Abstract
Background. Perceptual learning improves performance, but usually only at trained retinal locations. Exogenous attention can facilitate transfer of learning across locations in orientation discrimination tasks (Donovan, Szpiro & Carrasco, 2015). Location specificity is especially persistent in acuity tasks, in which performance is constrained by spatial resolution, and it is unknown whether attention can facilitate transfer in these tasks. Method. We trained observers for 3 days in either Landolt (gap location discrimination; Experiment 1) or Vernier (Gabor misalignment discrimination; Experiment 2) acuity tasks at locations in the peripheral visual field. Before and after Training, 75%-correct thresholds in were measured at Trained and Untrained locations. Half of observers were trained with valid exogenous pre-cues (Attention group), and the other half was trained with neutral pre-cues (Neutral group). Results. In the Landolt task (Experiment 1), the Neutral group showed location specificity: significant improvement in gap-size threshold at Trained locations, but not at Untrained locations; the Attention group showed location transfer: comparable improvement in gap-size threshold at both Trained and Untrained locations. In the Vernier task (Experiment 2), both Neutral and Attention groups showed location specificity: misalignment thresholds improved at Trained locations, but not at Untrained locations. Conclusions. Results from Experiment 1 show that exogenous spatial attention can facilitate transfer in an acuity task – Landolt gap discrimination. However, exogenous attention did not transfer learning in Experiment 2. Thus Vernier discrimination, associated with visual hyperacuity, shows more persistent location specificity than other tasks, i.e. Landolt acuity and orientation discrimination, even after training with exogenous attention.
Acknowledgement: NIH NEI RO1 – EY019693