Abstract
A salient cue in a scene can attract visual attention to its location and subsequently enhance information processing at that location. We investigated whether visual information that is rendered invisible through interocular suppression can still guide the distribution of spatial attention. Using a modified version of the classical Posner's attentional cuing paradigm, we presented two images, one intact and one scrambled, to the left and the right side of the fixation point. However, this pair of images was only presented to the observers' non-dominant eye while high contrast dynamic noises were presented to their dominant eye at the same spatial locations. Observers perceived identical noise patches on both side of the fixation point and were unaware of which side received the intact image. These invisible “cuing” stimuli were followed by a brief test probe of a small Gabor patch presented either at the location of the intact image or the scrambled image. Observers judged the orientation of the test probe which could be tilted slightly either CW or CCW. Even though observers were not aware of which side the intact image was located, results show that their performance was better for probes presented at the side where the intact image was presented. Pictures with high arousal value, though invisible, were particularly effective in attracting spatial attention. This result suggests that visual spatial attention can be guided by invisible information, possibly through subcortical pathways.
This research was supported by an award from the James S. McDonnell foundation and a National Institutes of Health Grant R01 EY015261-01.