Abstract
Introducing a temporal gap between extinction of fixation point (FP) and occurrence of a visual target (T) is known to reduce the reaction time (RT) of saccades performed from FP to T. In this ‘gap paradigm’, as it is called, the frequency distribution of saccadic RTs is typically bimodal with an early peak of very short latency saccades (express sac-cades, ES) and a second peak of regular saccades (Fischer and Boch 1983). There are considerable inter-individual differences. A large proportion of ES has been taken to indicate a weak fixation system which normally inhibits the generation of reflexive saccades, a finding in a subpopulation of dyslexic children (Biscaldi et al. 1996). Moreover, repeated practice of this paradigm may increase the percentage of ES in some normal subjects. Also, target eccentricity plays a role (ES are missing with eccentricities <1°;Weber et al. 1992). Finally, the phenomenon depends on gap duration; for instance, if FP extinction coincides with T appearance (‘simultaneous paradigm’) ES become rare and the RT distribution becomes unimodal.
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References
Biscaldi M, Fischer B, Stuhr V (1996) Human express saccade makers are impaired at suppressing visually evoked saccades. J Neurophysiol 76: 199–214
Cavegn D, Biscaldi M (1996) Fixation and saccade control in an express-saccade maker. Exp Brain Res 109(1):101–116.
Fischer B, Boch R (1983) Saccadic eye movements after extremely short reaction times in the monkey. Brain Res 260:21–26.
Krauzlis RJ, Miles FA (1996a) Decreases in the latency of smooth pursuit and saccadic eye movements produced by the “gap paradigm” in the monkey. Vision Res 36(13): 1973–85.
Krauzlis RJ, Miles FA (1996b) Release of fixation for pursuit and saccades in humans: evidence for shared inputs acting on different neural substrates. J Neurophysiol 76(5):2822–33.
Mayfrank L, Mobashery M, Kimmig H, Fischer B (1986) The role of fixation and visual attention in the occurrence of express saccades in man. Eur Arch Psychiatr Neurol Sci 235: 269–275.
Merrison AF, Carpenter RH (1995) “Express” smooth pursuit. Vision Res 35(10): 1459–62.
Weber H, Aiple F, Fischer B, Latanov A (1992) Dead zone for express saccades. Exp Brain Res 89:214–222.
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© 1999 Springer Science+Business Media New York
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Kimmig, H., Mutter, J., Biscaldi, M., Fischer, B., Mergner, T. (1999). Reaction Times of Smooth Pursuit Initiation in Normal Subjects and in “Express-Saccade Makers”. In: Becker, W., Deubel, H., Mergner, T. (eds) Current Oculomotor Research. Springer, Boston, MA. https://doi.org/10.1007/978-1-4757-3054-8_18
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DOI: https://doi.org/10.1007/978-1-4757-3054-8_18
Publisher Name: Springer, Boston, MA
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