We still don’t have a strong grasp on why we sleep. We know that not getting sleep can be extremely bad for you, but getting the right amount of sleep can be pretty helpful. A recent French study has shown that sleeping between lessons can actually help people learn by improving retention and relearning, even as much as six months after a lesson.

The study split people into two groups, one that had two lessons in the same day, and one that had lessons in the evening and following morning. In both cases, they were shown pairs of French and Swahili words to memorize.

Both groups had very similar results in their first lesson, based on how many attempts it took to translate all the French words into Swahili. But the group of people who got to sleep between lessons did better during the second lesson, recalling words faster and getting them correct after fewer attempts. A week after the initial test, the group that slept recalled more word pairs, which was true six months later as well.

“Our results suggest that interleaving sleep between practice sessions leads to a twofold advantage, reducing the time spent relearning and ensuring a much better long-term retention than practice alone,” says psychologist Stephanie Mazza of the University of Lyon, one of the scientists who conducted the study. “Previous research suggested that sleeping after learning is definitely a good strategy, but now we show that sleeping between two learning sessions greatly improves such a strategy.

While further study is certainly needed on this subject, it could open some interesting doors in education. Might it be better to schedule classes so that students alternate between evening and morning for a given subject? Does this process work for students who are engaging in multiple subjects, as they do in primary and secondary education?

The quality of sleep the participants got didn’t seem to matter, so sleep between lessons might be helpful for college students, who are notorious for not getting enough sleep but who certainly need to retain and recall information every day.