Mapping Neuroethics and fMRI Figure 3. Citation network of neuroethics publications with topic clustering. doi:10.1371/journal.pone.0018537.g003 discussions about the technical limitations, persuasive power, or evidentiary constraints of neuroimaging. For example: ‘‘Neuroimaging data seem particularly compelling to lay people and may present a ‘‘unique danger because of the appearance of scientific neutrality’’ [55]. ‘‘Ethical issues related to rights against self-incrimination have caused some companies developing forensic neurotechnologies to claim that their products will only be used to exonerate the innocent. In this context, the false-negative problem creates a real dilemma for companies developing memory detection tools’’ [56]. The ELSI literature also included several citations of fMRI studies of moral correlates, which were excluded from this analysis in order to reveal cross-citations indicative of substantive discussion of the ethics and implications of research itself. For example, Salvador and Folger [57] note that ‘‘in an fMRI study, Robertson et al. [58] presented Executive MBA students with story segments, some of which had moral content, while others had none’’, in the context of a separate discussion of research ethics surrounding fMRI. Discussion We began by arguing that that fMRI raises substantive ELSI issues for the conduct, application, and implications of research. We further argued that fMRI researchers should engage in debate about these ethical issues and the implications of research, and hypothesized that the increasing popularity and media coverage of neuroimaging studies, and discourse surrounding real-world implications and early commercial applications, might have led to growing cross-citation of the two literatures in recent years. Between 1999 and 2009 there have indeed been an increasing number of articles published with overlapping fMRI and ethics content. However, this number is surprisingly small in total, and we found very few citations of fMRI research by ELSI articles, and an even smaller number of fMRI articles that substantively cited the ELSI literature. In many fMRI studies, the only acknowledgment of research ethics was a mention of informed consent – necessary, in many cases, for publication, and a frustrating confound in our attempts to identify more substantive discussion. For example, there were frequent citations of the World Medical Association (Declaration of Helsinki) ethical principles for medical research including human subjects. While review boards can ensure that research is being carried out in accordance with stated principles, they cannot replace a meaningful discussion of ethics, particularly with respect to unique and underexplored features of a new domain [5]. In addition to the reliance on ethics review boards, there are practical, institutional, and incentive barriers to scientists taking ownership of the ethics and implications of their research. Indeed, a survey recently conducted with neuroimagers in Canada [59] suggested that many neuroscientists are indeed concerned with ethics issues, but are unsure of a productive vehicle for discussion and PLoS ONE | www.plosone.org 5 April 2011 | Volume 6 | Issue 4 | e18537