Dopamine boosts memory for angry faces in Parkinson's disease

The influence of emotional context on cognitive operations is of fundamental importance for the evolution of higher cognitive functions and their disturbance in neuropsychiatric disorders. The dopamine pathways projecting to prefrontal cortex and the basal ganglia are assumed to play a major role in such emotion-cognition interactions. Here we provide evidence for such a role by studying working memory for emotional faces in patients with Parkinson's Disease. We studied 25 patients with Parkinson's disease during their on and off medication states. Faces with emotional expressions (happy, angry, sad, neutral or fearful) were shown and the participants had to remember and later recall the identity of the faces ignoring the expressions. We found that dopaminergic medication enhances working memory for angry faces and suppresses it for sad faces. The results elucidate neurochemical mechanisms for the saliency of threatening information and support cognitive explanations of the antidepressant effects of dopamine. They also suggest a role for dopamine in changing emotional-cognitive biases rather than as a generic cognitive enhancer.