Thus far, we have largely considered technologies that are capable of changing persons’ mental states. However, today, a range of technologies are also being developed that can gain insight into the mental realms of others. One example is the measurement of brain activity, which has enabled researchers to make inferences about individual mental states and faculties. In particular, fMRI and EEG can measure brain activity in a way that allows for inferences about what a person remembers, recognises, thinks or feels. EEG has been used, for example, to identify concealed memories about a criminal offence; and fMRI has been used to reveal sexual orientation, political ideology or a person’s craving for cocaine. Recently, various research groups used neurotechnology together with emerging forms of artificial intelligence (AI) to decode mental content from brain activity, with some interesting first results. According to Brownsword, with the development of these kinds of “brain-reading” technologies, “researchers have a window into the brains and, possibly, into a deeper understanding of the mental lives of their participants”.