کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2045367 1073480 2006 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Daytime Light Exposure Dynamically Enhances Brain Responses
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم کشاورزی و بیولوژیک (عمومی)
پیش نمایش صفحه اول مقاله
Daytime Light Exposure Dynamically Enhances Brain Responses
چکیده انگلیسی

SummaryIn humans, light enhances both alertness and performance during nighttime and daytime 1, 2, 3 and 4 and influences regional brain function [5]. These effects do not correspond to classical visual responses but involve a non-image forming (NIF) system, which elicits greater endocrine, physiological, neurophysiological, and behavioral responses to shorter light wavelengths than to wavelengths geared toward the visual system 6, 7, 8, 9, 10 and 11. During daytime, the neural changes induced by light exposure, and their time courses, are largely unknown. With functional magnetic resonance imaging (fMRI), we characterized the neural correlates of the alerting effect of daytime light by assessing the responses to an auditory oddball task 12, 13, 14 and 15, before and after a short exposure to a bright white light. Light-induced improvement in subjective alertness was linearly related to responses in the posterior thalamus. In addition, light enhanced responses in a set of cortical areas supporting attentional oddball effects, and it prevented decreases of activity otherwise observed during continuous darkness. Responses to light were remarkably dynamic. They declined within minutes after the end of the light stimulus, following various region-specific time courses. These findings suggest that light can modulate activity of subcortical structures involved in alertness, thereby dynamically promoting cortical activity in networks involved in ongoing nonvisual cognitive processes.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: - Volume 16, Issue 16, 22 August 2006, Pages 1616–1621
نویسندگان
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