Cerebellum Brain Volume and Cognitive Performance
Frontal lobe atrophy is implicated in patterns of age-related cognitive decline. However, other brain areas, including the cerebellum, support the work of the frontal lobes and are also sensitive to the effects of ageing. A relationship between cerebellar brain volume and cognitive function in older adults is reported, but no study has separated variance associated with cerebellar gray matter volume and cerebellar white matter volume; and no study has examined whether or not brain volume in the cerebellum is related to cognitive function in older adults after statistical control for frontal lobe volume of gray and white matter.
We used voxel based morphometry (VBM) and structural equation modelling (SEM) to analyse relations between general cognitive ability (G) and volume of GM and WM in frontal areas and cerebellum in a sample of 228 older adults (121 males and 107 females).
Results indicate that GM volume in the cerebellum predicts G, even when total intracranial volume (TICV) and GM gray and WM volumes in frontal lobes are statistically controlled. However, results differ for males and females, with males showing a stronger relationship between brain volume in the cerebellum and G.
Results are discussed in light of neurological models of cognitive ageing and the significance of the cerebellum in models of cognitive functioning.
From press release:
Research suggests that intelligence in humans is controlled by the part of the brain known as the 'cortex', and most theories of age-related cognitive decline focus on cortical dysfunction. However, a new study of Scottish older adults, reported in the April 2011 issue of Elsevier's Cortex, suggests that grey matter volume in the 'cerebellum' at the back of the brain predicts cognitive ability, and keeping those cerebellar networks active may be the key to keeping cognitive decline at bay.
The study looked at 228 older adults living independently in the Aberdeen area, who had been part of the Scottish Mental Survey of 1947. This survey had tested Scottish children born in 1936 and at school on 4th June 1947 using the Moray House intelligence test. The cognitive abilities of the participants were tested again, now at age 63-65 years, and their brains were also scanned, using a neuroimaging technique called voxel-based morphometry (VBM), to determine the volumes of grey and white matter in frontal areas and the cerebellum.
The most interesting finding from this study is that grey matter volume in the cerebellum predicts general intelligence. However, results differ for men and women, with men showing a stronger relationship between brain volume in the cerebellum and general intelligence.
It has long been recognised that the cerebellum is involved in sensory-motor functions, including balance and timing of movements, but it is now believed that the cerebellum also plays an important role in higher-level cognitive abilities. "General intelligence is correlated with many basic aspects of information processing efficiency which I believe depend upon the functioning of the cerebellum, including the speed and consistency of our perceptions and decisions, and the speed with which we learn new skills," notes Dr. Michael Hogan, first author of the study. "This is exciting research, as it suggests that there may be a backdoor route into maintaining higher cortical functions in old age, that is, through the sustained activation of cerebellar networks via novel sensory-motor and cognitive activities, all of which I believe the cerebellum seeks to regulate and automate, working in concert with the cortex."
Michael J. Hogan, Roger T. Staff, Brendan P. Bunting, Alison D. Murray, Trevor S. Ahearn, Ian J. Deary, Lawrence J. Whalley.
Cerebellar brain volume accounts for variance in cognitive performance in older adults.