Monday, September 26, 2011

Thinking about talking

It is the holidays, apparently. For many postgrads this reads as 'work time where one does not teach'. For a PhD student, the concept of holidays is largely a self-directed process. It is perfectly legitimate to wake at 11am on a Monday and simply declare 'to hell with my work today' and spend the entire day in one's pyjamas . . . possibly writing a blog post or two (Note: I didn't actually do this, but the idea is a logical one).

Of course, provided your work ethic is not a withered broken husk that feeds upon guilt and shame (not to get too self-referential or anything) then you probably will come and work. For myself, this means experiments. Speaking of experiments, I mentioned that I would be doing so this blog around, and thus I shall avoid linguistically opening fire on the injustice of working during the holidays, and proceed with something more interesting. Potentially more dry, but just as interesting. At least, as far as I'm concerned it is, and I'm the important one in this relationship :)

The basic experimental design I use at the moment is called the Picture-Word Interference Paradigm, or PWI. Very simply, it is the presentation of a picture, with a word. The task is to identify the picture as quickly as possible. It's my kind of thing; gloriously simple and yet, when properly manipulated, can give you a true world of information to sink one's metaphorical chompers into.

We're using this design to work out how people select words to put into speech. True to form in the sciences, this is not nearly as simple as it sounds. It turns out there's quite a few stages in the speech process. You have a semantic/conceptual stage, where concepts are abstract representations without words or meaning attached (There is research to suggest that concepts are actually complex sensory representations). You then have a lexical stage, where the concept is attached to a kind of grammatical code, called a lemma. Then it gets actual sounds attached to it at the phonological stage, at which point we think it gets forwarded to motor areas to be turned into processes for your vocal cords etc. to deal with. And of course all this happens after your low-level visual processes have gone through and dealt with the basic properties of what you perceive.

Essentially the PWI throws a cognitive spanner in the works; by varying the relationship between the picture and word (sometimes the word is related to the picture, sometimes not), we can determine the process/structure by which we select words and meanings. Happily, in recent years there have been a few papers that generated an almighty stink amongst the researchers of speech production and thus new research is most welcome to try and resolve matters to some extent, which is what I'm aiming to do.

Speaking of which, my work ethic awakens with a roar and a snarl, and so I should get back into it. See you next week!

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