A Multivariate Exploration of Resting-State Networks and Sensory Measures of Olfaction and Taste

In neurodegenerative conditions such as Alzheimer's and Parkinson's diseases, a common symptom is the impairment of senses, particularly olfaction and gustation. More comprehensive neuroimaging studies are needed to elucidate the links between these sensory functions and neural circuit alterations. In this study, we used a subset of the Human Connectome Project (HCP) S1200 data containing both the neuroimaging and sensory test data (n = 50). Using high-order Group Independent Component Analysis (ICA) in combination with Multivariate Analysis of Covariance (MANCOVA), we studied the interplay between odor and taste sensory measures and spatiotemporal features of the resting-state networks. The findings revealed that a decline in olfaction was associated with decreased connectivity within the posterior default mode network, central executive network, and dorsal attention network. Similarly, a lower capacity for taste detection was linked to changes in the connectivity within the dorsal attention network. Conversely, enhanced taste detection was correlated with increased connectivity in the thalamus. We also found that olfaction was associated with the connectivity between the olfactory network and a cognitive network, which includes the inferior frontal orbital gyrus and Rolandic operculum. Taste, on the other hand, was associated with functional connectivity between the central executive network and the cerebellar network. Our study brings new insights into the relationship between olfaction, taste, and various resting-state networks.