Adaptations in visual and proprioceptive processing following long-term visual deprivation

Abstract

Visual deprivation has been shown to stimulate cortical plasticity in auditory and tactile processing but little is known about changes relative to movement. Based on our previous work, significant modulation of cerebral blood flow and motor behaviour were evident following 2-hour visual deprivation; here we extend these findings to neural (i.e. EEG) and behavioural changes following 8-hour visual deprivation. Subjects completed both control (8-hours full vision) and experimental (8-hours no vision) days. Pre- and post- 8-hour bouts, subjects performed a behavioural reaching and grasping task, followed by an oddball detection task. Behavioural: 80 trials to a circular target, using proprioceptive control (No-Vision) the first 40 trials, and visual control (Vision) for the last 40 trials. The subject's arm was passively moved to and from the target prior to each trial. Oddball: In separate tasks, SSEPs and VEPs were recorded in response to vibro-tactile and visual stimuli respectively (probability: 0.8 non-target, 0.2 target). Kinematic results, coupled with our previous findings, indicate early and late adaptation of behaviour in response to acute vision loss. While differences in ERP latencies consistent with the oddball task were observed, significant differences pre- and post-deprivation were not. Differences in ERP amplitude were seen only in the N2 response to vibrotactile stimulation, as a function of experimental day and pre- post-condition.

Acknowledgments: CFI, NSERC