A new day will now bring much more than another dollar for UA researcher Thomas Christensen. Having recently received a five-year, $1 million grant, Christensen hopes to determine the roles that attention and memory play in processing spoken language.
Originally involved with neurobiology research pertaining to olfactory communication among insects, Christensen has taken his passion for communication and tweaked it slightly to begin research on humans in the speech, language and hearing sciences department.
“”I hoped to do something new, to do something different, and to change my career,”” Christensen said.
Already, he is well on his way to accomplishing his goals. By using volunteers to research the way audio stimuli is received and then mapping active areas of the brain using a MRI, Christensen has proven that there is no correlation between dexterity and the localization of language in the opposite part of the brain.
Over the next five years – the grant was awarded in April – he will continue tracking the function of language and memory in the brain. He will conduct experiments similar to those of classical conditioning pioneer Ivan Pavlov, who trained dogs to salivate after hearing a bell they associated with feeding.
Christensen will only use sound as stimuli – there will be no reward. He wants to determine which parts of the brain are important in communicating and how much of an impact each area possesses.
“”We can see that (brain use) is far more complex than we believed a decade ago,”” Christensen said. “”We only now are beginning to understand the connection between sub-cortical and cortical (areas).””
In the past, much research has been done on cortical mechanisms, the primary way the brain processes language in the cerebral cortex, Christensen said. For example, the right hemisphere is responsible for attention and plays an important role in language, although primary processing occurs in left hemisphere.
While past research on the topic mostly involved reading, however, Christensen’s studies rely heavily on listening.
“”Previous neuro-imaging work in each of the areas of attention, memory, and language have not specifically considered the interactions among these cognitive skills,”” Elena Plante, department head of speech, language and hearing sciences, wrote in an e-mail. “”For example, a researcher studying language would not have considered that the participants would also need to pay attention to the language stimuli and how differing levels of attention might alter processing of language, or the ability to remember verbal information for later.
“”(Christensen’s) work specifically examines the interplay among these cognitive skills for a more complete picture of how individuals use their cognitive resources.””
In testing whether multiple parts in the brain collaborate, Christensen is relying largely on work with two different neurons, excitatory and inhibitory, involved with processing language.
Already he has found that humans do in fact use more than 10 percent of their brains for certain functions, and said he is now in the process of conducting research in regard to attention and listening.
“”When it comes to attention, one of the first things you tend to think of is the high (rate of) attention-deficit disorders diagnosed in children,”” Christensen said. “”It is quite disturbing that children as young as 2 years old are given drugs for ADD.””
“”By studying the brain and areas involved with language processing, we may be able to develop other types of treatments including behavioral treatments that target specific regions of the brain that will lessen a patient’s dependence on pharmaceutical drugs,”” Christensen added.
Students in Christensen’s field are voicing respect for how he has dispelled myths and uncovered new neurological facts.
“”He is turning everything topsy-turvy from what we previously knew,”” said Andrew Yost, a speech and hearing sciences junior.
