SPATIAL FEATURES OF ANGULAR DRAWING MOVEMENTS IN PARKINSONS-DISEASE PATIENTS

The present study shows that drawings from Parkinson's disease (PD) pa tients display specific spatial features when compared to those produc ed by age-matched controls. Their drawings are globally smaller, or mo re precisely, the larger the requested size, the greater the size redu ction. PD subjects have also more difficulties in producing obtuse tha n acute angles: angles of obtuse patterns are shrinking and their segm ent lengths are shortened. This could be due to the fact that an obtus e angle brings the effector joints close to the limits of their functi onal ranges of motion, which may be reduced in PD patients. Results re lated to segment direction show that PD patients are globally more imp recise than controls in the production of movement directions, but per form nevertheless relatively well for horizontals and verticals drawn in preferred directions. These results are referred to two contradicto ry models relating movement direction to the type of movement coordina tion involved. (C) 1998 Elsevier Science B.V. All rights reserved. Psy cINFO classification: 2330.