Scaling of Neural Responses to Visual and Auditory Motion in the Human Cerebellum

Abstract

The human cerebellum contains approximately half of all the neurons within the cerebrum, yet most experimental work in human neuroscience over the last century has focused exclusively on the structure and functions of the forebrain. The cerebellum has an undisputed role in a range of motor functions (Thach et al., 1992), but its potential contributions to sensory and cognitive processes are widely debated (Stoodley and Schmahmann, 2009). Here we used functional magnetic resonance imaging to test the hypothesis that the human cerebellum is involved in the acquisition of auditory and visual sensory data. We monitored neural activity within the cerebellum while participants engaged in a task that required them to discriminate the direction of a visual or auditory motion signal in noise. We identified a distinct set of cerebellar regions that were differentially activated for visual stimuli (vermal lobule VI and right-hemispheric lobule X) and auditory stimuli (right-hemispheric lobules VIIIA and VIIIB and hemispheric lobule VI bilaterally). In addition, we identified a region in left crus I in which activity correlated significantly with increases in the perceptual demands of the task (i.e., with decreasing signal strength), for both auditory and visual stimuli. Our results support suggestions of a role for the cerebellum in the processing of auditory and visual motion and suggest that parts of cerebellar cortex are concerned with tracking movements of objects around the animal, rather than with controlling movements of the animal itself (Paulin, 1993).

Inferior Olive Response to Passive Tactile and Visual Stimulation with Variable Interstimulus Intervals

“…Tactile stimulation also activated the inferior olive (Table 1). Visual stimulation activated multiple areas in the cerebellar cortex in agreement with previous studies [28]. …”

Effects of Attention and Perceptual Uncertainty on Cerebellar Activity During Visual Motion Perception

“…By contrast, attention to motion under high levels of perceptual uncertainty led to increased activity in two left hemispheric regions located in cerebellar lobule VI and Crus I, as well as lobule VIIB and Crus II. Our results therefore support the notion that the cerebellum facilitates the detection and discrimination of moving objects under conditions of high perceptual uncertainty [4,9], but are inconsistent with the idea that the cerebellum is crucial for sustained attentive tracking of salient motion stimuli [10][11][12][13].…”

“…It is important to emphasize that the cerebellar regions identified in our study are likely to be involved in perceptual functions beyond the visual modality, since activity in these regions has also been found during auditory tasks [9,32,37]. As with vision, the cerebellum is particularly active in auditory tasks that are perceptually complex or demanding.…”

“…covert motion tracking) [10][11][12][13] or in supporting the detection and discrimination of sensory signals in perceptually demanding situations [4,9,31,32].…”

Computational Structure of the Cerebellar Molecular Layer

“…Put another way, the cerebellum may be more "motor for sensory sake," than "sensory for motors sake" . Evidence consistent with such a role has now been obtained from human subjects performing tactile (Gao et al 1996), olfactory (Sobel et al 1998), visual (Baumann and Mattingley 2010;Shih et al 2009Shih et al , 2010, and auditory (Petacchi et al 2005(Petacchi et al , 2011 sensory discriminations.…”