Objective: With the help with functional magnetic resonance imaging (fMRI) technique, we aim to clarify whether the marginal division of the striatum (MrD) is involved in the working memory function of human brain for remembering numbers received through hearing.
Methods: Thirteen healthy volunteers were instructed to undertake both a working memory task, in which the subjects were asked to remember as many numbers read to them as possible, and a non-working memory control task, in which the subjects were not asked to remember the numbers. FMRI of the brain was performed in the 2 groups while the tests were being carried out separately, and the activity of the brain regions was compared between these 2 tasks.
Results: Eleven volunteers passed the working memory task for digit remembering. Highly active areas were observed in the prefrontal cortex and the MrD with predominance by the left side during performance of the working memory task, while other regions of the neostriatum were not excited. The prefrontal cortex and the MrD were not obviously activated during the performance in the control test.
Conclusion: The results suggest that the MrD, along with the prefrontal cortex in the human brain, is involved in working memory function in remembering numbers assigned through hearing. The MrD is probably a subcortical memory center, which is linked to other memory-related brain areas.