”Morn­ing larks” have weaker sleep spindles dur­ing night than “night owls”

A new study from the University of Helsinki shows that individual circadian preference is associated with brain activity patterns during the night. Sleep spindles are bursts of oscillatory brain activity visible on an EEG that occur mainly during stage 2 sleep. Sleep spindles are linked for example to sleep maintenance and strengthening of the memory traces during sleep.

Are learning and unlearning bedfellows?

We know that sleep helps us integrate knowledge acquired during the day. But can we learn new things while sleeping? By exposing subjects to repeated auditory stimuli, a team of researchers has just demonstrated that the brain is capable of learning such sound patterns during certain sleep stages—though they may be forgotten during deep sleep. Led by the Laboratoire de Sciences Cognitives et Psycholinguistique (CNRS / ENS / EHESS) in collaboration with the Laboratoire des Systèmes Perceptifs (CNRS / ENS) and the Centre du Sommeil et de la Vigilance (AP-HP / Paris Descartes University) at Hôtel Dieu Hospital, this study is the subject of an article published in Nature Communications on August 8, 2017.