In fact, although brain imagery has already been used in courts, it seems premature to endow these techniques with the ability to objectify. The techniques, which merely enable a visualisation of estimates of physiological markers of brain activity (variation in the electromagnetic field or in oxygenation of blood in the brain) are fallible and need to be approached with caution. Results of 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, neuro scientific evidence has a subjective dimension, precisely because it requires interpretation.