Sleep and Human Performance
Brain Imaging Studies
Positron emission tomography (PET) can be used to image the brain of a sleep-deprived healthy adult, using 18Fluorine-2-deoxyglucose, a marker for regional cerebral metabolic rate for glucose (CMRglu) and neuronal synaptic activity. These types of experiments reveal that specific brain areas show reduced metabolism, including portions of the thalamus (the major relay center for sensory input), the prefrontal cortex and posterior parietal lobes, which perform most complex cognitive tasks, manage working memory and executive functioning, and sustain attention networks essential for a wide range of performance.
Transcript of Videotaped Presentation (http://www.bioedonline.org/presentations/) When we use sophisticated scientific techniques like brain imaging—and this slide shows something called positron emission tomography, or PET imaging, where we look at the metabolic activity, glucose-based or basic sugar-based metabolism in the brain of sleep deprived people—what we see are these blue/green areas are areas of the brain that are less active when you’re sleep deprived. Now, this is important because these areas are the primary areas your brain uses for thinking, reacting, paying attention, remembering and processing information. So there’s reduced activity in this thalamus, the sensory relay center in the brain, which projects to the cortex up above, the upper brain. But there’s also reduced activity in the prefrontal cortex and in the parietal lobes. Now the prefrontal cortex, if you put your hand on your forehead, that’s the prefrontal cortex, right behind your forehead—that whole part of your brain is your executive attention system. It keeps track of everything you’re doing. It remembers that you have to go to football practice or play in the band at five o’clock; it’s the one that remembers what your assignment was in class; it’s the one that makes sure you can focus on that assignment when the time comes, and that shows reduced activity during sleep loss. And the other area that’s critical for compensating, for impairment of the prefrontal cortex and helps it out, is the parietal lobe back here (also shows reduced activity). So the worrisome part of this slide is the areas of your brain you most want to use for performance every day, whether it’s out on the basketball court or in physics class or English class or creative writing class—those are the parts of the brain that are most affected by inadequate amounts of sleep.
- Walter Reed Army Institute of Research—Psychiatry and Neuroscience. Image reflecting deactivation in specific brain regions following 24 hours of sleep deprivation. Sleep deprivation and complex cognitive function. Retrieved 05-07-2007 from http://www.wrair-psych.org/wrair_dobb-wwd.htm
- PET schema. Retrieved 04-30-07 from http://upload.wikimedia.org/wikipedia/commons/c/c1/PET-schema.png
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Funded by the following grant(s)
This work was supported by National Space Biomedical Research Institute through NASA cooperative agreement NCC 9-58.