Humans evolved as hunters and hunters; Although Homo sapiens can take down large prey, our species is also vulnerable to large predators. Now, new research reveals how the human brain switches between these two modes of survival.
The answer lies in the hypothalamus, a tiny structure nestled deep in the middle of the organ. This ancient area of ​​the brain predates the evolution of vertebrates and so appears in all vertebrates; similar brain regions also exist in invertebrates. The hypothalamus is known for performing very basic survival tasks such as regulating body temperature, triggering the release of hormones, regulation of circadian rhythms and send hunger signals.
The new study, published Thursday (June 27) in the journal PLOS Biologythey found that the hypothalamus also manages survival when switching between hunting and hunting.
The hypothalamus has previously been shown to take over this task in other mammals such as mice. But the new research is the first time this has been demonstrated in humans in the region, the study authors wrote in their paper.
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The hypothalamus is small—about the size of a pea—and is made up of even smaller nuclei that are too small for it. brain scanning techniques such as functional magnetic resonance imaging (fMRI) to image.
Researchers have used several methods to overcome this problem. One involved determining the pulse of cerebrospinal fluid—the clear fluid that flows around and into spaces in the brain and spinal cord—and then correcting for that movement in their fMRI data. They also used type Artificial Intelligence Deep learning is called deep learning to detect and classify activity patterns that might otherwise be too subtle to capture.
The team first had 277 volunteers play a video game in which they had to switch from hunting behavior to fleeing. The game consisted of a simple arena around which participants moved an avatar. The color of the edges of the arena told whether the participants were to hunt or escape from another computer character.
The brains of these participants were not scanned, but the researchers studied the volunteers’ actions to create a computer model that could distinguish whether someone was in hunt or flight mode.
Next, 22 other participants played the same game inside the fMRI scanner. This type of brain imaging takes an indirect measure of brain activity, which is based on the movement of blood and oxygen through different areas of the brain. When an area of ​​the brain is active, the flow of oxygenated blood to that area increases.
For comparison purposes, the same 22 participants also performed a task that only involved moving their avatar around the screen, with no particular effort to survive.
The results revealed that the hypothalamus functioned as a control center that facilitated switching between predator and prey behavior. It did this by communicating with a set of other areas of the brain, including amygdala, an area known for processing fear, and the ventromedial prefrontal cortex, which is known to be involved in decision-making tasks, including assessing risk in a given situation. This switch involved suppressing the behavior from the previous task.
The hypothalamus continues to coordinate the new behavior after this switch occurs and remains active throughout the process.
“These findings expand our understanding of the human hypothalamus from a region that regulates our internal body states to one that switches survival behaviors and coordinates strategic survival behaviors,” the authors wrote.
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