Counting sheep is a terrible bedtime coach. The image forces the brain to build a vivid visual scene, track motion, and keep a running total, all of which drive up working memory load and sustained attention instead of letting them drop.
What sleep researchers describe instead is a shift in networks. When you picture sheep hopping a fence, you recruit the dorsal attention network and visuospatial processing, then bind it with numerical monitoring in prefrontal cortex, a mix that keeps cortical arousal high. Quietly listing random verbs or naming cities, by contrast, is cognitively light; it taps semantic memory and phonological loops just enough to distract from rumination without spiking noradrenergic activity.
The counterintuitive point is that the right kind of mental task is not no task. A simple, low-emotion word stream gives the default mode network room to reassert its slow, drifting activity, which aligns with the onset of stage N1 sleep. No imagery to animate. No story to track. Just a thin trickle of language that bores the executive system into letting go.