Brain aging and psychometric intelligence: a longitudinal study

Area of Science:

• Neuroscience
• Gerontology
• Cognitive Psychology

Background:

• Aging is associated with structural brain changes and potential cognitive decline.
• Understanding the relationship between brain anatomy and intelligence in older adults is crucial.

Purpose of the Study:

• To investigate longitudinal changes in brain anatomy and their association with cognitive function in healthy older adults.
• To examine the relationship between brain structure (grey matter, white matter, ventricles, white matter lesions) and psychometric intelligence over four years.

Main Methods:

• Longitudinal study of 231 healthy older adults over 4 years with 4 measurement points.
• Utilized latent growth curve models to analyze brain anatomical measures (grey matter, normal-appearing white matter, lateral ventricles, white matter hypointensities) and intelligence (verbal, non-verbal).

Main Results:

• Significant decreases in grey matter (GM) and normal-appearing white matter (NAWM) were observed annually.
• Increases in white matter hypointensities (WMH) and lateral ventricle (LV) volumes were noted annually.
• Verbal and non-verbal IQ scores remained stable; positive associations between baseline GM/NAWM and IQ were found, but no significant longitudinal associations between brain changes and IQ changes.

Conclusions:

• Healthy older adults show age-related neuroanatomical decline over 4 years.
• Despite structural brain changes, cognitive functions like IQ remained stable in this cohort.
• Neuroanatomical decline does not necessarily correlate with simultaneous cognitive deterioration in healthy aging.