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Could Brain Imaging Reveal Your Mental State During a Crime?

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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?

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Why Is Your First Instinct After Hurting Your Finger to Put It in Your Mouth?
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If you close your fingers in a car door or slam your funny bone into a wall, you might find your first reaction is to suck on your fingers or rub your elbow. Not only is this an instinctive self-soothing behavior, it's a pretty effective technique for temporarily calming pain signals to the brain.

But how and why does it work? To understand, you need to know about the dominant theory of how pain is communicated in the body.

In the 17th century, French scientist and philosopher René Descartes proposed that there were specific pain receptors in the body that "rang a bell in the brain" when a stimulus interacted with the body, Lorne Mendell, a professor of neurobiology and behavior at Stony Brook University in New York, tells Mental Floss. However, no study has effectively been able to identify receptors anywhere in the body that only respond to painful stimuli.

"You can activate certain nerve fibers that can lead to pain, but under other circumstances, they don't," Mendell says. In other words, the same nerve fibers that carry pain signals also carry other sensations.

In 1965, two researchers at MIT, Patrick Wall and Ronald Melzack, proposed what they called the gate control theory of pain, which, for the most part, holds up to this day. Mendell, whose research focuses on the neurobiology of pain and who worked with both men on their pain studies, explains that their research showed that feeling pain is more about a balance of stimuli on the different types of nerve fibers.

"The idea was that certain fibers that increased the input were ones that opened the gate, and the ones that reduced the input closed the gate," Mendell says. "So you have this idea of a gate control sitting across the entrance of the spinal cord, and that could either be open and produce pain, or the gate could be shut and reduce pain."

The gate control theory was fleshed out in 1996 when neurophysiologist Edward Perl discovered that cells contain nociceptors, which are neurons that signal the presence of tissue-damaging stimuli or the existence of tissue damage.

Of the two main types of nerve fibers—large and small—the large fibers carry non-nociceptive information (no pain), while small fibers transmit nociceptive information (pain).

Mendell explains that in studies where electric stimulation is applied to nerves, as the current is raised, the first fibers to be stimulated are the largest ones. As the intensity of the stimulus increases, smaller and smaller fibers get recruited in. "When you do this in a patient at low intensity, the patient will recognize the stimulus, but it will not be painful," he says. "But when you increase the intensity of the stimulus, eventually you reach threshold where suddenly the patient will say, 'This is painful.'"

Thus, "the idea was that shutting the gate was something that the large fibers produced, and opening the gate was something that the small fibers produced."

Now back to your pain. When you suck on a jammed finger or rub a banged shin, you're stimulating the large fibers with "counter irritation," Mendell says. The effect is "a decrease in the message, or the magnitude of the barrage of signals being driven across the incoming fiber activation. You basically shut the gate. That is what reduces pain."

This concept has created "a big industry" around treating pain with mild electrical stimulation, Mendell says, with the goal of stimulating those large fibers in the hopes they will shut the gate on the pain signals from the small fibers.

While counter irritation may not help dull the pain of serious injury, it may come in handy the next time you experience a bad bruise or a stubbed toe.

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Bill Gates is Spending $100 Million to Find a Cure for Alzheimer's
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Jamie McCarthy/Getty Images for Bill & Melinda Gates Foundation

Not everyone who's blessed with a long life will remember it. Individuals who live into their mid-80s have a nearly 50 percent chance of developing Alzheimer's, and scientists still haven't discovered any groundbreaking treatments for the neurodegenerative disease [PDF]. To pave the way for a cure, Microsoft co-founder and philanthropist Bill Gates has announced that he's donating $100 million to dementia research, according to Newsweek.

On his blog, Gates explained that Alzheimer's disease places a financial burden on both families and healthcare systems alike. "This is something that governments all over the world need to be thinking about," he wrote, "including in low- and middle-income countries where life expectancies are catching up to the global average and the number of people with dementia is on the rise."

Gates's interest in Alzheimer's is both pragmatic and personal. "This is something I know a lot about, because men in my family have suffered from Alzheimer’s," he said. "I know how awful it is to watch people you love struggle as the disease robs them of their mental capacity, and there is nothing you can do about it. It feels a lot like you're experiencing a gradual death of the person that you knew."

Experts still haven't figured out quite what causes Alzheimer's, how it progresses, and why certain people are more prone to it than others. Gates believes that important breakthroughs will occur if scientists can understand the condition's etiology (or cause), create better drugs, develop techniques for early detection and diagnosis, and make it easier for patients to enroll in clinical trials, he said.

Gates plans to donate $50 million to the Dementia Discovery Fund, a venture capital fund that supports Alzheimer's research and treatment developments. The rest will go to research startups, Reuters reports.

[h/t Newsweek]

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