From typicallyspanish.com

Spanish Oddities
A 90 minute siesta can improve your memory according to new research
By h.b.
Jan 17, 2008 - 8:13 PM

A new study has shown that taking a 90 minutes siesta improves your long-term memory and improves your ability to retain data. The study was carried out by researchers in Israel at the Brain Behaviour Centre in the Haifa University.

They say they don’t know exactly what is going on, but their results suggest that the memory is enforced during the siesta and that in the future the memory could be consolidated artificially.

Two groups took part in the testing, and those who enjoyed a siesta adapted to a new learning task better than the other group, provided the comparison was made before nightfall. The following morning abilities were equal between both groups.