Deterioration of frontal lobe function in normal aging: influences of fluid intelligence versus perceptual speed

Neuropsychology. 1999 Oct;13(4):539-545. doi: 10.1037//0894-4105.13.4.539.


A group of young participants were compared with 2 groups of older participants (young-old, 65-74 years and old-old, 75 years or over) on a range of frontal lobe tasks. They were also assessed on the Digit Symbol Substitution Test (DSST), a test of digit cancellation (DC), the AH4 test of fluid intelligence, and the National Adult Reading Test (NART)-a measure of crystalized intelligence. Reliable age differences on all frontal measures except word fluency (FAS) were found. However, age effects were radically attenuated when either DSST speed or Alice Heim 4 (AH4) performance was used as a covariate. In contrast, DC and NART attenuated age-related variance to a much lesser degree. The authors conclude that a large proportion of age-related variance on measures of frontal lobe function may be attributed to a more general factor characterized jointly by DSST and AH4 performance.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Aging / physiology
  • Aging / psychology*
  • Analysis of Variance
  • Female
  • Frontal Lobe / physiology*
  • Humans
  • Intelligence*
  • Male
  • Perception / physiology*
  • Psychological Tests / standards
  • Psychomotor Performance / physiology*
  • Reaction Time
  • Reference Values
  • Regression Analysis