In this article, we discuss the hypothesis that affect is a fundamental, psychologically
irreducible property of the human mind. We begin by presenting historical perspectives on …

Background Over the last several years, it has become apparent that there are critical
problems with the hypothesis that brain dopamine (DA) systems, particularly in the nucleus …

The learning of new skills is characterized by an initial phase of rapid improvement in
performance and a phase of more gradual improvements as skills are automatized and …

The basal ganglia (BG) coordinate decision making processes by facilitating adaptive frontal
motor commands while suppressing others. In previous work, neural network simulations …

In the 20th century it was thought that novel behaviors are mediated primarily in cortex and
that the development of automaticity is a process of transferring control to subcortical …

The mesolimbic dopaminergic (ML-DA) system has been recognized for its central role in
motivated behaviors, various types of reward, and, more recently, in cognitive processes …

During the 1990s and early 2000s, cognitive neuroscience investigations of human category
learning focused on the primary goal of showing that humans have multiple category …

It has long been recognized that the striatum is composed of distinct functional sub-units that
are part of multiple cortico-striatal-thalamic circuits. Contemporary research has focused on …

Senescence affects the ability to utilize information about the likelihood of rewards for
optimal decision-making. Using functional magnetic resonance imaging in humans, we …

Midbrain dopamine (DA) neurons fire in 2 characteristic modes, tonic and phasic, which are
thought to modulate distinct aspects of behavior. However, the inability to selectively disrupt …