Changes in the presaccadic spike potential with age.

Presaccadic spike potentials were recorded from an electrode below the eye to 20 degrees horizontal saccades in 2 groups of 10 subjects; a young group with a mean age of 26 years and an old group with a mean age of 77 years. The onset and peak latencies, relative to the beginning of the eye movement, and the onset-peak amplitudes were measured for abduction and adduction movements separately. There was no significant difference in the onset or peak latencies of the 2 groups with either abduction or adduction. The amplitude, however, was significantly greater in the young group with both abduction (P less than 0.01) and adduction (P less than 0.025). Possible explanations of these results are given and the implications of the findings on the investigation of presaccadic spike potentials in both normal and pathological subject groups are discussed.