Neurophysiological Correlates of the Reflexive Orienting of Spatial Attention

There are two reflexive biases in orienting attention that assist in the exploration of the visual scene. A distinct object will draw, or capture, spatial attention to its locus. After this object has been inspected (and deemed irrelevant), inhibition of return prevents its repeated inspection. Here, we describe the neuro-physiological correlates of these biases in orienting attention. In the superior colliculus, both originate from changes in sensory processing—the capture of attention is linked to a strong neural representation of a visual target, whereas inhibition of return is associated with a weak representation of this target. We describe how changes in this sensory signal may produce changes in behavior and can explain the typical and anomalous findings associated with these biases in reflexively orienting attention.