Studies in cognitive psychology showed that personality (openness to experience, thin boundaries, absorption), creativity, nocturnal awakenings, and attitude toward dreams are significantly related to dream recall frequency (DRF). These results suggest the possibility of neurophysiological trait differences between subjects with high and low DRF. To test this hypothesis we compared sleep characteristics and alpha reactivity to sounds in subjects with high and low DRF using polysomnographic recordings and electroencephalography (EEG). We acquired EEG from 21 channels in 36 healthy subjects while they were presented with a passive auditory oddball paradigm (frequent standard tones, rare deviant tones and very rare first names) during wakefulness and sleep (intensity, 50 dB above the subject's hearing level). Subjects were selected as High-recallers (HR, DRF = 4.42 ± 0.25 SEM, dream recalls per week) and Low-recallers (LR, DRF = 0.25 ± 0.02) using a questionnaire and an interview on sleep and dream habits. Despite the disturbing setup, the subjects' quality of sleep was generally preserved. First names induced a more sustained decrease in alpha activity in HR than in LR at Pz (1000–1200 ms) during wakefulness, but no group difference was found in REM sleep. The current dominant hypothesis proposes that alpha rhythms would be involved in the active inhibition of the brain regions not involved in the ongoing brain operation. According to this hypothesis, a more sustained alpha decrease in HR would reflect a longer release of inhibition, suggesting a deeper processing of complex sounds than in LR during wakefulness. A possibility to explain the absence of group difference during sleep is that increase in alpha power in HR may have resulted in awakenings. Our results support this hypothesis since HR experienced more intra sleep wakefulness than LR (30 ± 4 vs. 14 ± 4 min). As a whole our results support the hypothesis of neurophysiological trait differences in high and low-recallers.
Keywords: dreaming, sleep, self, 8–12 Hz, consciousness, inhibition, oddball, novelty
Citation: Ruby P, Blochet C, Eichenlaub J-B, Bertrand O, Morlet D and Bidet-Caulet A (2013) Alpha reactivity to first names differs in subjects with high and low dream recall frequency. Front. Psychol. 4:419. doi: 10.3389/fpsyg.2013.00419
Received: 01 April 2013; Accepted: 19 June 2013;
Published online: 13 August 2013.
Edited by:Jennifer M. Windt, Johannes Gutenberg-University of Mainz, Germany
Reviewed by:Valdas Noreika, Medical Research Council, UK
Copyright © 2013 Ruby, Blochet, Eichenlaub, Bertrand, Morlet and Bidet-Caulet. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Perrine Ruby, INSERM U1028, Centre Hospitalier Le Vinatier (Bât. 452), 95, Boulevard Pinel, 69675 Bron Cedex, France e-mail: email@example.com