A Concern About Brain Scans
So we are reading this article The Neural Basis of Economic Decision-Making in the Ultimatum Game by Alan Sanfey et al. for our Philosophy of Mind class. The idea is, to get a better understanding of how decision-making processes in the brain work, these guys did an experiment where they had test subjects hooked up to some sort of brain scanning machine (functional magnetic resonances imaging; fMRI) and had them play what is called the Ultimatum Game. The Ultimatum Game is where:
“Two players are given the opportunity to split a sum of money. One player is deemed the proposer and the other, the responder. the proposer makes an offer as to how this money should be split between the two. The second player (the responder) can either accept or reject this offer. If it is accepted, the money is split as proposed, but if the responder rejects the offer, then neither player receives anything” (2003).
Now it seems to me that, although the results are interesting and worthy of discussion, there is a problem with this kind of method in that they are trying to deduce from this game being played in a lab, how our minds are working in every day life. But the problem is that being in a lab and especially being hooked up to all kinds of weird machines is nothing close to most environments in which we find ourselves making decisions. Could it not be the case that at least some of the brain activity showing up in the fMRIs is reflecting some of the nervousness or anxiety involved with being a part of some scientific experiment? Perhaps the test subject is worried that he is going to play the game wrong and waste everyone’s time, or that the brain scans will somehow reveal some dark secret that he has been hiding from friends and family for years (what does he know about what scientist can gather from a brain scan).
Maybe I’m missing the point or perhaps this difficulty has been dealt with already but it just seemed to me to be something that, if it is a problem, seriously skews the results for all research of this type.
While I’m not too sure about this, I think the way most such brain scans work is that they detect changes over time, while performing some activity, relative to the ‘base level’ of neural activity that occurs when you’re just sitting in the scanner doing nothing. That should help negate any “background effects” like anxiety, etc, (and just normal brain functioning), allowing us to isolate what is new and special about the particular activity being performed.
Comment by Richard — October 26, 2005 @ 11:15 pm
hey Sean,
Came across this blog while doing research for my paper on Sanfey’s results.
I don’t know if this will help at all, but one way that Sanfey might be able to claim that his results are reliable is by appealing to the overwhelming amount of research that has been done on the ultimatum game. In particular, the game has been studied outside of the lab with very similar behavioral results to the one’s he got in the lab. I don’t think it is too much of a stretch to argue that if the behavioral results are consistent both inside and outside of the lab, then the brain activity would be similar in and out of the lab as well.
Anyway, nice blog you guys have here.
Comment by Trevor — November 12, 2005 @ 4:48 pm