Two recent studies shed light on ways to optimize cognitive performance. Here’s what the researchers found.
- Sleeping seven to eight hours a night is best for cognitive performance for most people, according to a large study in the journal Sleep. Canadian researchers had more than 10,000 people from around the world complete online surveys and cognitive tests. Participants reported that they slept 6.4 hours per night, on average, during the past month. When the researchers correlated typical sleep durations with the cognitive test results, they found that, regardless of age, participants sleeping seven to eight hours per night performed best, on average, especially on tests of reasoning and verbal ability; short-term memory was not affected by sleep duration. People who regularly slept less than seven hours a night and those sleeping more than eight hours were equally impaired.
- Computerized brain training produces improvements only on the specific tasks undertaken, not on other cognitive tasks, even similar ones, according to a Canadian study in the journal Neuropsychologia. Researchers had 48 healthy participants train on a test of short-term working memory involving a search for tokens hidden behind squares on the screen (totaling 13 hours of training over 20 days). Not surprisingly, the participants became good at that test. But when they were subsequently tested on a different but very similar computerized task, they did no better than a control group who hadn’t done the first brain training.