Motivational deficits after brain injury: a neuropsychological approach using new assessment techniques

Deficits of motivation are recognized as a significant clinical problem following brain injury, and a neuropsychological model is postulated linking such deficits with cognitive deficits of a frontal type. However, few, if any, quantitative assessment measures exist; most descriptions in the literature are qualitative, and this has limited the scope and robustness of research into the problem. The authors in the present research have developed new tools for assessing patients' level of motivation in therapy (percent participation index) and their behavioral responsiveness to experimental incentive (the card-arranging reward responsivity objective test). Relationships among poor motivation, reward responsiveness, frontal lobe function, and mood were explored in a sample of 54 patients with nonfocal vascular or traumatic brain injury; the results were consistent with the neuropsychological model. Preliminary reliability and validation data on the new measures are reported.