Candidate cellular mechanisms underlying gray matter plasticity include axon sprouting, dendritic branching and synaptogenesis, neurogenesis and glial changes whereas the mechanisms underlying white matter changes include myelination, changes in fiber organization, astrocyte changes and angiogenesis (Zatorre et al., 2012). doi: 10.1016/j.neurobiolaging.20 Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text Filippi, M., and Agosta, F. Structural and functional network connectivity breakdown in Alzheimer’s disease studied with magnetic resonance imaging techniques. Thus, cognitive training has begun to receive increased attention in recent years as a non-pharmacological, cost-effective intervention and treatment of AD. Training-induced plasticity in older adults: effects of training on hemispheric asymmetry. Recent findings suggest that cognitive training results in neuroanatomical and functional changes that extend into advanced age. (2003) were among the first to show changes in occipito-parietal activity in older adults who benefited from memory training using O-15 HO PET. Since then, several functional MRI and PET studies have shown training-related changes in brain activity in healthy older adults [see Belleville and Bherer, 2012 for a review]. It has been shown that cognitive training can reduce age differences in ventral and dorsal prefrontal activation (Erickson et al., 2007) and decrease neocortical brain activity observed with functional MRI (Brehmer et al., 2011), and increase resting cerebral blood flow to the default-mode network and central executive network observed with perfusion MRI (Mozolic et al., 2010; Chapman et al., 2013) in older adults. These findings provide evidence for functional plasticity in old age and suggest a mixed pattern of increased and decreased activation in response to training in healthy older adults. doi: 10.1002/hbm.21370 Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text Engvig, A., Fjell, A.
These widespread neuronal changes suggest the importance of neuroimaging studies to investigate the overlap between neural networks rehabilitated by the training procedure and those affected in AD. Hippocampal subfield volumes correlate with memory training benefit in subjective memory impairment. doi: 10.1016/j.neuroimage.20 Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text Erickson, K.
Alzheimer’s disease (AD) is the most common form of dementia, a general term for memory loss and other intellectual abilities serious enough to interfere with daily life.
Recent World Alzheimer’s Report indicates that over 35 million people worldwide have AD in 2013 and this number is expected to triple by 2050 (Prince et al., 2013). In the United States, AD is the sixth leading cause of death across all ages (Murphy et al., 2013) and over 500,000 deaths annually may be attributable to AD in older adults aged 75 years and older in 2010 (James et al., 2014). Effects of a 6-month cognitive intervention program on brain metabolism in amnestic mild cognitive impairment and mild Alzheimer’s disease.
Evidence regarding training-related structural plasticity in old age is more recent.
Boyke et al.’s (2008) study was one of the earliest successful attempts that showed increased gray-matter volume in the middle temporal regions in older adults after 3 months of training on a three-ball cascade juggling. Memory training impacts short-term changes in aging white matter: a longitudinal diffusion tensor imaging study.