In a recent paper, Nia Ding and colleagues in David Poeppel’s lab, made a big discovery: When understanding language, our brains are sensitive to the abstract hierarchical structure that governs it.
However, the press (http://www.nyu.edu/about/news-publications/news/2015/12/07/chomsky-was-right-nyu-researchers-find-we-do-have-a-grammar-in-our-head.html) and the Chomskian’s seem to have jumped on this and interpreted these findings as support for Chomsky’s theory of language.
This claim was then repeated by other scientific news outlets (e.g., here and here) and has even spurred some heated enthousiasm/discussion on (Reddit).
In the original NYU press release, James Devitt, of NYU press office, makes the bold, and completely unsupported claim that “Chomsky was right, […] We do have a “grammar” in our head.”
James (of NYU)… Really?
[EDIT: 9/12/15 – 7:46PM CET] Dana Dovey (of Medical Daily)… Really?[/EDIT]
Here’s a simplified summary of what happens in the study:
Researchers presented sentences to speakers such as the ones below:
– “Dry fur rubs skin”
– “New plans gave hope”
If you’ve never studied language formally before (i.e., taken a linguistics course) you may be unaware that it is commonly assumed that behind these words, hides a certain hierarchy which governs how the words should be organised. It could look something like that:
Figure 1. Schema of the hierarchical structure of the sentence “New plans gave hope. Adapted from Ding et al., 2015.
By recording the activity of those speakers’ brains using a technique called magnetoencephalography (MEG) the researchers found that not only does the brain activates (i.e., does some processing work) when it is presented with the individual words, but it also activates when a phrase has just been presented to the brain. That is when “new plans” has just been presented but also when “gave hope” has been presented and once more when the whole sentence has been processed.
Schematically this is what happens in the brain:
Figure 2: Schematic representation of the activity patterns uncovered by Ding et al. (2015). In reality this is of course much more complicated but I invite you to read the paperfor that.
Now, this is really cool. It shows that the brain is able to derive structure from this stimuli. By this, I mean that the brain abstracts over the specific items it is processing.
In those specific examples it is probably now parsing the two sub groups as who (“new plans”) and “what” (“gave hope”) –phrase level– and then how what is caused by who –sentence level.
What’s even cooler is that the brain can do that even though it is likely that it has never heard these specific items in that specific order before, especially in the case of the “dry fur rubs skin” one.
Back to the reaction:
So, what do we conclude from that?
Well the authors in the paper are very very parsimonious and refrain from bold claims, it is important to note.
[EDIT: 10/12/15, 8.59AM] Although… It would seem that the article on Medical Daily has included quotes from the senior author of the research paper, David Poeppel, who may have steered these inaccuracies on the par of the journalist. Here’s a screen capture of Peoppel’s quote… Bad, Bad David!
The big take home message is that, the brain extracts/”imposes” some sort of hierarchy when processing language. **[EDIT 10/12/15, 11.21AM: David Adger raised a point about my word choice of “extracts”. According to him I should use “impose” because indeed there is no hierarchy to “extract” from the stimuli as they are. I added the alternate wording]
Now, is this support for Chomsky’s idea of language?
NO, big big no.
Sure, as a facebook user already pointed out to me, in response to my original reaction on a colleague’s post:
– What’s the problem? Chomsky’s idea of language is such that it has hierarchy so those data are compatible with his theory.”
– But so are the data compatible with most theories of language which all acknowledge the fact that language is hierarchical in some way.
– But so are the data compatible with most theories of learning, which all acknowledge that the brain abstracts over sensory experience to build some “hierarchy”
– But so are the data compatible with the fact that the brain is itself wired to promote the emergence of hierarchy.
Chomsky isn’t more right (or wrong) now than he was before!
Indeed, that data does not say anything of its specificity to language, it does not preclude that this “grammar” could have very well emerged from any kind of learning and exposure with language and it has yet to be proven that this pattern of activation would not be found in other animals.
Finally, the researchers find widespread activations, covering large areas of both the left and right hemisphere of the brain. If such a distributed network is support for the “modularity” of language, then thinking –all thinking is just as modular as language!
So why choose Chomsky as the only theory that this data supports, I don’t know… Maybe because he is famous and that’s sensational?
Well, I’m on my way to get my broken jaw fixed. Really… I fell off my bike on Friday!
Ding, N., Melloni, L., Zhang, H., Tian, X., & Poeppel, D. (2015). Cortical tracking of hierarchical linguistic structures in connected speech Nature Neuroscience DOI: 10.1038/nn.4186