A new approach to the rehabilitation of movement, based primarily on the principles of operant conditioning, was derived from research with deafferented monkeys. The analysis suggests that a certain proportion of excess motor disability after certain types of injury involves a learned suppression of movement and may be termed learned nonuse. Learned nonuse can be overcome by changing the contingencies of reinforcement so that they strongly favor use of an affected upper extremity in the chronic postinjury situation. The techniques employed here involved 2 weeks of restricting movement of the opposite (unaffected) extremity and training of the affected limb. Initial work with humans has been with chronic stroke patients for whom the approach has yielded large improvements in motor ability and functional independence. We report here preliminary data suggesting that shaping with verbal feedback further enhances the motor recovery.Key words: shaping, training, restriction, somatosensory deafferentation, stroke, rehabilitation medicine, impaired movement, monkeys, humans This article describes a new approach to the rehabilitation of movement in physical medicine. It is based in its essential features on the principles of operant conditioning. It is fitting that it appear in a tribute to Joseph V. Brady, because he persuasively endorsed the relevance and importance of applying the principles of the experimental analysis of behavior to new areas and in this way strongly influenced the development of this work.
Experiments with Deafferented MonkeysAlthough the present approach is fundamentally behavioral, the original observations were made in the context of studies of the neurophysiology of motor control and the role of sensory feedback in movement and learning. The spinal nerves, which are fundamental for these functions, emerge from the spinal cord in two roots. The dorsal root is sensory. Thus, animal-research enterprise, responded by saying, to quote him, "They will get those monkeys over my dead body." As a result, the monkeys were preserved so that significant experiments could be carried out (Pons et al., 1991;Rausell, Cusick, Taub, & Jones, 1992). These experiments will not be described here because their subject matter is not directly relevant to the main theme of this paper, but there is widespread recognition of their potential practical importance for the fields of cortical plasticity and physical rehabilitation (Barinaga, 1992;Palca, 1991;Stephens, 1991). Thus, Joe Brady resisted pressure that very few could have withstood, and thereby achieved a significant victory for animal research on several levels. However, his role in this incident is largely unknown. He is an unsung hero. It is hoped that this account will help to some extent to begin to rectify this situation.
