Ever been lost in thought and ignored your external senses? That's what they're describing, but with visual imagery included and not just however you may normally experience thoughts.
Not really, actually, and not for a lack of trying very very hard at times. Even when we tried LSD the most it did was make us more aware of the actual curvature of our eyes' lenses, lessening the mental illusion of uniformity.
Ever been lost in thought and ignored your external senses? That's what they're describing, but with visual imagery included and not just however you may normally experience thoughts.
Not really, actually, and not for a lack of trying very very hard at times. Even when we tried LSD the most it did was make us more aware of the actual curvature of our eyes' lenses, lessening the mental illusion of uniformity.