Training-induced cerebral changes in the elderly

As the demographic shift towards an aging population prevails, the improvement and/or maintenance of cognitive functioning appear increasingly important. To date, the effectiveness of cognitive, cardiovascular and sensorimotor training approaches in older adults has been demonstrated frequently using neuropsychological and behavioral performance measures. We present an overview of selected studies applying modern imaging techniques ( fMRI, PET) to assess practice-induced structural and functional changes in the brain. Structurally, practice is associated with volumetric increases. Functionally, reorganization of neural network recruitment, overall decreases and increases in activity levels are found. Thus, the human brain retains a high degree of plasticity in old age. Moreover, it seems that practice leads to more efficient processing, requiring less neural engagement to perform the same task. While the concept of economization finds widespread support in healthy populations, in patient groups this effect has proven to be absent or reversed. The concept of cognitive reserve and potentially compensatory mechanisms are discussed in this context.