During REM sleep, the locus coeruleus stops releasing noradrenaline. By blocking the cascade, the association between memory and emotional response is broken. This may not occur so frequently in restless sleepers, resulting in rumination and PTSD-like symptoms. For those who usually sleep well, embarrassing feelings experienced at night may be reduced by morning.
A new deep learning algorithm is able to quantify arousal and awareness in humans at the same time.