| 1. |
- Johanson, Mirja, et al.
(författare)
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How to assess ictal consciousness?
- 2011
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Ingår i: Behavioural Neurology. - : Hindawi Publishing Corporation. - 0953-4180 .- 1875-8584. ; 24:1, s. 11-20
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Tidskriftsartikel (refereegranskat)abstract
- Despite the complexity and methodological difficulties in defining the concept consciousness, it is a central concept in epileptology, and should thus be tractable for scientific analysis. In the present article, a two-dimensional model consisting of concepts related to the level and the contents of consciousness will be presented. This model has been found to be well suited for the description of seizure-induced alterations of consciousness, and is supported both by findings from neuroimaging and electrophysiological studies as well as from phenomenological studies. Further, we will review both traditional introspective methods as well as methods that have recently been developed or utilized in epilepsy research, summarize the main findings concerning first person experiences during epileptic seizures acquired with some of these methods, and discuss their strengths and weaknesses.
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| 2. |
- Noreika, Valdas, et al.
(författare)
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Consciousness lost and found : Subjective experiences in an unresponsive state
- 2011
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Ingår i: Brain and Cognition. - : Elsevier. - 0278-2626 .- 1090-2147. ; 77:3, s. 327-334
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Tidskriftsartikel (refereegranskat)abstract
- Anesthetic-induced changes in the neural activity of the brain have been recently utilized as a research model to investigate the neural mechanisms of phenomenal consciousness. However, the anesthesiologic definition of consciousness as ‘‘responsiveness to the environment’’ seems to sidestep the possibility that an unresponsive individual may have subjective experiences. The aim of the present study was to analyze subjective reports in sessions where sedation and the loss of responsiveness were induced by dexmedetomidine, propofol, sevoflurane or xenon in a nonsurgical experimental setting. After regaining responsiveness, participants recalled subjective experiences in almost 60% of sessions. During dexmedetomidine sessions, subjective experiences were associated with shallower ‘‘depth of sedation’’ as measured by an electroencephalography-derived anesthesia depth monitor. Results confirm that subjective experiences may occur during clinically defined unresponsiveness, and that studies aiming to investigate phenomenal consciousness under sedative and anesthetic effects should control the subjective state of unresponsive participants with post-recovery interviews.
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| 3. |
- Noreika, Valdas, et al.
(författare)
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Dream bizarreness and waking thought in schizophrenia
- 2010
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Ingår i: Psychiatry Research. - : Elsevier. - 0165-1781 .- 1872-7123. ; 178:3, s. 562-564
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Tidskriftsartikel (refereegranskat)abstract
- Dream diaries and reports of daytime waking thought were collected from five schizophrenia patients and matched controls. It was more difficult for blind judges to differentiate the patients' than the controls' dream reports from reports of waking thought, and patients reported shorter but more bizarre dreams than did the controls.
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| 4. |
- Revonsuo, Antti, et al.
(författare)
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Dreaming as a model system for consciousness research
- 2010
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Ingår i: New Horizons in the Neuroscience of Consciousness. - Amsterdam : John Benjamins Publishing Company. - 9789027252159 - 9789027288042 ; , s. 149-154
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Bokkapitel (refereegranskat)abstract
- Based on biological realism, that is, the philosophical assumption that con-sciousness is a real natural biological phenomenon in the brain, we argue that dreaming is a pure form of phenomenality, and suggest that the dreaming brain could be used as a model system for consciousness. The dreaming brain offers the most challenging model system that represents all the theoretically and philosophically interesting features of consciousness. Although difficult to study experimentally, the dreaming brain is the model system that fully preserves all the essential features of consciousness, and cannot be ignored by any theory that aims to explain consciousness.
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| 5. |
- Sandman, Nils, et al.
(författare)
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Nightmares : Prevalence among the Finnish General Adult Population and War Veterans during 1972-2007
- 2013
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Ingår i: Sleep. - : Associated Professional Sleep Societies, LLC. - 0161-8105 .- 1550-9109. ; 36:7, s. 1041-1050
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Tidskriftsartikel (refereegranskat)abstract
- Study Objectives: To investigate the prevalence of nightmares among the Finnish general adult population during 1972-2007 and the association between nightmare prevalence and symptoms of insomnia, depression, and anxiety in World War II veterans. Design: Eight independent cross-sectional population surveys of the National FINRISK Study conducted in Finland in 1972, 1977, 1982, 1987, 1992, 1997, 2002, and 2007. Setting: Epidemiologic. Participants: A total of 69,813 people (33,811 men and 36,002 women) age 25-74 years. Interventions: N/A. Measurements and Results: The investigation of nightmare prevalence and insomnia, depression, and anxiety symptoms was based on questionnaires completed by the participants. Among the whole sample, 3.5% of the men and 4.8% of the women reported frequent nightmares (P < 0.0001 for sex difference), but the prevalence was affected by the age of participants and the year of the survey. Nightmare prevalence increased with age, particularly among the men. The number of people reporting occasional nightmares increased roughly by 20% for both sexes from 1972 to 2007 (P < 0.0001). Participants with war experiences reported more frequent nightmares and symptoms of insomnia, depression, and anxiety than participants without such experiences (P < 0.0001). Conclusions: Prevalence of nightmares was affected by the sex and age of the participants, and occasional nightmares have become more common in Finland. Exposure to war elevates nightmare prevalence as well as insomnia, depression, and anxiety symptoms even decades after the war; large numbers of war veterans can affect nightmare prevalence on population level.
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| 6. |
- Sikka, Pilleriin, et al.
(författare)
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I know how you felt last night, or do I? : Self- and external ratings of emotions in REM dreams
- 2014
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Ingår i: Consciousness and Cognition. - : Elsevier. - 1053-8100 .- 1090-2376. ; 25, s. 51-66
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Tidskriftsartikel (refereegranskat)abstract
- We investigated whether inconsistencies in previous studies regarding emotional experiencesin dreams derive from whether dream emotions are self-rated or externally evaluated.Seventeen subjects were monitored with polysomnography in the sleep laboratoryand awakened from every rapid eye movement (REM) sleep stage 5 min after the onsetof the stage. Upon awakening, participants gave an oral dream report and rated their dreamemotions using the modified Differential Emotions Scale, whereas external judges rated theparticipants’ emotions expressed in the dream reports, using the same scale. The twoapproaches produced diverging results. Self-ratings, as compared to external ratings,resulted in greater estimates of (a) emotional dreams; (b) positively valenced dreams;(c) positive and negative emotions per dream; and (d) various discrete emotions representedin dreams. The results suggest that this is mostly due to the underrepresentationof positive emotions in dream reports. Possible reasons for this discrepancy are discussed.
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| 7. |
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| 8. |
- Valli, Katja, et al.
(författare)
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Can observers link dream content to behaviours in rapid eye movement sleep behaviour disorder? : A cross-sectional experimental pilot study
- 2012
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Ingår i: Journal of Sleep Research. - : Wiley-Blackwell. - 0962-1105 .- 1365-2869. ; 21:1, s. 21-29
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Tidskriftsartikel (refereegranskat)abstract
- Motor activity in rapid eye movement (REM) sleep behaviour disorder (RBD) has been linked to dream content. Systematic and controlled sleep laboratory studies directly assessing the relation between RBD behaviours and experienced dream content are, however, largely lacking. We aimed to investigate whether a link can be established between RBD behaviours and dream content when both are systematically sampled in a controlled setting. We investigated six patients with Parkinson syndrome and RBD who underwent 23 nights of videopolysomnographic recording during which they were awakened from REM sleep (10 min after the onset of the second and successive REM periods). Spontaneous free-worded dream reports and a structured dream questionnaire were obtained. Video recordings of motor manifestations were each combined with four dream reports, and seven judges had to match the video clip with the correctly reported dream content from a choice of four possibilities. Of the 35 REM sleep awakenings performed, a total of 17 (48.6%) motor-behavioural episodes with recalled dream content were obtained. The mean of correctly identified video-dream pairs was 39.5% (range 0100%). Our data showed that reported dream content can be linked to motor behaviours above chance level. Matching accuracy was affected mainly by the clarity of dream reports and the specific nature of movements manifest in video recordings.
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| 9. |
- Valli, Katja
(författare)
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Dreaming in the multilevel framework
- 2011
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Ingår i: Consciousness and Cognition. - : Elsevier. - 1053-8100 .- 1090-2376. ; 20:4, s. 1084-1090
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Tidskriftsartikel (refereegranskat)abstract
- Biological realism (Revonsuo, 2001, 2006) states that dreaming is a biological phenomenon and therefore explainable in naturalistic terms, similar to the explanation of other biological phenomena. In the biological sciences, the structure of explanations can be described with the help of a framework called ‘multilevel explanation’. The multilevel model provides a context that assists to clarify what needs to be explained and how, and how to place different theories into the same model. Here, I will argue that the multilevel framework would be useful when we try to construct scientific explanations of dreaming.
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