Journals of Gerontology Series B: Psychological Sciences and Social Sciences, Vol 52, Issue 2 P103-P107, Copyright © 1997 by The Gerontological Society of America
Initiation and inhibition of saccadic eye movements in younger and older adults: an analysis of the gap effect
J Pratt, RA Abrams and AL Chasteen
Department of Psychology, University of Toronto. pratt@psych.utoronto.ca
Previous research with young adults has shown that the latency to initiate
a saccadic eye movement is typically reduced when the visual fixation
stimulus is removed prior to the appearance of a peripheral target stimulus
(the "gap effect"). The present study sought to determine whether such
fixation offsets would produce similar reductions in reaction time in both
younger and older adults. The results indicated that older adults have
longer overall latencies to initiate saccadic eye movements and that they
exhibit the gap effect. However, the reduction in reaction time due to the
fixation offset was approximately equal between younger and older adults
relative to the overall saccadic latencies. These findings, along with some
other recent evidence, suggest that some of the mechanisms involved in the
production of saccadic eye movements may not reveal the changes often found
in the skeletal motor system with increasing age. The implications of the
findings to age-related differences in inhibitory function are discussed.
