As the neurosciences make their way beyond the laboratory, they become influential in a wide range of domains. How to understand this process? What are the prospects for, and dynamics of, influence, uptake and rejection? This article reports our attempts to track the emergence of neurosciences with particular reference to the emergence of the field of neuromarketing. Our key initial tasks included the identification and definition of the field, the negotiation of access, and establishing relations with participants and informants. These tasks gave rise to what are often construed as familiar methodological difficulties, such as how to define the field and what to make of the reactions and responses of those involved in neuromarketing. In this article we present some of our experiences of researching the empirical materials of neuromarketing to assess different responses to methodological difficulties in studying science and technologies in the making. We draw on analytic resources provided by Science and Technology Studies to address the challenge of studying emerging fields of science, practices and technologies. In particular, we draw on the concepts of multiplicity, performativity and practical ontology to argue that a particular approach to methodological difficulties can actually enrich our research objectives. We suggest that reflexivity be understood, not predominantly as a methodological corrective to the problems of detecting an antecedent object of research; but as revealing some of the ways in which neuromarketing is enacted.