  Working memory is responsible for the temporary manipulation and storage of
information to support reasoning, learning and comprehension in the human
brain. Background oscillations from subcortical structures may drive a gating
or switching mechanism during working memory computations, and different
frequency bands may be associated with different processes while working memory
tasks are performed. There are three well-known relationships between working
memory processes and specific frequency bands of subcortical oscillations,
namely: the storage of new information which correlates positively with
beta/gamma-frequency band oscillations, the maintenance of information while
ignoring irrelevant stimulation which is directly linked to theta-frequency
band oscillations, and the clearance of memory which is associated with
alpha-frequency band oscillations. Although these relationships between working
memory processes and subcortical background oscillations have been observed, a
full explanation of these phenomena is still needed. This paper will aid
understanding of the working memory's operation and phase switching by
proposing a novel and biophysical realistic mathematical-computational
framework which unifies the generation of subcortical background oscillations,
the role of basal ganglia-thalamo-cortical circuits and the influence of
dopamine in the selection of working memory operations and phases: this has
never been attempted before.
