Role of the Vermal Cerebellum in Visually Guided Eye Movements and Visual Motion Perception

2019 ◽  
Vol 5 (1) ◽  
pp. 247-268 ◽  
Author(s):  
Peter Thier ◽  
Akshay Markanday

The cerebellar cortex is a crystal-like structure consisting of an almost endless repetition of a canonical microcircuit that applies the same computational principle to different inputs. The output of this transformation is broadcasted to extracerebellar structures by way of the deep cerebellar nuclei. Visually guided eye movements are accommodated by different parts of the cerebellum. This review primarily discusses the role of the oculomotor part of the vermal cerebellum [the oculomotor vermis (OMV)] in the control of visually guided saccades and smooth-pursuit eye movements. Both types of eye movements require the mapping of retinal information onto motor vectors, a transformation that is optimized by the OMV, considering information on past performance. Unlike the role of the OMV in the guidance of eye movements, the contribution of the adjoining vermal cortex to visual motion perception is nonmotor and involves a cerebellar influence on information processing in the cerebral cortex.

1998 ◽  
Vol 80 (4) ◽  
pp. 2046-2062 ◽  
Author(s):  
R. J. Krauzlis ◽  
F. A. Miles

Krauzlis, R. J. and F. A. Miles. Role of the oculomotor vermis in generating pursuit and saccades: effects of microstimulation. J. Neurophysiol. 80: 2046–2062, 1998. We studied the eye movements evoked by applying small amounts of current (2–50 μA) within the oculomotor vermis of two monkeys. We first compared the eye movements evoked by microstimulation applied either during maintained pursuit or during fixation. Smooth, pursuitlike changes in eye velocity caused by the microstimulation were directed toward the ipsilateral side and occurred at short latencies (10–20 ms). The amplitudes of these pursuitlike changes were larger during visually guided pursuit toward the contralateral side than during either fixation or visually guided pursuit toward the ipsilateral side. At these same sites, microstimulation also often produced abrupt, saccadelike changes in eye velocity. In contrast to the smooth changes in eye velocity, these saccadelike effects were more prevalent during fixation and during pursuit toward the ipsilateral side. The amplitude and type of evoked eye movements could also be manipulated at single sites by changing the frequency of microstimulation. Increasing the frequency of microstimulation produced increases in the amplitude of pursuitlike changes, but only up to a certain point. Beyond this point, the value of which depended on the site and whether the monkey was fixating or pursuing, further increases in stimulation frequency produced saccadelike changes of increasing amplitude. To quantify these effects, we introduced a novel method for classifying eye movements as pursuitlike or saccadelike. The results of this analysis showed that the eye movements evoked by microstimulation exhibit a distinct transition point between pursuit and saccadelike effects and that the amplitude of eye movement that corresponds to this transition point depends on the eye movement behavior of the monkey. These results are consistent with accumulating evidence that the oculomotor vermis and its associated deep cerebellar nucleus, the caudal fastigial, are involved in the control of both pursuit and saccadic eye movements. We suggest that the oculomotor vermis might accomplish this role by altering the amplitude of a motor error signal that is common to both saccades and pursuit.


Neuron ◽  
2001 ◽  
Vol 32 (3) ◽  
pp. 527-535 ◽  
Author(s):  
Thomas Haarmeier ◽  
Friedemann Bunjes ◽  
Axel Lindner ◽  
Eva Berret ◽  
Peter Thier

NeuroImage ◽  
1996 ◽  
Vol 3 (3) ◽  
pp. S273
Author(s):  
P. Freitag ◽  
M.W. Greenlee ◽  
T. Lacina ◽  
K. Scheffler ◽  
W. Steinbrich ◽  
...  

Perception ◽  
1994 ◽  
Vol 23 (10) ◽  
pp. 1257-1264 ◽  
Author(s):  
Michael T Swanston

Evidence concerning the origin of the motion aftereffect (MAE) is assessed in terms of a model of levels of representation in visual motion perception proposed by Wade and Swanston. Very few experiments have been designed so as to permit unambiguous conclusions to be drawn. The requirements for such experiments are identified. Whereas retinocentric motion could in principle give rise to the MAE, data are not available which would enable a conclusion to be drawn. There is good evidence for a patterncentric origin, indicating that the MAE is primarily the result of adaptation in the systems responsible for detecting relative visual motion. There is evidence for a further contribution from the process that compensates retinocentric motion for eye movements, in the form of nonveridical information for eye movements. There may also be an effect at the level at which perceived distance and self-movement information are combined with egocentric motion to give a geocentric representation which provides the basis for reports of phenomenal experience. It is concluded that the MAE can be caused by changes in activity at more than one level of representation, and cannot be ascribed to a single underlying process.


2009 ◽  
Vol 102 (6) ◽  
pp. 3156-3168 ◽  
Author(s):  
A. Ignashchenkova ◽  
S. Dash ◽  
P. W. Dicke ◽  
T. Haarmeier ◽  
M. Glickstein ◽  
...  

Lesions of the cerebellum produce deficits in movement and motor learning. Saccadic dysmetria, for example, is caused by lesions of the posterior cerebellar vermis. Monkeys and patients with such lesions are unable to modify the amplitude of saccades. Some have suggested that the effects on eye movements might reflect a more global cognitive deficit caused by the cerebellar lesion. We tested that idea by studying the effects of vermis lesions on attention as well as saccadic eye movements, visual motion perception, and luminance change detection. Lesions in posterior vermis of four monkeys caused the known deficits in saccadic control. Attention tested by examination of acuity threshold changes induced by prior cueing of the location of the targets remained normal after vermis lesions. Luminance change detection was also unaffected by the lesions. In one case, after a lesion restricted to lobulus VIII, the animal had impaired visual motion perception.


2020 ◽  
Author(s):  
Xiuyun Wu ◽  
Austin C. Rothwell ◽  
Miriam Spering ◽  
Anna Montagnini

AbstractSmooth pursuit eye movements and visual motion perception rely on the integration of current sensory signals with past experience. Experience shapes our expectation of current visual events and can drive eye movement responses made in anticipation of a target, such as anticipatory pursuit. Previous research revealed consistent effects of expectation on anticipatory pursuit—eye movements follow the expected target direction or speed—and contrasting effects on motion perception, but most studies considered either eye movement or perceptual responses. The current study directly compared effects of direction expectation on perception and anticipatory pursuit within the same direction discrimination task to investigate whether both types of responses are affected similarly or differently. Observers (n = 10) viewed high-coherence random-dot kinematograms (RDKs) moving rightward and leftward with a probability of 50, 70, or 90% in a given block of trials to build up an expectation of motion direction. They were asked to judge motion direction of interleaved low-coherence RDKs (0-15%). Perceptual judgements were compared to changes in anticipatory pursuit eye movements as a function of probability. Results show that anticipatory pursuit velocity scaled with probability and followed direction expectation (attraction bias), whereas perceptual judgments were biased opposite to direction expectation (repulsion bias). Control experiments suggest that the repulsion bias in perception was not caused by retinal slip induced by anticipatory pursuit, or by motion adaptation. We conclude that direction expectation can be processed differently for perception and anticipatory pursuit.


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