A study led by researchers from the University of Exeter investigated if eating blueberries could enhance the brain. A group of healthy older adults were given blueberry concentrate for 12 weeks, then had their brains scanned, and performed tests of cognitive function similar to those from Creyos (formerly Cambridge Brain Sciences).
Relative to a control group, the blueberry consumers had increased brain activity in areas related with cognitive function. There was also a small boost in actual performance on a working memory task. The authors point out that there is building evidence that the flavonoids in blueberries have antioxidant and anti-inflammatory properties that could reduce age-related cognitive decline.
Read the paper's abstract here.
As usual, I'll point out that it's just one small study and the results should be interpreted with caution. But it won't hurt to eat more blueberries and monitor how your cognition changes using Creyos cognitive tasks.