Abstract
The basic phenomenon of task-irrelevant perceptual learning is that near-visual-threshold stimuli that are irrelevant to a central task can be learned due to their consistent and concurrent presentation during task performance. The temporal occurrence of central concentration paired with near-threshold stimuli increases perceptual sensitivity to the unattended, near-threshold stimulus. Research has implicated the central dorsal stream, specifically the V3a to the MT, as being at least partially responsible for one aspect of reading, namely, word decoding. Early research showed that perceptual thresholds of flicker processing are significantly lower in people with a reading disability. Interestingly, this is the same region of the brain that is responsible for processing motion, contrast, and flicker. Further, research has shown that task-irrelevant learning of near-threshold motion increases flicker perception. The present study employed a task-irrelevant motion-training paradigm consisting of a paired-shapes visual-recognition task, using colored polygon-shaped targets as salient, attended focal stimuli, with the goal of eliciting increased perceptual sensitivity to motion. It was hypothesized that improvements in motion detection would result in enhanced flicker perception and word-decoding ability in a reading disabled population of college-aged students. The study included pre-test, training, and post-test phases. Perceptual sensitivity changes were evaluated by comparing pre-test to post-test performances. Here, we show that reading disabled participants who were exposed to near-threshold motion-training improved in sensitivity in all measures. Control participants who were exposed to near-threshold tone changes in lieu of motion showed perceptual sensitivity improvements in tone discrimination but not motion detection, flicker perception, or word decoding. These findings demonstrate that a psychophysical visual learning paradigm may be employed to mediate some effects of reading difficulties. If our future research shows that improved performance on the current tasks generalizes to improve reading ability, we plan to deploy our paradigm as a computer-game-based intervention for reading disabled individuals.
Meeting abstract presented at VSS 2017