Researchers have shown that they can disrupt the brain region that chooses a suitable punishment for a crime, bringing about milder punishments without changing the perception of the culprit’s guiltiness.
In criminal cases in the court of law, usually a jury decides if a defendant is guilty while the judge determines a suitable punishment for the crime. However, the parts of the brain that calculate blame and punishment are actually located in different areas.
Fascinatingly, researchers at Vanderbilt University and Harvard University found that they could disrupt the part of the brain that sets punishment, altering the way study participants punished hypothetical criminals without changing the level of blame assigned to the crime.
"We were able to significantly change the chain of decision-making and reduce punishment for crimes without affecting blameworthiness," said René Marois, professor and chair of psychology at Vanderbilt and co-principal author of the study. According to Marois, these results strengthen evidence that the area of the brain associated with punishment, located in the prefrontal cortex, integrates information from other parts of the brain to come to a fair decision.
In order to alter the brain’s perception of suitable punishment, the researchers used repetitive transcranial magnetic stimulation (rTMS). In a pool of 66 male and female participants, half of the subjects received genuine rTMS while the other half received a placebo treatment. They were asked to determine blameworthiness and punishment based on a number of different criminal scenarios ranging from stolen property to grievous injury and death.
Across all study participants, both guiltiness and level of harm factored into the decision on how harshly a culprit should be punished. But those who were given rTMS settled on significantly milder punishments for suspects even when the level of blame didn’t change. The researchers speculate that the magnetic brain stimulation may have impaired the integration of signals for harm and culpability.
The research team hopes to expand on these findings by determining just how the brain assesses and decides upon the information regarding blame and punishment.
"This research gives us deeper insights into how people make decisions relevant to law, and particularly how different parts of the brain contribute to decisions about crime and punishment. We hope that these insights will help to build a foundation for better understanding, and perhaps one day better combatting, decision-making biases in the legal system," said co-author Owen Jones, professor of law and biological sciences at Vanderbilt.
While the court of law aims to implement the highest level of justice possible, different juries and judges hold varying beliefs on suitable punishments for the same crime. By studying the interplay between the two brain regions that work independently to come to this decision, there may be a way to implement a more uniform system of blame and punishment throughout future courtrooms.