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Beginning, middle, and end of the light exposure period relative to the midpoint of the melatonin profile
| Duration (hours) | Beginning ± SD | Middle ± SD | End ± SD |
|---|---|---|---|
| 1 | −1.1 ± 1.3 | −0.60 ± 1.3 | −0.10 ± 1.3 |
| 2 | −1.97 ± 1.0 | −0.97 ± 1.0 | 0.03 ± 1.0 |
| 3 | −2.37 ± 1.4 | −0.87 ± 1.4 | 0.63 ± 1.4 |
