Age-related neural dedifferentiation in the motor system.
Recent neuroimaging studies using multi-voxel pattern analysis (MVPA) show that distributed patterns of brain activation elicited by different visual stimuli are less distinctive in older adults than in young adults. However, less is known about the effects of aging on the neural representation of movement. The present study used MVPA to compare the distinctiveness of motor representations in young and older adults. We also investigated the contributions of brain structure to age differences in the distinctiveness of motor representations. We found that neural distinctiveness was reduced in older adults throughout the motor control network. Although aging was also associated with decreased gray matter volume in these regions, age differences in motor distinctiveness remained significant after controlling for gray matter volume. Our results suggest that age-related neural dedifferentiation is not restricted to sensory perception and is instead a more general feature of the aging brain.
Department of Psychology, University of Michigan, Ann Arbor, Michigan, USA. jmcarp@umich.edu
Joshua
J
Carp
Joonkoo
J
Park
Andrew
A
Hebrank
Denise C
DC
Park
Thad A
TA
Polk
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001921:Brain / Q000166:cytology / Q000502:physiology*; D002454:Cell Differentiation; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D055815:Young Adult