More Rapid Language Learning Using Non Invasive Vagus Nerve Stimulation

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A growing body of evidence suggests that processing of language and processing of music make use of similar cognitive abilities.

One audacious hypothesis argues that, outside of their basic building blocks, language and music are, in fact, the same phenomenon. This idea could help explain why it can be difficult for some people to focus on reading or carrying on a conversation while music is playing (or vice versa). According to this theory, it would be as if one was listening to two conversations (or two pieces of music) at the same time.

The distinction between the two blurs further with tonal languages like Mandarin Chinese.

In a tonal language, words can differ in tone, similar to pitches in music, in addition to consonants and vowels. Just as some phonemes can sound the same to people whose language does not include one of them (think of the R sound mistaken for L in Japanese speakers), some tones can sound the same to people who do not speak a tone language. These are the hardest part of learning a tone language.

Suppose you have tried in the past to learn Mandarin and failed. In that case, you should be encouraged by new research from neuroscientists at the University of Pittsburgh and the University of California San Francisco.

Improving Cognitive Performance

The researchers were able to boost native English speakers’ ability to tell the difference between Mandarin tones.

How did they do it?

They used non-invasive stimulation of the vagus nerve — the longest of the 12 cranial nerves that connect the brain to the rest of the body. Also, vagus nerve stimulation enabled research participants to pick up some Mandarin tones twice as fast.

The study results apply to other areas as well.

“Showing that non-invasive peripheral nerve stimulation can make language learning easier potentially opens the door to improving cognitive performance across a wide range of domains,”

according to lead author Fernando Llanos, Ph.D.

The Wandering Nerve

The vagus nerve begins in the brainstem, behind the ears. It reaches down either side of the neck, across the chest, and even down through the abdominal area.

‘Vagus’ is Latin for ‘wandering.’ This bundle of nerve fibers lives up to it’s name.

It meanders through the body, mingling the brain with the stomach and intestines, as well as the liver, lungs, heart, and kidneys. It also touches an assortment of other nerves involved in speech, eye contact, facial expressions, and your ability to tune in to other people’s voices.

The vagus nerve is associated with many different functions and brain regions. It regulates the body’s parasympathetic nervous system (the PNS oversees components of many unconscious functions, such as circulation, breathing, and digestion).

Currently, vagal nerve stimulation is used for therapy in treatment-resistant depression and intractable epilepsy.

And clinical research has been conducted to learn about its usefulness in treating other illnesses, including various anxiety disorders, obesity, alcohol addiction, chronic heart failure, prevention of arrhythmias that can cause sudden cardiac death, autoimmune disorders, and several chronic pain conditions.

The majority of these studies used invasive types of stimulation, entailing an impulse generator implanted in the chest.

Non-invasive Stimulation

In this study, researchers used a non-invasive technique called transcutaneous vagus nerve stimulation (tVNS). A small stimulator is placed in the outer ear and can activate the vagus nerve using unnoticeable electrical pulses to stimulate one of the nerve’s nearby branches.

Thirty-six native English-speaking adults were trained them to identify the four tones of Mandarin Chinese in examples of natural speech, using a set of tasks developed in the University of Pittsburgh’s Sound Brain Lab to study the neurobiology of language learning.

Participants who underwent undetectable tVNS while hearing two Mandarin tones that are usually easier for English speakers to distinguish demonstrated rapid improvements in learning to tell these tones apart. At the end of the training, those subjects were, on average, 13% better at categorizing tones and attained peak performance twice as fast as participants who wore the tVNS device but never received stimulation.

The researchers are now investigating if longer tVNS training sessions can improve participants’ ability to learn to discriminate two tones harder for English speakers to differentiate, which was not significantly improved in the current study.

Last Updated on November 7, 2023