Disorders of motivation are common across brain disorders. Neurologists and rehabilitation specialists frequently encounter pathological apathy across a range of conditions, including patients with stroke, small vessel cerebrovascular disease (SVD) and Parkinson’s disease (PD). It is now becoming understood that apathy has a poor prognosis for long-term functional outcome, cognitive state and engagement with rehabilitation. Unfortunately, we understand very little about the mechanisms underlying apathy.

In this talk, I shall put forward a conceptual framework with which we can begin to understand apathy by considering the processes that normally underlie motivated, goal-directed behavior. In particular I’ll focus on the ability to generate options for behavior and effort-based decision making for rewards. Recent studies of the latter have been particularly revealing in both healthy people and neurological patient populations.

Several lines of evidence suggest that when we make decisions about how much effort we might invest in actions, we weigh up the costs involved for the potential rewards to be obtained. Functional imaging in healthy people reveals both medial frontal and basal ganglia involvement when individuals make such decisions. In patients with apathy, this evaluation is altered. Apathetic patients show blunted sensitivity to rewards and less inclination to invest effort for low rewards than healthy individuals. Some evidence shows that these factors can be improved by dopaminergic medication. The findings support the view that it might be possible to provide a mechanistic account of the syndrome of apathy which might lead to treatments for the disorder.