Neuroscience is used in economics to improve the description and comprehension of individual choice behavior. It can also serve as a means of evaluating decision-makers’ rationality and regulating their behaviors. This paper analyzes the normative implications of neuroeconomics, i.e. the contributions of neuroscience to welfare economics and public economics. The economic interventions advocated by neuroeconomists (e.g. Bernheim and Rangel 2004) are interpreted as neoliberal politics in Michel Foucault’s sense (1978b). Neuroimaging techniques do not allow the “brain-manipulation” of decision-makers. They can detect pathological or irrational behaviors. This assessment calls for a behavioral regulation of welfare, which has to be distinguished from Sunstein and Thaler’s libertarian paternalism (Sunstein and Thaler 2003). The intervention targets the environment rather than the individual in both cases, but the theoretical justification is not the same. As for neuroeconomists, irrational behaviors such as addictions do not come from an individual’s cognitive bias but from an interaction with a pathological environment. The normative reflections in neuroeconomics continue the theoretical history proposed by Foucault in his works on biopolitics and neoliberalism (Foucault 2004b). Our analysis can thus be regarded as a contribution to studies on governmentality. It claims that there is a specific non-reductionist relationship between knowledge and power in Foucault’s thought.