A severely brain-injured man showed marked improvements after treatment with deep brain stimulation, a technique in which surgically implanted electrodes deliver electrical impulses to the brain. For six years the patient, who sustained head trauma during a violent assault, had been in a minimally conscious state—he could not communicate verbally, and he only sporadically seemed to be aware of himself and his surroundings. After the procedure, the 38-year-old man's attention, verbal and motor skills improved during intervals of brain stimulation, report researchers led by Nicholas D. Schiff of Weill Cornell Medical College. Over the course of a year the patient became able to speak intelligible words, chew and swallow food, and use objects in a purposeful manner (such as bringing a cup to his lips).
Although the results are promising, the researchers caution that every brain injury is unique; much more work is needed to understand whether the treatment with deep brain stimulation is truly responsible for the patient's improvement and to find out if the procedure can help others. The team is currently planning a more extensive study of 12 minimally conscious patients, to be completed in about two years.
▪ Conventional wisdom holds that women talk more than men do—one oft-quoted statistic puts female chattering at 20,000 words a day, compared with 7,000 words for men. But that sex difference is bunk, says the first study to systematically record the natural conversations of a large population. Researchers at the University of Arizona and the University of Texas at Austin listened in on nearly 400 college students and found that both sexes spoke about 16,000 words a day.
▪ Female mice grow new brain cells after getting a whiff of a dominant male's urine, reports a team from the University of Calgary. The alpha male's pheromones promote neurogenesis in the olfactory bulb and in the hippocampus, an area important for memory formation. The ability to recognize and remember pheromonal signatures could be important for regulating mating behavior in female mice, which prefer to mate with dominant males.
▪ Obesity is contagious, according to a new study from Harvard Medical School and the University of California, San Diego. Sociologists followed about 12,000 people for more than 30 years and found that a person's chance of becoming obese was greatly increased if a close friend, sibling or spouse gained weight. The scientists blame shifting attitudes—a person may become more accepting of fat if someone he or she esteems packs on the pounds.