46:30 - 47:30 older brain doesn't keep details, relies on abstractions, but the details are what can be remembered.
Dr. Merzenich claims old brain can be "rejuvenated" to some extent and is applying a software system for regular practice. The results from such tests can be improved significantly by practice, e.g. 70-80 year-old can achieve results of people in their 30s.
IMHO articles are a bit chatty, but you can filter out useful information.