Killgore William D S, McBride Sharon A
Division of Neuroscience, Department of Behavioral Biology, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
J Sleep Res. 2006 Jun;15(2):111-6. doi: 10.1111/j.1365-2869.2006.00502.x.
Brain imaging studies demonstrate that sleep deprivation reduces glucose metabolism and blood flow in the prefrontal cortex, and such reductions are associated with impairments in cognitive functioning. Although some of the greatest metabolic declines occur within the orbitofrontal cortex, little is known about the effects of sleep loss on the types of processes mediated by this region, including emotion, motivation, feeding, and olfaction. The present study tested odor identification accuracy when individuals were well rested and again following 24 h of wakefulness. Relative to rested baseline performance, sleep-deprived individuals demonstrated a significant decline in the ability to identify specific odors on the Smell Identification Test. This decrement in olfactory functioning occurred concomitantly with slowed psychomotor speed and increased ratings of self-reported sleepiness. Performance on a task that required complex mental set shifting did not change significantly following sleep deprivation, suggesting that the decrements in odor identification could not be attributed to task difficulty. Finally, while there was no relationship between subjective sleepiness and odor identification at rested baseline, greater subjective sleepiness was associated with better odor identification ability following 24 h of sleep loss. Possible implications of these findings are discussed.
脑成像研究表明，睡眠剥夺会降低前额叶皮质的葡萄糖代谢和血流量，而这种降低与认知功能受损有关。尽管一些最大的代谢下降发生在眶额皮质内，但关于睡眠不足对该区域所介导的各种过程（包括情绪、动机、进食和嗅觉）的影响却知之甚少。本研究测试了个体在充分休息时以及在清醒24小时后的气味识别准确性。相对于休息时的基线表现，睡眠剥夺的个体在嗅觉识别测试中识别特定气味的能力显著下降。嗅觉功能的这种下降与精神运动速度减慢和自我报告的困倦程度增加同时发生。在一项需要复杂心理定势转换的任务上的表现，在睡眠剥夺后没有显著变化，这表明气味识别能力的下降不能归因于任务难度。最后，虽然在休息基线时主观困倦与气味识别之间没有关系，但在睡眠剥夺24小时后，更大的主观困倦与更好的气味识别能力相关。讨论了这些发现的可能影响。
