Training-induced plasticity in older adults: effects of training on hemispheric asymmetry.
The extent to which cortical plasticity is retained in old age remains an understudied question, despite large social and scientific implications of such a result. Neuroimaging research reports individual differences in age-related activation, thereby educing speculation that some degree of plasticity may remain throughout life. We conducted a randomized longitudinal dual-task training study to investigate if performance improvements (a) change the magnitude or pattern of fMRI activation, thereby suggesting some plasticity retention in old age and (b) result in a reduction in asymmetry and an increase in age differences in fMRI activation as a compensatory model of performance-related activation predicts. Performance improvements were correlated with an increase in hemispheric asymmetry and a reduction in age differences in ventral and dorsal prefrontal activation. These results provide evidence for plasticity in old age and are discussed in relation to an alternative argument for the role of reduced asymmetry in performance improvements.
University of Illinois at Urbana-Champaign, Beckman Institute for Advanced Science and Technology, Department of Psychology, Urbana, IL, United States.
Kirk I
KI
Erickson
Stanley J
SJ
Colcombe
Ruchika
R
Wadhwa
Louis
L
Bherer
Matthew S
MS
Peterson
Paige E
PE
Scalf
Jennifer S
JS
Kim
Maritza
M
Alvarado
Arthur F
AF
Kramer
D000222:Adaptation, Physiological / Q000502:physiology; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009473:Neuronal Plasticity / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology*