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Tag: neuroscience

Brain Structure May Not Influence Personality After All

New study casts doubt on links between personality and brain structure. MRI scan courtesy of Annchen Knodt, Duke University

We know personality comes from the brain, but does that mean the brain’s shape and composition affect personality as well?

Previous studies have attempted to find links between brain structure and personality types, but new data indicates otherwise. A new study, the largest of its kind, suggests these links may not be so strong after all. In fact, they may not even exist.

Recently Duke researchers, led by Reut Avinun Ph.D., a postdoctoral associate at Professor Ahmad Hariri’s lab, analyzed the MRI scans of over a thousand people to determine potential links between personality and brain shape.

Although there are many personality neuroscience studies, consistent and reliable findings have not been established. While most previous studies used less than 300 individuals, this study has a large sample of 1,107 individuals. Additionally, this research comprehensively measures personality with 240 items.

“When I got into the field, people were collecting data sets with only 10 people and doing analysis with only 20 participants,” said Avram Holmes, an asssociate professor of psychology at Yale who was not involved in the study.

Personality studies such as this typically use the “Big Five” personality traits: neuroticism, extraversion, agreeableness, conscientiousness, and openness-to-experience. Extraverted people tend to be outgoing and social and those with high openness-to-experience are imaginative, curious, and enjoy trying new things. High neuroticism and low conscientiousness have been associated with negative health behaviors such as smoking. These were even connected to negative life outcomes, such as depression, anxiety, and poor sleep. By understanding what underlies these behaviors, scientists may be able to better treat them.

For brain shape, Avinun and her colleagues examined brain morphometry, cortical thickness, cortical surface area, subcortical volume, and white matter microstructural integrity. She used a univariate approach, looking at the relationship between one phenotype and one behavior. Statistical analysis also accounted for the factors of race/ethnicity, sex, and age.

Last year, researchers published a paper finding 15 correlations between specific personality traits and neuroanatomical structures. However, Avinun’s new research found that none of these connections held true in the large Duke Neurogenetics Study sample.

When scientists analyze an MRI dataset, there is a lot of freedom in the phenotypes collected and the types of analyses. “With so many degrees of investigative freedom and the expectation that you should see something there, researchers may accidentally find false positives. It’s easy to fall into the trap of making a story about why the effect has this particular brain pattern and see an association that doesn’t exist,” Holmes explained.

Ultimately, Avinun found no links between the Big Five personality traits and multiple features of brain structure.

While this may seem anticlimactic, even null findings are incredibly useful and could lead to recommendations to future research in this area. By showing that links between brain morphometry and personality tend to be small, this research may push the field toward studies with larger samples and guidelines for higher replication rates.

“The brain is plastic and it is affected every day by our experiences, so expecting to find straightforward associations between brain morphometry and personality traits may be too naïve,” Avinun said. “We are beginning to realize that large samples and multivariate methods  are needed in neuroscience. Trying to understand what makes us who we are is exciting. Research is really challenging as the field is constantly changing, but it is constantly improving as well.”

Niba Nirmal is a multimedia science communicator based in San Francisco, CA. She graduated in the Duke class of 2020, with a Master’s degree in Genetics. Find samples of her work at www.notesbyniba.com

How Many Neuroscientists Does it Take to Unlock a Door?

Duke’s Summer Neuroscience Program kicked off their first week of research on June 4 with a standard morning meeting: schedules outlined, expectations reiterated, students introduced. But that afternoon, psychology and neuroscience professor Thomas Newpher and undergraduate student services coordinator Tyler Lee made the students play a very unconventional get-to-know-you game — locking them in a room with only one hour to escape.

Not the usual team building activity: Students in Duke’s 8-week Summer Neuroscience Program got to know each other while locked in a room.

Bull City Escape is one of a few escape rooms in the Triangle, but the only one to let private groups from schools or companies or families to come and rent out the space exclusively. Like a live-in video game, you’re given a dramatic plot with an inevitably disastrous end: The crown jewels have been stolen! The space ship is set to self-destruct! Someone has murdered Mr. Montgomery, the eccentric millionaire! With minutes to go, your rag-tag bunch scrambles to uncover clues to unlock locks that yield more clues to yet more locks and so on, until finally you discover the key code that releases you back to the real world.

This summer’s program dips into many subfields, in hopes of pushing the the 16 students (most of them seniors) toward an honors thesis. According to Newpher, three quarters of the senior neuroscience students who participated in the 2018 SNP program graduated with distinction last May.

From “cognitive neuro” that addresses how behavior and psychology interacts with your neural network, to “translational neuro” which puts neurology in a medical context, to “molecular and cellular neuro” that looks at neurons’ complex functions, these students are handling subjects that are not for the faint of heart or dim of mind.

But do lab smarts carry over when you’re locked in a room with people you hardly know, a monitor bearing a big, red timer, blinking its way steadily toward zero?

Apparently so. The “intrepid team of astronauts” that voyaged into space were faced with codes and locks and hidden messages, all deciphered with seven minutes left on the clock, while the “crack-team of detectives” facing the death of Mr. Montgomery narrowly escaped, with less than a minute to spare. At one point, exasperated and staring at a muddled bunch of seemingly meaningless files, a student looked at Dr. Newpher and asked, “Is this a lesson in writing a methods section?”

The Bull City Escape website lists creative problem-solving, focus, attention to detail, and performance under pressure as a few of the skills a group hones by playing their game — all of which are relevant to this group of students, many of whom are pre-med. But hidden morals about clarity and strength-building aside, Newpher picked the activity because it allows different sides of people’s personalities to come out: “When you’re put in that stressful environment and the clock is ticking, it’s a great way to really get to know each other fast.”

By Vanessa Moss
By Vanessa Moss

Zapping Your Brain Is Dope

Emerging technology has created a new doping technique for athletic performance that is, as of now, perfectly legal.

Coined “neuro-doping,” this method sends electric current through one’s brain to facilitate quicker learning, enhanced muscular strength, and improved coordination. Use of this electronic stimulus has taken off in the sports world as a replacement for other doping methods banned by the World Anti-Doping Agency (WADA). Because it’s relatively new, WADA has yet to establish rules around neuro-doping. Plus, it’s virtually undetectable. Naturally, a lot of athletes are taking advantage of it.

Image result for doping

One specific method of neuro-doping is known as Transcranial Direct-Current Stimulation (tDCS). It works by sending a non-invasive and painless electrical current through the brain for around three to 20 minutes, in order to excite the brain’s cortex, ultimately increasing neuroplasticity (Park). This can be done commercially via a headset like device for $200.

Image result for transcranial direct current stimulation headset
The Halo Sport

Weight lifters, sprinters, pitchers, and skiers are just some of many types of athletes who can benefit from tCDS. By practicing with these headphones on, new neural pathways are constructed to help their bodies achieve peak performance. Dr. Greg Appelbaum, director of Opti Lab and the Brain Stimulation Research Center, says it’s especially useful for athletes where technique and motor skills triumph — such as a sprinter getting out of the blocks or an Olympic ski jumper hanging in the air. Top-tier athletes are pushing that fine limit of what the human body can accomplish, but neuro-doping allows them to take it one step further.

Neuro-doping has other applications, too. Imagine insanely skilled Air Force pilots, surgeons with exceptionally nimble hands, or soldiers with perfect aim. tCDS is being used to make progress in things like Alzheimer’s and memory function because of its impact on cognitive functioning in the forms of increased attention span and memory. You could even learn the guitar faster.

In this sort of context, it’s a no brainer that neuro-doping should be taken advantage of. But how ethical is it in sports?

The precedent for WADA to ban a substance or technique has been based on meeting two of the following three criteria: (1) drugs or tools that likely enhance performance to secure a winning edge; (2) drugs or tools that place athletes’ health at risk; (3) any substances or techniques that ruin the “spirit-of-sport” (Park). Lots of research has shown tCDS is pretty legit. As for health risks, tCDS is still in the experimental stage, so not much can be said about its side effects. Ethically, it causes a lot of controversy.

Many issues come into play when thinking about allowing athletes to neuro-dope. Given its similarities with other popular drugs, tCDS could introduce unfair advantages. Furthermore, not everyone may have access to the technology, and not everyone may want to use it. However, it’s important to note that sports already have unfair advantages. Access to things like proper coaching and nutrition may not be a reality for everyone. Sports are just inherently competitive.

Back when baseball players doped, it was awesome to watch them crush balls out of the park. Reintroducing performance enhancement through tCDS could mean we start seeing mountain bikers launching insane air and world records being smattered. The human body could achieve newfound heights.

Are the benefits worth it? Does neuro-doping ruin the “spirit of the sport?” Regardless of these important questions, tCDS is a fascinating scientific discovery that could make a difference in this world. So, what do you think?

Will Sheehan
Post by Will Sheehan

Park, Cogent Social Sciences (2017), 3: 1360462
https://doi.org/10.1080/23311886.2017.1360462

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