Modulating Subjective Time Perception with Transcranial Random Noise Stimulation (tRNS)

Understanding the neural and cognitive mechanisms underlying time estimation remains a challenge. Transcranial electric stimulations, such as transcranial randomnoise stimulation (tRNS), are useful tools to interfere with brain activity and identifying brain areas involved in temporal processing. Here, the aimis to investigate the specific role of primary sensory cortices (either V1 or A1) in temporal processing and to further investigate if the stimulation acts on either perceived duration or temporal sensitivity. Forty-eight university students were included in the study. Twenty-four participants were stimulated over A1, and 24 participants were stimulated over V1. All participants performed a time bisection task, either in a visual or auditory modality, involving standard durations lasting 300 ms (short) and 900 ms (long). When tRNS was delivered over A1, an effect of stimulation was observed on perceived duration (temporal over-estimation) under random stimulation compared to sham in both visual and auditory modalities. When tRNS was delivered over V1, the effect of stimulation was observed only in the visual modality (temporal over-estimation). No effect of stimulation was observed on temporal sensitivity in any condition. Our results showed for the first time that tRNS acts on modulating an individual’s perceived duration, but not on temporal sensitivity.