Forensic Neuroscience: Is it here?

The last few decades have seen outstanding progress in the field of forensic science. From fingerprints to ballistics to DNA profiling, crime detection has become less speculative and more scientific. Now, scientists are attempting to use brain imaging techniques as evidence of behaviors such as lying and psychopathic tendencies.

Neuroscience is a branch of biology that deals with the study of the nervous system. As the control center of the nervous system, the brain is the science’s obvious focus. However, the gargantuan complexity of the organ, combined with technological constraints means that there is still a great discrepancy between our understanding of the molecular structure and functioning of the brain, and its translation into individual behavior and personality.

However, scientists are making progress towards linking brain anatomy to behavior, and a great deal of the findings in this area can be attributed to fMRI (functional magnetic resonance imaging). fMRI can give scientists a vague idea of the localization of brain activity. It operates along the assumption that the areas of the brain that are most active will require the most oxygen and glucose (which are used by cells for energy). As oxygen and glucose are carried in the blood, the area with the most blood flow is the most active. fMRI evidence has shown what areas of the brain are connected with movement, learning and decision-making

The justice system is primarily concerned with the use of fMRI in lie detection and psychiatric diagnosis.

A reliable lie detection system could revolutionize the criminal justice system. The ‘not guilty’ plea could revoked entirely, with court cases focusing more on severity of sentence rather than the establishment of guilt. Malicious prosecution and wrongful imprisonment could also be greatly avoided. Polygraph tests (despite strong convictions within both the judicial and scientific communities of their inaccuracy) are still used as interrogation tools and attempted evidence. However, even the most recent research into lie detection using fMRI is unconvincing. Scientists haven’t been able to find specific indicators of dishonesty.

There has, however, been research suggesting the ability to detect predispositions towards overall honest or dishonest behavior. Given the extensive precedent for character witnesses, perhaps fMRI could play a role in establishing strength of character.

Psychiatric diagnosis has using fMRI has also received a great deal of attention. Diagnosis of psychopathy is highly regarded in criminal case proceedings. The current paradigm for this is the Hare Psychopathy Checklist – Revised (PCL-R) which uses a checklist of behavioral indicators for diagnosis. However, these behavioral indicators are proxies for abnormalities in brain function. The problem is, very little is known about what those abnormalities are. At very best, scientists have been able to show an overall difference in the size and activity of certain brain regions. Unfortunately, the parameters for normal and abnormal function overlap far too much to give a high degree of statistical certainty.

One must also take into account the effect that the use of fMRI could have on juries. The CSI effect is a well-known and extensively studied phenomenon. One aspect of this is the increased bias that juries show towards scientific evidence using ‘cutting-edge’ or ‘experimental’ technologies. Yet, these technologies (like fMRI) are not necessarily reliable. Hence, the use of fMRI as evidence could unfairly influence juries towards conclusions supported by the evidence, regardless of the validity of the evidence in question.

Therefore, I do not recommend that fMRI be admissible evidence in court cases. There are no fMRI indicators reliable enough to be convincing evidence of dishonesty or psychopathy, but the wonder and absoluteness associated with forensic techniques may cause juries to place undue worth in its findings.

5 responses to “Forensic Neuroscience: Is it here?”

  1. Brianna Margaret Cathey says:

    I agree with your position on the use of fMRI as evidence. It would not be good if juries made conclusions based on loose interpretation of scientific data of an individual. Do you think if the technology becomes more accurate in detecting brain activity that it should be used as evidence?

    • Madiha Shafquat says:

      I think the issue is not with the accuracy of the fMRI technology; the real issue lies with the fact that scientists cannot find distinguishable indicators of certain behaviors (like lying and psycopathy). Even if the fMRI technology becomes more accurate, I would still hope for a clear consensus on what those indicators are before the scans be used as evidence.

      • Carlos Aizenman says:

        Agreed. It’s not that the technology is not precise, but that there is too much variability in the normal population to be able to take a scan from one individual and conclusively say this person is abnormal. At most, we can say based on where in the range this person falls, that there is a higher or lower chance that the person is lying or a “psychopath”.

  2. Brooke Nawrocki says:

    I really agree with everything you said in your final paragraph. I also think that overuse of this technology can cause juries to find too much value in it for what it’s actually worth.

  3. Aiswarya Nagasubramony says:

    I completely agree with your last paragraph on why the fMRI should not be admissible at this point. Developing these methods could greatly improve the justice system, but until then, they cannot be solely relied on.

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