Last modified: Friday, February 13, 2004
News tips from the AAAS 2004 annual meeting
Feb. 12 - 16, Seattle
NOTE: The American Association for the Advancement of Science is holding its annual meeting Feb. 12-16 in Seattle. The following news tips are based on Indiana University presentations at the meeting. Each tip is embargoed by AAAS (see each tip for embargo date and time).
RELEARNING TO HEAR: GRADUAL ADAPTATION SYSTEM MAY IMPROVE COCHLEAR IMPLANT SUCCESS
Embargoed until Monday (Feb. 16) at 3:30 p.m. EST
Cochlear implants are surgically implanted devices that stimulate the auditory nerve to enable profoundly deaf persons to sense and understand speech. Adults who have lost their hearing must somehow match the signals provided by the implants to the speech sounds they heard and stored in memory before losing their hearing. To do so, they must overcome two simultaneous forms of distortion introduced by the implants -- the sound has lower frequency resolution and is shifted to a higher pitch. Mario Svirsky and his Indiana University School of Medicine colleagues tested whether a training regimen that gradually introduced subjects to the frequency shift could improve their ability to comprehend speech. The experiment was done with an "acoustic simulation" of a cochlear implant, which allows listeners who have normal hearing to hear sounds that are degraded and frequency-shifted in a way similar to that found in cochlear implants. They found that subjects introduced to the frequency shift in a gradual way adapted sooner than those who were introduced to the full frequency shift from the beginning. Brain scans performed by Thomas Talavage at Purdue University showed systematic changes in cortical responses in one of the subjects, who was tested before and after several hours of exposure to the degraded speech. Svirsky and Talavage concluded that human listeners can learn to understand an extremely impoverished and frequency-shifted acoustic signal, and this learning process can be facilitated by gradual exposure. These findings will be presented at the meeting of the American Association for the Advancement of Science.
To speak with Svirksy, contact Eric Schoch at 317-274-8205 or eschoch@iupui.edu.
"EVO-DEVO" BIOLOGY TACKLES EVOLUTIONARY HISTORY'S UNANSWERED QUESTIONS
Embargoed until Monday (Feb. 16) at 11 a.m. EST
The recent marriage of evolutionary biology with developmental biology has resulted in the birth of a new field, evolutionary developmental biology, or "evo-devo." Evo-devo scientists study the mechanisms that produce evolutionary changes in body plans over time. As one of the field's creators, Indiana University Bloomington biologist Rudolf Raff brings new understanding to the evolution of humans and other organisms by uniting fossil data and information about the genes that control development. Major historical questions about the origin of multicellular animals, the Cambrian radiation and the origins of animal larvae can now be addressed using evo-devo's mechanistic tools. Last month, the National Academy of Sciences chose Raff as the winner of its 2003 Elliott Medal for his role in founding evo-devo. Raff and IUB colleagues Loren Rieseberg, Thomas Kaufman, Michael Lynch and Jeffrey Palmer lead the largest concentration of evo-devo biologists in the nation. In a presentation at the meeting of the American Association for the Advancement of Science titled "The Quick and the Dead: Developmental Genetics Meets Extinct Organisms," Raff will discuss how evo-devo will expand our understanding of the fossil record. He will show how and why some complex features in animal development may have evolved much more quickly than expected.
To speak with Raff, contact David Bricker at 812-856-9035 or brickerd@indiana.edu.
LANDOWNERS' PURSUIT OF DIFFERENT LAND-USE STRATEGIES MAY CONFOUND POLICYMAKERS
Embargoed until Saturday (Feb. 14) 12 p.m. EST
A burgeoning human population has put increasing pressure on the world's land, so smart land-use strategies that prevent hunger, support economies and preserve ecological diversity are now more critical than ever. While exploring the interactions between natural and human systems within the forested regions of the American Midwest and the Brazilian Amazon, researchers at Indiana University Bloomington discovered differences in land-use strategies that lead to a heterogeneous landscape, which may complicate future policymaking decisions. Peter Deadman of IU's Center for the Study of Institutions, Population and Environmental Change said the implication for policymakers is that it may be very difficult to create a single, uniform policy for an entire region. By looking at satellite imagery and aerial photos of Brazil and the Midwest, the researchers learned how households develop land-use strategies and the factors, including crop prices, conservation plans and state and federal forest protection programs, that influence their decision-making process. CIPEC co-directors Elinor Ostrom and Emilio Moran and Associate Director Tom Evans participated in the study. The researchers' findings will be presented at the meeting of the American Association for the Advancement of Science.
To speak with Deadman, Ostrom, Moran or Evans, contact Ryan Piurek at 812-855-5393 or rpiurek@indiana.edu.
