Rapid eye movements in sleep are related to visual imagery of semantic contents but not to abstract objects

There is a controversial debate as to whether rapid eye movements (REM) in sleep are related to visual imagery during dreamy states supporting the notion that they may be involved in memory consolidation. Alternatively, they might just represent eye movements with the eyes closed. This study used kinematic parameters (velocity profiles) to compare REM with eye movements in awake volunteers with the eyes closed while they repeated their own visual exploration of previously explored visual targets immediately prior recordings. Polysomnographic recordings including eye movement recordings by EOG were performed in t…