“The more I study this disorder the more obvious it is to me how heterogeneous the population is, in terms of the etiology and in the reaction of the people to it,” she said. “It is a very complex disorder. We know hearing loss may trigger tinnitus, but only about 40 percent of persons with hearing loss develop tinnitus. One of the research questions I am trying to answer is: why do some people with hearing loss develop tinnitus while others do not?”
Husain said looking at larger samples using both computer models and data from experiments using techniques like fMRI should give a more complete understanding of tinnitus.
“We want to study a large enough population and then use our modeling and clever statistical analysis of our MRI experiments to try and identify the major sources of variance within the population and see if can we find something that is common for this population – apart from the fact that they have ringing in the ears,” Husain said. “What is it that is common? Can we figure out the brain functions, regions, and mechanisms that underlie this disorder? If we can get there, then we are halfway to developing therapies and our own interventions.”
Husain said she is looking at clinical populations to broaden her understanding of tinnitus and hearing impairment. That was part of the reason why she joined the faculty in Speech and Hearing Science.
“Because I’m looking at clinical populations, it made sense to be in the Speech and Hearing Science department,” she said. “But at the same time, because my background is so multidisciplinary, I want to use multiple tools and work with a range of researchers.”
Husain said she uses technologies like fMRI but her computer models are able to provide a more complete picture of brain function.
“For instance, in the processing of phonemes, fMRI does not tell me what mechanisms or computations are taking part in those regions that sub-serve that function,” she said. “A network of brain regions is activated when listeners are processing phonemes. But what exactly is going on in these regions? I am blind to that if I just look at the fMRI data.
“So I have to come up with a theory of what is going on and to do that, I create a model based on earlier experimental work. In some ways it is theory instantiated within a particular set of circumstances. In neuroscience right now we have tons of tools, very exciting tools, and we are coming up with data at new levels of specificity and clarity. But while we are rich in data, we are poor in theory. And we will continue to be richer in data as we get better tools. With modeling, we can begin to understand the mechanisms and make connections between different data sets (animal, human). We can see the big picture and ask big questions. That is what I see as the value of modeling.”
Husain is pursuing research lines other than tinnitus. She is interested in categorizing sounds and words, and is about to publish a paper looking at how people assess categories of different gestures. It will report on the commonalities shared by hearing people processing sound categories and deaf people processing the same gestural categories. Husain said language processing is all one area, regardless of how people communicate.
“Language acquisition to me is like high-level category acquisition,” she said. “The other major theme of my research has been investigating the acquisition and processing of categories. I’ve looked at that through speech and through sign language.”
Husain is also exploring collaborations with other Beckman researchers looking at topics such as language learning in older adults.
“I think I will always have a broad focus,” Husain said. “I learned a number of techniques and perspectives in my scenic route to get here but, finally, I can use them to understand not only the normal brain but also the disordered brain. Tinnitus is an illusory sound. The illusions and disorders of the brain tell us so much more about normal processing.
“In my tinnitus research, I see the culmination of all the tools and techniques I’ve learned and I can apply to them to a complex disorder and hopefully, we can develop better evaluations of therapies and develop new interventions so that we help people.”