Evolang 08 – Plenary Speakers Day 2

The next day brought a couple of plenary speakers who both spoke on fascinating topics but somehow managed to make them dull as hell or inpenetratable.

Rudolph Botha began by looking at exaptation and argued that it is a mechanism that is too frequently employed in accounts of language evolution. He painstakingly went through a series of examples in the literature where exaptation is heavily invoked and tried to show that it did not meet the standards for exaptation that most biologists would use. It was persuasive, and on an interesting topic, but somehow Botha contrived to make it duller than a Calvinist sermon. Come on Rudi, this subject is naturally cool, it shouldn’t have the life sucked out of it like this.

Next came Pulvermuller. A classic example of loved the subject, disliked the person. He’d been asking self-promotional questions the whole previous day, but his talk was actually very interesting. Unfortunately he delivered in a way that made it difficult to nail down what his overall position was. He’s a neuroscientist who’s published books on the neuroscience of language and I’ve now read up a bit to try and paint a broader picture of his position (or at least to fill in the blanks of my understanding from the presentation).

He has looked at the neurological hardware necessary for each part of language and has made some strong conclusions:

  • The cortex acts as the information processor for language and the various different motor aspects of speech (lips, tongue etc..) all map differently to the motor cortex and he showed scans of how the production of different words produces different activation. He also demonstrated that the brain responds more intensely to real words than pseudo-words, indicating some sort of mental lexicon-like structure in the brain architecture.
  • He demonstrated that syntax is functionally different in brain activation compared to semantics and this suggests a brain level syntactic processing capability, but rather than this being a reinforcement of innate grammar, he argued that this was due to a Hebbian learning process. Syntax is learnt not innate and exposure to syntax leads to the production of DDNAs (Discrete Distributed Neuronal Assemblies). He backed this up with evidence from neural networks.
  • He went on to propose that language was a complicated neural system with subtle and complex relationships between motor areas, semantic processing relays and syntactic processing structures. Many different areas of the brain are involved and the relationships between them are complex and interesting. Some are very specific and lateralised and others are more general. Here’s a list from one of his abstracts:

1.assemblies representing phonological word forms are strongly lateralized and distributed over perisylvian cortices;

2. assemblies representing highly abstract words, such as grammatical function words, are also strongly lateralized and restricted to these perisylvian regions;

3. assemblies representing concrete content words include additional neurons in both hemispheres;

4. assemblies representing words referring to visual stimuli include neurons in visual cortices;

5. assemblies representing words referring to actions include neurons in motor cortices.”

  • He also gave strong credence to the embodied cognition position, arguing that engagement with the outside world can alter linguistic processing. Words and phrases associated with leg movements (e.g. ‘kicked the bucket’) had a different neural activation to words and phrases associated with arm movements (e.g. ‘caught on’).

Overall, he argued that language was a skill based upon combining learnt structure with underlying physical and neurological traits. Learning then neuroplastically maps these structures together. He gave a list of these underlying skills/structures needed for language at the end, here’s the ones I managed to scribble down in time:

  • A babbling mechanism
  • Neural level learning processes
  • Rich local connectivity in language areas
  • Massive long distance links
  • Local associative connectivity
  • External sensori-motor links

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