- Published: September 26, 2012
There have been studies attempting to use brain scan as a lie detector. In Giorgio Ganis' birthdate experiment, they even showed 100% accuracy in detecting whether or not the subjects were lying about their birth date using fMRI images. However, this does not indicate that the technology is reliable. First of all, their accuracy fell to 33% with countermeasures. And even if they can make it 100% even with the countermeasures, they will still have to figure out how to apply this technology in the real world, outside of the simple laboratory environment. The lies that are truly harmful are far more complex than lying to a yes/no question in a lab. I can‘t say that it will be impossible to detect lies – before the advent of the technology, who would have imagined that DNA evidence will serve critical purposes in court? – but it‘s definitely a long, long way to go.
The judges in US have been rejecting the brain scans as evidence of any kind, but surprisingly, this doesn‘t seem to be the case in India. In 2008, a woman was convicted of murder based on the EEG recording. The technology supposedly reveals whether the person has experiential knowledge about the description of an event read out to him/her. The judge explicitly cited this as the basis of the murder conviction. After this case, two other states in India were impressed enough to set up labs to use this technology.
It is more than exciting to know that there is a possibility of detecting lies and using the technology to solve criminal cases, but we need to be careful in using the technology. At this point, the technology is not reliable to be used outside the lab. It is important to take time to make sure that the technology is good enough before it is used to determine whether a person is innocent or not.
Ganis, G. et al. "Lying in the scanner: Covert countermeasures disrupt deception detection by functional magnetic resonance imaging". Neuroimage. 55.1 (2010).
India's Novel Use of Brain Scans in Courts is Debated The New York Times Sep 14, 2008