Abstract
In four experiments participants were instructed to detect and localise a gap on a small vertical line. When the line was presented at the periphery, inattention produced a tendency to report broken lines as solid ones and also produced a substantial increase in coarse localisation errors. The results support the hypothesis (Tsal & Shalev, 1996) that the unattended visual field is composed of large attentional receptive fields (ARFs) within which there is no spatial resolution. A partial stimulation of such an ARF, by the broken line's inner ends producing the gap, signals the activation of the entire ARF resulting in the perceptual closure of the gap.