Vibration Alert to the Brain: Evoked and Induced MEG Responses to High-Frequency Vibrotactile Stimuli on the Index Finger of Dominant and Non-dominant Hand.

Min-Young Kim,Kiwoong Kim,Tae-Heon Yang,Hyukchan Kwon

doi:10.3389/fnhum.2020.576082

Abstract

Background: In recent years, vibrotactile haptic feedback technology has been widely used for user interfaces in the mobile devices. Although functional neuroimaging studies have investigated human brain responses to different types of tactile inputs, the neural mechanisms underlying high-frequency vibrotactile perception are still relatively unknown. Our aim was to investigate neuromagnetic brain responses to high-frequency vibrotactile stimulation, using magnetoencephalography (MEG).Methods: We measured 152-channel whole-head MEG in 30 healthy, right-handed volunteers (aged 20–28 years, 15 females). A total of 300 vibrotactile stimuli were presented at the tip of either the left index finger or the right index finger in two separate sessions. Sinusoidal vibrations at 150 Hz for 200 ms were generated with random inter-stimulus intervals between 1.6 and 2.4 s. Both time-locked analysis and time-frequency analysis were performed to identify peak responses and oscillatory modulations elicited by high-frequency vibrations. The significance of the evoked and induced responses for dominant and non-dominant hand stimulation conditions was statistically tested, respectively. The difference in responses between stimulation conditions was also statistically evaluated.Results: Prominent peak responses were observed at 56 ms (M50) and at 100 ms (M100) for both stimulation conditions. The M50 response revealed clear dipolar field patterns in the contralateral side with significant cortical activations in the contralateral primary sensorimotor area, whereas the M100 response was not as prominent as the M50. Vibrotactile stimulation induced significant suppression of both alpha (8–12 Hz) and beta (20–30 Hz) band activity during the mid-latency period (0.2–0.4 s), primarily in sensorimotor areas contralateral to the stimulation side. In addition, a significant alpha enhancement effect in posterior regions was accompanied with alpha suppressions in sensorimotor regions. The alpha suppression was observed in a broader distribution of cortical areas for the non-dominant hand stimulation.Conclusion: Our data demonstrate that high-frequency tactile vibrations, which is known to primarily activate Pacinian corpuscles, elicit somatosensory M50 and M100 responses in the evoked fields and induce modulations of alpha and beta band oscillations during mid-latency periods. Our study is also consistent with that the primary sensorimotor area is significantly involved in the processing of high-frequency vibrotactile information with contralateral dominance.

Highlights

The cutaneous sensory system provides information about the external environment by detecting tactile, thermal, and painful stimuli applied to the skin through mechanoreceptors, thermoreceptors, and nociceptors, respectively (Birder and Perl, 1994; McGlone and Reilly, 2010)
In an attempt to cope with the increasing demands for an objective evaluation of high frequency vibrotactile perception, we investigated the neuromagnetic responses to high frequency vibrotactile stimulation, using a custom-built, MEG-compatible vibrotactile device
When the Topographical Consistency Test (TCT) was applied to the Grandaverage ERFs (gERFs) of each stimulus condition, we found a consistent topography across all participants beginning from the stimulus onset for both conditions

Summary

Introduction

The cutaneous sensory system provides information about the external environment by detecting tactile, thermal, and painful stimuli applied to the skin through mechanoreceptors, thermoreceptors, and nociceptors, respectively (Birder and Perl, 1994; McGlone and Reilly, 2010). In contrast to traditional views of specialized functional roles for each type of mechanoreceptors, recent findings have indicated that inputs from multiple mechanoreceptor types are integrated in the cortex for tactile information processing (Bensmaia, 2008; Tommerdahl et al, 2010; Carter et al, 2014; Saal and Bensmaia, 2014; Kuroki et al, 2017). Signals from different mechanoreceptors contribute to the characterization of tactile sensation that include vibration, shape, motion, grip control, and texture (Saal and Bensmaia, 2014). Functional neuroimaging studies have investigated human brain responses to different types of tactile inputs, the neural mechanisms underlying high-frequency vibrotactile perception are still relatively unknown. Our aim was to investigate neuromagnetic brain responses to high-frequency vibrotactile stimulation, using magnetoencephalography (MEG)

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Discussion

Conclusion