Simulated central vision loss impairs implicit location probability learning

Abstract

Central vision loss (CVL) occurs in advanced forms of age-related macular degeneration (AMD). It impairs high-acuity vision and results in difficulties with oculomotor control. Goal-driven guidance of attention is less effective in people with CVL, but do central scotomas also affect implicit, experience-driven attention? We investigated how simulated central scotomas affect young adults’ ability to prioritize locations that frequently contain a visual search target (location probability learning). Experiment 1 successfully induced probability learning in a no scotoma phase, regardless of whether participants became aware of the target’s location probability. Subsequently, central scotomas were introduced using a gaze-contingent eye tracking paradigm. The previously learned spatial bias persisted for a short time in this phase, an effect that was statistically comparable for no-scotoma and scotoma testing. Experiment 2 investigated whether participants could acquire location probability learning when trained with a simulated central scotoma. Unlike Experiment 1, training with a central scotoma yielded location probability learning only in participants who were aware of the target’s location probability. This effect transferred to search with no scotoma in aware but not unaware participants. Together, the results show that simulated central vision loss interferes with the acquisition of implicitly learned location probability learning, supporting a role of central vision in implicit spatial attentional biases.