The Saccadic Component of Ocular Pursuit is Influenced by the Predictability of the Target Motion in Humans

Predictive control is an important aspect of the smooth pursuit eye movements: it has been shown that when the target motion is composed of a mixture of sinusoids of different frequencies it becomes unpredictable and there is a decline in gain for the lowest frequencies but not for the highest one. Using such a pseudo-random paradigm we studied the effect of predictability of the target motion on the saccadic component of pursuit. For both the saccadic and the smooth components of pursuit, we observed that the gains for the lowest frequencies were significantly lower than the gain for the highest frequency. Thus, predictability of the motion of a visual target seems to influence both the smooth pursuit component and the saccadic component of ocular pursuit in the same way.