There has been much fascination in recent years with the potential legal implications of discoveries and technologies in the neurosciences. One example of this fascination relates to the development of technologies for brain-based lie detection. There has also, in recent years, been a Law Reform debate concerning the appropriate test that should be applied when deciding which kinds of scientific evidence should be admitted to Irish courts. It has been argued, in particular, that Irish courts should begin to employ a Daubert-style reliability test when admitting scientific evidence. This article addresses the appropriateness of such reliability tests, along with the potential forensic uses of neuroscientific technologies, by analysing and drawing lessons from a recent US decision dealing with the admissibility of brain-based lie detection evidence.