Just about every election cycle and Superbowl Marco Iacoboni and his lab do some sort of neuroimaging study to determine what people are actually thinking about the political candidates or their teams. Every time these studies come out you can hear the popular press cheering and smiling while you can hear scientists and bloggers cringing in disgust. The most recent study, instead of being published in a peer review journal, was published in the NYTimes. Head over there to give it a read before you continue on.
People cite many reasons to be doubtful of these studies, some complete nonsense and some very good criticisms. Martha Farah, from the University of Pennsylvania's Center for Cognitive Neuroscience (where I used to work), has a great posting at the Neuroethics and Law blog with a great analysis of this research. Here's the heart of the post:
So why do I doubt the conclusions reported in today's Op Ed piece? The problems I see have less to do with brain imaging per se than with the human tendency to make up "just so" stories and then believe them. The scattered spots of activation in a brain image can be like tea leaves in the bottom of a cup - ambiguous and accommodating of a large number of possible interpretations. The Edwards insula activation might indicate disgust, but it might also indicate thoughts of pain or other bodily sensations or a sense of unfairness, to mention just a few of the mental states associated with insula activation. And of course the possibility remains that the insula activation engendered by Edwards represents other feeling altogether, yet to be associated with the insula. The Romney amygdala activation might indicate anxiety, or any of a number of other feelings that are associated with the amygdala - anger, happiness, even sexual excitement.
Some of the interpretations offered in the Op Ed piece concern the brain states of subsets of the subjects, for example just the men or just the most negative voters. Some concern the brain states of the subjects early on in the scan compared with later in the scan. Some concern responses to still photos or to videos specifically. With this many ways of splitting and regrouping the data, it is hard not to come upon some interpretable patterns. Swish those tea leaves around often enough and you will get some nice recognizable pictures of ocean liners and tall handsome strangers appearing in your cup!
The rest of her article is well worth reading. Check it out.