Walter Freeman III and the Chaotic Nature of Dreams.

The contributions and life of Walter Freeman III are celebrated through an understanding of the neurodynamics of the dreaming brain. Beginning with a brief review of the universal dynamics of self-organizing systems, this paper turns to an exploration of dreaming through the application of concepts from chaos theory to brain activity during REM-state dreaming. Recent studies of the electrophysiology of the brain during REM state dreaming are reviewed, such as the active inhibition of sensory stimulation and, especially in REM sleep, alterations in the brain's dominant neuromodulatory systems, bombardment of the visual cortex with bursts of PGO activity, increased limbic system activity, and a reduction of activity in the brain's prefrontal regions. The paper briefly examines these findings in terms of the experience of dreaming itself as revealed by dream reports. The results suggest a reconciliation of brain-based and content-based attempts to understand the nature of dreaming.