Detection of Arousal With Facial Micro-expression in Severe Brain-damaged Patient

Severe brain injuries lead to disorders of consciousness after coma. During this awakening period, detection of arousal is critical to the adaptation of medical strategy, but global paralysis, including facial expression, make the clinical assessment very difficult. Emotional facial expressions are a significant part of this clinical assessment. They are both a landmark of the internal state of the patient (comfort versus discomfort) and a landmark of the relational level with his environment. Visible emotional facial expression is a large temporal phenomenon lasting a couple of seconds, while a microexpression is barely noticeable and very brief. These micro expressions are usually produced when one tried to voluntary hide emotional expressions. In this study, we hypothesize that some patients awakening from coma could still produce microexpression before being able to produce visible emotional facial expressions. This ability to produce micro-expression could be an early landmark of relational awakening in severe brain lesions.