title: Resting brain activity varies with dream recall frequency between subjects.
abstract: Dreaming is still poorly understood. Notably, its cerebral underpinning remains unclear. Neuropsychological studies have shown that lesions in the temporoparietal junction (TPJ) and/or the white matter of the medial prefrontal cortex (MPFC) lead to the global cessation of dream reports, suggesting that these regions of the default mode network have key roles in the dreaming process (forebrain 'dream-on' hypothesis). To test this hypothesis, we measured regional cerebral blood flow (rCBF) using [(15)O]H2O positron emission tomography in healthy subjects with high and low dream recall frequencies (DRFs) during wakefulness (rest) and sleep (rapid eye movement (REM) sleep, N2, and N3). Compared with Low recallers (0.5 ± 0.3 dream recall per week in average), High recallers (5.2 ± 1.4) showed higher rCBF in the TPJ during REM sleep, N3, and wakefulness, and in the MPFC during REM sleep and wakefulness. We demonstrate that the resting states of High recallers and Low recallers differ during sleep and wakefulness. It coheres with previous ERP results and confirms that a high/low DRF is associated with a specific functional organization of the brain. These results support the forebrain 'dream-on' hypothesis and suggest that TPJ and MPFC are not only involved in dream recall during wakefulness but also have a role in dreaming during sleep (production and/or encoding). Increased activity in the TPJ and MPFC might promote the mental imagery and/or memory encoding of dreams. Notably, increased activity in TPJ might facilitate attention orienting toward external stimuli and promote intrasleep wakefulness, facilitating the encoding of the dreams in memory.
authors.affiliation: 1] CRNL-Lyon Neuroscience Research Center, INSERM U1028, CNRS UMR 5292, Brain Dynamics and Cognition Team, Centre Hospitalier Le Vinatier (Bât. 452), Lyon, France [2] University Claude Bernard Lyon 1, Lyon, France.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Eichenlaub
authors.affiliation: Unité d'Exploration Hypnologique, Centre Hospitalier Le Vinatier, Lyon, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Nicolas
authors.affiliation: 1] CRNL-Lyon Neuroscience Research Center, INSERM U1028, CNRS UMR 5292, Brain Dynamics and Cognition Team, Centre Hospitalier Le Vinatier (Bât. 452), Lyon, France [2] University Claude Bernard Lyon 1, Lyon, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Daltrozzo
authors.affiliation: CERMEP-Imagerie du Vivant, Lyon, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Redouté
authors.affiliation: CERMEP-Imagerie du Vivant, Lyon, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Costes
authors.affiliation: 1] CRNL-Lyon Neuroscience Research Center, INSERM U1028, CNRS UMR 5292, Brain Dynamics and Cognition Team, Centre Hospitalier Le Vinatier (Bât. 452), Lyon, France [2] University Claude Bernard Lyon 1, Lyon, France.
authors.forename: Perrine
authors.initials: P
authors.lastname: Ruby
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004325:Dreams; D004569:Electroencephalography; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D010104:Oxygen Radioisotopes; D010775:Photic Stimulation; D049268:Positron-Emission Tomography; D012146:Rest / Q000502:physiology*; D012890:Sleep / Q000502:physiology; D014851:Wakefulness / Q000502:physiology; D055815:Young Adult
chemical_list: D010104:Oxygen Radioisotopes