Résumé
The development of cognition and social cognition depends on motor skills. The control of motor skills requires intense, organized, synchronous and intact cognitive activity. Cognition results from a coupling between action representations and perception. Thus, every cognitive, emotional or affective process has a sensorimotor component. Therefore, there is a bidirectional relationship between motricity and cognition known as embodiment. The neurological basis of embodiment depends on wave synchrony between the sensorimotor cortex and the mirror neuron network, thus linking perception, action and cognition. Motor synchrony, which is a reflection of embodiment, is defined as the presence at the same time of similar movements between at least two people. It is often unintentional, and can be observed during social interactions. Evaluating motor synchrony is therefore a way of assessing embodiment, and could represent a useful early marker for diagnosing and monitoring patients suffering from diseases in which embodiment is impaired. The question raised by our pilot study is whether motor synchrony can be studied in the elderly, and if so, with what protocol. To answer this question, we recruited patients hospitalized at the geriatric medicine rehabilitation center of Montpellier University Hospital, and their caregivers. We then assessed motor synchrony using a simple, non-invasive technique to study the inter-relationship between cognition and motor skills.