Relationships between cognitive function and frontal grey matter volumes and thickness in middle aged and early old-aged adults: the PATH Through Life Study.
The study examined the relationship of lateral frontal cortical volume and thickness with cognitive function in two samples of healthy middle aged (MA, 44-48 years old) and early old-age (OA, 64-68 years old) adults. T1-weighted magnetic resonance imaging scans were acquired in 400 MA and 397 OA adults from respective random community samples. Cortical volumes and thickness were measured with a surface-based segmentation procedure (http://surfer.nmr.mgh.harvard.edu). Volumes of lateral frontal grey matter were found to be significantly lower for OA than MA. Structure-function relationships were investigated using path analyses. In OA, smaller lateral frontal volumes were associated with better episodic memory (EM) (p<0.012, B=-0.117), and Symbol-Digit Modalities Test (SDM) (p<0.031, B=-0.118) performance. Smaller frontal cortical thickness was also associated with better EM (p<0.01) and SDM (p<0.01) performance in OA. However, in MA greater cortical thickness was associated with better EM and (p<0.01) and reaction time (RT) (p<0.01). OA cohort showed significant positive correlations between Total Brain Volume and SDM, Digit-Backwards span and RT. Possible explanations and implications of the relationships in the context of cognitive aging in healthy adults, and limitations of cross-sectional research are discussed.
Centre for Mental Health Research, Australian National University, Canberra, ACT, Australia. prapti.gautam@anu.edu.au
Prapti
P
Gautam
Nicolas
N
Cherbuin
Perminder S
PS
Sachdev
Wei
W
Wen
Kaarin J
KJ
Anstey
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D004522:Educational Status; D016021:Epidemiologic Studies; D005260:Female; D005625:Frontal Lobe / Q000033:anatomy & histology* / Q000254:growth & development*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012959:Socioeconomic Factors; D055815:Young Adult