Cognitive training involves structured activities designed to enhance memory, reasoning, and speed of processing. There is encouraging but inconclusive evidence that a specific, computer-based cognitive training may help delay or slow age-related cognitive decline. However, there is no evidence that it can prevent or delay Alzheimer's-related cognitive impairment.
Studies show that cognitive training can improve the type of cognition a person is trained in. For example, older adults who received 10 hours of practice designed to enhance their speed and accuracy in responding to pictures presented briefly on a computer screen ("speed of processing" training) got faster and better at this specific task and other tasks in which enhanced speed of processing is important. Similarly, older adults who received several hours of instruction on effective memory strategies showed improved memory when using those strategies. The important question is whether such training has long-term benefits or translates into improved performance on daily activities like driving and remembering to take medicine.
Some of the strongest evidence that this might be the case comes from the NIA-sponsored Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial. In this trial, healthy adults age 65 and older participated in 10 sessions of memory, reasoning, or speed-of-processing training with certified trainers during 5 to 6 weeks, with "booster sessions" made available to some participants 11 months and 3 years after initial training. The sessions improved participants' mental skills in the area in which they were trained (but not in other areas), and improvements persisted years after the training was completed. In addition, participants in all three groups reported that they could perform daily activities with greater independence as many as 10 years later, although there was no objective data to support this.
Findings from long-term observational studies—in which researchers observed behavior but did not influence or change it—also suggest that informal cognitively stimulating activities, such as reading or playing games, may lower risk of Alzheimer's-related cognitive impairment and dementia. For example, a study of nearly 2,000 cognitively normal adults 70 and older found that participating in games, crafts, computer use, and social activities for about 4 years was associated with a lower risk of MCI.
Scientists think that some of these activities may protect the brain by establishing "reserve," the brain's ability to operate effectively even when it is damaged or some brain function is disrupted. Another theory is that such activities may help the brain become more adaptable in some mental functions so it can compensate for declines in others. Scientists do not know if particular types of cognitive training—or elements of the training such as instruction or social interaction—work better than others, but many studies are ongoing.