Visuohaptic convergence in a corticocerebellar network

Abstract

The processing of visual and haptic inputs, occurring either separately or jointly, is crucial for everyday-life object recognition, and has been a focus of recent neuroimaging research. Previously, visuohaptic convergence has been mostly investigated with matching-task paradigms. However, much less is known about visuohaptic convergence in the absence of additional task demands. We conducted two functional magnetic resonance imaging experiments in which subjects actively touched and ⁄ or viewed unfamiliar object stimuli without any additional task demands. In addition, we performed two control experiments with audiovisual and audiohaptic stimulation to examine the specificity of the observed visuohaptic convergence effects. We found robust visuohaptic convergence in bilateral lateral occipital cortex and anterior cerebellum. In contrast, neither the anterior cerebellum nor the lateral occipital cortex showed any involvement in audiovisual or audiohaptic convergence, indicating that multisensory convergence in these regions is specifically geared to visual and haptic inputs. These data suggest that in humans the lateral occipital cortex and the anterior cerebellum play an important role in visuohaptic processing even in the absence of additional task demands.

Resting-state functional connectivity of the vermal and hemispheric subregions of the cerebellum with both the cerebral cortical networks and subcortical structures

“…In these loops, visual or auditory information can reach the cerebellum through the pontine nuclei and return through the thalamus. The involvement of the cerebellum in the processing of visual and auditory information has been revealed in a plethora of previous neuroimaging studies (Baumann and Mattingley, 2010;Pastor et al, 2008;Petacchi et al, 2005), which suggests that the cerebellum plays a role in the integration of multi-modal sensory information (Gentile et al, 2011;Naumer et al, 2010) and sensorimotor information (Baumann and Greenlee, 2007;Bengtsson et al, 2009;Hagura et al, 2009). Such integration in the cerebellum is reflected in the finding that some cerebellar subregions (such as hemispheric VI) displayed strong rsFC with the visual-, auditory-, somatosensory-, and motor-related cerebral cortices.…”

The left fusiform gyrus hosts trisensory representations of manipulable objects

“…A direct comparison of conditions with versus without haptic exploration suffers from a confounding effect of motor activity which is present during the former but not the latter (Naumer et al, 2010). We dealt with this confound by contrasting conditions with versus without haptic exploration only in conjunction with other contrasts where no haptic exploration was involved.…”

Are visual texture-selective areas recruited during haptic texture discrimination?

“…Interestingly, there is accumulating evidence from fMRI that laterally-located 'visual' shape-selective areas are also invoked during haptic shape processing (Allen and Humphreys, 2009;Grefkes et al, 2002;James et al, 2002;Naumer et al, 2010;Pietrini et al, 2004;Stilla and Sathian, 2008;Tal and Amedi, 2009;Zhang et al, 2004). Most notably, Amedi and colleagues demonstrated that a sub-region of the LOC, which they termed the lateral occipital tactile-visual area (LOtv), was activated both when participants palpated objects with different shapes and when they viewed the different objects.…”

“…Examinations of haptic perception have found that visually shape-selective regions of the ventral stream (LOC) are also activated when participants investigate object shape via touch Allen and Humphreys, 2009;Grefkes et al, 2002;James et al, 2002;Naumer et al, 2010;Pietrini et al, 2004;Stilla and Sathian, 2008;Tal and Amedi, 2009;Zhang et al, 2004). Importantly, asked participants both to palpate a number of objects and view images of the same objects while inside the fMRI scanner.…”