Intellectual and cognitive stimulation appears to have beneficial effects on cognitive function in the elderly. Few studies, however, have measured the effects of cognitive training on daily functioning, particularly in a large, diverse sample, with a control group. Ball and colleagues tested three cognitive interventions to determine their effect on basic cognitive measures and cognitively demanding functions of daily activity.

The Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial recruited older adults from diverse community sources, including local churches, rosters of senior citizen and community organizations, and rosters of assistance and service programs for low-income elderly persons. Participants with severe physical limitations or substantial cognitive decline were excluded from the study.

The randomized, controlled, single-blinded study included three separate intervention groups and one no-intervention control group. The interventions, which had been chosen for their promising results in laboratory investigations and their correlation with instrumental activities of daily living, included training in memory, inductive reasoning, or speed of processing.

Over five to six weeks, the study participants received training in 10 small-group, 60- to 75-minute sessions, with emphasis on specific skills such as mnemonics (memory training), serial pattern identification (reasoning training), or visual search and identification skills (speed-of-processing training). A shorter series of booster sessions (four 75-minute training periods conducted over two to three weeks) was offered to a randomly chosen subgroup of participants 11 months after the initial training period.

Outcome measures included a test of cognitive abilities (proximal outcome); primary outcomes were aspects of performance-based and self-reported functional activities. Outcome composite scores were compared with baseline scores and control-group scores.

Of the 5,000 persons contacted for participation, 2,832 (65 to 94 years of age) were found to be eligible for the study, and 2,802 were successfully randomized. Training was completed by 89 percent of the participants; 80 percent of the sample remained in the study at two-year follow-up.

Each training program resulted in an immediate positive effect on its corresponding cognitive ability. Study participants who were trained in memory showed a post-test net effect size of 0.257 (P <0.001). Those who completed reasoning training had a post-test net effect size of 0.480 (P <0.001), and those who finished speed training had the greatest net effect size, –1.463 (P <0.001). The beneficial effects persisted, although in slightly attenuated form, over the 24-month observation period. Booster training had an additional positive effect on reasoning and speed but not on memory skills.

Although secondary analyses showed reliable improvement in 87 percent of speed-trained participants, 74 percent of reasoning-trained participants, and 26 percent of memory-trained participants, a comparable proportion of control subjects also improved. Significant effects on functional outcome were not found.

This large-scale study demonstrated that cognitive training results in improvement in the particular cognitive domain for which training was received. However, the improvement did not carry over to actual functional living skills. Booster training had an additional positive effect, and training continued to have some lasting impact over the two-year study period. The authors surmised that the study failed to show functional improvement because of the high-level baseline functioning of the participants and because, as previous research has shown, age-related declines in measures of everyday functioning tend to occur later than declines in the specific basic cognitive abilities measured by the ACTIVE study.