Sometimes the brain's electrical activity, measured with an electroencephalogram (EEG), and other findings recorded during a sleep test don't always match up perfectly with a person's subjective experience, says Arand, who is the clinical director of the Kettering Sleep Disorders Center in Dayton, Ohio. "They might say, ‘I had a great night's sleep,' but the EEG parameters might not really indicate that."
Sleep is not only subjective, but preferences for sleep surfaces are individual, Arand says. "There's quite a bit of variability between individuals in terms of what type of surface -- whether it's firm, hard, or soft -- they prefer when they're sleeping," she says. "As far as we know, there is no rhyme or reason for that."
Many of Arand's patients who use memory foam have offered unsolicited glowing reports like these about memory foam: "I'm sleeping great." "Best sleep I've ever had." "I love going to bed at night." Arand says these anecdotal responses may be one-sided. That's because she and other staff don't ask all their patients about their sleep surfaces. "We may only be hearing the good stuff," Arand says.
Kathy R. Gromer, MD, sleep specialist with the Minnesota Sleep Institute in Minneapolis, agrees that memory foam may improve sleep. "It can, if it relieves painful pressure points," she says. But Gromer adds that memory foam doesn't do anything for sleep apnea or other sleep-breathing disorders -- and sleep disorders are the primary complaint of most her patients.
"When you lie on the memory foam, the heat from your body softens it in appropriate points," Arand says, "so this helps to support your body along the curves and natural lines of the body." Memory foam manufacturers claim this helps relieve pain and thereby promotes more restful sleep. And, though consumers often believe that very firm mattresses are best, more "giving" mattresses like these may lead to better sleep in people with back pain, according to the National Sleep Foundation.
Although there aren't scientific data to support the hypothesis, Arand wonders whether memory foam sleep surfaces might be especially helpful for older people. For them, minimizing extra movement could reduce the number of times they awaken during the night. Being less aware of a bed partner's movements might be an extra benefit, she adds. "Without the coiled springs, you feel your sleep partner's movement less, and that might help, too."