A variety of conceptualizations and commentary as to the nature of sleep-talking are to be found mostly in diffuse and dispersed fragments in the clinical-anecdotal literature. People do not dream or sleep-talk unless something has been left awakened in their psychic activities during sleep, and the more that sleep approaches waking by imperceptible degrees, the more favourable are the conditions under which dreams and sleep-talking will occur. Sleep-speech occurs whenever the psychophysical innervation is active independently of the conscious and the will, and ceases when it becomes inactive. Sleep-talkers as a group form a most heterogeneous population and, in repeatedly attempting to hypnotize several adult sleep-talkers, only some were capable of achieving states of consciousness classically considered as evidence of deep hypnosis. In G. H. Estabrooks opinion, sleep-talkers are generally good hypnotic subjects, and he describes a method of hypnotic induction used with sleeping subjects without their consent or conscious knowledge.