AGING, BRAIN SIZE, AND IQ

Brain size and certain aspects of intellectual functioning, in particu lar nonverbal, perceptual motor abilities as measured by the Performan ce Intellectual Quotient (PIQ) of the Wechsler Adult Intelligence Scal e-Revised (WAIS-R), decline with age. This investigation examined whet her cross-sectional rates of decline for brain volume and PIQ were equ ivalent over the years 16-65. Whole brain volume changes determined by magnetic resonance (MR) imaging techniques, were based on normative d ata presented by Flatter et al. (1995). PIQ sums of scaled scores were from the WAIS-R standardization sample as analyzed by Kaufman et al. (1991). Results of univariate regression analyses indicate remarkably similar rates of decline. The potential relationship between magnetic resonance (MR) identified anatomic atrophic changes in whole brain vol ume and perceptual motor decline associated with age is discussed.