Face your baby when you talk: Infants lip-read to learn the language

Have you ever noticed a baby watching your mouth while you speak?  They all do it - but only at very specific ages.

A new study just published in the Proceedings of the National Academy of Sciences reports that babies pay selective attention to either the eyes or mouth of the speaker, depending on the infant's age and developmental stage. Watching a speaker's mouth probably helps babies learn to shape the words they hear. Watching the speaker's eyes helps them master social cues. 

The ingenious experiment to assess changes in babies' attention to facial features was conducted by scientists at Florida Atlantic University. The researchers tested 179 infants at ages 4, 6, 8, or 12 months. All the babies were from English-speaking uni-lingual families. Each infant was shown a 50-second movie of a woman talking in either English or Spanish. The baby's eye gaze was recorded with standard eye-tracking methods. See a photo of the testing set-up here.

Babies learn to lip-read when they start to babble
Infants at 4 months looked significantly longer at the speaker's eyes than the mouth. At 6 months, they looked equally at the eyes and the mouth.  At 8 months, the infants looked mainly at the mouth of the speaker. "Babies start to lip-read when they learn to babble," said primary researcher David Lewkowitz.

At 12 months, the infants begin to shift their gaze back from the mouth to the eyes of the speaker. With a growing language mastery, the babies can at that time afford to look back at the speaker's eyes to improve their understanding of the words' emotional and social meaning.

Babies surprised by an unfamiliar language
Lewkowitz and graduate student Amy Hansen-Tift also tested infants by showing them a speaker of an unfamiliar language (Spanish). The results were the same, except that the 12-month shift from mouth to eyes did not occur. The 12-month-olds continued to watch the mouth of the Spanish speaker, presumably because mastery of the language sounds had not occurred. The scientists also reported that infants watching Spanish speakers showed increasing pupil dilation between 8 and 12 months, an indication of surprise at finding an unfamiliar language.

A future tool for autism screening?
It's known that 2-year-olds with autism tend to avoid eye contact and instead watch speakers' mouths.  Lewkowitz said that it's possible his study could be helpful in screening children on the road to autism. But autism researchers say there is no research showing that children who continue to look at the mouths of native-language speakers past the age of 1 year are more likely to develop autism or other communication problems than are children who switch to looking at eyes.

How is this useful for parents?
Pediatrician and author Dr. Martin T. Stein says he tells parents to "narrate their lives" to their children at each moment, to improve their language and speech development. Given this new information about how children learn language, he says he'll now tell parents to narrate their lives while looking at their children's faces.

More info:
David Lewkowitz' publications and research  pages.

Keywords: infants baby language baby talk learning to talk language acquisition babies lip-read David Lewkowitz Amy Hansen-Tift Florida Atlantic University

South Carolina dog knows more than 1000 words, says NY Times

 
Border collie. Photo: Wikimedia Commons

A retired psychology professor has taught his dog 1022 nouns as well as several verbs, reports the New York Times. Dr. John Pilley set out to beat the record of a German border collie that had learned to recognize 200 objects. Pilley, who taught at Wofford College for 30 years, read about the German dog in the journal Science in 2004. He bought his own border collie, Chaser, as a puppy in the same year. They've been working together four to five hours a day ever since.

Border collies are among the smartest of dogs. They're working dogs, bred to herd sheep, and have a strong instinct to work and to learn commands from humans. Pilley says Chaser seems to love the lessons and always wants more.

Chaser's lessons

To teach Chaser the name of an object, Pilley shows it to Chaser, says the name of it up to 40 times, then hides it and asks Chaser to find it, while repeating the name over and over. For the first few years, Pilley taught Chaser 1 or 2 new names a day, and continued to reinforce any names she had forgotten.

Within 3 years of starting the lessons, Chaser had learned the names for 800 cloth animals, 116 balls, 26 Frisbees and a collection of plastic objects.  When the dog had learned 1000 names, Pilley decided to begin exploring other aspects of language than just nouns. He has demonstrated now that she also has the capacity to understand verbs. (This isn't surprising, given that a sheep herder's commands to his border collie are often verbs directing the dog's actions.)  Chaser  quickly learned to either paw, nose, or take an object in response to Pilley's commands, demonstrating that she understands that verbs have meaning.

Chaser has also learned categories. For example, she knows that "Fetch a Frisbee" means any of her 26 Frisbees, or "Fetch a ball" means any of the balls.

She can also identify a new object by exclusion - selecting it from among objects that she already knows.

Visual cues ruled out

Pilley has confirmed Chaser's vocabulary in settings where she can hear him but can't see him. This rules out the use of visual clues, such as facial expressions or subtle gestures, that could tell Chaser when she has the correct object. Border collies have been bred to be especially observant of gestures because they are part of the communication between a herder and his or her dog.

Pilley's findings to date are reported in the current issue of the journal Behavioural Processes. The retired professor says he's continuing to work on grammar with Chaser, and developing ways to improve communication between people and dogs.

Juliane Kaminski, part of the research team that worked with the German dog (Rico), says that demonstrating syntax would be interesting.  Syntax would include recognizing that changing the order of words can change the meaning of the sentence.& (As in "Bite cat" versus "Cat bites.")

Chimps and gorillas use American Sign Language

There's been a lot of research on teaching language to other animals. Chimps and gorillas lack the vocal anatomy to talk, but they can use their hands to make signs.  I worked with Dr. Roger Fouts at the University of Oklahoma teaching American Sign Language to a small colony of chimpanzees. The chimps lived on a small island at the Primate Institute. Fouts was a pioneer in this field, along with his mentors, the Gardners, at the University of Nevada. The Gardners were the first to teach a chimpanzee (Washoe) to communicate with ASL. Dr. Penny Patterson was the first to teach a gorilla (Koko) to use ASL.

Alex the African Grey Parrot impressed language scientists

Parrots have also demonstrated abilities to learn and understand human language. Alex the African Grey Parrot was the most of parrot pupils. Dr. Irene Pepperberg taught Alex to name colors, shapes, to count small numbers, and to speak around 150 words that he could put into categories. Of course parrots can vocalize, although most birds that speak human words have no idea of the meaning of what they're saying.

Dogs and touch screens?

Dogs are different in that they have neither the vocal anatomy to speak, or hands to allow signing. So at least for now, Chaser is limited to recognizing names of objects and responding to requests or commands. I don't know of any experiments where dogs can be taught to "speak" by, for example, selecting words by touching symbols on a touch screen. It could be done. But has it been done? I don't know.

Keywords: Chaser dogs Roger Fouts parrots language border collie John Pilley Wofford Sue Savage-Rumbaugh