Symmetry Perception and Psychedelic Experience

This review of symmetry perception has six parts. Psychophysical studies have investigated for over 100 years (part 1). Neuroscientific on accumulated in the last 20 years. Functional MRI and EEG experiments conclusively shown that regular visual arrangements, such as reflectional symmetry, Glass patterns, 17 wallpaper groups all activate extrastriate cortex. activation generates an event-related potential (ERP) called sustained posterior negativity (SPN). SPN amplitude scales with degree regularity display, is generated whether participants attend to or not 2). It likely some forms are detected automatically, unconsciously, pre-attentively 3). might be brain hardwired detect 4), this could contribute its aesthetic appeal 5). Visual fractal geometry prominent hallucinations induced by psychedelic drug N,N-dimethyltryptamine (DMT), flicker 6). Integrating what we know about processing features a new frontier neuroscience. We propose cortex can generate aesthetically fascinating symmetrical representations spontaneously, absence external stimuli.