In this post, Jesse Marczyk argues that psychological neuroscience research often doesn't add much value per dollar spent and therefore is not worth the cost.

In my last post, when discussing some research by Singer et al (2006), I mentioned as an aside that their use of fMRI data didn’t seem to add a whole lot to their experiment. Yes, they found that brain regions associated with empathy appear to be less active in men watching a confederate who behaved unfairly towards them receive pain; they also found that areas associated with reward seemed slightly more active. Neat; but what did that add beyond what a pencil and paper or behavioral measure might? That is, let’s say the authors (all six of them) had subjects interact with a confederate who behaved unfairly towards them. This confederate then received a healthy dose of pain. Afterwards, the subjects were asked two questions: (1) how bad do you feel for the confederate and (2) how happy are you about what happened to them? This sounds fairly simple, likely because, well, it is fairly simple. It’s also incredibly cheap, and pretty much a replication of what the authors did. The only difference is the lack of a brain scan. The question becomes, without the fMRI, how much worse is this study?

There are two crucial questions in mind, when it comes to the above question. The first is a matter of new information: how much new and useful information has the neuroscience data given us? The second is a matter of bang-for-your-buck: how much did that neuroscience information cost? Putting the two questions together,we have the following: how much additional information (in whatever unit information comes in) did we get from this study per dollar spent?

...I’ll begin my answer to it with a thought experiment: let’s say you ran the initial same study as Singer et al did, and in addition to your short questionnaire you put people into an fMRI machine and got brain scans. In the first imaginary world, we obtained results identical to what Singer et al reported: areas thought to be related to empathy decrease in activation, areas thought to be related to pleasure increase in activation. The interpretation of these results seems fairly straightforward – that is, until one considers the second imaginary world. In this second world, we see the results of brain scan show the reverse pattern: specifically, areas thought to be related to empathy show an increase in activation and areas associated with reward show a decrease. The trick to this thought experiment, however, is that the survey responses remain the same; the only differences between the two worlds are the brain pictures.

This makes interpreting our results rather difficult. In the second world, do we conclude that the survey responses are, in some sense, wrong? The subjects “really” feel bad about the confederates being hurt, but they are unaware of it? This strikes me as a bit off, as far as conclusions go. Another route might be to suggest that our knowledge of what areas of the brain are associated with empathy and pleasure is somehow off: maybe increased activation means less empathy, or maybe empathy is processed elsewhere in the brain, or some other cognitive process is interfering. Hell; maybe it’s possible that the technology employed by fMRIs just isn’t sensitive to what you’re trying to look at. Though the brain scan might have highlighted our ignorance as to how the brain is working in that case, it didn’t help us to resolve it. Further, that the second interpretative route seems like a more reasonable one than the first, it also brings to our attention a perhaps under-appreciated fact: we would be privileging the results of the survey measure above the results of the brain scan.

...While such a thought experiment does not definitely answer the question of how much value is added by neuroscience information in psychology, it provides a tentative starting position: not the majority. The bulk of the valuable information in the study came from the survey, and all the subsequent brain information was interpreted in light of it.