New Research by Cal State Long Beach Professors Indicates Tongue May Not Be Essential for Taste or Speech

According to new research at California State University, Long Beach (CSULB), we may not need our tongues to taste or speak. This information could prove invaluable when it comes to helping rehabilitate those who have lost or damaged their tongues as a result of cancer or other means. In addition, Betty McMicken, an associate professor in CSULB’s Department of Speech-Language Pathology and one of the study’s co-creators, received the highest honor awarded by the American Speech-Language-Hearing Association (ASHA) at the organization’s annual convention last week.

McMicken and her colleague, Assistant Professor Long Wang, have been investigating Isolated Congenital Aglossia (ICA), a rare condition in which a person is born without a tongue. The researchers conducted a series of tests on a volunteer with ICA, which included the detection of basic tastes and the involvement of different parts of the mouth and throat during the pronunciation of different speech sounds. They hypothesized that the subject would not taste anything or be able to speak and be understood. However, in the laboratory, the ICA volunteer detected all the basic tastes: sour, sweet, bitter, salty and umami. It was also the first study to report that umami was sensed by an ICA subject. In addition, in perceptual studies, the subject demonstrated 78 percent intelligible vowels and consonants and completely intelligible contextual speech.

“The research findings are significant because they demonstrate that the tongue is not essential for humans to detect taste or to produce intelligible speech,” said Wang. “There are currently unknown receptors and other structures of signal delivery in this subject that serve as an alternative mechanism for taste recognition and the production of speech.”

Currently, less than 10 people in the world are known to live with ICA. Additionally, the Centers for Disease Control and Prevention reports that more than 40,000 people have been diagnosed with oral or pharyngeal cancer and many of those identified have their tongues surgically removed.

“With these findings, additional research on the subject can be conducted to develop rehabilitation regimens that could potentially allow those without a tongue to regain their ability to taste and to speak in a more understandable manner,” said McMicken. “The results of these investigations may be promising in maintaining and improving quality of life.”

Also, last week, McMicken traveled to Orlando, Fla. to accept the “Honors of the Association” from the American Speech-Language-Hearing Association. The distinction recognizes those in communication sciences and disorders for excellence in the areas of teaching, research, community service and professional expertise. Honorees must be well-known in the profession and have presented papers nationally and internationally.

“I feel a bit overwhelmed by this honor. Previous recipients have included my mentors - people who took me under their wings and I am grateful to now be considered among them,” said McMicken. “If I can make a difference to others in the way my mentors did for me, that would be a wonderful bonus.”

McMicken has been a professor, clinician and researcher in speech-language pathology for more than 48 years.

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