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bioRxiv · 10.64898/2025.12.18.695315

Salient auditory stimuli evoke spatially segregated phasic and sustained neural responses in the human brain

Joshi, S.·Polat, M.·Chai, D. C.·Pantis, S.·Buch, V. P.·Ramayya, A. G.
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Abstract

Salient sensory stimuli are known to evoke neural activations across distributed brain regions. However, the temporal dynamics of these responses over sub-second timescales remain poorly understood, in part due to limitations in the temporal resolution of non-invasive neuroimaging methods. We examined the spatiotemporal dynamics of neural activations evoked by salient sensory stimuli (rare sounds) using 1,194 widely distributed intracranial electrodes in 5 neurosurgical patients. Salient stimuli preferentially activated 263 of 1,194 electrodes (22%), with responses segregating into two largely distinct spatiotemporal patterns: (1) phasic activation in sensorimotor regions, and (2) sustained activation within the salience network. Cross-correlation analysis revealed that phasic sensorimotor activation preceded sustained salience network activation on a trial-by-trial basis. These findings support an updated view of salience processing in the human brain, revealing that salient stimuli evoke two sequential stages of neural activation--phasic sensorimotor responses followed by sustained salience network activity--rather than simultaneous widespread activation.

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Joshi, S., Polat, M., Chai, D. C., Pantis, S., Buch, V. P., Ramayya, A. G.. 2025-12-19. Salient auditory stimuli evoke spatially segregated phasic and sustained neural responses in the human brain. https://doi.org/10.64898/2025.12.18.695315

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