COVERT PROCESSING OF INFORMATION IN HEMIANESTHESIA - A CASE-REPORT

A 69-year-old patient with a cortical lesion of the primary sensory ar ea showed a surprising sensorimotor control of the anesthetized arm. T his observation suggested the existence of residual capacities of some sthetic information processing. This hypothesis was tested using a for ced choice procedure on four tasks involving discrimination between di fferent characteristics of the tactual-kinaesthetic stimulus. Whereas the patient was unable to identify the direction of movement or to dis criminate between different letters, she could detect the occurrence o f the stimulation or its dynamic quality signficantly well. These resu lts are discussed in reference to an anatomo-functional organization a nalogous to the one underlying the processing of visual information.