Monday, October 13, 2014

How the Brains Works to Produce Words That You Speak

Bob McMurray, associate professor in the Department of Psychology, the Department of Communication Sciences and Disorders and the Delta Center at the University of Iowa, informs at WaPo:

The first thing to know is that producing a word is hard. Most people know more than 60,000 different words, and well-educated folks...know more than 100,000. To construct a sentence is to choose a few words from this paralyzing array of choices, and to do it at a rate of 3-4 words per second! Moreover, each word requires a speaker to coordinate a five to six different parts of your vocal tract (tongue, lips, larynx, etc.) with millisecond precision.

The fact that we’re able to get a word out at all is an extraordinary feat.

This second thing to know is that these decision processes occur as a sort of competition. The brain selects many candidate words, and they compete over time until one wins. For example, if you were trying to talk about your living room, you might consider both the words sofa and couch, or even less common ones like davenport. Over time, these options compete until one wins, the one you end up saying.  Of course, this competition is playing out over 60,000 potential candidates...

The crucial thing about this competition is that it isn’t orderly. The word that makes the most sense doesn’t always win, particularly in a challenging situation like speech production. It’s more like a PTA meeting or the Iowa Caucuses than a simple vote – lots of noisy interactions from multiple parts of language...

[A]t the same time that this competition is brewing among words, other things are happening too. Most importantly, people need to start planning their physical production of the sounds, and the motor system can’t wait for this competition among words to finish or people would speak way too slowly. So, even as sofa and couch are duking it out to be the winner, the brain is already planning what the mouth, vocal chords and the rest of motor system must do to say both... As the brain weighs different options for a word, the production systems for specific sounds start sending signals back to the part of the brain trying to select the right word. These signals have a little input on which word is ultimately selected. This is helpful: it ensures that the selected word matches the selected motor commands. It’s a way of checking that all of the parts of this noisy competition are working together: Otherwise you might say “cheese” when you think “bread.

1 comment:

  1. Those 60k and 100k figures sound too good... or is it passive vocabulary - with names and other labels included?