title: Resting-state neuronal oscillatory correlates of working memory performance.
abstract: OBJECTIVE
  Working memory (WM) represents the brain's ability to maintain information in a readily available state for short periods of time. This study examines the resting-state cortical activity patterns that are most associated with performance on a difficult working-memory task.
  
  
  METHODS
  Magnetoencephalographic (MEG) band-passed (delta/theta (1-7 Hz), alpha (8-13 Hz), beta (14-30 Hz)) and sensor based regional power was collected in a population of adult men (18-28 yrs, n = 24) in both an eyes-closed and eyes-open resting state. The normalized power within each resting state condition as well as the normalized change in power between eyes closed and open (zECO) were correlated with performance on a WM task. The regional and band-limited measures that were most associated with performance were then combined using singular value decomposition (SVD) to determine the degree to which zECO power was associated with performance on the three-back verbal WM task.
  
  
  RESULTS
  Changes in power from eyes closed to open revealed a significant decrease in power in all band-widths that was most pronounced in the posterior brain regions (delta/theta band). zECO right posterior frontal and parietal cortex delta/theta power were found to be inversely correlated with three-back working memory performance. The SVD evaluation of the most correlated zECO metrics then provided a singular measure that was highly correlated with three-back performance (r = -0.73, p<0.0001).
  
  
  CONCLUSIONS
  Our results indicate that there is an association between WM performance and changes in resting-state power (right posterior frontal and parietal delta/theta power). Moreover, an SVD of the most associated zECO measures produces a composite resting-state metric of regional neural oscillatory power that has an improved association with WM performance. To our knowledge, this is the first investigation that has found that changes in resting state electromagnetic neural patterns are highly associated with verbal working memory performance.
authors.affiliation: Department of Radiology, University of California San Diego, San Diego, California, United States of America. dheister@ucsd.edu
authors.forename: David
authors.initials: D
authors.lastname: Heister
authors.forename: Mithun
authors.initials: M
authors.lastname: Diwakar
authors.forename: Sharon
authors.initials: S
authors.lastname: Nichols
authors.forename: Ashley
authors.initials: A
authors.lastname: Robb
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Angeles
authors.forename: Omer
authors.initials: O
authors.lastname: Tal
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Harrington
authors.forename: Tao
authors.initials: T
authors.lastname: Song
authors.forename: Roland R
authors.initials: RR
authors.lastname: Lee
authors.forename: Mingxiong
authors.initials: M
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology; D002540:Cerebral Cortex / Q000166:cytology / Q000502:physiology; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009474:Neurons / Q000166:cytology*; D012146:Rest / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult