Abstract

Visual perceptual learning is an effective way to overcome the limitations of the visual system when processing the visual environment accurately. A number of perceptual learning studies have focused on improving sensitivity to basic perceptual features such as contrast and orientation. The current study focused on whether perceptual learning can reduce visual illusions to enable accurate perception of the visual environment. In particular, we explored whether the curveball illusion could be eliminated through training. Participants performed the task of aligning the global motion direction of the disc presented in the peripheral vision as vertical as possible. The gratings inside the disc were either stationary or moved to the left or right. During the three-day training sessions, participants assigned to the experimental group performed the task with the inside-moving disc (causing the illusion), while participants in the control group did with the stationary disc (not causing the illusion). As a result of training, the curveball illusion effect was significantly reduced in the post-test compared to the pre-test only in the experimental group. This result shows that visual illusions are effectively eliminated by perceptual learning.