Impact of food-related emotional changes on cerebral hemodynamic response

This study aimed to examine how the emotional valence of food differentially modulates cortical hemodynamic responses. We investigated the neural basis of food preference by comparing brain activity during the intake of individually selected palatable and unpalatable foods. Twenty-one healthy right-handed participants (10 males, 11 females; mean age: 28.1 ± 3.7 years) were included in the study. Palatable and unpalatable foods were selected based on pre-experimental questionnaires, and all participants fasted for 3 h before testing. Functional near-infrared spectroscopy (fNIRS) was used to assess hemodynamic changes in the bilateral frontoparietal regions during food ingestion. To reduce motion artifacts, only soft-textured foods were used. Emotional valence was evaluated using a visual analog scale (VAS), and raw fNIRS data were processed using spatial filtering to eliminate systemic effects. A general linear model was applied to extract activation related specifically to emotional responses, and cortical activity maps were generated from the oxygenated hemoglobin signals. One-sample t-tests were performed to identify common activation patterns in both palatable and unpalatable conditions. The left dorsolateral prefrontal cortex (DLPFC) showed significant activation correlating with emotional valence intensity for both food types. Importantly, palatable and unpalatable foods engaged distinct subregions of the prefrontal cortex, suggesting that the qualitative direction of emotional valence, positive or negative, is encoded by distinct neural substrates rather than merely reflecting response intensity. These findings imply that the DLPFC plays a significant role in the expression of food preferences, enhancing our understanding of the neural mechanisms underlying food-related emotions and potentially informing strategies to address maladaptive eating behaviors.