Cerebellar Contributions to the Processing of Saccadic Errors

Abstract

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.

A cerebellar role in performance monitoring – Evidence from EEG and voxel-based morphometry in patients with cerebellar degenerative disease

“…Overall, the present findings are consistent with the notion that performance monitoring is altered in patients with cerebellar damage (Brunamonti et al, 2014), and support a critical role of the cerebellum for fast classification of saccadic accuracy (Peterburs et al, 2012;van Broekhoven et al, 2009). Interestingly, in the previous study (Peterburs et al, 2012) patients with post-acute focal vascular lesions of the cerebellum showed altered patterns of neural responses, i.e.…”

“…Such a deflection, termed "correct-related negativity" (CRN) (Coles et al, 2001;Falkenstein et al, 2000;Luu et al, 2000;Vidal et al, 2000), has been associated with processes of (response) conflict evaluation (Yeung et al, 2004;Yeung and Cohen, 2006;Suchan et al, 2007) and cognitive control (Grützmann et al, 2014). The observed pattern of results in the present study resembles previous findings in focal cerebellar lesion patients (Peterburs et al, 2012), and suggests that the cerebellum is not only involved in (saccadic) error processing (van Broekhoven et al, 2009) but in performance monitoring in general, as also implicated by recent findings of impaired performance of a stop signal task in cerebellar lesion patients (Brunamonti et al, 2014). There was no correlation between ERN amplitude and error rates.…”

“…Despite a growing body of evidence for a functional topography within the cerebellum, linking cognitive functions to more posterior and motor-related processing to anterior regions (Stoodley and Schmahmann, 2009), most previous studies (Peterburs et al, 2012;van Broekhoven et al 2009;Peterburs et al, 2013aPeterburs et al, , 2013b have failed to show evidence for a role of specific cerebellar subregions for saccadic performance monitoring, although recent findings show more severe deficits when lesions affected the deep nuclei (Brunamonti et al, 2014). By applying VBM, the present study attempted to further elucidate the association between specific cerebellar subregions and performance monitoring.…”

“…Reduced ERN and increased error rates were hypothesized to be particularly linked to volume reduction in posterolateral cerebellar regions (Crus I and II) which have previously been shown to be involved in cognitive (Stoodley and Schmahmann, 2009) and specifically executive functions (E et al, 2014), and in cerebellar lobules VIII-X which have previously been implicated in the processing of saccadic errors (van Broekhoven et al, 2009). …”

An Electrophysiological Study of Visual Processing in Spinocerebellar Ataxia Type 2 (SCA2)

“…The entry visual information is conveyed by the magnocellular pathway for low contrast and low spatial frequencies of stimuli [10], and the N2 peak of M-VEPs is related to the activation of the parietal and mediotemporal areas [11]. These areas, connected to the frontal eye fields that receive input from cerebellum [12], are important for smooth pursuit [13] and saccadic eye movements [14] that are often impaired in SCA2 [2].…”