Frontal theta activity in humans increases with memory load in a working memory task

Recent theoretical work has suggested that brain oscillations in the theta band are involved in active maintenance and recall of working memory representations. To test this theoretical framework we recorded neuromagnetic responses from 10 subjects performing the Sternberg task. Subjects were required to retain a list of 1, 3, 5 or 7 visually presented digits during a 3-s retention period. During the retention period we observed ongoing frontal theta activity in the 7-8.5-Hz band recorded by sensors over frontal brain areas. The activity in the theta band increased parametrically with the number of items retained in working memory. A time-frequency analysis revealed that the task-dependent theta was present…

• SO
  Sundhed og Sygdom, Det Frie Forskningsråd
• NI
  National Institutes of Health
• NI
  National Institute of Neurological Disorders and Stroke