Sleep and Dreams

The visual system is highly dependent on sleep for the organization of the brain and learning about the visual world. During the first year of life, one of the steepest periods of experience-dependent learning, infants sleep 70 to 80% of the time each day. Sleep deprivation during critical periods of kitten visual development produces abnormal organization of the visual cortex. These studies indicate that normal development of perception and the brain structures subserving perception are dependent on early experience and sleep. Although sleep needs changes throughout the lifespan, research shows that sleep is essential for health, memory, and restorative processes, including visual learning.

Dreams during rapid eye movement (REM) sleep are considered perceptual processes without the constraints of external stimuli. Dreams are multisensory experiences for both sighted and congenitally blind individuals. This indicates that the ability to form visual images may be independent of visual perception. This entry focuses on sleep basics, dreams and experience, visual learning and nocturnal sleep, and visual learning and naps.