Abstract
Goal. Visual perceptual learning (VPL) is usually specific to the trained retinal location, which is often attributed to plasticity in early visual cortex. Recent findings show that VPL transfers to untrained locations given specific training procedures. For instance, exogenous attention has been found to transfer VPL to untrained, distant locations. Here, we investigated whether exogenous attention differentially affects transfer within and across visual hemifields, thereby comparing different cortical distances while holding retinal distance constant. Methods. Observers completed an orientation discrimination task on 5-consecutive days. They reported the orientation of a single Gabor patch of varying contrast. On the Pre– and Post–tests (sessions 1 and 5, respectively), the target was presented at one of 4 peripheral locations, equidistant from fixation and the vertical and horizontal meridians. During Training (sessions 2-4), the target appeared at one of 2 locations: both on the same side of either the vertical meridian (Same–Hemifield) or horizontal meridian (Different–Hemifield). During Training, half of the observers in each group were presented with a peripheral pre-cue adjacent to the target location (Cued-group) and the other half with a neutral cue at fixation (Neutral-group). Results. We assessed VPL at trained and untrained locations as the change in performance (d') between Pre– and Post–tests. Whereas for the Neutral condition learning occurred at the trained but not untrained locations, for the Cued condition there was significant learning in both trained and untrained locations. This pattern of results emerged to a similar extent for both Hemifield conditions. These results reveal that attention facilitates transfer of VPL to untrained locations both within and across visual hemifields. This finding suggests that attention's benefits are interhemispheric and likely mediated by both low and higher visual cortical areas.
Meeting abstract presented at VSS 2014