Cerebellar Contributions to the Processing of Saccadic Errors

Department of Neuroscience, Erasmus MC, Rotterdam 3000 CA, The Netherlands.
The Cerebellum (Impact Factor: 2.72). 06/2009; 8(3):403-15. DOI: 10.1007/s12311-009-0116-6
Source: PubMed


Saccades are fast eye movements that direct the point of regard to a target in the visual field. Repeated post-saccadic visual errors can induce modifications of the amplitude of these saccades, a process known as saccadic adaptation. Two experiments using the same paradigm were performed to study the involvement of the cerebrum and the cerebellum in the processing of saccadic errors using functional magnetic resonance imaging and in-scanner eye movement recordings. In the first active condition, saccadic adaptation was prevented using a condition in which the saccadic target was shifted to a variable position during the saccade towards it. This condition induced random saccadic errors as opposed to the second active condition in which the saccadic target was not shifted. In the baseline condition, subjects looked at a stationary dot. Both active conditions compared with baseline evoked activation in the expected saccade-related regions using a stringent statistical threshold [the frontal and parietal eye fields, primary visual area, MT/V5, and the precuneus (V6) in the cerebrum; vermis VI-VII; and lobule VI in the cerebellum, known as the oculomotor vermis). In the direct comparison between the two active conditions, significantly more cerebellar activation (vermis VIII, lobules VIII-X, left lobule VIIb) was observed with random saccadic errors (using a more relaxed statistical threshold). These results suggest a possible role for areas outside the oculomotor vermis of the cerebellum in the processing of saccadic errors. Future studies of these areas with, e.g., electrophysiological recordings, may reveal the nature of the error signals that drive the amplitude modification of saccadic eye movements.

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    • "† 7 Reflexive saccades > fixation Simó et al., 2005 [6]* 10 Reflexive saccades > fixation Nelles et al., 2007 [38] 10 Reflexive saccades > fixation de Haan et al., 2008 [39] 10 Reflexive saccades > fixation Ettinger et al., 2008 [40] 36 Reflexive saccades > fixation Haller et al., 2008 [41] 14 Reflexive saccades > fixation Ettinger et al., 2009 [42] 24 Reflexive saccades > fixation Nelles et al., 2009 [43] 11 Reflexive saccades > fixation Petit et al., 2009 [44] 27 Reflexive saccades > fixation Schraa-Tam et al., 2009 [21] 18 Reflexive saccades > fixation van Broekhoven et al., 2009 [45] 17 Reflexive saccades > fixation Krebs et al., 2010 [46]* 16 Reflexive saccades > fixation Grosbras et al., 2001 [47]* 9 Memory-guided saccades > fixation Matsuda et al., 2004 [5] 21 Antisaccades > fixation Sugiura et al., 2004 [48] 19 Memory-guided saccades > fixation Camchong et al., 2006 [49] 14 Memory-guided saccades > fixation Tu et al., 2006 [50]* 10 Antisaccades > fixation Ettinger et al., 2008 [51] 17 Antisaccades > fixation Fukumoto-Motoshita et al., 2009 [52] 18 Antisaccades > fixation Camchong et al., 2008 [3] 15 Antisaccades + memory-guided saccades > fixation DeSouza et al., 2003 [53] ‡ 10 Antisaccades + reflexive saccades > fixation performed and for each voxel, the beta coefficient was obtained for the stimulus timing as convolved with the hemodynamic response. The anatomical and functional images were warped to Talairach space. "
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    ABSTRACT: Saccades are rapid eye movements that move the eyes to a location of interest. Regions within posterior parietal cortex (PPC) have consistently shown activation in brain imaging studies of saccades, ostensibly reflecting shifts of visual attention and the transformation of sensory input into motor commands. Saccades range from the most basic reflexive glances toward a target to more complex saccades, which require some form of cognitive control (such as working memory or inhibition of reflexive responses). This study sought to summarize and parse the relative contribution of various brain regions (and parietal regions in particular) to reflexive and complex saccades. We conducted an activation likelihood estimation (ALE) meta-analysis of functional MRI studies of saccades in healthy adult humans. Twenty-two studies were identified that met our criteria. These studies provided 338 participants and 375 foci for the meta-analysis, which was conducted using the GingerALE application from BrainMap. Separate analyses were conducted for all saccades, reflexive saccades only, and complex saccades only. In addition, a subtraction analysis was done to determine significant differences in activation probability between reflexive and complex saccades. No part of this digital document may be reproduced, stored in a retrieval system or transmitted commercially in any form or by any means. The publisher has taken reasonable care in the preparation of this digital document, but makes no expressed or implied warranty of any kind and assumes no responsibility for any errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of information contained herein. This digital document is sold with the clear understanding that the publisher is not engaged in rendering legal, medical or any other professional services.
    Full-text · Chapter · Jul 2012
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    • "Several studies support that the parietal lobe modulates its activity for saccadic [25], [26], [27] and disparity (the input to vergence) [28], [29] stimulation. The cerebellum has also been implicated in error processing for motor learning for both saccadic [30], [31], [32] and vergence [33], [34], [35] movements. "
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    ABSTRACT: Eye movement research has traditionally studied solely saccade and/or vergence eye movements by isolating these systems within a laboratory setting. While the neural correlates of saccadic eye movements are established, few studies have quantified the functional activity of vergence eye movements using fMRI. This study mapped the neural substrates of vergence eye movements and compared them to saccades to elucidate the spatial commonality and differentiation between these systems. The stimulus was presented in a block design where the 'off' stimulus was a sustained fixation and the 'on' stimulus was random vergence or saccadic eye movements. Data were collected with a 3T scanner. A general linear model (GLM) was used in conjunction with cluster size to determine significantly active regions. A paired t-test of the GLM beta weight coefficients was computed between the saccade and vergence functional activities to test the hypothesis that vergence and saccadic stimulation would have spatial differentiation in addition to shared neural substrates. Segregated functional activation was observed within the frontal eye fields where a portion of the functional activity from the vergence task was located anterior to the saccadic functional activity (z>2.3; p<0.03). An area within the midbrain was significantly correlated with the experimental design for the vergence but not the saccade data set. Similar functional activation was observed within the following regions of interest: the supplementary eye field, dorsolateral prefrontal cortex, ventral lateral prefrontal cortex, lateral intraparietal area, cuneus, precuneus, anterior and posterior cingulates, and cerebellar vermis. The functional activity from these regions was not different between the vergence and saccade data sets assessed by analyzing the beta weights of the paired t-test (p>0.2). Functional MRI can elucidate the differences between the vergence and saccade neural substrates within the frontal eye fields and midbrain.
    Full-text · Article · Nov 2011 · PLoS ONE
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    • "Recent studies have also implicated the cerebellar hemispheres in ocular motor learning. For example, fMRI studies show that the hemispheric lobules VIII–X are active in processing of saccadic errors (van Broekhoven et al., 2009), and TMS over the hemispheric lobule Crus I has a dual effect on saccadic plasticity; potentiating adaptive lengthening and depressing adaptive shortening of saccade amplitudes (Panouilleres et al., 2011). There is also evidence for involvement of the cerebellar hemispheres in adaptation for more voluntary, internally generated saccades such as memory-guided saccades, as opposed to the OMV involvement in more reflexive, visually guided saccades (Nitschke et al., 2004; Alahyane et al., 2008; Kojima et al., 2010b). "
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    ABSTRACT: An intact cerebellum is a prerequisite for optimal ocular motor performance. The cerebellum fine-tunes each of the subtypes of eye movements so they work together to bring and maintain images of objects of interest on the fovea. Here we review the major aspects of the contribution of the cerebellum to ocular motor control. The approach will be based on structural-functional correlation, combining the effects of lesions and the results from physiologic studies, with the emphasis on the cerebellar regions known to be most closely related to ocular motor function: (1) the flocculus/paraflocculus for high-frequency (brief) vestibular responses, sustained pursuit eye movements, and gaze holding, (2) the nodulus/ventral uvula for low-frequency (sustained) vestibular responses, and (3) the dorsal oculomotor vermis and its target in the posterior portion of the fastigial nucleus (the fastigial oculomotor region) for saccades and pursuit initiation.
    Full-text · Article · Sep 2011 · Frontiers in Neurology
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