Dusk Simulation. Dusk is disorienting. It's that sudden, anticipatory hush that settles upon an audience when the house lights start to dim. Drawing our attention from the scattered din of daytime concerns, dusk invites us inward, to the focused, quiet performance of night. If we're willing, dusk will gently reorient us from daytime consciousness to a nighttime consciousness.
Falling asleep is a gradual process, which begins long before bedtime. An honest encounter with dusk teaches us that it's the environmental analogue of sleep onset. By nature, we go down gradually with the sun. Dusk and darkness are natural sedatives: they serve to draw our attention from the waking world, slow us down by diminishing visual stimulation, and trigger the production of melatonin. Darkness itself is the best sleep medicine.
Many of us are familiar with melatonin, the neurohormone that mediates night, sleep, and dreams. Melatonin is a primordial molecule released when the pineal gland— Descartes's "third eye"—senses darkness. It's the essential biological mediator of night consciousness. It plays a powerful role in managing our night biology, informing the body and brain of the arrival and presence of night. Our melatonin levels rise steadily through the night, peaking out in the early-morning hours and dropping off with awakening. Peak levels of it are associated with increased REM sleep or dreaming.
Even small amounts of light at night will suppress melatonin, impeding night consciousness and sleep. The most natural way to restore normal melatonin levels is through exposure to dusk and darkness, a technique referred to as dusk simulation. I encourage most of my insomnia clients to simulate dusk by dimming the lights in their homes for a couple of hours before bedtime. If they wish to read or write, I suggest they use low-wattage book lights. Dusk simulation also requires avoiding televisions and computer monitors, both of which radiate significant amounts of blue wavelengths of light—a potent melatonin suppressant.
In addition to easing the transition to sleep, dusk simulation encourages us to process backlogged psychological material. So much of what we rebuff, deny, suppress, and project throughout our driven days gets relegated to our nights. Night becomes a repository for everything from unresolved daily stress to lingering shadow issues. Like a self-storage space packed to capacity, this material bulges and threatens to break out when our inner watchman dares to rest or sleep.
In a sense, dusk simulation provides us with an opportunity to process some of our anxieties and nightmares before getting into bed. Avoidance of this kind of evening review can drive the material farther into the night, where it commonly erupts as insomnia at sleep onset or in the middle of the night. I frequently remind my clients that we certainly don't have to resolve all of our anxieties to get to and stay sleep—we simply need to be willing to release them.