Individual differences in the visual component of prism adaptation.

The centrality of individual differences in the visual component of perceptual adaptation was examined in a massed-practice-terminal-exposure, prism-viewing paradigm. With positive (adaptive) adjustments in the judgment of the visual straight-ahead, target-pointing aftereffects were found to be equivalent to the sum of the visual and proprioceptive (head-arm) aftereffects. For subjects showing negative visual adjustments to prism exposure, the target-pointing aftereffect was not significantly different from the change in proprioception alone. Implications of these findings for hypotheses concerning the process of perceptual adaptation are discussed.