Shifting spatial attention makes you flip: Exogenous visual attention triggers perceptual alternations during binocular rivalry.

Although it has been argued that visual attention and the dynamics of binocular rivalry are closely linked, strong evidence for this proposition is still lacking. Here, we investigate how perceptual alternations during binocular rivalry are affected by spatial attention by employing a cuing paradigm. We show a tight link between the occurrence of perceptual alternations and the spatiotemporal properties of visual attention: Alternations occurred earlier and more frequently at locations where visual attention was summoned by an exogenous cue. We argue that cuing a location where rival images are presented leads to a transient increase in the effective contrast of these rival images. This transient increase in effective contrast increases the probability of an alternation at that location. Furthermore, we suggest that an occipito-fronto-parietal network known to be involved in selective attention and binocular rivalry mediates perceptual alternations by boosting the neural response at attended locations.