Spatiotemporal distribution of facilitation and inhibition of return arising from the reflexive orienting of covert attention

Currently, there is debate regarding both the spatial and temporal relation ship between facilitation and inhibition of return (IOR) components of atte ntion, as observed on the covert orienting of visual attention task (COVAT) . These issues were addressed in a series of experiments where the spatial and temporal relationships between cue and target were manipulated. Facilit ation occurred only when the stimulus onset asynchrony (SOA) was short and there was temporal overlap between cue and target IOR occurred only when SO A was long and there was no temporal overlap between cue and target. Facili tation encompassed the cued location and all locations between the cue and fixation, whereas IOR arose for the entire cued hemifield. These findings s uggest that the facilitation and IOR found on COVATs that use noninformativ e peripheral cues are separable and stimulus-driven processes.