Friday, November 24, 2006

My current research project (fall 06) - Electrophysiology and stereotypes...


Since I am doing the "C-course" in psychology at Lund University, I am expected to carry out a research project. I was lucky to be allowed to use the rather new EEG lab that has been set up. This allowed me to do an experiment that I have been thinking about since the spring but which I have not had the chance to do until now

So what is my project about? I am actually trying to do something as sexy as measuring peoples' stereotypes using EEG. An EEG (see picture) measures the electrical activity that the brain generates. This electrical activity differs depending on what the brain is doing. If you are sleepy the brain will start to generate what is referred to as alpha waves (a funny consequence of this is that you can actually see when your subjects are starting to get fed up with your experiment), if you are dead there will be a straight line, an epileptic seizure is characterized by wild activity etc etc. In fact, the brain also generates characteristic wave patterns in response to certain events, these patterns are called event-related potentials or ERPs.

In my experiment I am looking at a specific wave called the N400, N because it is a negative deflection, and 400 because it occurs 400 milliseconds after the stimuli was presented. The N400 appears when our brain perceives something unexpected. For example, when the brain hears a sentence such as "Jack took the bus to town to meet some of his boxershorts", the brain says, wrooong!! (an N400 wave appears). Similarly, if famous faces from different occupations e.g. Robert De Niro and Billy the clown, are presented serially, the N400 also appears, thus suggesting that our brain has recognized that these two stimuli did not belong to the same category.

I am reasoning that stereotype incongruency, that is, things that go against your stereotype, will also elicit this N400 component. To test this prediction I have obtained a collection of attractive and unattractive faces as well as a collection of negative and positive words. Presumably the N400 component will appear when I present to my participants an attractive face followed by a negative word, or conversely an unattracitve face followed by a positive word. The reason I believe so is that there is a lot of evidence suggesting that we associate attractive faces with positive characteristics and unattractive faces with negative characteristics. To be continued...

3 comments:

furiku said...

This sounds extremely interesting and I'm looking forward to hearing about your results!

rasmussenanders said...

Thank you (for your comments as well as your interest)! I actually just recieved some preliminary results and it is looking good, the N400 wave is indeed greater for stereotype incongruent face-word pairs. That is pairs that do not agree with the stereotype. This is based on three subjects though, so I have to wait and see...

furiku said...

Well, if you weren't in the wrong part of Sweden I'd offer to be a test subject. :P

(By the way, why have you linked to the page about me rather than my blog's front page? Just curious. You may also want to consider joining various blog ranking sites to get more traffic and more comments on your blog. ;))