In fact, although brain imagery has already been used in courts, it seems premature to endowthese techniques with the ability to objectify. The techniques, which merely enable a visualisationof estimates of physiological markers of brain activity (variation in the electro-magnetic field orin oxygenation of blood in the brain) are fallible and need to be approached with caution. Resultsof neuro scientific tests need to be interpreted by an expert, and the judge needs to be able to assess the validity and reliability of this interpretation. Alongside, neuroscientific evidence has a subjective dimension, precisely because it requires interpretation.