Could Brain Imaging Reveal Your Mental State During a Crime?


Imagine that you are asked by someone at the airport to carry a suitcase for them. Somehow, against your better judgment, you agree. Later at the security checkpoint you are searched, and the suitcase contains illegal material. The punishment you’ll receive will depend on your mental state when you agreed to carry the baggage: Did you know that it certainly contained contraband, or were you merely aware of the risk that it might?

Judges and juries often have to gauge a defendant’s state of mind at the time he or she committed a crime. They have to decide whether a defendant committed a crime "knowingly" or "recklessly." In some cases, the difference could be a matter of life or death.

Now a new study, published this week in the Proceedings of the National Academy of Sciences, has turned to the brain to find a basis for this distinction. The researchers were able to find distinct brain activity patterns that revealed whether participants knew they were committing a (virtual) crime or were recklessly taking a risk.

“All the elements of the crime being the same, depending on which mental state the court decides that you were in when you committed the crime, you can get probation or 20 years in jail,” says the study co-author Read Montague, a neuroscientist at the Virginia Tech Carilion Research Institute. “I can't think of anything more important than loss of your liberty, so understanding these distinctions or the subtleties in them is important.”

For this study, 40 participants played a game inside a brain scanner. They had to decide to carry a suitcase that could contain sensitive documents through a maze where they could encounter one or more guards. The number of suitcases and the guards were altered in each round of the game to play with the level of risk the participants had to take.

The researchers used a machine-learning method of data analysis that looks at activity across the entire brain to find patterns. This revealed two activity patterns that corresponded to the conditions in which participants knowingly decided to carry a suitcase containing contraband, or the conditions where the participants made an uncertain but risky choice.

The distinct brain patterns they found suggest that these two legally defined mental states—knowing and reckless—are not arbitrary, but indeed map to different psychological states.

Montague is quick to point out that this study is not something you could use to avoid harsher punishment.

“It has no implications within a courtroom, and probably won't for quite a while,” Montague tells mental_floss. “This is a proof-of-principle study that informs the idea of mental-state distinctions.”

In fact, what neuroscience in general could potentially offer in a courtroom is heavily debated.

Our relatively recent ability to scan the brain and look for otherwise undetectable injuries has raised the idea that neuroscience could be used to inform the circumstances of a criminal case. If you have a brain lesion, after all, your behavior could be profoundly affected.

A number of real life cases have highlighted this idea: Take Charles Whitman, for instance, who experienced a sudden change of personality and ultimately opened fire at the University of Texas in 1966, killing 14 people. An autopsy on Whitman revealed a tumor in his brain pressing against his amygdala, the brain area involved in regulating emotions. In another case, a 40-year-old man suddenly developed a strong interest in child pornography and eventually got charged for child molestation. He was later found to have a growing brain tumor. He underwent a surgery to remove the tumor, and his sexual interests returned to normal. Months later, the urges were back—and so was the tumor, the doctors found. After the tumor was removed, the man’s urges once again subsided.

Even in these extreme cases that involve visible tumors, however, establishing a cause and effect between brain injury and criminal behavior is tricky. It’s all the more difficult when dealing with subtler brain differences.

Nevertheless, the use of brain evidence to argue for a milder sentence is growing. In high-profile cases, such as death penalty trials, brain evidence has been used to argue that defendant is not fully mentally competent and therefore should be spared the death penalty. In the case of Brian Dugan, for example, lawyers used brain results to argue that Dugan was a psychopath and could not stop himself from committing murder. The jury considered the evidence but decided for the death penalty anyway.

In response to the growing use of neuroscientific evidence in the court, a number of researchers have also warned about the limitations of neuroscience.

As Judith Edersheim, an assistant professor of psychiatry at Harvard Medical School and co-founder of the Center for Law, Brain, and Behavior at Massachusetts General Hospital recently explained at Undark, most neuroscience findings (such as a brain signature of psychopathy) are based on research on a group of people, and don’t necessarily translate to an individual. “Using group data to predict individual behavior is a very complicated leap,” she said.

Still, neuroscience could find legally relevant insights about the human mind—for example, about the way eyewitness memory works (not very well) or the way we make decisions (not always rationally).

Next, Montague and his team are planning to study whether people make different decisions based on what’s in the suitcase. Would their choices change, he asks, if instead of top-secret documents the suitcases contain an illegal substance like cocaine?

More Studies See Links Between Alzheimer's and Herpes

Although it was discovered in 1906, Alzheimer’s disease didn’t receive significant research attention until the 1970s. In 1984, scientists identified the plaque-like buildup of amyloid beta proteins in brain tissue that causes nerve damage and can lead to symptoms like memory loss, personality changes, and physical debility.

Now, researchers are learning why amyloid beta tends to collect in brain tissue like barnacles on a ship. It might not be rallying expressly to cause damage, but to protect the brain from another invader: the herpes simplex virus.

As The Atlantic recently noted, a number of studies have strengthened the notion that amyloid beta activity is working in response to herpes, the virus that travels along nerve pathways and typically causes cold sores around the mouth (HSV-1) or genitals (HSV-2). In a study involving mice, those engineered to produce more amyloid beta were more resistant to the herpes virus than those who were not.

But when too much amyloid beta is produced to combat the virus, the proteins can affect the brain’s neurons. And while herpes tends to target specific pathways in the body that result in external sores, it’s possible that the virus might act differently in an older population that is susceptible to more widespread infection. Roughly half of adults under age 50 in the U.S. are infected with HSV-1 and 12 percent with HSV-2, which suggests that a large swath of the population could be vulnerable to Alzheimer's disease. Two other strains of the virus, HHV-6A and HHV-7, have also been found to be more common in the brains of deceased Alzheimer’s patients than in the general population.

More research will be needed to further understand the possible relationship between the two. If more findings support the theory, then it’s possible that antiviral drugs or vaccines targeting herpes might also reduce the chances of amyloid beta buildup.

[h/t Atlantic]

Heatwaves Can Affect Your Ability to Think Clearly and Make Decisions

Dehydration and body odor aren't the only things to hate about oppressive heat. According to new research reported by The Guardian, living through a heatwave without relief hampers your ability to think quickly and clearly.

For their study, published recently in PLOS Medicine, researchers at the Harvard T.H. Chan School of Public Health tested the mental performance of 44 students during a heatwave in Boston in 2016. Roughly half the students were living in newer dorm buildings with central AC, with the other half living in older dorms without it.

Over 12 days, researchers had participants take cognition tests on their phones immediately after waking up. The students living without AC took about 13 percent longer to respond to the questions and their answers were about 13 percent less accurate.

The results indicate that even if high temperatures don't pose an immediate threat to someone's health, they can impair them in other ways. “Most of the research on the health effects of heat has been done in vulnerable populations, such as the elderly, creating the perception that the general population is not at risk from heat waves,” Jose Guillermo Cedeño-Laurent, research fellow at Harvard Chan School and lead author of the study, said in a statement. “Knowing what the risks are across different populations is critical considering that in many cities, such as Boston, the number of heat waves is projected to increase due to climate change.”

Summers are gradually becoming hotter and longer in Boston—a trend that can be observed throughout most of the rest of the world thanks to the rising temperatures caused by human activity. In regions with historically cold winters, like New England, many buildings, including Harvard's oldest dorms, are built to retain heat, which can extend the negative effects of a heat wave even as the weather outside starts to cool. If temperatures continue to rise, we'll have to make a greater effort to keep people cool indoors, where American adults spend 90 percent of their time.

Our thinking isn't the only thing that suffers in the stifling heat. A study published last year found that hot weather does indeed make you crankier—which may not be as bad as bombing a test, but it's not exactly not fun for the people around you.

[h/t The Guardian]


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