All participants will perform cognitive tasks: reaction time (Alert TEA, Zimmermann and Fimm, 2005), Edinburgh laterality questionnaire (Oldfield, 1971), IQ test (IQ: PM38, Raven, 1960), and the PANSS (Positive and Negative Syndrome Scale, Kay et al., 1987). Controls will only have the first three tasks (cognitive spots Alert and laterality). Then all will perform all tasks in successive order (task 1 and task 2). For both tasks, photographs of 20 objects of everyday life typical grip with one hand are presented in 4 orientations. The instruction is to say if the object is presented upright or inverted; The second task differs from the first only by the introduction of a prime: presenting a hand in position "catching" before the picture of an object
