CONTROLLING ACCESS TO WORKING MEMORY
The term working memory, proposed by Miller, Galanter and Pribram in 1960, in recent years has been developed to emphasize the functional role of short term memory (STM) as part of an integrated system for holding and manipulating information during the performance of complex cognitive tasks. Storage capacity of our working memory is limited, and it seems that part of the space is taken up by irrelevant information. In a new research work, McNab and Klingberg show, using functional magnetic resonance imaging (fMRI), that the basal ganglia (specifically the globus pallidus) have an important role in filtering out such irrelevant information to make working memory more efficient (McNab F. & Klingberg T. Prefrontal cortex and basal ganglia control access to working memory. Nature Neuroscience 11 (1), 103-107, 2008).
Trials revealed that the “preparatory filtering activity” in the prefrontal cortex and globus pallidus correlated positively with the voluntary’s working memory capacity.
In brief, findings indicate a role for the globus pallidus in filtering out information that does not have to be stored in working memory and a contribution by prefrontal cortex activity in flagging information that is necessary or worth remembering.
Variation in activity and connections in these areas might explain individual differences in working memory capacity and help understanding some features of attention-deficit disorders.