Implicit learning is a form of learning that we are usually not aware of. As opposed to explicit learning, which includes things like learning new words or ideas, implicit learning involves acquiring motor skills like typing or playing tennis. Using implicit motor tasks, researchers are able to gauge how well new skills are learned in a controlled setting. How well these skills are learned is thought to be a marker of how efficiently the brain is working. Interestingly, quality sleep is known to greatly benefit the acquisition of motor skills. Since we know those with untreated sleep apnea often do not have quality sleep, can their learning of these skills be impacted?
Using a common motor learning task, a research team trained 12 subjects with sleep apnea and 12 subjects without sleep apnea on a finger-tapping sequence. Subjects used one hand to repeatedly type a 5-digit sequence. They were told to do so 12 times, and all subjects greatly improved over the course of the 12 trials. Subjects then underwent an overnight sleep study and were retested on the finger-tapping sequence in the morning.
Typically, subjects improve greatly on this task after they sleep. However, in this case, results showed that only the group without sleep apnea improved after sleep, meaning those with sleep apnea did not learn the new skill. This may be related to the fact that the sleep apnea subjects spent much more time awake during the night than the non-sleep apnea group. However, there was no correlation between sleep measures and overnight improvement in either group1.
While a finger-tapping task may not seem real-life relevant, poor performance after sleep is reflective of learning dysfunction. In this population, those with sleep apnea were unable to acquire the motor skills learned by the non-sleep apnea group, showing that their brain does not efficiently pick up new memories the way it should. A follow-up study showing how those with treated sleep apnea do indeed learn after sleep would be the final piece to this puzzle, so stay tuned!
Pre-publication, Journal of Clinical Sleep Medicine: “The Impact of Obstructive Sleep Apnea on Motor skill Acquisition and Consolidation”