What if a jury could decide a man's guilt through mind reading? What if reading a defendant's memory could betray their guilt? And what constitutes 'intent' to commit murder?

Legal expert Megan Meyercord, said the advances in neurotechnology are creating an unequal development in international criminal law which are influencing national jurisdiction. "Neuroscience is still very much in its infancy around the world, yet many countries are seriously considering using neuroscience on those who are seized, treated, and transported before their court date."

Meyercord stated that tensions are building between legal professionals in states, regional and international courts on inevitable abuse mechanisms from the use of neurotechnology which will endorse jurisdictional doctrines that ignore the traditional legal process and potentially affect how a perpetrator appears before the court. "Neurolaw could effectively allow a medical device to declare an innocent man guilty before he is even given the opportunity to speak or given a trial," said Meyercord.

In the article "Neurolaw," in the inaugural issue of WIREs Cognitive Science, co-authors Walter Sinnott-Armstrong and Annabelle Belcher assess the potential for the latest cognitive science research to revolutionize the legal system.

Neurolaw, also known as legal neuroscience, builds upon the research of cognitive, psychological, and social neuroscience by considering the implications for these disciplines within a legal framework. The claim of some neuroscientisits is that these disciplinary collaborations have increased our knowledge of the way the human brain operates, and now neurolaw continues this trend.

One of the most controversial ways neuroscience is being used in the courtroom is through 'mind reading' and the detection of mental states. While only courts in New Mexico currently permit traditional lie detector, or polygraph, tests there are a number of companies claiming to have used neuroscience methods to detect lies. Some of these methods involve electroencephalography (EEG), whereby brain activity is measured through small electrodes placed on the scalp. This widely accepted method of measuring brain electrical potentials has already been used in two forensic techniques which have appeared in US courtrooms: brain fingerprinting and brain electrical oscillations signature (BEOS). Brain fingerprinting purportedly tests for 'guilty knowledge,' or memory of a kind that only a guilty person could have. Other forms of guilt detection, using functional magnetic resonance imaging (fMRI), are based on the assumption that lying and truth-telling are associated with distinctive activity in different areas of the brain. These and other potential forms of 'mind reading' are still in development but may have far-reaching implications for court cases.

Should courts be in the business of deciding when to mitigate someone's criminal responsibility because his brain functions improperly, whether because of age, in-born defects or trauma? As we learn more about criminals' brains, will we have to redefine our most basic ideas of justice?

Two of the most ardent supporters of the claim that neuroscience requires the redefinition of guilt and punishment are Joshua D. Greene, an assistant professor of psychology at Harvard, and Jonathan D. Cohen, a professor of psychology who directs the neuroscience program at Princeton. Greene got Cohen interested in the legal implications of neuroscience, and together they conducted a series of experiments exploring how people's brains react to moral dilemmas involving life and death. In particular, they wanted to test people's responses in the f.M.R.I. scanner to variations of the famous trolley problem, which philosophers have been arguing about for decades.

"To a neuroscientist, you are your brain; nothing causes your behavior other than the operations of your brain," Greene says. "If that's right, it radically changes the way we think about the law. The official line in the law is all that matters is whether you're rational, but you can have someone who is totally rational but whose strings are being pulled by something beyond his control." In other words, even someone who has the illusion of making a free and rational choice between soup and salad may be deluding himself, since the choice of salad over soup is ultimately predestined by forces hard-wired in his brain. Greene insists that this insight means that the criminal-justice system should abandon the idea of retribution -- the idea that bad people should be punished because they have freely chosen to act immorally -- which has been the focus of American criminal law since the 1970s, when rehabilitation went out of fashion. Instead, Greene says, the law should focus on deterring future harms. In some cases, he supposes, this might mean lighter punishments. "If it's really true that we don't get any prevention bang from our punishment buck when we punish that person, then it's not worth punishing that person," he says.

"Some proponents of neurolaw think that neuroscience will soon be used widely throughout the legal system and that it is bound to produce profound changes in both substantive and procedural law," conclude the authors. "Other leaders in neurolaw employ a less sanguine tone, urging caution so as to prevent misuses and abuses of neuroscience within courts, legislatures, prisons, and other parts of the legal system. Either way we need to be ready to prevent misuses and encourage legitimate applications of neuroscience and the only way to achieve these goals is for neuroscientists and lawyers to work together in the field of neurolaw."

Meyercord suggests that neuroscience be thoroughly examined for its violative nature and practical use before being implemented as a permanent staple to measure innocence or guilt.

Neuroethics at the World Science Festival


Raymond Tallis - Free Will and the Brain


Kelley Bergman is a media consultant, critic and geopolitical investigator. She has worked as a journalist and writer, specializing in geostrategic issues around the globe.

• The Neuroscience of Theory of Mind