Beta oscillations support somatosensory temporal integration for body ownership

Abstract

The sense of body ownership, the perceptual experience of what belongs to ones body, relies on the integration of self-related signals across multiple sensory modalities. Alpha oscillations modulate the temporal resolution of visuotactile integration for body ownership by constraining how visual and tactile signals from the body are temporally combined or segregated. However, body ownership can be supported and modulated in the absence of vision, for example during self-touch, raising the question of whether the same alpha-based temporal mechanism supports purely somatosensory integration. Here, we show that individual beta frequency (IBF), rather than alpha, predicts the temporal integration of tactile signals between the two hands in a somatic rubber hand illusion self-touch paradigm. IBF predicted the temporal window within which two tactile stimuli were judged as simultaneous and within which illusory self-touch body ownership was experienced. Moreover, while individual alpha frequency did not contribute to this purely somatosensory integration, IBF also did not predict the temporal resolution of visuotactile integration when visual body-related inputs were available. Together, these findings suggest a double dissociation in which frequency-specific oscillatory processes reflect the temporal integration of bodily signals in a modality-dependent manner: beta frequency emerges as the key correlate of somatosensory integration during self-touch, whereas alpha frequency governs visuotactile integration when vision is available.