Sensory and Cognitive Modulation of Saltiness Processing in Everyday Food: Evidence from Two fNIRS Experiments

Maintaining the palatability of low-salt foods while reducing salt intake is an important challenge in the promotion of such products. Reducing salt content may decrease food palatability and may also lead consumers to form negative taste expectations before actually tasting the food. Two experiments using functional near-infrared spectroscopy (fNIRS), each involving 30 participants, examined whether umami substances and olfactory cues could act as sensory factors, and package cues as a cognitive factor, to influence perceived saltiness in soups with complex flavor profiles. Experiment 1 showed no significant saltiness-enhancing effects for the tested saltiness enhancers. Descriptive rating patterns highlight the need to further examine the potential role of food flavor context. In Experiment 2, no significant effects of package cues on saltiness or palatability ratings were detected, while exploratory neural findings suggested condition-related response differences, including possible sensitivity to package–soup mismatch. Overall, these findings motivate further investigation of sensory and cognitive factors in the evaluation of everyday foods with complex flavor profiles.