It has long been known that memory is not a single process. Rather, there are different kinds of memory
that are supported by distinct neural systems. This idea stemmed from early findings of dissociable patterns
of memory impairments in patients with selective damage to different brain regions. These studies
highlighted the role of the basal ganglia in non-declarative memory, such as procedural or habit learning,
contrasting it with the known role of the medial temporal lobes in declarative memory. In recent years,
major advances across multiple areas of neuroscience have revealed an important role for the basal ganglia
in motivation and decision making. These findings have led to new discoveries about the role of the
basal ganglia in learning and highlighted the essential role of dopamine in specific forms of learning. Here
we review these recent advances with an emphasis on novel discoveries from studies of learning in
patients with Parkinson’s disease. We discuss how these findings promote the development of current
theories away from accounts that emphasize the verbalizability of the contents of memory and towards
a focus on the specific computations carried out by distinct brain regions. Finally, we discuss new challenges
that arise in the face of accumulating evidence for dynamic and interconnected memory systems
that jointly contribute to learning.