Modelling of congenital nystagmus waveforms produced by saccadic system abnormalities

Abstract. Models of the mechanisms of normal eye movements are typically described in terms of the block diagrams which are used in control theory. An alternative approach to understanding the mechanisms of normal eye movements involves describing the eye movement behaviour in terms of smooth changes in state variables. The latter approach captures the burst cell firing against motor error (difference between target gaze angle and current gaze angle) phase plane behaviour which is found experimentally and facilitates the modelling of variations in burst cell behaviour. A novel explanation of several types of congenital nystagmus waveforms is given in terms of a saccadic termination abnormality.

[1]  L. Stark,et al.  The main sequence, a tool for studying human eye movements , 1975 .

[2]  E. C. Zeeman,et al.  Differential equations for the heartbeat and nerve impulse , 1973 .

[3]  Shihab A. Shamma.  Spatial and temporal processing in central auditory networks , 1989 .

[4]  R. A. Clement,et al.  Dynamical systems analysis: a new method of analysing congenital nystagmus waveforms , 1997, Experimental Brain Research.

[5]  R. Tusa,et al.  Voluntary control of congenital nystagmus , 1992 .

[6]  L. Glass,et al.  PATHOLOGICAL CONDITIONS RESULTING FROM INSTABILITIES IN PHYSIOLOGICAL CONTROL SYSTEMS * , 1979, Annals of the New York Academy of Sciences.

[7]  C. Scudder.  A new local feedback model of the saccadic burst generator. , 1988, Journal of neurophysiology.

[8]  Richard V Abadi,et al.  Retinal slip velocities in congenital nystagmus , 1989, Vision Research.

[9]  L. Optican,et al.  Slow saccades in spinocerebellar degeneration. , 1976, Archives of neurology.

[10]  Ralph Worfolk,et al.  Quick phase programming and saccadic re-orientation in congenital nystagmus , 1991, Vision Research.

[11]  L. Osso.  CONGENITAL NYSTAGMUS WAVEFORMS AND FOVEATION STRATEGY , 1975 .

[12]  L. Glass,et al.  Understanding Nonlinear Dynamics , 1995 .

[13]  J. Gnadt,et al.  Analysis of the step response of the saccadic feedback: computational models , 1997, Experimental Brain Research.

[14]  D S Zee,et al.  Microsaccadic flutter. , 1991, Brain : a journal of neurology.

[15]  S. Gielen,et al.  A quantitative analysis of generation of saccadic eye movements by burst neurons. , 1981, Journal of neurophysiology.

[16]  C. Harris.  Problems in modelling congenital nystagmus: Towards a new model , 1995 .

[17]  J. J. Eggermont,et al.  Reconstruction of neural control signals for saccades based on an inverse method , 1985, Vision Research.

[18]  Michael A. Arbib,et al.  Colliding saccades evoked by frontal eye field stimulation: artifact or evidence for an oculomotor compensatory mechanism underlying double-step saccades? , 1997, Biological Cybernetics.

[19]  D. Robinson.  The mechanics of human saccadic eye movement , 1964, The Journal of physiology.