Smooth pursuit eye movements allow us to maintain the image of a moving target on the fovea. Smooth pursuit consists of separate phases such as initiation and steady-state. These two phases are supported by different visual-motor mechanisms in cortical areas including the middle temporal (MT), the medial superior temporal (MST) areas and the frontal eye field (FEF). Retinal motion signals are r...

We compared horizontal and vertical smooth pursuit eye movements in five healthy human subjects. When maintenance of pursuit was tested using predictable waveforms (sinusoidal or triangular target motion), the gain of horizontal pursuit was greater, in all subjects, than that of vertical pursuit; this was also the case for the horizontal and vertical components of diagonal and circular tracking...

The ability to predict upcoming events is important to compensate for relatively long sensory-motor delays. When stimuli are temporally regular, their prediction depends on a representation of elapsed time. However, it is well known that the allocation of attention to the timing of an upcoming event alters this representation. The role of attention on the temporal processing component of predic...

For the majority of human smooth pursuit eye movements made to a horizontal ramp target of unpredictable direction, the reciprocal of the latency appears to have a Gaussian distribution of the same general form as for saccades to step targets, but with smaller median. There are more latencies shorter than some 100 msec than would be expected from such a distribution: they form a distinct popula...

It has been demonstrated in normal subjects that smooth pursuit latency is reduced in gap pursuit tasks. We have now measured smooth pursuit latency in a group of schizophrenic subjects in both gap and non-gap conditions. In non-gap tasks pursuit latency was longer in the schizophrenic subjects than in controls. While the addition of gaps produced reductions in pursuit latency in the schizophre...

Smooth pursuit eye movements have been linked to perception by a common attentional mechanism. We investigated whether perceptual performance was traded for smooth pursuit performance. While tracking a red target cross, observers had to discriminate the orientation of a flashed peripheral grating. Wemanipulated the priority given to the two tasks. Pursuit gain changed according to observers’ ef...

Citation: Ke SR, Lam J, Pai DK, Spering M. Directional asymmetries in human smooth pursuit eye movements. Invest Ophthalmol Vis Sci. 2013;54:4409–4421. DOI:10.1167/iovs.12-11369 PURPOSE. Humans make smooth pursuit eye movements to bring the image of a moving object onto the fovea. Although pursuit accuracy is critical to prevent motion blur, the eye often falls behind the target. Previous studi...

Smooth pursuit eye movements (SPEM) has been reported to be abnormal in schizophrenic patients. 30 schizophrenic patients and 15 normal subjects were examined for the quality of their smooth pursuit performance. 73.33% of the schizophrenics and 40% of the normal subjects had 'impaired' pursuit performance. The significance of the findings has been discussed.

The smooth pursuit eye movement system incorporates various control features enabling adaptation to specific tracking situations. In this work, we analyzed the interplay between two of these mechanisms: gain control and predictive pursuit. We tested human responses to high-frequency perturbations during step-ramp pursuit, as well as the pursuit of a periodically moving target. For the latter ta...

The smooth pursuit system is traditionally employed using a single small target moving on a homogeneous background. It still is not fully understood, however, how accurate tracking is sustained in the presence of a structured background, which will activate global motion processing in the opposite direction as a consequence of the ongoing eye movement. To further study this interaction, we used...