Cognitive Control Structures in the Imitation Learning of Spatial Sequences and Rhythms-An fMRI Study

Learning through imitation involves social learning in which new behaviors are acquired using observed behaviors as a model. The imitative process underlies the development of communication from early childhood; it promotes social interaction and emotional regulation skills, and is critical to sensorimotor development and social functioning. Imitative learning also plays a crucial role in cultural development that enables the transfer of knowledge within socially and culturally determined contexts. Imitation learning involves the acquisition of novel motor patterns based on action observation (AO). In the present study, we used event-related functional magnetic resonance imaging to investigate which brain areas are involved in imitative learning by focusing specifically on learning spatial sequences and rhythms during AO, motor imagination (MI), and imitative execution of musical sequences. While both tasks engaged the fronto-parietal mirror circuit, the spatial sequence task recruited posterior parietal and dorsal premotor regions more strongly. The rhythm task involved an additional network for auditory working memory. This partial dissociation supports the concept of task-specific mirror mechanisms. Two regions of cognitive control were identified: 1) dorsolateral prefrontal cortex (DLPFC) was found to be more strongly activated during MI of novel spatial sequences, which allowed us to extend the 2-level model of imitation learning by Buccino et al. (2004) to spatial sequences. 2) During imitative execution of both tasks, the posterior medial frontal cortex was robustly activated, along with the DLPFC, which suggests that both regions are involved in the cognitive control of imitation learning. The musicians’ selective behavioral advantage for rhythm imitation was reflected cortically in enhanced sensory-motor processing during AO and by the absence of practice-related activation differences in DLPFC during rhythm execution.