Fig. 2.

The olfactory network as isolated with Independent Component Analysis (ICA) of the olfactory fMRI. (A) One independent component was associated with an olfactory network, consisting of the posterior piriform cortex, anterior insula and thalamus bilaterally, as well as the right orbitofrontal cortex. The hand motor area of the left precentral gyrus was also part of this network, due to the response monitoring task. (B) This independent component (IC) coincided temporally (time course in red) with the olfactory stimulation of the tested fMRI task design (blue). (C) The s-mode values (measure of the effect size for each participant) were significantly higher in healthy controls than PD patients (p = .014). Color bars are given in terms of T-statistic. R: right hemisphere. The spatial brain map was created with FSLeyes (FMRIB Analysis Group, University of Oxford, UK).