Posted on
Zain Tariq | October 23, 2022

Why do criminals commit crimes? How does a jury choose an appropriate punishment? How can we decide whether to put a person into prison or a mental asylum?

The McArthur Foundation Research Network on Law and Neuroscience, headquartered at Vanderbilt University, focuses on finding answers to these questions. The foundation is headed by the Network Director, Owen D. Jones, a Professor of Law and a Professor of Biological Sciences at Vanderbilt University. The foundation has research in two fundamental areas relating to neuroscience: brain development and mental states. This article aims to dissect each area of research and explain how advances in neuroscience research have changed our fundamental understanding of justice.

Brain development refers to how the brain changes in its capabilities and decision making as a person gets older. This is why justice systems typically have separate prisons or courts labeled “Juvenile Courts” for offenders below a certain age, with under-developed brains. Some states, however, have no minimum age below which a person cannot be tried as an adult. For example, in Tennessee offenders below the age of 18 can be tried as an adult for specific crimes such as aggravated robbery, kidnapping, and murder. Thus, a common debate centers on the question: at what age should a human being become completely responsible for their actions?

In a BBC Documentary called “Neurolaw and Order”, Professor Jones explains that 18 is not a universal biological marker for a fully developed brain. In fact, most brains are only fully developed by 25 and socioeconomic conditions such as drug abuse, child abuse, and trauma can actually stunt the growth of the brain. Furthermore, as neuroscientists have discovered through brain imaging technologies such as fMRI, reward centers in the brain of adolescents are much more responsive than those in adults. This makes adolescents more susceptible to “thrill-seeking behaviors”, as Professor Jones puts it, which can include reckless criminal behaviors. Knowing this, how do we reform our legal system to better accommodate adolescents?

San Francisco could provide one answer to this question. Authorities in the city recently created a first-of-its-kind Young Adult Court that places 18-25 year olds in intensive programs to help them reform back into society, with the understanding that their brains have not fully developed. It is the hope of Professor Jones and colleagues that other cities will similarly use neuroscience research to better help adolescent offenders navigate the justice system and avoid becoming re-offenders.

(Picture of a Young Adult Court graduate Alonso (Middle) alongside Institute Case Manager Ashli Rocha (Left) and Judge Bruce E. Chan (Right) Source: (

Many laws not only take the age of offenders into account, but also their specific mental states at the time of the crime. An example is how the Tennessee justice system treats first-degree murder versus voluntary manslaughter. First-degree murder is defined as “premeditated” or planned murder with a specific intent such as robbery. Voluntary manslaughter is defined as a crime of “passion” which includes self-defense and irrational acting. The difference between the punishment for these crimes is massive: first-degree murder carries a sentence of death or life imprisonment, while voluntary manslaughter carries a 3 to 15 year sentence.

However, how does a body of human jurors identify the mental state of a person while they committed a crime? It’s hard to determine whether someone was in a state of rage, mental psychosis, or a “normal” mental state. The topic becomes more complex with charges such as reckless homicide that leave it to the jury to define “recklessness”. 

This is where neuroscience research plays a significant role in distinguishing brain states. In a paper titled “Detecting Mens Rea in the Brain”, Professor Jones explains how jurors confuse the terms “knowing” and “reckless” about 50% of the time, adding that “in such a case, that’s nearly coin-flipping odds of false conviction.”

Can neuroscience help us better differentiate a criminal’s mental state during a crime and give a more suitable punishment?  In the hopes of answering this question, Professor Jones devised an experiment in which participants were asked to play a game where they had to try to successfully smuggle contraband across the border. Some participants were given one suitcase which definitely had contraband. This group comprised the “knowing” crowd, since they were 100% aware that what they were doing was a crime. The other group had choices of multiple suitcases, with only one containing contraband. This group comprised the “reckless” crowd since there was an element of chance regarding whether they were actually committing a crime, and were therefore less likely to be cautious. The experiment was conducted while imaging each participant’s brain. Finally, a computer was used to predict if the participant was acting “recklessly” or “knowingly”, based on images collected of the participants’ brains.

Brain Images of the Knowing/Reckless crowd highlighting key differences in brain activity between the two mental states. Sourced from (

Result showed that the computer was able to correctly identify the “reckless” crowd versus “knowing” crowd 71% of the time, compared to 50% of the time when jurors were correct. The implication is that the system of using a group of human jurors to determine a criminal’s brain state is not the most fair system. Thus, Professor Jones proposes that we need to train jurors better to help them understand the psychology and neuroscience behind different brain states. 

As our knowledge of the human brain advances, the way we serve justice and ensure the best practices for rehabilitation of prisoners should also advance. In the future we could see more courts adopt a separate juvenile court for offenders under 25 or we could have new laws created alongside neuroscience research in areas like memory, pain assessment and evaluating brain states.  With researchers such as Professor Jones and foundations such as the McArthur Foundation leading the way in the field of neurolaw, we will continue to see changes in the courtroom that will hopefully lead to a more equitable justice system.

One Reply to “Neuroscience in the Courtroom”

  1. Haseeb Tariq says:

    A good read! Lots to think about for a future juror. Curious as to what needs to happen on the legislative side to enact some much needed reform!

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