Reward revisted: Understanding the manifold influence of reward on human cognition

Motivation in general, and reward processing in particular, are central topics in psychology, and research on the underlying psychological and neural processes has experienced a veritable boom in the recent past. The topic is not only interesting in its own right, but at least as much because of its modulatory effects on numerous other cognitive functions. The present proposal seeks to investigate exactly such influences. More specifically, over the past decade an increasing number of neuroscientific studies, including my own, have started to demonstrate motivational influences on relatively specific cognitive functions like target discrimination, conflict resolution, inhibitory control, and memory formation. This ubiquitous impact of motivation is mirrored in cognitive deficits in a number of neurological and psychiatric disorders that have been argued to also affect motivational processes, including attention-deficit hyperactivity disorder (ADHD), addiction, and Parkinson's disease (PD). Intriguingly, on the neural level, the majority of these disorders have been related to disturbances in two important neurotransmitter systems, the dopaminergic (DA) and the noradrenergic (NA) system, which are known to be critical for motivational processes in healthy cognitive functioning. Neuroscientific data indicates that both systems exert their effects through projections from their source regions in the brainstem to their target regions in the basal ganglia (BG) and the prefrontal cortex (PFC). While some progress has been made in investigating the processing of reward values in the human brain, our understanding of how exactly the prospect of reward influences the wide range of complex cognitive operations that are generally amenable to such influences remains rudimentary.