Yvonne Delevoye Unité de Recherche en Sciences Cognitives et Affectives
The planning of Environment-based and Intentional-based Sequential Actions in Schizophrenia
In the field of motor control, it is known that the processes for motor planning and motor learning are different when considering the planning of environment-based actions and intentional-based actions. Nevertheless, this distinction is rarely taken into account in the construction of theoretical models for motor control. This is especially the case in cognitive models for pathology. We have used a series of motor tasks in order to better understand the motor deficits characterising schizophrenia. Overall, this work has revealed that patients with schizophrenia have close to normal motor control when performing environment-based actions. However, large deficits are revealed when patients are required to act intentionally on the bases of an internal representation of action goal. Using dual tasks paradigms and neuropsychological tools, we have shown that the motor deficits may be due to abnormal allocation of attention ressources during the critical moment of motor preparation. I will discuss the possibility that the abnormal dynamics of attention focus may be due to a difficulty in these patients to generate and to maintain through time, an efference trace that is persistent enough to guide the planning of intentional sequential actions. Hence, patients suffering from schizophrenia would be inclined to plan all actions in the environment-based mode, step by step, feeling at a pre-reflective level of body awareness as if external forces were controlling the initiation of their own movements. I will end my talk by sharing the idea that adapted physical acitivity may be used as an innovating cognitive remediation technique to reinforce the coherence and the strength of motor representations for reactivating the intention-based mode of action planning.