A synesthete describes the visual similarities and differences between her lifelong synesthetic photisms (triggered by sensory input) and hypnagogic visions that began in 2013 (which occur without a trigger). She compares triggers, location, appearance, colors, and commonalities of the two phenomena. The hypnagogic visions have changed over time, and now both types of visions sometimes occur together. She reports finding other synesthetes who also experience both synesthesia and hypnagogia.
Upper Paleolithic cave art includes many geometric signs alongside diverse animal depictions. Human or hybrid human-animal figures are rare, while these aniconic, often geometric forms are more numerous than animals. Interpreting the intentionality behind early cave painting is challenging, with signs being the most enigmatic aspect. Thirty years ago, Lewis-Williams and Dowson proposed a neuropsychological model linking entoptic phenomena to universal signs in cave art, suggesting shamanic visionary origins. This interpretation has sparked debate in France. The text questions whether the neuropsychological model can coherently explain archaeological data and symbolic constructions in decorated caves.