Localizing Language In the Brain 79
RogerRoast writes "A new study by MIT scientists pinpoints areas of the brain used exclusively for language (PDF), providing a partial answer to a longstanding debate in cognitive science. According to the study, there are parts of our brain dedicated to language and only language. After having their subjects perform the initial language task, which they call a 'functional localizer,' they had each one do a subset of seven other experiments: one on exact arithmetic, two on working memory, three on cognitive control, and one on music; since these are the functions 'most commonly argued to share neural machinery with language.' The authors say the results don't imply that every cognitive function has its own dedicated piece of cortex; after all, we're able to learn new skills, so there must be some parts of the brain that are both high-level and functionally flexible."
The latest shot fired in a long battle (Score:2, Informative)
For those who need a bit of background about what this is all about, and why this study is so important to the study of cognitive linguistics, we turn to a bit of history.
Linguistics has always been closely intertwined with psychology. So much so, in fact, that both modern cognitive linguistics and psychology approaches stem from reactions to an idea called behaviorism [wikipedia.org]. Everyone's 'favorite' linguist, Noam Chomsky [wikipedia.org], was one of the first to try and go beyond behaviorism's explanations. Much has been said and written, and I won't go into that whole mess, but suffice to say after the dust settled Chomsky had decided that the human acquisition of language is very much an innate property of our species, something inherent in our brains, which he would come to refer to as the 'black box' that just acquires language like a sponge that dries up after a certain age in childhood. Once again, the whole debate around this topic is what cognitive linguistics is currently bent on figuring out--a question that has existed since man first wondered "why language?"
Anyway, before this becomes a true wall of text, I'll come down to what this study means to cognitive science: the two camps directly affected by this study are named 'nativists,' who believe that the human brain has structures specifically designed for the acquisition, processing, and production of language, and the other side are called 'structuralists,' who believe that the natural human proclivity for pattern recognition is naturally reinforced during language acquisition, bootstrapping its own language recognition abilities by simply recognizing patterns. Pinpointing specific, exclusive areas for language supports the nativist conclusion, dealing a blow to the structuralist theory. Evolution at work, perhaps?
Individual analysis is what is interesting (Score:5, Informative)
From the article: "It’s the same way for brains. 'Brains are different in their folding patterns, and where exactly the different functional areas fall relative to these patterns,' Fedorenko says. 'The general layout is similar, but there isn’t fine-grained matching.' So, she says, analyzing data by 'aligning brains in some common space is just never going to be quite right. Ideally, then, data would be analyzed for each subject individually; that is, patterns of activity in one brain would only ever be compared to patterns of activity from that same brain."
This process of aligning brains is called registration. Even if you are just working within one subject, there is registration involved (between the functional scan, in this case, and the structural - so you know what part of the brain is being activated). I spend about 25% of my imaging work dealing with checking registrations or trying to improve registrations. It's really a key step in neuroimaging work, one that not enough researchers consider seriously enough. So that's why this approach to fMRI is interesting - the researchers are trying to minimize the effects of poor registration, which can lead to completely invalid results.