Air Date: Week of September 10, 2004

Living on Earth’s Jennifer Chu reports on a study that identifies the dream center of the brain.

Transcript

CURWOOD: Just ahead: the promises and perils of water power high in Himalayas. First, this Note on Emerging Science from Jennifer Chu.

[SCIENCE NOTE THEME]

CHU: Can hard science help to explain the mysteries of how and why we dream? In a study published this month in The Annals of Neurology, a pair of Swiss researchers point to a specific area of the brain as the likely place where our dreams originate. It’s located deep in the back part of the brain called the inferior lingual gyrus.

Recent research shows that this neighborhood of the brain is involved in the visual processing of faces and landmarks, as well as emotions and visual memories. The scientists in the latest study traced dream-generation to this particular spot by mapping the brain of a 73-year-old woman who stopped dreaming a few days after she suffered a stroke.

The woman’s sight was also damaged by the stroke--including her ability to see in color-- but within a few days these visual problems cleared up, and she had no trouble recognizing familiar faces or describing familiar places. But her dream loss, which began around the same time her visual problems resolved, did not recover until months later.

Throughout her four-week stay at the hospital, the scientists monitored the woman’s sleep cycles. They found that her rapid eye movement, or REM sleep, the deep sleep state associated with dreaming, was normal. The woman remembered dreaming three to four times a week before her stroke, but couldn’t recall any dream experiences afterwards – even when scientists woke her up from REM sleep. Researchers believe their observations support research that REM sleep and dreaming, while linked, may depend on independent generators.

That’s this week Note on Emerging Science. I’m Jennifer Chu.

CURWOOD: And you’re listening to NPR’s Living on Earth.

ANNOUNCER: Support for NPR comes from NPR stations, and: The Noyce Foundation, dedicated to improving math and science instruction from kindergarten through grade 12; Ford, presenting the Escape Hybrid, whose full hybrid technology allows it to run on gas or electric power. Full hybrid technology details at fordvehicles.com; The Annenberg Fund for excellence in communications and education; and, The Kellogg Foundation, helping people help themselves by investing in individuals, their families, and their communities. On the web at w-k-k-f dot org. This is NPR -- National Public Radio.

[MUSIC: Fontanelle “Counterweight” FONTANELLE (Kranky – 2000)]