Deaf people who use sign language are quicker at recognizing and interpreting body language than hearing non-signers, according to new research from investigators at UC Davis and UC Irvine. The work suggests that deaf people may be especially adept at picking up on subtle visual traits in the actions of others, an ability that could be useful for some sensitive jobs, such as airport screening. "There are a lot of anecdotes about deaf people being better able to pick up on body language, but this is the first evidence of that, " said David Corina, professor in the UC Davis Department of Linguistics and Center for Mind and Brain. Corina and graduate student Michael Grosvald, now a postdoctoral researcher at UC Irvine, measured the response times of both deaf and hearing people to a series of video clips showing people making American Sign Language signs or "non-language" gestures, such as stroking the chin.
A study published in the December issue of Archives of Otolaryngology - Head & Neck Surgery, one of the JAMA/Archives journals, found that among children treated at a pediatric tertiary care clinic in Canada, the overall percentage of re-implantation of cochlear implants as result of device failure seems was low. However, the risk of device failure seems to be increased among those who develop hearing loss due to bacterial meningitis before implantation. The first implantation was implemented nearly four decades ago, since then multichannel cochlear implantation (CI) has become considerably more refined. The researchers say: "Not all CIs survive for long periods of use, and surgical replacement will potentially become the most common complication experienced by patients who undergo implantation.
Today's ubiquitous MP3 players permit users to listen to crystal-clear tunes at high volume for hours on end - a marked improvement on the days of the Walkman. But according to Tel Aviv University research, these advances have also turned personal listening devices into a serious health hazard, with teenagers as the most at-risk group. One in four teens is in danger of early hearing loss as a direct result of these listening habits, says Prof. Chava Muchnik of TAU's Department of Communication Disorders in the Stanley Steyer School of Health Professions at the Sackler Faculty of Medicine and the Sheba Medical Center. With her colleagues Dr. Ricky Kaplan-Neeman, Dr. Noam Amir, and Ester Shabtai, Prof. Muchnik studied teens' music listening habits and took acoustic measurements of preferred listening levels.
Providing clues to deafness, researchers at Washington University School of Medicine in St. Louis have identified a gene that is required for proper development of the mouse inner ear. In humans, this gene, known as FGF20, is located in a portion of the genome that has been associated with inherited deafness in otherwise healthy families. "When we inactivated FGF20 in mice, we saw they were alive and healthy, " says senior author David M. Ornitz, MD, PhD, the Alumni Endowed Professor of Developmental Biology. "But then we figured out that they had absolutely no ability to hear." The results, published online Jan. 3 in PLoS Biology, show that disabling the gene causes a loss of outer hair cells, a special type of sensory cell in the inner ear responsible for amplifying sound. While about two-thirds of the outer hair cells were missing in mice without FGF20, the number of inner hair cells, the cells responsible for transmitting the amplified signals to the brain, appeared normal.
People with dyslexia often struggle with the ability to accurately decode and identify what they read. Although disrupted processing of speech sounds has been implicated in the underlying pathology of dyslexia, the basis of this disruption and how it interferes with reading comprehension has not been fully explained. Now, new research published by Cell Press in the December 22 issue of the journal Neuron finds that a specific abnormality in the processing of auditory signals accounts for the main symptoms of dyslexia. "It is widely agreed that for a majority of dyslexic children, the main cause is related to a deficit in the processing of speech sounds, " explains senior study author, Dr. Anne-Lise Giraud and Franck Ramus from the Ecole Normale SupĂ rieure in Paris, France. "It is also well established that there are three main symptoms of this deficit: difficulty paying attention to individual speech sounds, a limited ability to repeat a list of pseudowords or numbers, and a slow performance when asked to name a series of pictures, colors, or numbers as quickly as possible.