Abstract: | ![]() Two studies of information processing in normal human sleep are reported. In Experiment I it was found that subjects responded differentially in stage 2 sleep to “own name,”“other name,” and tone stimuli (decreasing in that order) as reflected in both the finger plethysmograph (FP)and heart rate (HR) and to some extent the EEG K-complex response, and similarly in REM sleep as reflected in the FP measure and to some extent the HR measure, but not in sleep stage 3–4. In Experiment II it was found that conditioned discrimination acquired during wakefulness persisted in sleep stage 4, as reflected in the FP and HR measures, and sleep stage 2, as reflected in the K-complex response, but not in REM sleep. Results are compared to other studies of information processing in sleep. It is concluded that the results appear to indicate differential availability of the mechanisms of long-term memory, short-term memory, and stimulus preprocessing in the various stages of sleep. The authors further noted a bifurcation of the autonomic nervous system in sleep into two discrete effector limbs: electrodermal and cardiovascular. |