Neural correlates of variable working memory load across adult age and skill: dissociative patterns within the fronto-parietal network

Scand J Psychol. 2009 Feb;50(1):41-6. doi: 10.1111/j.1467-9450.2008.00678.x. Epub 2008 Aug 12.


We examined neural changes related to variations in working memory load by using an n-back task with three levels and functional magnetic resonance imaging. Younger adults were divided into high- and low-performing groups (Young-High; Young-Low) and compared with older adults. Relative to Young-High, capacity-constraints in working memory were apparent between load 1-2 for the elderly and between load 2-3 for Young-Low. Capacity-constraints in neural activity followed this pattern by showing a monotonically increasing response in parietal cortex and thalamus for Young-High, whereas activity leveled off at 1-back for the elderly and at 2-back for Young-Low. The response in dorsal frontal cortex followed a similar pattern with the addition that the magnitude of activation differed within capacity limitations (Old > Young at 1-back; Young-Low > Young-High at 2-back). These findings indicate that an important determinant of WM capacity is the ability to keep the frontal cortex adequately engaged in relation to current task demands.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aging / physiology*
  • Brain Mapping*
  • Cerebral Cortex / physiology
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Memory / physiology*