract

Recent work has illustrated the importance of a sensory component to inhibition of return (IOR). A recent study exploring the contributions from the parvocellular (P) and magnocellular (M) pathways to location based IOR through bottom-up sensory (target spatial frequency) and top-down attentional (objects) manipulations (Brown & Guenther, 2008) suggests conditions favoring P/ventral relative to M/dorsal processing should produce greater IOR magnitude and vice versa. To further explore the roles of the P and M pathways to IOR, the present study used a different sensory manipulation presenting cues and targets either abruptly (producing a strong M response) or ramped on and off (producing a relatively weaker M response). Greater IOR was expected to ramped targets because of the weaker M response. Less IOR was expected to abrupt targets due to a greater M response. This particular sensory manipulation by itself was unable to produce differences in IOR; however, when combined with increased P/ventral activity due to the presence of objects (2-D or 3-D) differences in IOR between abrupt and ramped conditions emerged. The results highlight the importance of sensory factors on IOR and provide an example of how they can interact with other perceptual variables to influence IOR.