Perceived valence of ambient odor is associated with listening comprehension and subjective effort but not Fronto-parietal alpha connectivity.

Ambient odors are pervasive features of everyday environments, yet their influence on cognition and its neural mechanisms remains poorly understood. We investigated whether the perceived hedonic valence of an ambient odor modulates comprehension, perceived cognitive effort, and fronto-parietal alpha-band connectivity during a naturalistic listening task. Twenty-one healthy adults were exposed to three ambient odorants (menthol, triethyl citrate, cadaverine), with odor order held constant, while listening to audiobooks, with EEG recorded throughout. After each condition, comprehension and perceived effort were measured with a dedicated test and the NASA-TLX questionnaire. Fronto-parietal alpha coherence was computed using magnitude-squared coherence between frontal and parietal electrodes. Treating perceived valence as a continuous subjective predictor in linear mixed-effects models, we found that higher perceived valence was associated with better comprehension (p = .034) and lower perceived effort (p = .016). Fronto-parietal alpha coherence was not modulated by perceived valence (p = .761). These findings show that post-condition perceived odor pleasantness is associated with sustained listening both behaviorally and subjectively, while this association is not accompanied by detectable changes in fronto-parietal alpha synchronization in this sample. They highlight the need for future studies with larger samples and more sensitive neural markers to better capture the underlying mechanisms.