The parallel programming of voluntary and reflexive saccades.
A novel two-step paradigm was used to investigate the parallel programming of consecutive, stimulus-elicited ('reflexive') and endogenous ('voluntary') saccades. The mean latency of voluntary saccades, made following the first reflexive saccades in two-step conditions, was significantly reduced compared to that of voluntary saccades made in the single-step control trials. The latency of the first reflexive saccades was modulated by the requirement to make a second saccade: first saccade latency increased when a second voluntary saccade was required in the opposite direction to the first saccade, and decreased when a second saccade was required in the same direction as the first reflexive saccade. A second experiment confirmed the basic effect and also showed that a second reflexive saccade may be programmed in parallel with a first voluntary saccade. The results support the view that voluntary and reflexive saccades can be programmed in parallel on a common motor map.
Department of Psychology, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK. robin.walker@rhul.ac.uk
Robin
R
Walker
Eugene
E
McSorley
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D011601:Psychophysics; D012018:Reflex / Q000502:physiology*; D012438:Saccades / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*