Comparison of Mentation Associated with NREM Sleep-Speech and NREM Silent Sleep
Rather than being a valid reflection of sleep mentation, is it possible that microdissociative sleep-talking merely indicates the mental content of the movement-arousal episode (as defined by the standard criteria, Rechtschaffen & Kales, 1968) and is essentially unrelated to sleep mentation as such? The results of studies in several different laboratories have a bearing on this question.
First, with regard to REMP-associated sleep-talking, the high proportion of concordance between sleep-speech content and the usual relatively elaborate REMP mentation reports described as dreams by the subject provides convincing evidence that REMP-associated sleep-speech arises out of and reflects previous ongoing REMP mentation. On the other hand, the same conclusion with regard to NREM-associated utterances cannot be drawn quite so easily. This caution is required by the lack of well-established electrographic correlates of NREM sleep mentation, in contrast to those of REMPs. That is, in the latter instance, electrographic signs of Stage REM permit a reasonably valid inference that dreamlike mentation was in progress immediately prior to the actual onset of the sleep-utterance and continuous with it, whereas this is not yet the case with NREM sleep.
An effort was made by us ( Arkin, Antrobus, Toth, Baker, and Jackler, 1972a) to approach this problem by comparing NREM mentation reports elicited immediately after NREM-associated sleep-utterance to reports