Are words that are harder to pronounce by default more difficult to understand? Or is it the other way around and our ability to recognize a word is what affects how easy it is to say? This question has puzzled researchers for many years and stands at the heart of helping dyslexic children learn to overcome their disability. A recent study used electromagnetic readings of volunteers' brains in order to answer this question, and what researchers found may change the way we perceive how our brains learn a language.

Humans have the amazing ability to tell which phrases sound like part of a human language and which sound like just an arbitrary mixture of sounds. For example, whether you speak English, French, Russian, or Arabic, the sound combination “blog” will nearly always sound more linguistic than “lbog.” In fact, even nonverbal infants can make this distinction. Now, it’s quite obvious that “lbog” has certain phonetic constraints that make it difficult to pronounce, but this doesn’t seem to be the reason for its absence from languages around the globe.

Iris Berent, Northeastern University researcher and professor of psychology, and her colleagues have found that sound combinations such as “lbog” and “lbif” are exempt from the majority of human languages, not because they are too difficult for the tongue to pronounce, but rather because our brains have a natural born preference for linguistic tones.

In order to answer this question which has puzzled linguists for many years, the team used TMS, a noninvasive technique that induces focal cortical current via electro-magnetic induction to temporarily inhibit specific brain regions, the press release explained. In a study, which will be published in the online journal, Proceedings of the National Academy of Sciences, researchers explained that with this technique the scientists could see what was going on in volunteers’ brains when they pronounced both common and uncommon sound combinations. The results showed that the way participants perceived a word affected the articulatory motor system in their bodies — that is, your mouth, tongue, vocal chords. In other words, it’s your brain, not your body, which determines if you will find something difficult to pronounce.

"This study helps to solve a longstanding debate in the literature: What part of speech depends on experience and what part depends on relatively experience-independent grammatical rules, or some kind of logic system," explained Albert Galaburda, co-author of the paper, in the press release.

Although this study holds weight for the entire linguistic field, it is of particular interest to those working with dyslexic individuals. "This question can be transformed to ask whether dyslexics have a primary disorder of grammar, or a primary disorder of experience with language, as in poor perception of speech reaching their ears when babies," Galaburda added.

Although the study did show that perception influenced how difficult our body found it to pronounce a word, it was also clear that there were aspects of these two facets of language which remained distinct.

"Language is designed to optimize motor action, but its knowledge consists of principles that are disembodied and potentially abstract," the researchers concluded.

Source: Berent I, et al. Proceedings of the National Academy of Sciences. 2015.