title: Decreases in theta and increases in high frequency activity underlie associative memory encoding.
abstract: Episodic memory encoding refers to the cognitive process by which items and their associated contexts are stored in memory. To investigate changes directly attributed to the formation of explicit associations, we examined oscillatory power captured through intracranial electroencephalography (iEEG) as 27 neurosurgical patients receiving subdural and depth electrodes for seizure monitoring participated in a paired associates memory task. We examined low (3-8Hz) and high (45-95Hz) frequency activity, and found that the successful formation of new associations was accompanied by broad decreases in low frequency activity and a posterior to anterior progression of increases in high frequency activity in the left hemisphere. These data suggest that the observed patterns of activity may reflect the neural mechanisms underlying the formation of novel item-item associations.
authors: Department of Psychology, University of Pennsylvania, 19104, USA.
authors: Jeffrey A
authors: JA
authors: Greenberg
authors: Department of Psychology, University of Pennsylvania, 19104, USA.
authors: John F
authors: JF
authors: Burke
authors: Surgical Neurology Branch, NINDS, National Institutes of Health, 20892, USA.
authors: Rafi
authors: R
authors: Haque
authors: Department of Psychology, University of Pennsylvania, 19104, USA.
authors: Michael J
authors: MJ
authors: Kahana
authors: Surgical Neurology Branch, NINDS, National Institutes of Health, 20892, USA. Electronic address: kareem.zaghloul@nih.gov.
authors: Kareem A
authors: KA
authors: Zaghloul
mesh_terms: D000328:Adult; D001245:Association Learning / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D058256:Brain Waves; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D061212:Memory, Episodic; D008875:Middle Aged; D013826:Theta Rhythm; D055815:Young Adult
keywords: Associative memory encoding; Episodic memory; Subsequent memory effect; iEEG