The FOXP2 Gene and Speech
The FoxP2 gene is the so-called “language gene,” as it plays a role in the neural development that is related to vocalization. Greg Laden reviews a study from PLoS Biology, with the title of Incomplete and Inaccurate Vocal Imitation after Knockdown of FoxP2 in Songbird Basal Ganglia Nucleus Area X. The study looks at “FOXP2 Knockdown” individuals (individuals with a somewhat broken FOXP2 gene)”—-zebra finches, in the experiment. Laden summarizes the work of researchers Sebastian Haesler et al.:
Do special “human” genes provide the biological substrate for uniquely human traits, such as language? Genetic aberrations of the human FoxP2 gene impair speech production and comprehension, yet the relative contributions of FoxP2 to brain development and function are unknown. Songbirds are a useful model to address this because, like human youngsters, they learn to vocalize by imitating the sounds of their elders. Previously, we found that when young zebra finches learn to sing or when adult canaries change their song seasonally, FoxP2 is up-regulated in Area X, a brain region important for song plasticity. Here, we reduced FoxP2 levels in Area X before zebra finches started to learn their song, using virus-mediated RNA interference for the first time in songbird brains. Birds with experimentally lowered levels of FoxP2 imitated their tutor’s song imprecisely and sang more variably than controls. FoxP2 thus appears to be critical for proper song development. These results suggest that humans and birds may employ similar molecular substrates for vocal learning, which can now be further analyzed in an experimental animal system.
While the “breaking down” of the FoxP2 gene system does seem to be connected to developmental abnormalities in neural development and while it may be one of several genes involved in language development, it seems less the case that this gene has a specific human-language function. FoxP2 is a regulatory gene and the experiment suggests that vocal learning may involve “interaction among brain and body parts via motor control systems,” and specifically the role of motor ability in the production of speech. Writes Laden:
The human core deficit affects the production of rapid, sequential mouth movements, which are required for speech articulation [43], and is thought to be caused by erroneous brain development. Perhaps the speech impairment results from a problem with motor learning rather than motor performance during speech learning…….
“Rapid, sequential mouth movements” are precisely one reason that I suspect Charlie has difficulties talking. Charlie’s understanding of language is far greater than what he himself can say and I can see him concentrating extra hard to move his mouth muscles and tongue in lips in just the right way, to get the right sounds out. Years of speech therapy have helped, as has a lot of physical exercise: As Charlie’s gross motor abilities (in biking, swimming, running) have developed, so has his speech become, slowly, slowly, clearer. Charlie has long been able to sing phrases of music in tune, though the words are not always clear or even spoken by him. Speech therapy is not the only path to better speech, perhaps.
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POSTED IN: Animals, Genetics, Health, Language, Music, Neuroscience
2 opinions for The FOXP2 Gene and Speech
athina
Dec 5, 2007 at 3:12 am
When my son was about to turn two and before the diagnosis, I used to perform my own “speech therapy” to him. I used to put him in a swing, sit in a chair opposite to him and sing songs while looking him in the eyes. Back then it was like a very fun game for both of us, as I noticed that he was much more focused while swinging in the swing and imitated my singing more and more each passing day. Then I would sing the first words of a song and let him sing the rest and the result was that he could sing more than 50 songs all alone by the time he was 2. Then I tried having a conversation with him while swinging and it actually worked. I think that swinging has helped him a lot in this matter, probably because I was sitting opposite to him and he had no choice but to look me in the eyes and mouth and pay attention to what I was saying. Or maybe the swinging part provided his brain with the necessary sensory stimulant in order to be able to process speech. I don’t really know, but I do know that in our case it helped a lot.
Marcie
Dec 5, 2007 at 9:53 am
The head of our local ASA, who is a teacher, says that its been shown that jumping, yelling, and spinning helps form connections in the brain, especially for boys. I wish I had a source for that. But it doesn’t surprise me.
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