Assessing the effective connectivity of premotor areas during real vs imagined grasping: a DCM-PEB approach

The parieto-frontal circuit underlying grasping, which requires the serial involvement of anterior intraparietal area (aIPs) and ventral premotor cortex (PMv), has been recently extended enlightening role dorsal (PMd). supplementary motor (SMA) also suggested to encode grip force for grasping actions; furthermore, both PMd SMA are known play a crucial in imagery. Here, we aimed at assessing dynamic couplings between left aIPs, PMv, PMd, primary (M1) by comparing executed imagined right-hand using Dynamic Causal Modelling (DCM) Parametrical Empirical Bayes (PEB) analyses. 24 subjects underwent an fMRI exam (3T) during they were asked perform or imagine movement visually cued photographs commonly used objects. We tested whether two conditions a) exert modulatory effect on forward feedback among our areas interest, b) differ terms strength sign these parameters. Results real condition confirmed PMv M1. exerted positive influence SMA, but received inhibitory only from PMd. Our results suggest that general program is planned aIPs-PMv circuit; then, high-level features movement. During imagery, connection aIPs was weaker information flow stopped PMv; thus, less complex planned. Moreover, cooperate prevent execution. In conclusion, comparison execution imagery reveals dynamically interplay different ways, depending task demands.