Action Observation and Mirror Neuron System Recruitment: Effect of Type of Task on Motor Facilitation (P7.196)

OBJECTIVE: Using functional MRI (fMRI), we assessed whether the effect of Action Observation (AO) on motor facilitation during the performance of a motor task with the dominant upper limb varies according to the type of executed movement (simple, complex and finalistic). BACKGROUND: AO facilitates motor performance through a modulation of Mirror Neuron System (MNS) recruitment. DESIGN/METHODS: Using a 3T scanner, fMRI scans during the execution (E) of a motor task, the observation (O) of a video showing the same task performed by a another person and the simultaneous execution and observation (EO) of the task were obtained from three groups of healthy subjects (15 subjects x group) randomized to perform: a simple motor task (SM) (flexion-extension of the last four fingers of the right hand), a complex motor task (CM) (flexion-extension alternated to abduction-adduction of the last four fingers of the right hand) and a finalistic motor task (FM) (use of an object with the right hand). Manual dexterity was assessed using the 9-hole peg test (9HPT) and maximum finger tapping frequency (FT). fMRI data were analyzed using SPM8. RESULTS: Demographic and manual dexterity data did not differ between groups. During O task, SM and FM groups had an increased activation of the bilateral inferior frontal gyrus compared to CM. During O and OE tasks, FT group experienced a higher activation of the left inferior parietal lobe compared to ST and CT; whereas the CT group had higher activation of the superior parietal gyrus than the FT and ST ones. CONCLUSIONS: Both the modality of administration and the type of task modulate MNS recruitment during AO. This has important practical implications for the use of this strategy in rehabilitation studies. Partially supported by a grant from FISM (FISM2012R15) and Italian Ministry of Health (RF-2011-02350374).