Behavioural and electrophysiological correlates of sensory attenuation in the somatosensory and auditory modality within a virtual reality setup

Sensory attenuation is the phenomenon that self-produced stimulations are suppressed compared to externally generated ones, both at the subjective and electrophysiological level. Despite the extensive literature on this phenomenon, it remains unclear whether electrophysiological attenuations are consistent across senses and whether they do reflect subjective attenuations of perceived intensity for self-produced sensations. Therefore, the aim of the present study is twofold: first we aimed to collect behavioural and electrophysiological measures of sensory attenuation in a controlled virtual reality setup, both in the auditory and somatosensory domain. Secondly, we correlated behavioural and electrophysiological indices of sensory attenuation to formally test whether the suppression for potentials evoked by self-generated stimulations reflects the sensory suppression revealed by behavioural measures. A total of 28 participants were included to compare the intensity of a first stimulation, which was self-generated or externally administered, to a second stimulation, which was administered at rest with varying intensity. The stimulations could be either electrical pulses at the fingertip or auditory clicks. Participants were also required to undergo a control task in which no stimulation was administered. The behavioural results indicate a reduced perceived intensity for self-produced compared to externally administered stimuli for the auditory domain. In contrast, no such difference was observed for the somatosensory domain. EEG results revealed suppression of the P2 for the auditory modality and the P200 in the somatosensory modality. Furthermore, a positive correlation between the P2 suppression and subjective intensity attenuation was found for the auditory modality. Together, our results suggest that electrophysiological suppression at mid-latency components reflect the perceived subjective attenuation of self-produced stimulation. This relationship, however, might be dependent on the sensory domain.