Predictive scaling of grip force in healthy controls and patients with Parkinson's disease

Introduction: Patients with Parkinson's disease (PD) show impairments in both preparation and adaptation of motor force control. We hypothesize that – as a function of putaminal dopamine – motor force preparation utilizes probabilistic advance information (predictive signal) and is modulated by the difference between actual necessary force and predicted force (prediction error signal). Without this error-signal dependent modulation, applied motor forces will be relatively rigid. Aim: To demonstrate that i) motor force normally is modulated by probabilistic advance information, and ii) motor force of PD patients…