University of Montana, Missoula.
240 university students were given The Cognitive Laterality Battery as well as a questionnaire, the answers to which were used to identify those who had experienced an "Old Hag Attack." This refers to a hypnagogic sleep disorder in which there is paralysis and, quite often, terrifying hallucinations. Those suffering from this disorder showed a statistically significantly different profile of scores from normal subjects on The Cognitive Laterality Battery. The implications of this finding for existing theories concerning "Old Hag Attacks" are discussed.