Bullshit.
The BHI is designed to detect both improvements and declines in brain health. It measures three primary areas: clarity, emotional balance, and connectedness to people and purpose.
"The BrainHealth Index brings together about 20 metrics, including validated gold-standard measures like the Pittsburgh Sleep Quality Index and the Oxford Happiness Questionnaire, as well as tasks designed at the Center for BrainHealth to focus on more complex thinking skills," said Lori Cook MS'02, PhD'09, CBH director of clinical research and corresponding author of the Scientific Reports study. "This battery of assessments produces insights into individual brain health and change over time. Progress is measured by comparing results with participants' own earlier scores."
They couldn't find a single metric that showed what they wanted. So they crumpled all the metrics into a big meaningless ball, and said sometimes in some aspects things get better.
And it seems like a reasonable expectation is that the elderly who saw improvement, just saw a short term bump from becoming more mentally active. It's a good bump and people should stay mentally active.
But acting like a small bump overcomes the natural effects of aging is fucking ridiculous.
Like if a 600lb person loses 50lbs. It's an improvement, but it doesn't mean they're healthy. Just less unhealthy.