How do we understand all the chatter?
“Dog” and “fog” sound very similar. But even preschoolers know you’re talking about a puppy or the weather.
Now, the Georgetown university medical center in Washington, scientists have identified a two-step process to help our brains, first identify and then categorize new voice, even if the difference is very small.
It turns out that this process is very similar to how the human brain categorizes visual information, the Georgetown team reported Wednesday in the journal Neuron.
The author of the study, the neurological sciences at Georgetown university school of medicine, Maximilian Riesenhuber said: “this is very exciting, because it shows that the general principles of the work here is that the brain how to understand the world.”
The finding could also help explain problems such as dyslexia, which could damage the brain’s ability to understand what it sees and hears, Riesenhuber said.
The study began to understand how the brain recognizes familiar words, even when speaking with an accent or unusual pronunciation.
“You hear me,” said Riesenhuber, a slight German accent. “You may have never heard of me before, but you can easily recognize what I’m talking about.”
To study the process of learning new sounds in all changes, the team had 16 people learning to identify calls from rhesus monkeys.
Can you tell the difference between the calls used in these studies?
These phones are ideal because they contain certain features of human speech, but they do not convey any meaning to anyone.
But for a monkey, these calls make sense. “One meaning: good, good food, and the other: there’s no such good food,” said Alison huber. “If you were a monkey, of course, you would say, wow, that sounds great.”
Not telling human volunteers what that means. But after several hours of practice, they learned to recognize the calls and divide them into two distinct categories, even if the computer operation made the difference less obvious.
The team then looked at brain images and showed which regions were active in response to various calls.
“We’ve seen the head of people, when they have never heard the phone, and then after they understand, then you can see which parts of the brain has changed, and in what way,” said Riesenhuber.
It is these changes that point to the two-step learning process. First, neurons in one area of the brain start firing, indicating that they have learned to recognize new sounds. Then, when the neurons in the second area identify which category the sound is suitable for, they launch.
So, using children to learn about dogs and fog, research shows that a brain region learns to understand the nuances of these words. Then, the second area learned to put a group of sounds in the animal category, and the other in the weather category, even if the sound had a German accent.
Early studies have found that the brain USES similar methods to categorize things we see, such as faces and places.
Such research can help explain learning disabilities, such as dyslexia, says Guinevere Eden, a professor of pediatrics at Georgetown who directs the study center there.
The garden of Eden says dyslexia is often described as a reading problem. But the researchers found that children with the disease also tended to have difficulty classifying sounds.
“If you take a four-year-old and you play a rhyming game (‘ hat, cat, dog, mat, this is a strange one? “It’s difficult for struggling children to keep reading,” says Eden.
Brain imaging studies like the monkey phone can help show how the brains of children with dyslexia differ, says Dr. Eden. They can also advise on how to help children overcome this problem.
“Where we see this change,” she said. “Do their brains look more like children who have never learned to read, or are they exposed to other areas of compensation?”
Researchers still don’t know, says Eden. But research is already underway.