The term stage 2 nightmare was introduced in or shortly before 1968 by the American sleep researchers Charles Fisher (1908-1988), Joseph V Byrne, and Adele Edwards It refers to a type of night terror which may occur during the stage of light sleep, characterized on the electroencephalogram (EEG) by sleep spindles and K complexes This sleep stage used to be referred to as stage 2 sleep, hence the term stage 2 nightmare The latter is traditionally used to denote a rather unusual type of night terror, characterized by arousal from stage N2 sleep with anxiety As noted by the American psychiatrist Ernest Hartmann (b 1934), the choice of the term stage 2 nightmare is unfortunate, because it falsely suggests a connection with the * nightmare (which is regarded as different, in a conceptual and phenomenological sense, from night terror) The term stage 2 nightmare is used in opposition to the term * stage 4 nightmare
References
Fisher, C., Byrne, J.V., Edwards, A. (1968). NREM and REM nightmares. Psychophysiol-ogy, 5, 221-222.
Hartmann, E. (1984). The nightmare. The psychology and biology ofterrifying dreams. New York, NY: Basic Books.
Dictionary of Hallucinations. J.D. Blom. 2010.