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Grassini, S., Revonsuo, A., Castellotti, S., Petrizzo, I., Benedetti, V. & Koivisto, M. (2019). Processing of natural scenery is associated with lower attentional and cognitive load compared with urban ones. Journal of Environmental Psychology, 62, 1-11
Open this publication in new window or tab >>Processing of natural scenery is associated with lower attentional and cognitive load compared with urban ones
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2019 (English)In: Journal of Environmental Psychology, ISSN 0272-4944, E-ISSN 1522-9610, Vol. 62, p. 1-11Article in journal (Refereed) Published
Abstract [en]

Environmental psychology has provided evidence for psychologically favorable effects of exposure to natural settings, by means of controlled laboratory experiments as well as outdoor field studies. Most of these studies have employed subjective rating scales to assess processes and outcomes of exposure to nature, while only few of them have used physiological measures to assess the neural correlates of these benefits. The present study used electroencephalography (EEG) to explore how the brain engages in processing of images of natural vs. urban scenery. During EEG recording, the participants (n = 32) were presented with a series of photos depicting urban or natural scenery. Participants rated the sceneries for their subjective relaxing value. Images of natural scenery were rated as more relaxing compared to the images of urban scenery. Event related potentials suggested a lower attentional demand for images of natural scenery compared to urban ones. Signal spectral analyses revealed differences in brain activity level and cognitive demand between natural and urban scenery. Our data suggest that the visual perception of natural environments calls for less attentional and cognitive processing, compared with urban ones. © 2019 Elsevier Ltd

Keywords
Attention, Attention restoration theory (ART), Cognitive load, EEG, Perception, Environmental psychology
National Category
Psychology (excluding Applied Psychology) Neurosciences
Research subject
Consciousness and Cognitive Neuroscience
Identifiers
urn:nbn:se:his:diva-16653 (URN)10.1016/j.jenvp.2019.01.007 (DOI)2-s2.0-85061318570 (Scopus ID)
Available from: 2019-02-22 Created: 2019-02-22 Last updated: 2019-02-26Bibliographically approved
Tuominen, J., Stenberg, T., Revonsuo, A. & Valli, K. (2019). Social contents in dreams: An empirical test of the Social Simulation Theory. Consciousness and Cognition, 69, 133-145
Open this publication in new window or tab >>Social contents in dreams: An empirical test of the Social Simulation Theory
2019 (English)In: Consciousness and Cognition, ISSN 1053-8100, E-ISSN 1090-2376, Vol. 69, p. 133-145Article in journal (Refereed) Published
Abstract [en]

Social Simulation Theory (SST) considers the function of dreaming to be the simulation of social events. The Sociality Bias and the Strengthening hypotheses of SST were tested. Social Content Scale (SCS) was developed to quantify social events. Additionally, we attempted to replicate a previous finding (McNamara et al., 2005, Psychological Science) of REM dreams as predisposed to aggressive, and NREM dreams to prosocial interactions. Further, we investigated the frequency and quality of interactions in late vs early REM and NREM dreams. Data consisted of wake, REM and NREM home dream reports (N = 232, 116, 116, respectively) from 15 students. Dreams overrepresented social events compared to wake reports, supporting the Sociality Bias hypothesis. However, the Strengthening Hypothesis was not supported. We weren't able to replicate the McNamara et al. finding, and no time of night effect was found. While SST gained partial support, further research on social contents in dreams is required. © 2019 Elsevier Inc.

Keywords
Continuity hypothesis, Dreaming, Functions of dreaming, NREM sleep, REM sleep, Social simulation theory, Sleep, Social Cognition
National Category
Psychology (excluding Applied Psychology)
Research subject
Consciousness and Cognitive Neuroscience
Identifiers
urn:nbn:se:his:diva-16654 (URN)10.1016/j.concog.2019.01.017 (DOI)000460197200011 ()30769273 (PubMedID)2-s2.0-85061351162 (Scopus ID)
Available from: 2019-02-22 Created: 2019-02-22 Last updated: 2019-03-14Bibliographically approved
Hurme, M., Koivisto, M., Revonsuo, A. & Railo, H. (2019). V1 activity during feedforward and early feedback processing is necessary for both conscious and unconscious motion perception. NeuroImage, 185, 313-321
Open this publication in new window or tab >>V1 activity during feedforward and early feedback processing is necessary for both conscious and unconscious motion perception
2019 (English)In: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 185, p. 313-321Article in journal (Refereed) Published
Abstract [en]

The study of blindsight has revealed a seminal dissociation between conscious vision and visually guided behavior: some patients who are blind due to V1 lesions seem to be able to employ unconscious visual information in their behavior. The standard assumption is that these findings generalize to the neurologically healthy. We tested whether unconscious processing of motion is possible without the contribution of V1 in neurologically healthy participants by disturbing activity in V1 using transcranial magnetic stimulation (TMS). Unconscious processing was measured with redundant target effect (RTE), a phenomenon where participants respond faster to two stimuli than to one stimulus, when the task is just to respond as fast as possible when one stimulus or two simultaneous stimuli are presented. We measured the RTE caused by a motion stimulus. V1 activity was interfered with different stimulus onset asynchronies (SOA) to test whether TMS delivered in a specific time window suppresses conscious perception (participant reports seeing only one of the two stimuli) but does not affect unconscious processing (RTE). We observed that at each SOA, when TMS suppressed conscious perception of the stimulus, the RTE was also eliminated. However, when visibility of the redundant target was suppressed with a visual mask, we found unconscious processing of motion. This suggests that unconscious processing of motion depends on V1 in neurologically healthy humans. We conclude that the neural mechanisms that enable motion processing in blindsight are modulated by neuroplastic changes in connectivity between subcortical areas and the visual cortex after the V1 lesion. Neurologically healthy observers cannot process motion unconsciously without functioning of V1. 

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
blindsight, motion perception, redundant target effect, TMS, unconscious vision, V1, adult, article, controlled study, ego development, female, human, human experiment, male, movement perception, stimulus, transcranial magnetic stimulation, visibility, visual cortex
National Category
Neurosciences Psychology Production Engineering, Human Work Science and Ergonomics
Research subject
Consciousness and Cognitive Neuroscience
Identifiers
urn:nbn:se:his:diva-16412 (URN)10.1016/j.neuroimage.2018.10.058 (DOI)000451628200029 ()30366074 (PubMedID)2-s2.0-85055542590 (Scopus ID)
Available from: 2018-11-21 Created: 2018-11-21 Last updated: 2019-02-11Bibliographically approved
Grassini, S., Railo, H., Valli, K., Revonsuo, A. & Koivisto, M. (2019). Visual features and perceptual context modulate attention towards evolutionarily relevant threatening stimuli: Electrophysiological evidence. Emotion, 19(2), 348-364
Open this publication in new window or tab >>Visual features and perceptual context modulate attention towards evolutionarily relevant threatening stimuli: Electrophysiological evidence
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2019 (English)In: Emotion, ISSN 1528-3542, E-ISSN 1931-1516, Vol. 19, no 2, p. 348-364Article in journal (Refereed) Published
Abstract [en]

The snake detection hypothesis claims that predatory pressure from snakes has shaped the primate visual system, but we still know very little about how the brain processes evolutionarily important visual cues, and which factors are crucial for quick detection of snakes. We investigated how visual features modulate the electrophysiological markers of early attentional processes. In Experiment 1, we compared snake, rope, gun, and bird images to isolate the effects due to curvilinearity of the stimuli. The results showed that both snake and rope images elicited enhanced P1 and N1 event-related potential components as well as early posterior negativity (EPN). In Experiment 2, we studied whether nonthreatening curvilinear images (i.e., ropes) still elicit the enhanced electrophysiological responses when snake images are not presented as stimuli, and therefore the context does not provoke top-down attention to curvilinear shapes. Rope images still evoked an enhanced EPN, suggesting that curvilinear shapes are preferably captured by attentional processes. However, this effect was smaller than in Experiment 1, in which snake images were present. Thus, our results hint to the possibility that the perceptual context may interact with processing of shape information, drawing attention to curvilinear shapes when the presence of snakes is expectable. Furthermore, we observed that spatial frequency of the visual stimuli modulated especially the early electrophysiological responses, and decreased the differences between stimulus categories in EPN without completely eliminating them. The findings suggest that low-level and high-level mechanisms interact to give an attentional priority to potentially threatening stimuli.

Place, publisher, year, edition, pages
American Psychological Association (APA), 2019
Keywords
Evolution psychology, ERP
National Category
Behavioral Sciences Biology
Research subject
Consciousness and Cognitive Neuroscience
Identifiers
urn:nbn:se:his:diva-15100 (URN)10.1037/emo0000434 (DOI)000458951400014 ()29578746 (PubMedID)2-s2.0-85044303603 (Scopus ID)
Available from: 2018-04-26 Created: 2018-04-26 Last updated: 2019-03-07Bibliographically approved
Revonsuo, A. (2018). Biological naturalism and biological realism (1ed.). In: Rocco J. Gennaro (Ed.), The Routledge Handbook of Consciousness: (pp. 188-201). New York: Taylor & Francis
Open this publication in new window or tab >>Biological naturalism and biological realism
2018 (English)In: The Routledge Handbook of Consciousness / [ed] Rocco J. Gennaro, New York: Taylor & Francis, 2018, 1, p. 188-201Chapter in book (Other academic)
Abstract [en]

Consciousness is a real, natural biological phenomenon, produced by and realized in higher-level neurophysiological processes going on inside the brain.

Place, publisher, year, edition, pages
New York: Taylor & Francis, 2018 Edition: 1
National Category
Philosophy Neurosciences
Research subject
Consciousness and Cognitive Neuroscience
Identifiers
urn:nbn:se:his:diva-16056 (URN)10.4324/9781315676982 (DOI)2-s2.0-85046930629 (Scopus ID)9781317386810 (ISBN)9781138936218 (ISBN)9781315676982 (ISBN)
Available from: 2018-09-10 Created: 2018-09-10 Last updated: 2019-02-27Bibliographically approved
Laaksonen, L., Kallioinen, M., Långsjö, J., Laitio, T., Scheinin, A., Scheinin, J., . . . Scheinin, H. (2018). Comparative effects of dexmedetomidine, propofol, sevoflurane, and S-ketamine on regional cerebral glucose metabolism in humans: a positron emission tomography study. Paper presented at 10th International Symposium on Memory and Awareness in Anesthesia (MAA), Helsinki, Finland, June 19-21, 2017. British Journal of Anaesthesia, 121(1), 281-290
Open this publication in new window or tab >>Comparative effects of dexmedetomidine, propofol, sevoflurane, and S-ketamine on regional cerebral glucose metabolism in humans: a positron emission tomography study
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2018 (English)In: British Journal of Anaesthesia, ISSN 0007-0912, E-ISSN 1471-6771, Vol. 121, no 1, p. 281-290Article in journal (Refereed) Published
Abstract [en]

IntroductionThe highly selective α2-agonist dexmedetomidine has become a popular sedative for neurointensive care patients. However, earlier studies have raised concern that dexmedetomidine might reduce cerebral blood flow without a concomitant decrease in metabolism. Here, we compared the effects of dexmedetomidine on the regional cerebral metabolic rate of glucose (CMRglu) with three commonly used anaesthetic drugs at equi-sedative doses.

MethodsOne hundred and sixty healthy male subjects were randomised to EC50 for verbal command of dexmedetomidine (1.5 ng ml−1n=40), propofol (1.7 μg ml−1n=40), sevoflurane (0.9% end-tidal; n=40) or S-ketamine (0.75 μg ml−1n=20) or placebo (n=20). Anaesthetics were administered using target-controlled infusion or vapouriser with end-tidal monitoring. 18F-labelled fluorodeoxyglucose was administered 20 min after commencement of anaesthetic administration, and high-resolution positron emission tomography with arterial blood activity samples was used to quantify absolute CMRglu for whole brain and 15 brain regions.

ResultsAt the time of [F18]fluorodeoxyglucose injection, 55% of dexmedetomidine, 45% of propofol, 85% of sevoflurane, 45% of S-ketamine, and 0% of placebo subjects were unresponsive. Whole brain CMRglu was 63%, 71%, 71%, and 96% of placebo in the dexmedetomidine, propofol, sevoflurane, and S-ketamine groups, respectively (P<0.001 between the groups). The lowest CMRglu was observed in nearly all brain regions with dexmedetomidine (P<0.05 compared with all other groups). With S-ketamine, CMRgludid not differ from placebo.

ConclusionsAt equi-sedative doses in humans, potency in reducing CMRglu was dexmedetomidine>propofol>ketamine=placebo. These findings alleviate concerns for dexmedetomidine-induced vasoconstriction and cerebral ischaemia.

National Category
Other Medical Sciences not elsewhere specified
Research subject
Consciousness and Cognitive Neuroscience
Identifiers
urn:nbn:se:his:diva-15615 (URN)10.1016/j.bja.2018.04.008 (DOI)000439025500072 ()29935583 (PubMedID)2-s2.0-85046622088 (Scopus ID)
Conference
10th International Symposium on Memory and Awareness in Anesthesia (MAA), Helsinki, Finland, June 19-21, 2017
Available from: 2018-06-15 Created: 2018-06-15 Last updated: 2018-09-03Bibliographically approved
Scheinin, A., Kallionpää, R. E., Li, D., Kallioinen, M., Kaisti, K., Långsjö, J., . . . Scheinin, H. (2018). Differentiating Drug-related and State-related Effects of Dexmedetomidine and Propofol on the Electroencephalogram. Anesthesiology, 129(1), 22-36
Open this publication in new window or tab >>Differentiating Drug-related and State-related Effects of Dexmedetomidine and Propofol on the Electroencephalogram
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2018 (English)In: Anesthesiology, ISSN 0003-3022, E-ISSN 1528-1175, Vol. 129, no 1, p. 22-36Article in journal (Refereed) Published
Abstract [en]

BACKGROUND

Differentiating drug-related changes and state-related changes on the electroencephalogram during anesthetic-induced unconsciousness has remained a challenge. To distinguish these, we designed a rigorous experimental protocol with two drugs known to have distinct molecular mechanisms of action. We hypothesized that drug- and state-related changes can be separated.

METHODS: 

Forty-seven healthy participants were randomized to receive dexmedetomidine (n = 23) or propofol (n = 24) as target-controlled infusions until loss of responsiveness. Then, an attempt was made to arouse the participant to regain responsiveness while keeping the drug infusion constant. Finally, the concentration was increased 1.5-fold to achieve presumable loss of consciousness. We conducted statistical comparisons between the drugs and different states of consciousness for spectral bandwidths, and observed how drug-induced electroencephalogram patterns reversed upon awakening. Cross-frequency coupling was also analyzed between slow-wave phase and alpha power.

RESULTS: 

Eighteen (78%) and 10 (42%) subjects were arousable during the constant drug infusion in the dexmedetomidine and propofol groups, respectively (P = 0.011 between the drugs). Corresponding with deepening anesthetic level, slow-wave power increased, and a state-dependent alpha anteriorization was detected with both drugs, especially with propofol. Negative phase-amplitude coupling before and during loss of responsiveness frontally and positive coupling during the highest drug concentration posteriorly were observed in the propofol but not in the dexmedetomidine group.

CONCLUSIONS: 

Electroencephalogram effects of dexmedetomidine and propofol are strongly drug- and state-dependent. Changes in slow-wave and alpha activity seemed to best detect different states of consciousness.

National Category
Biological Sciences
Research subject
Consciousness and Cognitive Neuroscience
Identifiers
urn:nbn:se:his:diva-15616 (URN)10.1097/ALN.0000000000002192 (DOI)000435563800006 ()29642080 (PubMedID)
Available from: 2018-06-15 Created: 2018-06-15 Last updated: 2018-09-11Bibliographically approved
Sikka, P., Revonsuo, A., Sandman, N., Tuominen, J. & Valli, K. (2018). Dream emotions: a comparison of home dream reports with laboratory early and late REM dream reports. Journal of Sleep Research, 27(2), 206-214
Open this publication in new window or tab >>Dream emotions: a comparison of home dream reports with laboratory early and late REM dream reports
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2018 (English)In: Journal of Sleep Research, ISSN 0962-1105, E-ISSN 1365-2869, Vol. 27, no 2, p. 206-214Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to compare the emotional content of dream reports collected at home upon morning awakenings with those collectedin the laboratory upon early and late rapid eye movement (REM) sleep awakenings. Eighteen adults (11 women, seven men; mean age = 25.89 ± 4.85) wrote down their home dreams every morning immediately upon awakening during a 7-day period. Participants also spent two non-consecutive nights in the sleep laboratory where they were awoken 5 min into each continuous REM sleep stage, upon which they gave a verbal dream report. The content of a total of 151 home and 120 laboratory dream reports was analysed by two blind judges using the modified Differential Emotions Scale. It was found that: (1) home dream reports were more emotional than laboratory early REM dream reports, but not more emotional than laboratory late REM dream reports; (2) home dream reports contained a higher density of emotions than laboratory (early or late REM) dream reports; and (3) home dream reports were more negative than laboratory dream reports, but differences between home and early REM reports were larger than those between home and late REM reports. The results suggest that differences between home and laboratory dream reports in overall emotionality may be due to the time of night effect. Whether differences in the density of emotions and negative emotionality are due to sleep environment or due to different reporting procedures and time spent in a sleep stage, respectively, remains to be determined in future studies.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
Keywords
dreams, dreaming, emotions, content analysis, REM sleep, sleep stages
National Category
Psychology
Research subject
Consciousness and Cognitive Neuroscience
Identifiers
urn:nbn:se:his:diva-13634 (URN)10.1111/jsr.12555 (DOI)000426866500008 ()28568911 (PubMedID)2-s2.0-85020126304 (Scopus ID)
Available from: 2017-06-06 Created: 2017-06-06 Last updated: 2018-05-17Bibliographically approved
Radek, L., Kallionpää, R. E., Karvonen, M., Scheinin, A., Maksimow, A., Långsjö, J., . . . Valli, K. (2018). Dreaming and awareness during dexmedetomidine- and propofol-induced unresponsiveness. Paper presented at 10th International Symposium on Memory and Awareness in Anesthesia (MAA), Helsinki, Finland, June 19-21, 2017. British Journal of Anaesthesia, 121(1), 260-269
Open this publication in new window or tab >>Dreaming and awareness during dexmedetomidine- and propofol-induced unresponsiveness
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2018 (English)In: British Journal of Anaesthesia, ISSN 0007-0912, E-ISSN 1471-6771, Vol. 121, no 1, p. 260-269Article in journal (Refereed) Published
Abstract [en]

Background: Experiences during anaesthetic-induced unresponsiveness have previously been investigated by interviews after recovery. To explore whether experiences occur during drug administration, we interviewed participants during target-controlled infusion (TCI) of dexmedetomidine or propofol and after recovery. Methods: Healthy participants received dexmedetomidine (n = 23) or propofol (n = 24) in stepwise increments until loss of responsiveness (LOR1). During TCI we attempted to arouse them for interview (return of responsiveness, ROR1). After the interview, if unresponsiveness ensued with the same dose (LOR2), the procedure was repeated (ROR2). Finally, the concentration was increased 1.5-fold to achieve presumable loss of consciousness (LOC), infusion terminated, and the participants interviewed upon recovery (ROR3). An emotional sound stimulus was presented during LORs and LOC, and memory for stimuli was assessed with recognition task after recovery. Interview transcripts were content analysed. Results: Of participants receiving dexmedetomidine, 18/23 were arousable from LOR1 and LOR2. Of participants receiving propofol, 10/24 were arousable from LOR1 and two of four were arousable from LOR2. Of 93 interviews performed, 84% included experiences from periods of unresponsiveness (dexmedetomidine 90%, propofol 74%). Internally generated experiences (dreaming) were present in 86% of reports from unresponsive periods, while externally generated experiences (awareness) were rare and linked to brief arousals. No within drug differences in the prevalence or content of experiences during infusion vs after recovery were observed, but participants receiving dexmedetomidine reported dreaming and awareness more often. Participants receiving dexmedetomidine recognised the emotional sounds better than participants receiving propofol (42% vs 15%), but none reported references to sounds spontaneously. Conclusion: Anaesthetic-induced unresponsiveness does not induce unconsciousness or necessarily even disconnectedness.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
awareness, consciousness, dexmedetomidine, interview, propofol
National Category
Psychology
Research subject
Consciousness and Cognitive Neuroscience
Identifiers
urn:nbn:se:his:diva-16026 (URN)10.1016/j.bja.2018.03.014 (DOI)000439025500070 ()29935581 (PubMedID)2-s2.0-85046688138 (Scopus ID)
Conference
10th International Symposium on Memory and Awareness in Anesthesia (MAA), Helsinki, Finland, June 19-21, 2017
Available from: 2018-08-02 Created: 2018-08-02 Last updated: 2018-10-22Bibliographically approved
Revonsuo, A. (2018). Foundations of Consciousness. New York: Routledge
Open this publication in new window or tab >>Foundations of Consciousness
2018 (English)Book (Refereed)
Place, publisher, year, edition, pages
New York: Routledge, 2018. p. 173
Keywords
Consciousness
National Category
Behavioral Sciences Biology
Research subject
Consciousness and Cognitive Neuroscience
Identifiers
urn:nbn:se:his:diva-14674 (URN)10.4324/9781315115092 (DOI)2-s2.0-85040658258 (Scopus ID)0-415-59467-7 (ISBN)978-0-415-59467-7 (ISBN)978-0-415-59466-0 (ISBN)978-1-315-11509-2 (ISBN)9781351629621 (ISBN)
Note

eBook Published 20 July 2017

Available from: 2018-01-22 Created: 2018-01-22 Last updated: 2018-02-13Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-2771-1588

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