Grids, zigzags, spirals and curves. These "form constants" as called by the neurologist Heinrich Klüver are the patterns we see from drug induced hallucinations, migraines, sensory deprivation and the hypnagogic state that occurs in the transition from wakefulness to sleep. They are the intrinsic properties of our visual nervous system. Most neurons in our primary visual cortex occur in repeating structures and are organised geometrically. The spontaneous activity of these neural networks creates these patterns.
Is this why we find them so aesthetically pleasing?
They recur throughout history since prehistoric times used by cultures to decorate and to convey their interpretations of the world around them. They are used to invest the object with meaning and anima, to animate the inanimate.