Right PMd subregions defined by their co-activation patterns

The right dorsal premotor cortex (PMd) of humans has been reported to be involved in a broad range of motor and cognitive functions. The basis of this behavioral heterogeneity was explored by performing a connectivity-based parcellation using meta-analytic approach applied to PMd coactivations. The connectivity-based parcellation (CBP) results of this study were compared to parcellations obtained through resting-state functional connectivity and probabilistic diffusion tractography. Functional connectivity profiles and behavioral decoding of the resulting PMd subregions allowed characterizing their respective behavior profile. These procedures divided the right PMd into five distinct subregions that formed a cognitive-motor gradient along a rostro-caudal axis: (i) a rostral subregion functionally connected with prefrontal cortex, which likely supports high-level cognitive processes, such as working memory (ii) a central subregion showing a mixed behavioral profile and functional connectivity to parietal regions of the dorsal attention network (iii) a caudal subregion closely integrated with the motor system (iv) a dorsal subregion, preferentially related to hand movements and connected to both cognitive and motor regions (v) a ventral subregion, whose functional profile fits the concept of an eye-movement related field. In conclusion, right PMd may be considered as a functional mosaic formed by five subregions.