Neuroimaging and Inferential Distance

Abstract

Brain images are used both as scientific evidence and to illustrate the results of neuroimaging experiments. These images are apt to be viewed as photographs of brain activity, and in so viewing them people are prone to assume that they share the evidential characteristics of photographs. Photographs are epistemically compelling, and have a number of characteristics that underlie what I call their inferen-tial proximity. Here I explore the aptness of the photography analogy, and argue that although neuro-imaging does bear important similarities to photogra-phy, the details of the generation and analysis of neuroimages significantly complicate the relation of the image to the data. Neuroimages are not inferen-tially proximate, but their seeming so increases the potential for misinterpretation. This suggests caution in appealing to such images in the public domain. Functional magnetic resonance imaging (fMRI) has grown rapidly in popularity and scope since its inception in the early 1990s. The past decade and a half has seen the publication of tens of thousands of scientific articles that employ fMRI as a research tool. A sizeable proportion of these studies have been de-voted to exploring the neural basis of cognition [9, 10]; many others are technical and methodological papers aimed at improving cognitive neuroimaging tech-niques. While methods papers typically are concerned with improving the kind or quality of information provided by fMRI, and thus have epistemic conse-quences, little explicit attention has been paid to the epistemic status of neuroimages themselves, either actual or apparent. What is the relation between fMRI data and the conclusions of cognitive neuroimaging experiments? How are neuroimages perceived and in-terpreted? How should they be? Answers to these ques-tions have implications for the role neuroimages play in the scientific process, and for how results are received and interpreted beyond the scientific community. In everyday life, and in science, vision is one of our most important faculties for gaining knowledge about our world. Vision seems effortless and " direct " : we just see things as the objects they are, or see that something is the case.