An hour of bright white light in the early morning improves performance and advances sleep and circadian phase during the Antarctic winter
Previous work has demonstrated that exposure to an hour of bright light in the morning and the evening during the Polar winter has beneficial effects on circadian phase. This study investigated the effect of a single hour of bright white morning light on circadian phase, sleep, alertness and cogniti...
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ftnerc:oai:nora.nerc.ac.uk:20092 2024-02-11T09:57:48+01:00 An hour of bright white light in the early morning improves performance and advances sleep and circadian phase during the Antarctic winter Corbett, R.W. Middleton, B. Arendt, J. 2012 http://nora.nerc.ac.uk/id/eprint/20092/ http://www.elsevier.com/locate/neulet unknown Elsevier Corbett, R.W.; Middleton, B.; Arendt, J. 2012 An hour of bright white light in the early morning improves performance and advances sleep and circadian phase during the Antarctic winter. Neuroscience Letters, 525 (2). 146-151. https://doi.org/10.1016/j.neulet.2012.06.046 <https://doi.org/10.1016/j.neulet.2012.06.046> Publication - Article PeerReviewed 2012 ftnerc https://doi.org/10.1016/j.neulet.2012.06.046 2024-01-26T00:03:20Z Previous work has demonstrated that exposure to an hour of bright light in the morning and the evening during the Polar winter has beneficial effects on circadian phase. This study investigated the effect of a single hour of bright white morning light on circadian phase, sleep, alertness and cognitive performance. Nine individuals (eight male, one female, median age 30 years), wintering at Halley Research Station (75◦S), Antarctica from 7th May until 6th August 2007, were exposed to bright white light for a fortnight from 08:30 to 09:30 h, with two fortnight control periods on either side. This sequence was performed twice, before and following Midwinter. Light exposure, sleep and alertness were assessed daily by actigraphy, sleep diaries and subjective visual analogue scales. Circadian phase (assessed by urinary 6-sulphatoxymelatonin rhythm) and cognitive performance were evaluated at the end of each fortnight. During light exposure circadian phase was advanced from 4.97 ± 0.96 decimal hours (dh) (mean ± SD) to 4.08 ± 0.68 dh (p = 0.003). Wake-up time was shifted by a similar margin from 8.45 ± 1.83 dh to 7.59 ± 0.78 dh (p < 0.001). Sleep start time was also advanced (p = 0.047) but by a lesser amount, consequently, actual sleep time was slightly reduced. There was no change in objective or subjective measures of sleep quality or subjective measures of alertness. An improvement in cognitive performance was found with both the Single Letter Cancellation Test (p < 0.001) and the Digit Symbol Substitution Test (p = 0.026) with preserved circadian variation. These beneficial effects of a single short duration light treatment may have implications not only for the Antarctic but other remote environments where access to natural light and delayed circadian phase, is problematic. These results require validation in larger studies at varying locations. Article in Journal/Newspaper Antarc* Antarctic Antarctica Natural Environment Research Council: NERC Open Research Archive Antarctic Halley Research Station ENVELOPE(-26.209,-26.209,-75.605,-75.605) Midwinter ENVELOPE(139.931,139.931,-66.690,-66.690) The Antarctic Neuroscience Letters 525 2 146 151 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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description |
Previous work has demonstrated that exposure to an hour of bright light in the morning and the evening during the Polar winter has beneficial effects on circadian phase. This study investigated the effect of a single hour of bright white morning light on circadian phase, sleep, alertness and cognitive performance. Nine individuals (eight male, one female, median age 30 years), wintering at Halley Research Station (75◦S), Antarctica from 7th May until 6th August 2007, were exposed to bright white light for a fortnight from 08:30 to 09:30 h, with two fortnight control periods on either side. This sequence was performed twice, before and following Midwinter. Light exposure, sleep and alertness were assessed daily by actigraphy, sleep diaries and subjective visual analogue scales. Circadian phase (assessed by urinary 6-sulphatoxymelatonin rhythm) and cognitive performance were evaluated at the end of each fortnight. During light exposure circadian phase was advanced from 4.97 ± 0.96 decimal hours (dh) (mean ± SD) to 4.08 ± 0.68 dh (p = 0.003). Wake-up time was shifted by a similar margin from 8.45 ± 1.83 dh to 7.59 ± 0.78 dh (p < 0.001). Sleep start time was also advanced (p = 0.047) but by a lesser amount, consequently, actual sleep time was slightly reduced. There was no change in objective or subjective measures of sleep quality or subjective measures of alertness. An improvement in cognitive performance was found with both the Single Letter Cancellation Test (p < 0.001) and the Digit Symbol Substitution Test (p = 0.026) with preserved circadian variation. These beneficial effects of a single short duration light treatment may have implications not only for the Antarctic but other remote environments where access to natural light and delayed circadian phase, is problematic. These results require validation in larger studies at varying locations. |
format |
Article in Journal/Newspaper |
author |
Corbett, R.W. Middleton, B. Arendt, J. |
spellingShingle |
Corbett, R.W. Middleton, B. Arendt, J. An hour of bright white light in the early morning improves performance and advances sleep and circadian phase during the Antarctic winter |
author_facet |
Corbett, R.W. Middleton, B. Arendt, J. |
author_sort |
Corbett, R.W. |
title |
An hour of bright white light in the early morning improves performance and advances sleep and circadian phase during the Antarctic winter |
title_short |
An hour of bright white light in the early morning improves performance and advances sleep and circadian phase during the Antarctic winter |
title_full |
An hour of bright white light in the early morning improves performance and advances sleep and circadian phase during the Antarctic winter |
title_fullStr |
An hour of bright white light in the early morning improves performance and advances sleep and circadian phase during the Antarctic winter |
title_full_unstemmed |
An hour of bright white light in the early morning improves performance and advances sleep and circadian phase during the Antarctic winter |
title_sort |
hour of bright white light in the early morning improves performance and advances sleep and circadian phase during the antarctic winter |
publisher |
Elsevier |
publishDate |
2012 |
url |
http://nora.nerc.ac.uk/id/eprint/20092/ http://www.elsevier.com/locate/neulet |
long_lat |
ENVELOPE(-26.209,-26.209,-75.605,-75.605) ENVELOPE(139.931,139.931,-66.690,-66.690) |
geographic |
Antarctic Halley Research Station Midwinter The Antarctic |
geographic_facet |
Antarctic Halley Research Station Midwinter The Antarctic |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_relation |
Corbett, R.W.; Middleton, B.; Arendt, J. 2012 An hour of bright white light in the early morning improves performance and advances sleep and circadian phase during the Antarctic winter. Neuroscience Letters, 525 (2). 146-151. https://doi.org/10.1016/j.neulet.2012.06.046 <https://doi.org/10.1016/j.neulet.2012.06.046> |
op_doi |
https://doi.org/10.1016/j.neulet.2012.06.046 |
container_title |
Neuroscience Letters |
container_volume |
525 |
container_issue |
2 |
container_start_page |
146 |
op_container_end_page |
151 |
_version_ |
1790593346674098176 |