An anonymous reader writes "Why can some people sleep through anything? According to this article in Wired Science, some lucky people have an extra helping of a certain kind of brain static that essentially blocks out noise and other stimuli. These 'sleep spindles' can be detected via EEG, and show up as brief bursts of high-frequency brain waves; some people naturally produce more than others. The researchers say these spindles are produced by the thalamus, the brain region that acts as a waystation for sensory information. If the thalamus is busy producing sleep spindles, sensory information can't make it through the thalamus to the cortex, the perceptive part of the brain."