Gaze-contingent stimulus removal leads to subsequent changes in overt attentional allocation

Spatial neglect is a debilitating neurological disorder marked by reduced exploration of contralesional space. We developed an intervention in which eye movements to and within one half of a search display were reduced over the course of several hundred trials. The aim of this study was to determine whether this intervention had an effect on the deployment of attention of healthy participants as a first step towards application in patients. The participants carried out a visual search task during which the stimuli in one half of the search display were removed whenever the participants made eye movements towards it. The stimuli in the other half were unaffected by eye movements. Indeed, this led to a steady relative decrease in fixations within the affected half over the course of the intervention. In five experiments, the performance in different spatial attention paradigms was measured before and after this intervention. In two visual search paradigms (feature and conjunction search), exploration of the affected half decreased compared to the unaffected half. In a Posner task with exogenous cues, a partial effect of the intervention was found. However, an attempt at replicating this effect was not successful. The fifth experiment showed that performance in a line bisection paradigm was not significantly influenced by the intervention. To conclude, the intervention showed the potential to influence the behavior of healthy participants in overt attentional exploration tasks.