Causal Connectivity Transition from Action Observation to Mentalizing Network for Understanding Other’s Action Intention

Abstract

The previous neuroimaging studies have found that two major cognitive sub-processes, action perception and mental inference, participate in understanding others’ action intention, but it is unclear that the role of action observation network (AON) for mentalizing network (MZN) of intention inference. To provide direct causal evidence about the relationship between the two systems, this EEG study adopted Granger causality method to detect the circuit of directed information transfer from action perception to intention inference process during a “hand-cup interaction” observation task with two types of actions, i.e., usual intention-oriented action and unintelligible action. The graph-theoretical results of causal connectivity network show that left-lateral posterior parietal-occipital brain area acts as “effect” nodes in AON during action perception period but plays the role of “cause” nodes in MZN, especially for understanding other’s unintelligible action that requires higher cognitive function for mentalizing inference. From the evidence, this study suggests that left-lateral parietal-occipital brain area can be viewed as a hub of internodal directed connection transition from AON to MZN, so that the two systems could cooperate with each other by means of temporal reception and transmission of perceptional information to judge other’s actual intention.