Decomposition of Vergence Dynamics Using Independent Component Analysis

This study investigated the underlying components of vergence responses in binocularly healthy individuals and subjects with convergence insufficiency (CI). Convergent and divergent eye movements were recorded from seven subjects using step stimuli. In addition, four CI subjects participated in six weeks of vision rehabilitation. The goal of this study was to use an independent component analysis (ICA) algorithm to dissect the vergence responses into two underlying components (transient and sustained) for comparison. Preliminary data suggest the healthy controls have greater peak velocity and the magnitude of the transient component was larger compared to patients with CI. After training, the peak velocity and magnitude of the transient component increased for the CI patients and these behaviors were maintained after the training. Data suggest that training modifies the cortical signal responsible for generating the transient component signal and these changes are sustained post rehabilitation.