Revolutionizing Sleep Science: A Narrative Review of the Historical Origins and Current Applications of Sleep Neuroimaging.

Sleep neuroimaging is a subfield of sleep science that goes beyond polysomnography by combining neuroimaging techniques with validated sleep research methods to characterize sleep-wake states and investigate sleep-related processes across the 24-hour day. In this article, we review the historical advancements and applications that grew out of somnography leading to current sleep neuroimaging methods. We highlight the power of somnoimages to help visualize sleep research results and communicate complex information about sleep processes. We also suggest several ways in which applying neuroimaging during sleep has opened new avenues to more fully capture the nature of sleep, uncovered mechanisms of sleep-wake regulation, and increased understanding of sleep-related processes. Current applications and future directions of sleep neuroimaging are also discussed.