I t is difficult enough in the intense environment of a courtroom for a jury, provided with evidence and witness testimonies, to discern guilt from innocence. Even trickier is determining the level of intent behind a crime, when often all you have to go by is the word of the accused. So far technology has proved inaccurate, consigning polygraph tests to talk show host Jerry Springer and his ilk.
Help may be at hand. A team of neuroscientists from Yale University and the Virginia Tech Carilion Research Institute have published findings from a computerised experiment in which participants had their brains scanned while they carried a suitcase across a virtual border. Some of the subjects were aware their suitcase contained drugs, some were not. Using machine learning, computers were able to analyse the brain images and pick out those who were aware of their contraband.
Remarkable though the results are, there’s no rush to bring MRI machines into the docks. The findings will need to be verified by further study, and the brain scans measured intent while the crime was being committed; gauging it months or years after the deed may not be possible.
“We are not replacing juries with brain scanners,” said Gideon Yaffe, a professor of law, philosophy and psychology at Yale. “But we can now say that some debated differences in degree of criminal intent have a real neural basis.”
Some psychologists refute the notion of ‘degrees of criminal intent’, but that scepticism may now be put to rest. Criminal justice systems which vary sentencing based on perceived intent appear to have been vindicated, and further study may allow scientists to identify the precise level of intent.
“Does an addict who leaves his child in a hot car while he seeks drugs really understand the risks involved?” Professor Yaffe asked. “Maybe not. Or maybe he is even more vividly aware of them than non-addicts. Neuroscience might help us to answer those questions.”