The saccadic eye movements in infant monkey.

Previous studies showed that the static and dynamic characteristics of eye movements between cat and kitten are different. The aim of this research is to study the effects of maturation, if there are any effects, on spatio-temporal characteristics of eye movements in the monkey. The experiments were carried out on one infant monkey (aged 80-90 days) and three adult monkey (Macaca nemestrina). Eye movements were detected by means of a magnetic field technique, in the dark and in the light. For painless fixation of the head Evart's technique was employed in adult monkeys while in the infant monkey a soft cup fixed to a suitable chair was used. The behavioural state was monitored by EEG and EMG. Eye movements were analised off-line by a PDP 11/73. Preliminary results show that the spatio-temporal pattern is prevalently vertical or slightly oblique in the infant monkey; on the contrary it is prevalently horizontal or oblique in the adults. Furthermore, the amplitudes of the saccades are smaller and the peak velocities are slower in the infant than in the adults. We may then argue that maturative processes act on ocular motility