Miriam C. Wollman’s research while affiliated with CUNY Graduate Center and other places

Cognitive variables and cortical arousal levels were examined in order to determine whether differences in cortical arousal levels within REM and waking could account for different aspects of mentation derived from the two states. Cognitive variables were derived from mentation reports collected from 30 subjects in both the waking state and after being awakened from REM sleep. Mentation reports were independently scored on seven content rating scales, by two judges blind to the conditions. These scales include among others, Total Recall Count (TRC), a count of all words in which the subject described his/her experience during the previous interval. The EEG activity, obtained from left and right midtemporoparietal and central sites, was recorded for 5-min periods before obtaining mentation reports. The absolute power of the EEG activity was calculated for each of six bandwidths. EEG power data from both waking and REM were entered into multiple linear regression equations to predict TRC. No relationships were found between TRC and general cortical activation, as measured by the EEG. Other statistical analyses, including relationships between EEG and scales of visual imagery, are discussed.

This article describes some of the variables that distinguish waking and sleeping (REM) thought. Mentation reports from the waking state, as described here, tend to have more topic shifts than those from the REM state, which often have a single-theme storylike quality. It is assumed that heightened response thresholds to sensory stimuli, in conjunction with the state of high cortical activation typical of REM sleep, account for the storylike quality of REM imagery. In this experiment, an intermittent auditory stimulus was the model for environmental influences on waking mentation. It was hypothesized that the removal of this intermittent auditory stimulation, simulating in waking subjects the increased sensory thresholds of REM sleep, would decrease the number of topic shifts in spontaneous thought. It was expected that this reduction in number of topics would approach levels achieved in REM sleep. Thirty subjects participated in individual sessions in which they lay in a sound-attenuated, lightproof room with eyes closed. They were asked for mentation reports as follows: after lying awake with external stimulation (W), after lying awake without external stimulation (WO), and after being wakened from REM sleep. Transcribed mentation reports were scored on seven content rating scales, including total recall count, a count of all words in which the subject was describing his/her experience during the previous interval, and number of thought units (TU) per report, a count of the distinct, thematically homogeneous thought sequences. Hotelling t-squared tests were performed with the different states as the independent variables and the scores on the cognitive scales as the dependent variables. The major factor distinguishing mentation reports of waking subjects and subjects wakened from REM sleep was the TU count, with waking subjects changing topics more frequently. Removal of the intermittent auditory stimulus reduced the number of topic shifts in waking subjects, with a significance approaching the 95% confidence limit.

Describes 2 experiments with 26 graduate and undergraduate students that examined the relationship between external auditory nonspecific stimulation and disruption of the thematic sequencing of spontaneous thought and imagery. The experiments simulated the long thematic sequences of dreaming in the waking state by comparing the disruptive effects of 2 levels of ambient auditory stimulation. Evidence is found that the process of REM mentation, as distinguished from Stage 2 sleep mentation and waking mentation, in understimulated as well as stimulated contexts, can be accounted for by 2 factors that modify waking cognitive processes: (1) cognitive activation and (2) perceptual thresholds. These factors influence memory for recent nonspecific perceptual responses, thereby creating a hallucinatory context for endogenous image generation that supplants the awareness of the external environment. (PsycINFO Database Record (c) 2012 APA, all rights reserved)