(See the paper for many more model dissections!) So, why does this happen? Is it just a quirk of the brain? We argue that, given computational constraints, it may be optimal to strengthen memories according to their temporal regularity. … 16/

That is, information repeated hourly and then not again will likely only be important for the next few hours-days. But information repeated monthly could be important for months-years. This arrangement allows for optimizing storage according to temporal regularity. 17/