Syndicate content

Whistled Turkish Language Perception Employs Both Brain Hemispheres Equally; Finding Debunks Theory of Left-Brain Dominance in Processing of All Languages

Researchers at the Ruhr-Universität Bochum in Germany have debunked the theory that the left brain hemisphere is dominant in the processing of all languages. To date, it has been assumed that this dominance is not determined by the physical structure of a given language. However, the Bocum biopsychologists have demonstrated that both hemispheres are equally involved in the perception of whistled Turkish. Dr. Onur Güntürkün, Dr. Monika Güntürkün, and Dr. Constanze Hahn report on this in an open-access article in the August 17, 2015 issue of Current Biology. The article is titled “Whistled Turkish Alters Language Asymmetries.” The perception of all spoken languages; including those with clicks, written texts, and even sign language; involves the left brain hemisphere more strongly than the right one. The right hemisphere, on the other hand, processes acoustic information via slow frequencies, pitch, and melody. According to the current commonly held opinion, the asymmetry in language processing is not determined by the physical properties of a given language. "The theory can be easily verified by analyzing a language which possesses the full range of physical properties in the perception of which the right brain hemisphere is specialized," says Dr. Güntürkün. "We can count ourselves lucky that such a language exists, namely whistled Turkish." The Bochum team tested 31 inhabitants of Ku?köy, a village in Turkey, who speak Turkish and whistle it as well. Via headphones, these inhabitants were presented either whistled or spoken Turkish syllables. In some test runs, they heard different syllables in both ears, in other runs, the same syllables. They were asked to state which syllable they had perceived. The left brain hemisphere processes information from the right ear, the right hemisphere from the left ear. For spoken Turkish, a clear asymmetry emerged: If the participants heard different syllables, they perceived the syllables from the right ear much more frequently, demonstrating a dominance of the left brain hemisphere.

That asymmetry did not exist in whistled Turkish. "The results have shown that brain asymmetries occur at a very early signal processing stage," concludes the researcher from Bochum.

Whistled Turkish contains the same vocabulary and follows the same grammatical rules as Turkish. "It is simply a different format, in the same way as written and spoken Turkish are," describes Dr. Güntürkün. A small group of people in the mountainous north-eastern part of Turkey use whistled language which can be heard over distances of several kilometres.

"Even though I am Turkish, I had, strangely enough, never heard of whistled Turkish. I encountered it in Australia for the first time, when a colleague told me about it," explains the biopsychologist.

"I knew instantly that nature had thus provided the perfect method for verifying the theory regarding asymmetry of language perception."

Photo is credited to Alex Christie Miller.

[Press release] [Current Biology article]