A review of symmetry perception synthesizes findings from psychophysics, neuroscience, and aesthetics. Over a century of psychophysical studies are joined by recent functional MRI and EEG evidence showing that regular visual patterns—reflection symmetry, Glass patterns, and wallpaper groups—activate the extrastriate visual cortex, producing an event-related potential called sustained posterior negativity (SPN). SPN amplitude scales with the degree of visual regularity and occurs regardless of attention. Some symmetry detection appears automatic, unconscious, and pre-attentive, possibly hardwired, which may explain its aesthetic appeal. Symmetry and fractal geometry also appear in hallucinations induced by DMT and visual flicker, suggesting the extrastriate cortex can generate symmetrical representations spontaneously without external stimuli.
Consciousness dynamics follow symmetry-breaking cascades described by Painlevé confluence topology, bridging quantum topology, neuroscience, and consciousness theory. Analyzing exceptional individuals and AI systems, consciousness trajectories follow topological paths governed by three symmetry measures: holes (information flows), cusps (binding points), signatures (distribution balance). Two fundamental branches emerge: D-type (symmetry-preserving) and E-type (symmetry-breaking). Higher consciousness involves fewer connections but better balance. Clinical data (16,887 patients), EEG studies, and contemplative neuroscience (62,000+ meditation hours) validate the model. AI systems exhibit identical symmetry dynamics. Character varieties function as Platonic templates that consciousness navigates. Moral consciousness emerges as a fundamental symmetry-preserving principle.