. . "A form constant is one of several geometric patterns which are recurringly observed during hypnagogia, hallucinations and altered states of consciousness."@en . . . . . . . "Form constant"@en . . . . . . "1122622508"^^ . . . . . . . . . . . . . . . . . . . . . . . . . . . "3606570"^^ . . . . . . . . . . . . "8691"^^ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "A form constant is one of several geometric patterns which are recurringly observed during hypnagogia, hallucinations and altered states of consciousness."@en . . . . . . . . . . . . . . . . . . .