Facilitation instead of inhibition for repeated right-sided events in left neglect.

When two visual events appear consecutively in the same spatial location, our response to the second event is slower than that to the first. This inhibition for repeated events may reflect a bias toward sampling novel locations, a bias useful for exploring the visual space. Patients with right hemisphere damage and left neglect explore asymmetrically a visual scene. They are initially attracted by right-sided items and become stuck to them, being unable to reorient their attention toward the left. Here we show that neglect patients show facilitation instead of inhibition for repeated events on the right, non-neglected side. Patients without neglect showed normal inhibition. Our observation may explain why neglect patients' exploration of space cannot extend beyond a few right-sided objects.