The article from Medical News Today  does a wonderful job of discussing the research:
Now, Dr. Lavretsky and colleagues say practicing yoga and meditation may be just as effective – if not better – for protecting cognitive function.
For their study, the researchers enrolled 25 participants aged 55 and older.
For 12 weeks, 14 of the participants took part in a 1-hour Kundalini yoga class once a week and practiced Kirtan Kriya meditation for 20 minutes every day.
Kundalini yoga is referred to as the “yoga of awareness,” incorporating breathing techniques, meditation, and chanting.
Kirtan Kriya meditation involves chanting, hand movements, and light visualization. Dr. Lavretsky notes that this form of meditation has been practiced in India for hundreds of years as a way to maintain cognitive function in older adults.
The remaining 11 participants engaged in 1 hour of memory enhancement training – through activities such as crossword puzzles or computer games – once a week for 12 weeks, and they also spent 20 minutes a day completing memory exercises.
At the beginning and end of the 12-week study period, all participants completed memory tests and underwent functional magnetic resonance imaging (fMRI), enabling the researchers to assess their cognitive function and brain activity.
The team found that both groups showed improvements in verbal memory skills – the ability to remember names and lists of words – at the end of the 12 weeks.
However, the participants who practiced yoga and meditation demonstrated greater improvements in visual-spatial memory skills – the ability to navigate and remember locations – than those who engaged in memory enhancement training.
The team says the latter finding is particularly relevant for people who experience MCI, as the condition can be emotionally difficult to come to terms with.
“When you have memory loss, you can get quite anxious about that and it can lead to depression,” notes Dr. Lavretsky.
On assessing participants’ brain activity, the researchers found that improvements in verbal memory and visual-spatial memory correlated with changes in brain connectivity.