Introduction The neurotransmitter dopamine has frequently been implicated in reward
processing but is also, increasingly, implicated in punishment processing. We have …

Individual variability in reward-based learning has been ascribed to quantitative variation in
baseline levels of striatal dopamine. However, direct evidence for this pervasive hypothesis …

Dopamine is critical for reward‐based decision making, yet dopaminergic drugs can have
opposite effects in different individuals. This apparent discrepancy can be accounted for by …

Drugs that alter dopamine transmission have opposite effects on reward and punishment
learning. These opposite effects have been suggested to depend on dopamine in the …

Rationale Dopaminergic therapy improves some cognitive functions and worsens others in
patients with Parkinson's disease (PD). These paradoxical effects are explained by the …

BackgroundDepression is one of the most common and debilitating non-motor symptoms of
Parkinson's disease (PD). The neurocognitive mechanisms underlying depression in PD are …

Striatal dopamine (DA) is central to reward-based learning. Less is known about the
contribution of DA to the ability to adapt previously learned behavior in response to changes …

Psychostimulants such as methylphenidate are widely used for their cognitive enhancing
effects, but there is large variability in the direction and extent of these effects. We tested the …

Impaired ability to learn from positive and negative feedback in changing environments is
associated with some psychiatric disorders, such as parkinsonism, and impulse control …

Catecholamines, particularly dopamine, have been implicated in various aspects of the
reward function including the ability to learn through reinforcement and to modify flexibly …