Somatosensory working memory performance in humans depends on both engagement and disengagement of regions in a distributed network

Hum Brain Mapp. 2010 Jan;31(1):26-35. doi: 10.1002/hbm.20842.


Successful working memory (WM) requires the engagement of relevant brain areas but possibly also the disengagement of irrelevant areas. We used magnetoencephalography (MEG) to elucidate the temporal dynamics of areas involved in a somatosensory WM task. We found an increase in gamma band activity in the primary and secondary somatosensory areas during encoding and retention, respectively. This was accompanied by an increase of alpha band activity over task-irrelevant regions including posterior and ipsilateral somatosensory cortex. Importantly, the alpha band increase was strongest during successful WM performance. Furthermore, we found frontal gamma band activity that correlated both with behavioral performance and the alpha band increase. We suggest that somatosensory gamma band activity reflects maintenance and attention-related components of WM operations, whereas alpha band activity reflects frontally controlled disengagement of task-irrelevant regions. Our results demonstrate that resource allocation involving the engagement of task-relevant and disengagement of task-irrelevant regions is needed for optimal task execution.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Alpha Rhythm
  • Attention / physiology
  • Biological Clocks / physiology
  • Brain Mapping
  • Evoked Potentials / physiology
  • Female
  • Frontal Lobe / anatomy & histology
  • Frontal Lobe / physiology
  • Humans
  • Magnetoencephalography
  • Male
  • Memory, Short-Term / physiology*
  • Nerve Net / anatomy & histology
  • Nerve Net / physiology*
  • Neural Pathways / anatomy & histology
  • Neural Pathways / physiology*
  • Neuropsychological Tests
  • Physical Stimulation
  • Psychomotor Performance / physiology
  • Somatosensory Cortex / anatomy & histology
  • Somatosensory Cortex / physiology*
  • Touch Perception / physiology*
  • Young Adult