Abstract
The study investigates neural processing underlying the perception of vanillin and structurally similar odorants, vanitrope, and vanillyl ethyl ether (VEE), aiming to discern subtle differences in odor perception using functional magnetic resonance imaging (fMRI). Despite similar psychophysical ratings of intensity, pleasantness, and familiarity for the odors, fMRI analysis with 44 individuals revealed distinct activation patterns in brain regions associated with olfactory processing, memory retrieval, and odor recognition. Specifically, increased activations were observed in the parahippocampal gyrus and left amygdala during the perception of vanillin compared to vanitrope and VEE. This indicates a link between emotional responses and familiarity; particularly during vanillin's resemblance to the familiar scent of vanilla. Results from further analysis could imply that the orbitofrontal cortex is involved in the diffentiation of odors, especially in linking vanillin to the the familiar aroma of vanilla, while the hippocampus might be involved in consolidating odor-induced memories. The findings underscore the intricate interplay between olfactory perception, emotional processing, and memory consolidation within the human brain. The study demonstrates the utility of fMRI in elucidating subtle perceptual differences in similar odorants and sheds light on the underlying neural mechanisms governing odor discrimination and recognition.