Exogenous Attention and Inhibition of Return are not Constrained by the Effective Oculomotor Range

Abstract

The oculomotor system has been proposed to play a critical role in both exogenous attentional facilitation and inhibition of return (IOR). According to the premotor theory of attention, enhanced sensory processing arises from the preparation of an eye movement, and within this framework, IOR is thought to result primarily from the inhibition of a saccade back to a previously cued location. Although a growing consensus now suggests that early attentional capture (AC) can occur outside the effective oculomotor range—implying that attentional orienting may operate independently of the motor system—the evidence regarding IOR remains considerably more mixed. Furthermore, focusing solely on the oculomotor system appears increasingly unwarranted, as preparation of movements with other effectors is likely to be equally relevant for perceptual processing. Using the eye-abduction paradigm, we tested whether AC or IOR are constrained by the oculomotor range in a sample substantially larger than in any previous study. We also implemented a previously proposed condition involving combined eye and head rotation, designed to restrict movement toward the temporal hemifield for an additional effector. Our results clearly show that neither AC nor IOR is affected by presumed limitations in eye or head–eye motor programming. These findings challenge the central claims of the premotor theory and suggest that both AC and IOR can operate independently of the ability to prepare movements toward the cued location.