That same study revealed that training in each of those three functions did not meaningfully improve scores on performance of real-world cognitive tasks, a result that would have been especially meaningful.
Here’s how the study worked: Over 2,800 normal, healthy seniors (65 and up) from six American cities were recruited for the study, which began in 1998. Participants were randomized to receive training in only ONE of these three areas:
- reasoning (training in solving problems that contain serial patterns)
- processing speed (exercises in visual search and analyzing increasingly complex information presented ever more briefly), or
- memory (instruction and exercises aimed at improving verbal episodic memory
The three active groups received ten training sessions of 60-75 minutes each over a period of about six weeks. In addition, 39% of the subjects undergoing training received four “booster sessions” -- which targeted their specific cognitive training domain -- after 11 months and again after 35 months of the initial training.
Objective Tests and Self-Assessments
In addition to other testing, participants provided their own assessments about how they believed they functioned in performing regular, everyday tasks. They also received objective tests to measure those same abilities.
After ten years, researchers compiled data to measure the effect that those training sessions had over time.
- Processing speed: This cognitive domain seemed most positively affected by training. After ten years, the seniors who had this training actually improved by an average of 24 points on a 1,500 point scale. By contrast, the other three groups (control, memory trainees, and reasoning trainees) averaged a 130 point decline on that same scale of 1,500.
- Reasoning: Trainees in this discipline lost 0.5 points on a 75 point scale after ten years. The others averaged a decline of about 3.5.
- Memory: Curiously, control group members lost (only) 9.4 points on a scale of 132, while the other groups averaged a slightly greater decline (about 11.5) based on lab tests after ten years.
- Cognitive training resulted in improved cognitive abilities that lasted for 10 years after training in reasoning ability and speed-of-processing when compared to older adults who were not trained.
- These gains were even greater for those who got additional “booster” sessions over the next three years.
- The older adults who received brief cognitive training also reported they had less difficulty in performing important everyday tasks.
- Older adults who participated in the cognitive training (memory, reasoning or speed-of-processing) reported less difficulty with everyday tasks than did those who were not trained. Specifically, about 60% of the older adults who participated in the cognitive training compared with 50% of those who were not trained were at or above their starting level of daily function (using medications, cooking, managing their finances).
- Although memory performance improved up to five years following the intervention, there was no longer a significant difference between trained and untrained participants at 10 years.
- Importantly, reasoning and speed-of-processing trained participants still showed significant improvements relative to untrained participants in the trained skills even at 10 years.
- The team also found that a four-session booster training at 11 and at 35 months after the initial training sessions produced additional and durable improvements in the reasoning and speed-of-processing groups.
Salloway also questioned the limited focus of the study -- testing only healthy seniors – adding, "I don't think this is a home run by any means." Still, he thought the study suggested we might “enhance cognitive function with a pretty low-intensity type of training experience.”