Navigation Links
Secrets of human speech uncovered
Date:2/20/2013

A team of researchers at UC San Francisco has uncovered the neurological basis of speech motor control, the complex coordinated activity of tiny brain regions that controls our lips, jaw, tongue and larynx as we speak.

Described this week in the journal Nature, the work has potential implications for developing computer-brain interfaces for artificial speech communication and for the treatment of speech disorders. It also sheds light on an ability that is unique to humans among living creatures but poorly understood.

"Speaking is so fundamental to who we are as humans nearly all of us learn to speak," said senior author Edward Chang, MD, a neurosurgeon at the UCSF Epilepsy Center and a faculty member in the UCSF Center for Integrative Neuroscience. "But it's probably the most complex motor activity we do."

The complexity comes from the fact that spoken words require the coordinated efforts of numerous "articulators" in the vocal tract the lips, tongue, jaw and larynx but scientists have not understood how the movements of these distinct articulators are precisely coordinated in the brain.

To understand how speech articulation works, Chang and his colleagues recorded electrical activity directly from the brains of three people undergoing brain surgery at UCSF, and used this information to determine the spatial organization of the "speech sensorimotor cortex," which controls the lips, tongue, jaw, larynx as a person speaks. This gave them a map of which parts of the brain control which parts of the vocal tract.

They then applied a sophisticated new method called "state-space" analysis to observe the complex spatial and temporal patterns of neural activity in the speech sensorimotor cortex that play out as someone speaks. This revealed a surprising sophistication in how the brain's speech sensorimotor cortex works.

They found that this cortical area has a hierarchical and cyclical structure that exerts a split-second, symphony-like control over the tongue, jaw, larynx and lips.

"These properties may reflect cortical strategies to greatly simplify the complex coordination of articulators in fluent speech," said Kristofer Bouchard, PhD, a postdoctoral fellow in the Chang lab who was the first author on the paper.

In the same way that a symphony relies upon all the players to coordinate their plucks, beats or blows to make music, speaking demands well-timed action of several various brain regions within the speech sensorimotor cortex.

Brain Mapping in Epilepsy Surgery

The patients involved in the study were all at UCSF undergoing surgery for severe, untreatable epilepsy. Brain surgery is a powerful way to halt epilepsy in its tracks, potentially completely stopping seizures overnight, and its success is directly related to the accuracy with which a medical team can map the brain, identifying the exact pieces of tissue responsible for an individual's seizures and removing them.

The UCSF Comprehensive Epilepsy Center is a leader in the use of advanced intracranial monitoring to map out elusive seizure-causing brain regions. The mapping is done by surgically implanting an electrode array under the skull on the brain's outer surface or cortex and recording the brain's activity in order to pinpoint the parts of the brain responsible for disabling seizures. In a second surgery a few weeks later, the electrodes are removed and the unhealthy brain tissue that causes the seizures is removed.

This setting also permits a rare opportunity to ask basic questions about how the human brain works, such as how it controls speaking. The neurological basis of speech motor control has remained unknown until now because scientists cannot study speech mechanisms in animals and because non-invasive imaging methods lack the ability to resolve the very rapid time course of articulator movements, which change in hundredths of seconds.

But surgical brain mapping can record neural activity directly and faster than other noninvasive methods, showing changes in electrical activity on the order of a few milliseconds.

Prior to this work, the majority of what scientists knew about this brain region was based on studies from the 1940's, which used electrical stimulation of single spots on the brain, causing a twitch in muscles of the face or throat. This approach using focal stimulation, however, could never evoke a meaningful speech sound.

Chang and colleagues used an entirely different approach to studying the brain activity during natural speaking brain using the implanted electrodes arrays. The patients read from a list of English syllables like bah, dee, goo. The researchers recorded the electrical activity within their speech-motor cortex and showed how distinct brain patterning accounts for different vowels and consonants in our speech.

"Even though we used English, we found the key patterns observed were ones that linguists have observed in languages around the world perhaps suggesting universal principles for speaking across all cultures," said Chang.


'/>"/>

Contact: Jason Socrates Bardi
jason.bardi@ucsf.edu
415-502-6397
University of California - San Francisco
Source:Eurekalert

Related medicine news :

1. Pioneering research helps to unravel the brains vision secrets
2. Weight Loss Author Reveals 3 Secrets For Raising Your Metabolism
3. Get Bigger Buttocks
4. How “Bigger Butt Secrets” Helps Women Boost Their Butt Naturally – Tony Nguyen
5. Your Genetic Secrets May Not Be as Safe as You Think
6. Dr. Tracy McClelland, Nursing Visionary and President of Nursing Success System, Reveals the Secrets to Becoming a Successful Nursing Entrepreneur
7. Scott Tischler unveils his secrets for rapid muscle recovery just in time to help with New Years resolutions
8. Joseph Sorbara Explains the Secrets behind Paleo Diet and Fast Weight Loss
9. Scott Tischler Announces 5 Cooking Secrets to Making Christmas Healthier
10. CuReviewScam's Muscle Gaining Secrets Review About Fitness Program by Jason Feruggia, Now Available at Official Website of Muscle Gaining Secrets
11. PsychiatristSites (Websites for Psychiatrists) is Offering a Webinar, "5 Ways To Make More Money In Your Practice - Secrets From The Pros"
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/13/2017)... ... October 13, 2017 , ... Ellevate Network, the leading network for professional women, ... towards gender equality at their inaugural Summit in New York City in June. The ... social audience of over 3 million. To watch the Mobilize Women video, click ...
(Date:10/13/2017)... VA (PRWEB) , ... October 13, 2017 , ... ... of DevOps and Agile Software Development, has been awarded a contract by the ... Blanket Purchase Agreement (BPA) aims to accelerate the enterprise use of Agile methodologies ...
(Date:10/12/2017)... ... October 12, 2017 , ... CitiDent and San Francisco ... using cutting-edge Oventus O2Vent technology. As many as 18 million Americans are estimated ... in breathing. Oral appliances can offer significant relief to about 75 percent of ...
(Date:10/12/2017)... ... 2017 , ... The American College of Medical Informatics (ACMI) will present the ... Opening Session of AMIA’s Annual Symposium in Washington, D.C. AMIA’s Annual Symposium ... a pioneer in the field of medical informatics, this prestigious award is presented to ...
(Date:10/12/2017)... , ... October 12, 2017 , ... HMP , ... recipient of a 2017 Folio Magazine Eddie Digital Award for ‘Best B-to-B Healthcare Website.’ ... on October 11, 2017. , The annual award competition recognizes editorial and design excellence ...
Breaking Medicine News(10 mins):
(Date:10/11/2017)... Oct. 11, 2017  Caris Life Sciences ® , ... the promise of precision medicine, today announced that St. ... Precision Oncology Alliance™ (POA) as its 17 th ... St. Jude Crosson Cancer Institute will help develop standards ... of tumor profiling, making cancer treatment more precise and ...
(Date:10/10/2017)...   West Pharmaceutical Services, Inc. (NYSE: WST), ... administration, today shared the results of a study highlighting ... intradermal administration of polio vaccines. The study results were ... 2017 by Dr. Ondrej Mach , Clinical Trials ... (WHO), and recently published in the journal Vaccine. ...
(Date:10/4/2017)... Mass. , Oct. 4, 2017  According to the Centers for ... the end of October . PhysicianOne Urgent Care is helping communities across ... Westchester, NY , by offering no-cost* flu shots through the ... as mandated by certain health insurance regulations. ... The best time to get a flu shot is by the ...
Breaking Medicine Technology: