Importantly, however, the gains were not maintained after a 90-day period of non-juggling, providing important evidence that there are many constraints on plasticity, and that the familiar “use or lose it” adage was disappointingly relevant in this particular study. Other evidence shows that older men who played a demanding spatial navigational game every other day for 4 months exhibited stability of hippocampal volume over a 4-month period, whereas control subjects declined.34 Additionally, these trained subjects showed an increase in structural integrity

of the hippocampus which was maintained when training ceased. Overall, however, the evidence that one can improve volume of neural structures Inhibitors,research,lifescience,medical through training is relatively sparse. The limited data available suggest that gains that are realized from

a sustained training program most likely need to be maintained with continued performance. An important question is whether continuous improvement and challenge Inhibitors,research,lifescience,medical on a task is required to maintain gains, or whether mere maintenance of a high level of improved but asymptotic performance would be sufficient to preserve gains. It seems likely that it will be important for individuals to enjoy the Inhibitors,research,lifescience,medical tasks they are performing over the very long term so that the behavior can be sustained and gains maintained. This may be the greatest challenge associated with training the aging human brain. From a clinical perspective, daily “brain training” could become a boring and effortful task, such that gains realized might be offset by the negative consequences of performing a task that over time could become a dreaded obligation rather than a pleasurable and stimulating activity. Changes in neural activity A more common finding Inhibitors,research,lifescience,medical than volumetric increase is a change in neural activity with training. The change can be in the form of activation of new regions, or decreases or

increases in neural activity in task related structures that were activated before the training. Inhibitors,research,lifescience,medical The neural differences between pretest and post-test can be quite hard to interpret, and may or may not reflect a fundamental change in brain function or organization. Noack et al35 argue that many changes in activation as a result of training reflect flexibility in deployment of resources due to strategy change rather than a manifestation of plasticity resulting others in an increase in intrinsic neural or cognitive capacity. They argue that the rich knowledge base that accrues as we age provides an excellent mechanism for utilizing ZD1839 nmr wisdom and knowledge to facilitate performance, rather than a true change in the neurocognitive system. They suggest that younger adults have more neural plasticity than old, and that the young are most likely to show an increase in intrinsic neural capacity with training, whereas the old are more likely to recognize gains due to flexibility in strategy use.