Investigating pungency-induced enhancement of saltiness perception: An EEG-based study

The mechanism by which pungency enhances saltiness perception remains unclear. This study investigated the effects of low and moderate pungency levels, induced by compounds derived from Sichuan pepper oleoresin, on saltiness perception. It also examined potential neural mechanisms underlying this enhancement using electroencephalogram (EEG) analysis. The Generalized Labeled Magnitude Scale (gLMS) showed that pungency increased the perceived intensity of saltiness by up to 40.8% at low NaCl concentrations with low pungency stimulation. Higher time-frequency power was observed in regions of interest linked to saltiness perception, particularly during later processing stages (after 0.4 s). Following pungency stimulation, spectral analysis revealed significant differences in the theta and alpha bands in the frontal lobes ( p < 0.05 ). Additionally, the weighted phase lag index indicated increased coupling of neural oscillatory activities between the parietal lobes in the theta band and between the central region and occipital lobes in the alpha band ( p<0.05 ). Collectively, these findings suggest that a hierarchical integration process, involving interactions between saltiness and pungency and potential top-down effects on primary sensory regions, enhances saltiness perception. This study provides a foundation for exploring how sensory interactions amplify saltiness perception.