Bahadori, M. | Search bioRxiv

bioRxiv2024

Enhancement of Temporal Processing via Transcutaneous Vagus Nerve Stimulation

BackgroundThe vagus nerve, a crucial component of the parasympathetic nervous system, serves as a vital communication link between the brain and body. Recent studies indicate that auricular stimulation of the vagus nerve can influence executive functions by increasing activity in brain regions like the prefrontal cortex. While prefrontal areas are associated with temporal processing, it remains unclear whether vagus nerve stimulation can also impact time perception. HypothesisThe stimulation of the vagus nerve via its auricular branch may enhance performance in temporal processing by boosting activities in prefrontal brain areas related to temporal processing. MethodsTemporal processing abilities were assessed using an anisochrony detection task, where participants identified temporal irregularities in otherwise isochronous sequences while undergoing transcutaneous Vagus Nerve Stimulation (tVNS) or sham stimulation. ResultsThe results of this study, for the first time, revealed that participants could recognize smaller temporal shifts when the vagus nerve was stimulated, compared to the sham condition. ConclusionThe findings suggest that vagus nerve stimulation modulates temporal processing, supporting the notion that transcutaneous stimulation of the vagus nerve can influence cognitive functions related to temporal processing, possibly by enhancing prefrontal activities.

neuroscience↗

bioRxiv2020

Action Planning and Affective States Within the Auditory Peripersonal Space.

Fast reaction to approaching stimuli is vital for survival as for sounds entering the individual auditory Peripersonal Space (PPS). Closer sounds have found to provoke higher motor cortex activation particularly for highly arousing sounds, showing the close relationship for perceptual components of the sounds and motor preparation. Here Normal Hearing (NH) individuals and Cochlear Implanted (CI) individuals have been compared in their ability to recognize evaluate and react to affective stimuli entering the PPS. Twenty (seven females) NH and ten (three females) CI participants were asked to react to Positive (P), Negative (Ne), Neutral, (Nu) affective sounds virtually ending at five different distances from their body by performing fast arms flexion. Pre-motor Reaction Times (pm-RTs) were detected via EMG from postural muscles to measure action anticipation at different sound stopping distances; furthermore, the same sounds were evaluated for their level of valence and arousal perceived. Both groups showed the ability to localize the sound distances but only NH individuals modulated their pm-RTs based on the sound distance. Interestingly when the sound was not carrying affective components, as for Nu sounds, both NH and CI individuals triggered the promptest pre-motor reaction time (shorter pm-RT) when compared to P and N sounds. Only NH individuals modulated sound distance with the level of sound arousal, while sounds valence was similarly perceived by both NH and CI individuals. These results underline the role of emotional states in action preparation and describe the specific perceptual components necessary to properly react to approaching sounds within peripersonal space.

neuroscience↗