Non-rapid eye movement sleep activation occurs during NREM that is comparable to the type that occurs during REM. It is this sub-cortical activation that results in dreaming during the NREM stage during the morning hours. During non-REM sleep, the tonic drive to most respiratory muscles of the upper airway is inhibited. This has two consequences: However, because the diaphragm is largely driven by the autonomous system, it is relatively spared of non-REM inhibition. As such, the suction pressures it generates stay the same. This narrows the upper airway during sleep, increasing resistance and making airflow through the upper airway turbulent and noisy. For example,
Eye movement in scene viewing Eye movement in scene viewing Eye movement in scene viewing refers to the visual processing of information presented in scenes. This phenomenon has been studied in a range of areas such as cognitive psychology and psychophysics, where eye movement can be monitored under experimental conditions. A core aspect in these studies is the division of eye movements into saccades, the rapid movement of the eyes, and fixations, the focus of the eyes on a point. There are several factors which influence eye movement in scene viewing, both the task and knowledge of the viewer (top-down factors), and the properties of