Lateral saccadic latencies and handedness.

Lateral saccadic latencies were determined in 18 right-handers and 18 left-handers. Within the right-handed group the mean latency was significantly shorter when looking from the left to the right (242.7 msec) than from right to left (265.0 msec), whereas no significant directional difference was found in the left-handed group. An age effect was also found with longer latencies being associated with increased age. These findings agree with those of Pirozzolo and Rayner (Neuropsychologia 18, 225-229, 1980) and provide further evidence of the pervasiveness of functional asymmetry in the human brain. The present findings suggest that motoric or central integrative mechanisms may contribute more to saccadic directional asymmetries than do perceptual differences.