Too Good to Be True

When you think of lie detection tests, it is likely that you visualize a CSI episode where investigators use the device to solve a crime. However, these tests actually have an important usage in the real world, and their acceptance into the courtroom has been widely debated for many years. A new form of technology known as the fMRI (functional magnetic resonance imaging) utilizes neuroscience to perform lie-detection tests. Although researchers boast about the immense power of the fMRI, problems within the device and the research done on it justify why it should not be used in the courtroom for the time being.

The fMRI works by tracking blood flow to activated brain areas. When people lie, it is assumed that their brain must work harder. Thus, more blood flows to these brain regions, which is indicated in the fMRI reports. A few published papers have claimed that the accuracy rates of the device range from 70 to 90 percent. Furthermore, eight different laboratories have published twelve peer-reviewed articles on fMRI-based lie detection. Similar to the fMRI, the polygraph is an older lie-detection test that you are likely more familiar with. This device has been around for almost a hundred years, and it has been widely used to assess the honesty of countless people. The polygraph measures indications of anxiety that appear when a person lies by checking for high levels of blood pressure, heart rate, breathing rate, and galvanic skin response. Currently, the polygraph is used by government agencies such as the FBI as a pre-screening technique for jobs. However, since the device is not entirely accurate (70%) and could lead to the false conviction or acquittal of a defendant, it has been deemed inadmissible in the courtroom for almost all cases. Since the fMRI utilizes newer technology and potentially performs at a higher accuracy rate than the polygraph, you may be wondering why it hasn’t surpassed it as the go-to lie-detection test.The short answer is that several flaws lie within the research done on the fMRI that demean its credibility. None of the eight laboratories publishing research on the fMRI have replicated their work. Thus, it is unclear whether or not their findings are accurate since their trials have not been repeated by others to obtain a consistent result. Furthermore, the studies were conducted using a sample of people that are not representative of the population that fMRI tests will likely be used on, which shows that there is no known error rate for fMRI-based detection in real world settings. Finally, the results of an fMRI test can easily be skewed. If subjects even slightly move their head or tongue, the fMRI will produce bad-quality data that is unreliable. Thus, a solution must be found for this problem to ensure that data is consistently accurate.

Since 2006, only two companies, No Lie MRI and Sephos, have offered fMRI lie detection services to the public. The latter company closed in 2010 after the United States District Court for the Western District of Tennessee ruled in U.S. v. Semrau that the device cannot be used in a court of law. The judge for the case stated that the lack of a true known error rate for the fMRI makes it impossible to be used as credible evidence. If more research is conducted to validate the accuracy rates of the fMRI and ensure that its data cannot be falsified, then it will likely work as a complement to the polygraph for vetting government job candidates. However, it seems unlikely that the fMRI will be admissible in court any time soon.

In his major review article in the American Journal of Law and Medicine, as highlighted by the Scientific American, Henry Greely states, “The danger is that people’s lives can be changed in bad ways because of mistakes in the technology.” The current lack of credible research done on the fMRI explains why the device cannot be used as a tool for determining the credibility of those in the courtroom, especially when one’s life is at stake. However, one should not rush to the judgement that the device will never be able to get there. With enough time and research, the fMRI could very well develop into an incredibly powerful tool in the future.