Perceptual processing time differences owing to visual field asymmetries.

Recent experiments have reported increased endpoint accuracy for movements performed in the lower vs. the upper visual field, suggesting that there is superior feedback-based processing in the lower visual field owing to a visuomotor subsystem processing advantage. Differences, however, in the perceptual subsystem may also play a role in the lower visual field advantage. In this study, participants performed an inspection time task, a measure of perceptual processing time, requiring the identification of an asymmetrical 'pi' stimulus presented in the central, upper, or the lower visual field for a brief period. Significant differences between the percentage of correct identifications between visual fields indicated a lower visual field advantage over upper visual field for perceptual identification.