Topic: NREM sleep

How sleep contributes to visual perceptual learning

Sleep is crucial for the continuity and development of life. Sleep-related problems can alter brain function, and cause potentially severe psychological and behavioral consequences. However, the role of sleep in our mind and behavior is far from clear. In this talk, I will present our research on how sleep may play a role in visual perceptual learning (VPL) by using simultaneous magnetic resonance spectroscopy and polysomnography in human subjects. We measured the concentrations of neurotransmitters in the early visual areas during sleep and obtained the excitation/inhibition (E/I) ratio which represents the amount of plasticity in the visual system. We found that the E/I ratio significantly increased during NREM sleep while it decreased during REM sleep. The E/I ratio during NREM sleep was correlated with offline performance gains by sleep, while the E/I ratio during REM sleep was correlated with the amount of learning stabilization. These suggest that NREM sleep increases plasticity, while REM sleep decreases it to solidify once enhanced learning. NREM and REM sleep may play complementary roles, reflected by significantly different neurochemical processing, in VPL.

40-Hz stimulation during NREM sleep induces a specific auditory steady-state response and an increase in the sleep-spindle power associated with up and down cortical states

Coupling during NREM sleep between the prelimbic cortex, nucleus reuniens, and hippocampus remains stable under cognitive and ho-meostatic demands

Increased cortical plasticity enhances one-trial memory but leads to increased interference of semantic-like memory and changes in NonREM sleep oscillations in rats