title: Assessing sleep consciousness within subjects using a serial awakening paradigm.
abstract: Dreaming-a particular form of consciousness that occurs during sleep-undergoes major changes in the course of the night. We aimed to outline state-dependent features of consciousness using a paradigm with multiple serial awakenings/questionings that allowed for within as well as between subject comparisons. Seven healthy participants who spent 44 experimental study nights in the laboratory were awakened by a computerized sound at 15-30 min intervals, regardless of sleep stage, and questioned for the presence or absence of sleep consciousness. Recall without content ("I was experiencing something but do not remember what") was considered separately. Subjects had to indicate the content of the most recent conscious experience prior to the alarm sound and to estimate its duration and richness. We also assessed the degree of thinking and perceiving, self- and environment-relatedness and reflective consciousness of the experiences. Of the 778 questionings, 5% were performed during wakefulness, 2% in stage N1, 42% in N2, 33% in N3, and 17% in rapid eye movement (REM) sleep. Recall with content was reported in 34% of non-REM and in 77% of REM sleep awakenings. Sleep fragmentation inherent to the study design appeared to only minimally affect the recall of conscious experiences. Each stage displayed a unique combination of characteristic features of sleep consciousness. In conclusion, our serial awakening paradigm allowed us to collect a large and representative sample of conscious experiences across states of being. It represents a time-efficient method for the study of sleep consciousness that may prove particularly advantageous when combined with techniques such as functional MRI and high-density EEG.
authors: Department of Psychiatry, University of Wisconsin Madison, WI, USA.
authors: Francesca
authors: F
authors: Siclari
authors: Joshua J
authors: JJ
authors: Larocque
authors: Bradley R
authors: BR
authors: Postle
authors: Giulio
authors: G
authors: Tononi
keywords: EEG; consciousness; dreaming; sleep; wakefulness
references: Psychophysiology. 2004 Mar;41(2):298-305
references: 15032995
references: Conscious Cogn. 2000 Dec;9(4):488-509
references: 11150218
references: Int J Psychophysiol. 2009 Oct;74(1):14-8
references: 19596384
references: J Exp Psychol. 1957 May;53(5):339-46
references: 13428941
references: J Pers Soc Psychol. 1965 Aug;2:170-9
references: 14316977
references: Sleep. 1983;6(3):265-80
references: 6622882
references: Biol Psychol. 2011 May;87(2):251-6
references: 21419827
references: Am J Psychol. 1991 Fall;104(3):413-25
references: 1759696
references: Sleep. 2004 Nov 1;27(7):1255-73
references: 15586779
references: Sleep. 2001 Mar 15;24(2):171-9
references: 11247053
references: Conscious Cogn. 1998 Mar;7(1):67-84
references: 9521833
references: Sleep. 1982;5(1):11-27
references: 7071448
references: J Abnorm Psychol. 1965 Aug;70:231-43
references: 14341704
references: Int Rev Neurobiol. 2010;92:181-95
references: 20870068
references: Conscious Cogn. 1995 Sep;4(3):275-99
references: 7497109
references: Int J Neurosci. 1996 Mar;85(1-2):19-30
references: 8727679
references: Conscious Cogn. 2011 Sep;20(3):494-514
references: 20933437
references: Trends Cogn Sci. 2010 Feb;14(2):88-100
references: 20079677
references: J Abnorm Psychol. 1975 Feb;84(1):66-75
references: 1110274
references: J Abnorm Soc Psychol. 1962 Jul;65:14-25
references: 13894288
references: Biol Psychiatry. 1986 Jul;21(8-9):717-23
references: 3730456
references: Psychol Bull. 1976 May;83(3):452-81
references: 778884
references: Psychol Sci. 2001 Jan;12(1):30-6
references: 11294225
references: Behav Brain Sci. 2000 Dec;23(6):793-842; discussion 904-1121
references: 11515143
references: Science. 2013 May 3;340(6132):639-42
references: 23558170
references: Conscious Cogn. 1997 Mar;6(1):132-47
references: 9170565
references: J Cogn Neurosci. 2011 Mar;23(3):570-8
references: 20515407