Characteristics of smooth eye movements with stabilized targets

Eye movements of two subjects were recorded with a Double Purkinje Image Tracker while they pursued horizontal triangle or ramp stimuli (1, 2, 4 or 8 degrees/sec, p--p 8 degrees). Subjects then attempted to imitate their smooth pursuit eye movement patterns with an electronically-stabilized target or with an afterimage. Next, they attempted to reset the velocity of the stimulus to their memory of the velocity they had previously pursued. The smooth pursuit eye movements of both subjects were very similar. Their attempts to imitate this pattern of eye movements with a stabilized target were only partially successful and subject to large, qualitative individual differences. These differences did not arise from faulty memories of the nature of the pursuit stimuli. Similar results were obtained on the vertical meridian, with a lighted background, and with the stabilized target in eccentric retinal positions. We conclude that stabilization techniques are of dubious value in elucidating properties of the human smooth pursuit subsystem.

[1]  Eileen Kowler,et al.  The effect of expectations on slow oculomotor control—I. Periodic target steps , 1979, Vision Research.

[2]  E. P. Tamminga.  Human fixation and voluntary pursuit: the interaction between central and peripheral motion stimuli. , 1983 .

[3]  Eileen Kowler,et al.  The effect of expectations on slow oculomotor control—II. Single target displacements , 1979, Vision Research.

[4]  Robert M. Steinman,et al.  Velocity matching during smooth pursuit of different targets on different backgrounds , 1978, Vision Research.

[5]  H D Crane,et al.  Accurate two-dimensional eye tracker using first and fourth Purkinje images. , 1973, Journal of the Optical Society of America.

[6]  R M Steinman,et al.  Tracking eye movements with and without saccadic correction. , 1969, Vision research.

[7]  S. Heywood,et al.  Voluntary Control of Smooth Eye Movements and their Velocity , 1972, Nature.

[8]  Brian J. Murphy,et al.  Simple forms and fluctuations of the line of sight: Implications for motor theories of form processing , 1974 .

[9]  J T DOESSCHATE,et al.  A new form of physiological nystagmus. , 1954, Ophthalmologica. Journal international d'ophtalmologie. International journal of ophthalmology. Zeitschrift fur Augenheilkunde.

[10]  D H Kelly,et al.  Disappearance of stabilized chromatic gratings. , 1981, Science.

[11]  Arien Mack,et al.  Perceived movement of the afterimage during eye movements , 1969 .

[12]  Eileen Kowler,et al.  The effect of expectations on slow oculomotor control—III. Guessing unpredictable target displacements , 1981, Vision Research.

[13]  Eileen Kowler,et al.  The effect of expectations on slow oculomotor control—IV. Anticipatory smooth eye movements depend on prior target motions , 1984, Vision Research.

[14]  H. Collewijn,et al.  Human smooth and saccadic eye movements during voluntary pursuit of different target motions on different backgrounds. , 1984, The Journal of physiology.