The presence of another human in our immediate or distant environment is a crucial factor for survival and social behavior. Our actions vary depending on the other person’s relative proximity, involving integration of brain functions subserved by neural oscillations, to generate the most appropriate behavior. This study highlights the alpha EEG role and its neural generators in interpersonal space sensitivity (IPSS). To investigate this, participants stood face-to-face, gazing into each other’s eyes, and while wearing a mask preventing them from staring at each other. An auditory order instructed them to alternately close and open their eyes. It was observed that alpha power of occipito-parietal region increased as the distance decreased, transitioning from extra-personal space (4 m) to peri-personal space (<40 cm) when the eyes were closed. Conversely, alpha power decreased for the same distances when the eyes were open. These significant event-related synchronization (ERS) and desynchronization (ERD) effects were absent when participants’ heads were masked. Beta oscillations were not significantly involved in IPSS. The number of spontaneous blinks was not significantly influenced by IPSS. Source modeling identified alpha ERS and ERD in cortical and subcortical generators significantly involved in IPSS with independent components localized in: The parietal cortex bilaterally (BA7), the left limbic gyrus (BA23), the anterior cingulate cortex (ACC) (right BA31, left and right BA24, right BA32), the right premotor cortex (BA6, including the supplementary motor area (SMA), and the right frontal eye fields (BA8). These cortical areas were accompanied by the recruitment of the thalamus and cerebellum.

Sensory perception emerges from the integration of multisensory inputs, a process previously attributed to higher-order cortices. However, increasing evidence suggests that the primary visual cortex (V1) also processes non-visual stimuli. Here, we investigated the response of V1 to visual, auditory, and somatosensory stimuli in awake, head-fixed mice using evoked local field potentials (eLFP), multi- and single-unit recordings. Our results demonstrate that V1 responds to auditory and somatosensory inputs with distinct frequency band modulations and firing rate patterns across monocular and binocular regions. Notably, somatosensory stimuli elicited the fastest response latencies, suggesting a privileged role in murine sensory processing. Auditory and somatosensory stimuli modulated V1 activity similarly to contralateral visual inputs, whereas ipsilateral visual stimulation resulted in weaker responses. These findings indicate that V1 is not solely dedicated to vision but also responds to auditory and somatosensory stimuli, supporting a potential role in multisensory processing.