ReviewEvaluation of net causal influences in the circuit responding to premotor control during the movement-readiness state using conditional Granger causality

•Movement readiness (MR) is important to comprehend formation of movement pattern.•The circuit of MR reveals lateralization of causal flows during unimanual MR.•Comparing with monkey, human has more complex causal influences during MR.•We find the brain asymmetry of causal influences responding to right or left-hand MR.This article is part of a Special Issue entitled SI: Brain and Memory.This article is part of a Special Issue entitled SI: Brain and Memory.

As an initialization procedure for brain responding to subsequent movement execution (ME), the movement-readiness (MR) state is important for understanding the formation processes from daily movement training to long-term memory of movement pattern. As such, based on functional magnetic resonance imaging (fMRI), the net causal influences among regions contributing to premotor control during the MR state were explored by means of conditional Granger causality (CGC) and graph-theory methods in the present study. Our results found that net causal circuits responding to unimanual MR were identified during right-hand or left-hand MR, involving in the anterior cingulate cortex (ACC), posterior cingulate cortex (PCC), upper precuneus (UPCU), caudate nucleus (CN), cingulate motor area (CMA), supplementary motor area (SMA) and primary sensorimotor area (S1M1). Moreover, the contralateral CN, SMA and S1M1 revealed greater net causal influences during unimanual MR, which highlighted the contralateral dominant modulations during unimanual MR. Furthermore, according as the graph-theory analysis, the higher In+Out degrees of upper precuneus (UPCU) during right-hand MR or higher In+Out degrees of cingulate motor area (CMA) and posterior cingulate cortex (PCC) during left-hand MR implied the brain asymmetry of causal connectivity in the circuit responding to right-hand or left-hand MR.This article is part of a Special Issue entitled SI: Brain and Memory.