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This Article Full Text Full Text (PDF) All Versions of this Article: 291/3/R822    most recent 00550.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Goel, N. Search for Related Content PubMed PubMed Citation Articles by Goel, N.

SLEEP AND TEMPERATURE REGULATION

An arousing, musically enhanced bird song stimulus mediates circadian rhythm phase advances in dim light

Department of Psychology, Wesleyan University, Middletown, Connecticut

Submitted 26 July 2005 ; accepted in final form 5 April 2006

A musically enhanced bird song stimulus presented in the early subjective night phase delays human circadian rhythms. This study determined the phase-shifting effects of the same stimulus in the early subjective day. Eleven subjects (ages 18–63 yr; mean ± SD: 28.0 ± 16.6 yr) completed two 4-day laboratory sessions in constant dim light (<20 lux). They received two consecutive presentations of either a 2-h musically enhanced bird song or control stimulus from 0600 to 0800 on the second and third mornings while awake. The 4-day sessions employing either the stimulus or control were counterbalanced. Core body temperature (CBT) was collected throughout the study, and salivary melatonin was obtained every 30 min from 1900 to 2330 on the baseline and poststimulus/postcontrol nights. Dim light melatonin onset and CBT minimum circadian phase before and after stimulus or control presentation was assessed. The musically enhanced bird song stimulus produced significantly larger phase advances of the circadian melatonin (mean ± SD: 0.87 ± 0.36 vs. 0.24 ± 0.22 h) and CBT (1.08 ± 0.50 vs. 0.43 ± 0.37 h) rhythms than the control. The stimulus also decreased fatigue and total mood disturbance, suggesting arousing effects. This study shows that a musically enhanced bird song stimulus presented during the early subjective day phase advances circadian rhythms. However, it remains unclear whether the phase shifts are due directly to effects of the stimulus on the clock or are arousal- or dim light-mediated effects. This nonphotic stimulus mediates circadian resynchronization in either the phase advance or delay direction.

nonphotic; alerting; melatonin; core body temperature; phase shifts