HUMAN MOTOR PLANNING, MOTOR PROGRAMMING, AND USE OF NEW TASK-RELEVANTINFORMATION WITH DIFFERENT APRAXIC SYNDROMES

Patients with ideomotor apraxia (n = 2) or ideational apraxia (n = 2) after left brain stroke and patients with constructional apraxia (n = 2) after cerebrovascular accident of the right hemisphere, as well as 16 non-brain-damaged control subjects, were given a standardized simpl e motor task: they were asked to make triangular arm movements of spec ific size, configuration and spatial orientation without visual contro l. Motion was analysed three-dimensionally in great detail prior to an d after kinaesthetic training using a triangular stencil, and 1 day la ter. The experiment was conceptualized to assess three aspects of moto r behaviour: (i) motor planning, operationalized as specification of c ontent parameters of the movement as a whole; (ii) motor programming, the specification of spatiotemporal parameters of movement segments; a nd (iii) the ability to make use of task-relevant information provided by the training. Patients with ideational apraxia showed signs of imp aired motor planning: they had difficulty in selecting the body parts to be moved, and movement concept and configurational aspects were def icient. The kinaesthetic sensorimotor training given seemed not adequa te to reduce behavioural deficits. Kinematic peculiarities of patients with ideomotor apraxia can be understood as deficits in programming m ovement elements. Submovements were more segmented, showed irregularit ies as well as additional, not-requested elements. Their impairments c ould be reduced by task-specific sensorimotor training. Patients suffe ring from visuoconstructive apraxia after right brain damage might hav e difficulties in making use of new sensorimotor information relevant for spatial-motor aspects, as suggested by training-induced behavioura l impairment with a severely constructional apraxic patient.