What has functional neuroimaging told us about the mind (so far)?

cognition is by cognitive neuroimaging – by recording neural activity in a person’s brain while the recorded person is carrying out some cognitive activity. There are numerous different reasons for doing this kind of work. I will consider only one of these reasons, namely, to try to learn more about cognition itself. All other motivations for doing cognitive neuroimaging (e.g., to seek to localise specific cognitive functions in specific brain regions) are beyond the scope of this paper. Although there exists a huge volume of recent literature reporting the results of cognitive neuroimaging studies, there are surprisingly few papers which have evaluated this technique as a way of studying cognition itself. Some of these papers offer rather negative conclusions. Some of these negative conclusions are modest in scope (‘What has functional neuroimaging told us about the mind so far?’, ‘Nothing so far in one cognitive domain, viz., language’; Poeppel, 1996), whereas others are much more sweeping (‘What has functional neuroimaging told us about the mind so far?’, ‘Nothing, and it never will: the nature of cognition is such that this technique in principle cannot provide evidence about the nature of cognition’; van Orden and Paap, 1997; see also Uttal, 2001). Henson (2005) has provided an invaluable framework for considering the role of brainimaging data in cognitive psychology. He writes: “My main argument is that, provided one makes the assumption that there is some ‘systematic’ mapping from psychological function to brain structure, then functional neuroimaging data simply comprise another dependent variable, along with behavioural data, that can be used to distinguish between competing psychological theories” (p. 194). I want to challenge this argument directly. I fully accept Henson’s assumption that there is some systematic mapping from psychological function to brain structure. Nevertheless, I’ll claim that no functional neuroimaging research to date has yielded data that can be used to distinguish between competing psychological theories. I emphasize that the scope of my claim is much narrower than the scope of Henson’s. He is considering whether functional neuroimaging data can ever (i.e., in principle) be used to distinguish between competing psychological theories. I will be considering only whether functional neuroimaging data has already been successfully used to distinguish between competing psychological theories. Are there already clear examples of such successful use? If there are not, that of course does not imply that there won’t be in the future. However, given the enormous volume of published recent empirical work in this area, if it turns out that none of this work can be used to distinguish between competing psychological theories, the in-principle question of whether cognitive neuroimaging data can ever serve this function will deserve much more attention than it has so far been given. But I will not be discussing this in-principle question: this paper is solely concerned with an in-practice so-far question: What have we learned so far about the mind from cognitive-neuroimaging research?