Archive for September 22nd, 2007

Mirror Neurons Again – Brain Activation in Linguistic Processing (Meister & Iacoboni, 2007)

This neat little paper adds more fuel to a mirror neuron based account of language evolution. This study showed that the brain responded the same to both linguistic and perceptual processing of stimuli. Subjects were presented with identical video stimuli and asked to perform both linguistic and perceptual tasks, whilst having an fMRI scan. The results showed almost identical patterns of stimulation despite the tasks engaging perceptual and linguistic responses separately. The authors of the paper claim this adds fuel to the argument that mirror neurons were exapted from action-execution systems, into use for language.

It seems increasingly likely that the visual cognitive systems play a larger part in the preadaptations for language than some linguistic accounts have traditionally recognized. I still agree with Jim Hurford’s claim however, that this stage doesn’t account for the basis of language. Mirror neurons don’t help us understand how we crossed the symbolic barrier into a system of arbitrary meanings attached to utterances. I am prepared to buy however, the idea that the motorcortical action-execution system is the most likely first step towards the evolution of the language faculty.

Koran Elephant Apparently Shows Vocal Mimicry

I was at a conference recently where elephant language expert Joyce Poole showed this video – the voice you can hear in the background is not the trainer, it is (supposed to be) the elephant itself. If it’s true it represents a massive change in the way we look at the animal, moving it into the category of animals that we consider capable of vocal imitation (albeit after being heavily encultured). Joyce was just as amazed and skeptical as most people are at the video, and St Andrews have dispatched a Korean speaking researcher to go and check the story out.

After the talk I was much more prepared to consider that the video might be genuine. The picture painted of Elephant vocal communication was a fascinating one. Elephants were shown to be complicated social creatures who used vocal communication to express a wide range of emotions and intentions. Joyce and her team have slowly been collecting data on these vocalisations and have begun to map specific sounds to specific meanings, although as yet few have been conclusively proven using playback studies. There’s a nice summary of her Savannah Elephant Vocalisation Project here.

Big brained, complex, social and vocally communicative. Elephants seem to be emerging as a fascinating new piece in the puzzle that is the evolution of communication.

New FOXP2 Developments

Just following on from the comments on the last FOXP2 post. A new paper (Li G, Wang J, Rossiter SJ, Jones G, Zhang S, 2007) has revealed that FOXP2, a gene sequence implicated in the development language, is also rapidly evolved in echo-locating bats. Most vertebrates possess FOXP2, but several recent papers it was thought that only humans had significant species difference in the gene, being a full two amino acids different from chimpanzees. Given that this gene was implicated in both speech motor coordination and comprehension, it was felt that this was the first major example of a language gene – a gene heavily responsible for our evolved capacity for language.

This new paper follows in the line of some other recent papers that have shown FOXP2 manipulations in other animals, and which have suggested that FOXP2 is not a language gene per se, but a gene implicated in sophisticated communication and vocal production. The researchers sequenced the gene in both echolocating and non-echolocating bat species and found evidence of divergent selection and accelerated FOXP2 evolution compared to other vertebrates. Interestingly they performed a similar survey of cetations and found no significant results.

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