Poster at the Human Brain Mapping conference, San Francisco June 2009

Healthy aging is often accompanied by a decline in motor function, in particular a decrease in the speed  of movements and a loss of coordination.  Functional brain imaging makes it possible to  compare movement-related brain activity between  younger and older individuals. In many of these  studies, brain function of older participants has been  characterized by under- and over-activation in parts of the neural circuitry when compared with  younger adults. These functional changes may result  from neuroplasticity in the aging brain, compensat-  ing for loss of sensorimotor function and contribut- ing to maintaining of behavioral performance.  Our results indicate that healthy aging is associated  with changes in the cerebral control of movements.  These changes are characterized by areas of over-  activation (in particular, the supplementary motor  area) and under-activation (including the sensori-  motor cortex, cingulate motor area, insula, and cere-  bellar hemispheres) in the aging brain as compared  to younger adults.  Increased activation in brain areas that subserve  movement initiation and control is compatible with  the hypothesis that healthy aging is accompanied by  a shift from automatic to a more controlled pro-  cessing of movement (Heuninckx et al. 2005). The  underlying patho-anatomical mechanisms for this  cerebral reorganization of movement control are un-  clear and might involve gray matter atrophy, disrup-  tion of white matter fiber tracts, and alterations in  regional neurotransmission. More studies are war-  ranted to illicit structural and functional changes in  the healthy aging brain.