Long-lasting effects of a gaze-contingent intervention on change detection in healthy participants - Implications for neglect rehabilitation

Abstract

Patients with spatial neglect show an ipsilesional exploration bias. We developed a gaze-contingent intervention that aims at reducing this bias and tested its effects on visual exploration in healthy participants: During a visual search, stimuli in one half of the search display are removed when the gaze moves into this half. This leads to a relative increase in the exploration of the other half of the search display - the one that can be explored without impediments. In the first experiment, we tested whether this effect transferred to visual exploration during a change detection task (under change blindness conditions), which was the case. In a second experiment, we modified the intervention (to an intermittent application) but the original version yielded more promising results. Thus, in the third experiment, the original version was used to test the longevity of its effects and whether its repeated application produced even stronger results. To this aim, we compared two groups: the first group received the intervention once, the second group repeatedly on three consecutive days. The change detection task was administered before the intervention and at four points in time after the last intervention (directly afterwards, + 1 hour, + 1 day, and +4 days). The results showed long-lasting effects of the intervention, most pronounced in the second group. Here the intervention changed the bias in the visual exploration pattern significantly until the last follow-up. We conclude that the intervention shows promise for the successful application in neglect patients.

Keywords: Attention; Change blindness; Change detection; Eye movements; Spatial neglect.