Friday, March 9, 2007

Smells, sleep, and memory

The hypothesis: "Olfactory sensing pathways in the brain lead more directly to the hippocampus than visual and auditory ones. That may be why smells can be linked so closely to memory, and may revive forgotten joys, humiliations and other remembrances of things past. "

Here's what they did: "In the study, neuroscientists from the University of Lubeck and the University Medical Center, Hamburg-Eppendorf, had groups of medical students play a version of concentration, memorizing the location of card pairs on a computer screen. Upon learning the location of each pair, the students received a burst of rose scent in their noses, through a mask they wore. The researchers delivered the fragrance in bursts because the nose quickly adjusts to strong smells in the air and begins to ignore them. "

Then, while the subjects were asleep: "The brain is thought to process newly acquired facts, figures and locations most efficiently in deep sleep. This restful state usually descends within the first 20 minutes or so after head meets pillow, and it may last an hour or more, then recur later in the night. The researchers delivered pulses of rose bouquet during this slow-wave state; the odor did not interrupt sleep, and the students said they had no memory of it. "

Here's what they found: "But their brains noticed, and they retained an almost perfect memory of card locations. The students scored an average of 97 percent on the card game, compared with 86 percent when they played the concentration game and slept without being perfumed by nighttime neuroscience fairies.
The students did not get the same boost when they received bursts of the fragrance before falling asleep, and their improvements were not a result of practice, the study found. "

Just think, someday soon I could peddle my lavender sachets as study aids or memory enhancers.

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