HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Yasui, S Articles by Young, L R Search for Related Content PubMed PubMed Citation Articles by Yasui, S Articles by Young, L R

Smooth pursuit and saccadic components of foveal visual tracking as well as more involuntary ocular movements of optokinetic (o.k.n.) and vestibular nystagmus slow phase components were investigated in man, with particular attention given to their possible input-adaptive or predictive behaviour. Each component in question was isolated from the eye movement records through a computer-aided procedure. The frequency response method was used with sinusoidal (predictable) and pseudo-random (unpredictable) stimuli. When the target motion was pseudo-random, the frequency response of pursuit eye movements revealed a large phase lead (up to about 90 degrees) at low stimulus frequencies. It is possible to interpret this result as a predictive effect, even though the stimulation was pseudo-random and thus 'unpredictable'. The pseudo-random-input frequency response intrinsic to the saccadic system was estimated in an indirect way from the pursuit and composite (pursuit + saccade) frequency response data. The result was fitted well by a servo-mechanism model, which has a simple anticipatory mechanism to compensate for the inherent neuromuscular saccadic delay by utilizing the retinal slip velocity signal. The o.k.n. slow phase also exhibited a predictive effect with sinusoidal inputs; however, pseudo-random stimuli did not produce such phase lead as found in the pursuit case. The vestibular nystagmus slow phase showed no noticeable sign of prediction in the frequency range examined (0 approximately 0.7 Hz), in contrast to the results of the visually driven eye movements (i.e. saccade, pursuit and o.k.n. slow phase) at comparable stimulus frequencies.

This article has been cited by other articles:

				D. Gagnon, T. Paus, M.-H. Grosbras, G. B. Pike, and G. A. O'Driscoll Transcranial Magnetic Stimulation of Frontal Oculomotor Regions during Smooth Pursuit J. Neurosci., January 11, 2006; 26(2): 458 - 466. [Abstract] [Full Text] [PDF]

				M. Suh, H.-C. Leung, and R. E. Kettner Cerebellar Flocculus and Ventral Paraflocculus Purkinje Cell Activity During Predictive and Visually Driven Pursuit in Monkey J Neurophysiol, October 1, 2000; 84(4): 1835 - 1850. [Abstract] [Full Text] [PDF]

				R. E. Kettner, S. Mahamud, H.-C. Leung, N. Sitkoff, J. C. Houk, B. W. Peterson, and A. G. Barto Prediction of Complex Two-Dimensional Trajectories by a Cerebellar Model of Smooth Pursuit Eye Movement J Neurophysiol, April 1, 1997; 77(4): 2115 - 2130. [Abstract] [Full Text] [PDF]