Abstract
In visual perceptual learning, the ability to respond to visible stimuli is improved through practice. The visual input on our retina, however, is intrinsically ambiguous, supporting a multitude of valid representations. The brain selects one out of many possible visual interpretations, which is neurally enhanced, while alternative interpretations remain perceptually suppressed. Here, we show that not only visibility can improve through training, but that suppression can also be trained. Throughout training (in total 2560 trial), an oriented grating presented to one eye was constantly suppressed by a high-contrast expanding bull’s eye presented to the other eye. This suppression-trained grating was always presented to the same eye, always with the same orientation within an observer. Pre- and post training detection thresholds were measured for target gratings with the suppression-trained orientation and for gratings with the orthogonal orientation, in the trained and untrained eye, independently, using an adaptive Quest procedure. The target gratings competed with a low-contrast expanding bull’s eye presented to the opposite eye. Performance showed a stronger improvement after training compared to before training for gratings presented to the eye that was dominant during training (where the bull’s eye was presented), indicating eye-based learning. Most interestingly, we found a stimulus-specific effect of suppression learning, where improvement was significantly worse for detecting the trained orientation, relative to detection of the orthogonal orientation. Hereby, we show stimulus selectivity in binocular suppression, and that observers can be trained to suppress a certain stimulus. These findings are indicative of the plasticity of inhibitory networks responsible for perceptual suppression.
Meeting abstract presented at VSS 2015