The occurrence of daydreams as part of the association to dreams provides an opportunity for the study of the daydream and ego functioning. Ego regression resulting in a daydream is an adaptive device to attain control over a threatened break-through of unacceptable content not adequately handled by the dream. In formation of the daydream more neutralization of unconscious cathexis occurs at the preconscious-conscious censorship barrier than occurred at the unconscious-preconscious barrier in the dream. Generally the daydream follows the same laws as the night dream, the night dream being more closely related to the unconscious and the daydream to the preconscious. Rubin also discusses the theory of perception and the concept of 'binding'.