Neuro-perceptive discrimination on fabric tactile stimulation by Electroencephalographic (EEG) spectra

Abstract

The precise evaluation of sensory perceptions during fabric-skin interactions is still poorly understood in neuroscience. This study aims to investigate the cortical sensory response to fabric stimuli with different textiles by Electroencephalographic (EEG) spectral intensities, and evaluate the relationships between EEG frequency bands, traditional subjective questionnaires, and the materials’ physical properties. Twelve healthy adult participants were recruited to test three fabrics with different textile compositions of 1) cotton, 2) nylon, and 3) polyester and wool. The physical properties of the fabrics were quantitatively evaluated by a Fabric Touch Tester (FTT). Subjects were invited to rate the sensory perception of the fabric samples via a subjective questionnaire and objective EEG recording. Significant differences in the EEG relative spectral power of Theta and Gamma bands were acquired in response to the different fabric stimuli ( P <0.05). The Theta and Gamma powers demonstrated a significant correlation with the most of the subjective sensations evaluated by questionnaire and the fabrics’ physical properties by FTT ( P <0.05). The EEG spectral analysis could feasibly be used for the discrimination of fabric stimuli with different textile compositions and further indicates sensory perceptions during fabric stimulation. This finding may provide evidence for further exploratory research of sensory perceptions via EEG spectral analysis, which could be applied to the study of brain generators of skin tactility in future prostheses and the automatic detection of sensory perception in industries.

Seeing the piles of the velvet bending under our finger sliding over a tactile stimulator improves the perception of the fabric

“…Theta oscillations could be instrumental in binding visuo-tactile information to increase touch sensation. This is supported by studies showing that higher amplitudes of theta oscillations encode for touch intensity (Michail et al, 2016), fabric physical properties (e.g., warmness, softness, overall comfort, Jiao et al, 2020) as well as for more salient sensory stimuli (Iannetti et al, 2008). The dynamic velvet-like visual feedback could have also primed tactile representation of the velvet fabric.…”

Neurophysiological correlates of tactile width discrimination in humans

“…Contrary to previous studies, we have not observed changes in the gamma frequency band for electrode C3. These modulations have been associated with tactile processing in other tactile discrimination tasks (Michail et al, 2016;Jiao et al, 2020;Ross et al, 2022), tactile spatial attention (Bauer et al, 2006), and multisensory communication (Misselhorn et al, 2019).…”

Neurophysiological correlates of tactile width discrimination in humans

“…Lastly, the theta frequency band in the parietal region has been reported to participate in the regulation of attention and emotion during tactile processing [31]. Gamma band oscillations in the primary somatosensory cortex have been associated with tactile processing in other tactile discrimination tasks [32,33], tactile spatial attention (namely, when simultaneous alpha and beta band suppression occurs in the parieto-occipital cortex) [34], and multisensory communication [35]. Here, no differences or signi cant changes in power were observed in the gamma frequency band for the C3/4 electrodes, possibly due to the long duration of the periods analyzed [13].…”