• Sat, Oct 20 2007

Going Really Batty

I don’t mean me in particular (though it’s been one of those mornings—-I’ve been trying to grade quizzes, email students, write this post, pay bills, and talk to Charlie’s ABA therapist all at once; Charlie has been having mood swings, smiling one moment, unhappy the next, and now back to smiling while working on his reading program). There may be something for all of us to learn from bats in regards to language: A team of British and Chinese scientists have found that the FOXP2 gene, which is involved in human language development, is also involved in bat echolocation. Researchers at Texas A & M are studying how bats organize syllables into songs in the hope of understanding how to better help those (humans) with speech disorders. From the October 19th Science Daily:

Mexican Freetail bats sing mostly in ultrasonic frequencies that are right above the upper limit of human hearing. Humans can sometimes hear little bits of bat songs, however, when parts of syllables drop low enough.

Bats communicate at such high frequencies because of their ability to echolocate, which means they project sound and use the echoes to determine the direction and distance of objects. As the frequency of the bat’s sound gets higher, it can detect a more detailed picture of its surroundings.

[Michael] Smotherman says Mexican Freetail bats use between 15 and 20 syllables to create calls. Every male bat has its own unique courtship song. The pattern of all courtship songs is similar, but each male bat uses a different syllable in its distinctive song. Bats also use sophisticated vocal communication to draw territorial borders, define social status, repel intruders, instruct offspring and recognize each other.
“No other mammals besides humans are able to use such complex vocal sequences to communicate,” Smotherman says.

The songs bats sing are similar to bird songs. Scientists have understood the link between bird songs and the bird brain for years, but “the architecture of a bird brain is very different from that of a mammal brain,” Smotherman explains, “so it is difficult to apply knowledge about bird communication to human speech.”
The brains of all mammals are organized in basically the same way, so a bat brain has many of the same structures as a human brain. This makes it easier to infer things about human speech from studying bat communication.

Charlie sometimes hums with a sort of vibratory burrrr: Might he be situating himself in space? The sounds that seem to upset him the most are high-pitched, especially if made by the human voice, and I have wondered if he is able to hear pitches that most of us can’t.

In the spirit of Halloween (less than two weeks away……), I guess I’ll take a more kindly view of those dark-winged creatures.

And if you’d rather not be in the dark with the bats but out in the light, Daily Tomorrow has a post about the 2007 Solar Decathlon, a competition of sustainable solar homes on the National Mall in Washington, D.C., where there is also an autism walk.

Bat photo courtesy of howardpennphoto via Flickr.

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  • Tanya

    My son also hums and I think that is a good question: are they situating themselves in their environment? This reminds me of a story I saw featured on Oprah about a young boy blinded early in life who was able to use clicking his tongue as a form of echolocation. Proof it’s possible!

  • http://motherofshrek.blogspot.com/ Casdok

    My son hums, whistles and high pitched squeels, but dosnt speak.
    For my son i thought it was more to block the noise of the outside world out. But it could be about situating himself? Will think on that one!

  • http://www.autismvox.com Kristina Chew, PhD

    I have thought that Charlie hums to block out sounds too—-and I also think he likes the sounds of his voice, and maybe the way it feels to hum and make one’s vocal chords vibrate. Jim and I are big talkers and I do think he wants to make sure he gets his say in!

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