Duke and MIT scientists partner up in a successful attempt to discover which part of the brain is actually responsible for speech timing.
Speech timing is an important part of what makes up a coherent speech and thanks to a certain part of the brain, we are capable of recognizing short language sounds called phonemes even though they only last for about 30-60 milliseconds. Other parts of the speech such as syllables last longer, around 300 milliseconds and whole words can last a lot longer on a person`s lips.
The human brain has learned long ago how to process a high amount an information that arrives through sound and this happened partially because of an important area in the brain, that recognizes speech structure and pattern. However, not all is known about the areas of the brain that permit humans to interact through speech.
So how come the human brain is able to distinguish between sounds that make up a language and sounds that are environmental?
First, scientists broke down words from foreign languages into small pieces of 90 to 960 milliseconds in length. They then patched those sound up through an algorithm newly developed and they named the resulting sounds speech quilts.
And after placing several volunteers in functional MRI machines, scientists proceeded to scan their brain, to see which area lights up when they hear a speech quilt.
Thus the area of they have found to be responsible for recognizing speech time is the superior temporal sulcus (STS). This area became highly active when listening to 460-960 quilts.
Other areas of the brain responsible for processing sound did not show any different patterns regardless of how long the quilt they heard was.
It was previously known that the STS has an important function in integrating sounds and tactile information, but its role in speech time has never before been demonstrates.
In order to demonstrate that the 460 to 960 quilts that activated the superior temporal sulcus was actually responded for speech time and not just any sound of that length, researches played environmental sounds and various noises to the test subjects and thus proved without a shadow of a doubt that the STS area of the brain only got activated by speech timing.
The next experiment that the Duke and MIT scientists are drafting is meant to test if the superior temporal sulcus responds differently to sounds from various foreign languages, for example English and Mandarin.
They also mean to test whether or not the STS responds differently to speech that is familiar to the brain.
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