Neural mechanisms underlying touch-induced visual perceptual suppression: An fMRI study

Abstract

Crossmodal studies have demonstrated inhibitory as well as facilitatory neural effects in higher sensory association and primary sensory cortices. A recent human behavioral study reported touch-induced visual perceptual suppression (TIVS). Here, we introduced an experimental setting in which TIVS could occur and investigated brain activities underlying visuo-tactile interactions using a functional magnetic resonance imaging technique. While the suppressive effect of touch on vision was only found for half of the participants who could maintain their baseline performance above chance level (i.e. TIVS was not well replicated here), we focused on individual differences in the effect of touch on vision. This effect could be suppressive or enhancement, and the neuronal basis of these differences was analyzed. We found larger inhibitory responses in the anterior part of the right visual cortex (V1, V2) with higher TIVS magnitude when visuo-tactile stimuli were presented as spatially congruent. Activations in the right anterior superior temporal region, including the secondary somatosensory cortical area, were more strongly related to those in the visual cortex (V1, V2) with higher TIVS magnitude. These results indicate that inhibitory neural modulations from somatosensory to visual cortices and the resulting inhibitory neural responses in the visual cortex could be involved in TIVS.

Differential Effects of Sustained Manual Pressure Stimulation According to Site of Action

“…A new finding in the context of lower limb stimulation is the deactivation in areas outside the sensorimotor system, such as the temporal and occipital cortices. Similar cross-modal deactivations have been observed in humans only during somatosensory processing of tactile input from the upper limbs and they have been speculated to enhance the somatosensory processing by suppressing unnecessary sensory input (Kawashima et al, 1995; Merabet et al, 2007; Ide et al, 2016).…”

“…In contrast to the task-positive motor activations, the differences in the IPL (Figure 3A, Cluster 1) are more likely related to cross-modal deactivations (Kawashima et al, 1995; Merabet et al, 2007; Ide et al, 2016) as discussed in the Section “Deactivations Associated With Pressure Stimulation.” The posterior IPL (cytoarchitectonically the area PGp) is considered a part of the default mode network, specifically its medial temporal lobe subsystem (Igelström and Graziano, 2017). Similar stimulus-related deactivations in parts of the default mode network have been previously observed during sustained electrical stimulation (Hu et al, 2015).…”

A primary sensory cortical interareal feedforward inhibitory circuit for tacto-visual integration

“…Here, we demonstrate that visually evoked responses in VISp are also cross-modally modulated by the sense of touch. In line with our findings, cross-modal suppression is a frequently observed feature of multimodal tactile integration in sensory cortical areas both in humans (Ide et al, 2016) and other species (Meredith and Allman, 2015; Rao et al, 2014). For instance, whisker stimulation causes a global suppression of sound evoked activity in mouse AUDp (Lohse et al, 2021).…”

Auditory stimuli degrade visual performance in virtual reality

“…In particular, crossmodal inhibitory interactions have been found in humans for auditory and visual modalities 7 , and for tactile and visual modalities 8,9 . Several brain imaging studies have also shown crossmodal inhibitory or modulatory cortical responses [10][11][12][13] in what were previously considered unimodal processing areas. The areas where neural suppression occurs are also identified, including parts of the sensory cortices.…”