Blank hallucinations are defined as stereotyped sensory perceptions without appropriate external stimuli, lacking content which relates them to persons, objects, or events. Some examples offered are cloudlike phenomena, hazy blurring of perception, changes in body size, sensations of electric currents flooding the body, and sandy, gritty, and doughy feelings in the mouth. The author also includes the blank hallucinations of the Isakower phenomenon, the dream screen of Lewin, and the abstract perceptions of Deutsch and Murphy. These experiences are explained as defensive repetitions of responses to oral deprivation; the blank hallucination is a revival of a sensation experienced by the infant in an early traumatic situation. Individuals who suffer severe trauma in the postnatal phase of life establish patterns that become the prototypes of later psychic trauma; in the phallic and Oedipal phase, overstimulation during sleep leads to pavor nocturnus. Blank hallucinations occur at times of stress, when falling asleep, and in dreams; they point to a specific pathology derived from excessive oral trauma.