Intensive language learning and increases in rapid eye movement sleep: evidence of a performance factor

Ten anglophone students taking a 6-week French immersion course were recorded in the sleep laboratory during 4 consecutive nights before the course, during the course and after the course. There was a positive and significant ( P < 0.05) correlation between language learning efficiency and increases in the percentage of rapid eye movement (REM) sleep from pre-course to course periods. This observation suggests that learning performance may be an important factor in the relationship between information processing and REM sleep.