What drives people to take risks like base-jumping? Recent research indicates that brain anatomy differs between people who engage in risky behaviors and those who do not.
Researchers have found that adventurous people with a seemingly insatiable need for far-flung journeys or adrenaline-fueled, extreme activities may not just have different personalities but different brain structures too. Interestingly, this may also have links to substance abuse.
Along with a team of researchers from Harvard University and Massachusetts General Hospital in Boston, Yale University psychologist Avram Holmes found that increases in impulsive and thrill-seeking behavior in healthy young adults was linked to distinct differences in the structure of their brain, specifically, the areas involved in decision-making and self-control.
According to the Society for Neuroscience, the study builds on well-established links between impulsivity, sensation-seeking, and substance abuse. Prior research has indicated that genes play a role in these behaviors, while other studies have found substance use can affect brain anatomy and function over time — but scientists still don't know the extent to which brain abnormalities, present prior to drug-taking, contribute to the likelihood that a person will develop a substance abuse disorder.
Using magnetic resonance imaging (MRI) to measure the size of particular regions of the brain, as well as questionnaires to establish the participants’ need for novel and intense experiences, willingness to take risks, and tendency to make rapid decisions in addition to alcohol, tobacco, and caffeine usage, the researchers studied 1,234 males and females aged 18 to 35 with no history of psychiatric disorders or substance dependence.
The findings, published in The Journal of Neuroscience, suggest that subjects who reported seeking high levels of stimulation or excitement had reduced cortical thickness, or gray matter, in brain regions associated with decision making and self-control. The strongest links occurred in brain areas related to the ability to regulate emotions and behavior, the anterior cingulate and middle frontal gyrus. Changes in those brain structures also correlated with heightened use of alcohol, tobacco, or caffeine as well as with the participants' self-reported tendency to act impulsively, according to the Society for Neuroscience.
The significance of individual differences in brain anatomy is still a subject of debate, said Holmes, but “the findings allow us to have a better understanding of how normal variation in brain anatomy in the general population might bias both temperamental characteristics and health behaviors, including substance abuse," he said in a press release.
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