Neuroscience of choking under pressure

The experience of choking under pressure—in an exam, at the free-throw line, or in a presentation—is a familiar one. This week a study published in The Journal of Neuroscience attempted to explain what goes on in the brain when the stakes are raised.

While monitoring their brains with an MRI scanner, researchers had participants play a video game. They were then told that they could win or lose varying amounts of money depending on how they played.

The results were somewhat counterintuitive. Individuals with high loss aversion performed best when they risked losing money. In other words, people who were most scared of losing money performed best when they had a lot to lose. When offered a large sum for winning, though, these loss-averse gamers choked.

The opposite was true for less loss-averse individuals. High rewards elicited better performance, and potential losses caused them to choke.

The researchers found that the part of the brain related to this phenomenon was a region called the ventral striatum. Increased activity of the ventral striatum was linked to improved performance. Those who were highly loss-averse experienced the most activity when they risked losing money, while the less loss-averse experienced decreased activity in the ventral striatum.

These results may have wide-reaching implications, especially for individuals in high-stress jobs like surgeons and pilots.

Bats create sounds to ‘jam’ sonars

Life is tough for the Mexican free-tailed bat. Not only does it have to contend with parasites and predators, but new research shows that it also experiences sonar jamming from other bats.

This species lives in some of the largest colonies in the animal kingdom, with some caves housing up to a million bats. These massive groups necessitate intricate social systems, involving over a dozen different vocalizations used in communication. One of these signals, it turns out, does a lot more than say hello.

Bats hunt via echolocation, which involves using sound waves to determine the location of their prey. Right as they swoop in on their dinner, they emit a series of high-pitched vocalizations called a feeding buzz. Sometimes the sound waves produced by two bats can jam each other, but usually when this happens, one or both of the bats will switch to a different frequency.

A biologist from Johns Hopkins University has found that these bats can deliberately jam each other by producing a sound that interferes with a feeding buzz. When a recording of this particular sound was played right as bats honed in on the moths they were hunting, it caused them to miss their targets.

So far the Mexican free-tailed bat is the only bat species to exhibit this behaviour, although one species of moth has also been found to jam its predators’ sonar.

Direct brain-to-brain interface in humans

Telepathy may sound like something out of a fantasy novel, but a recent paper published in PLOS ONE indicates that it may not be as far off as we once thought.

A team of scientists from the University of Washington have succeeded in creating a non-invasive interface through which humans can communicate brain-to-brain. The researchers used electroencephalography (EEG) to measure brain activity from one subject, then transmitted that information over the internet to a device that used transcranial magnetic stimulation (TMS) to activate different parts of a second subject’s brain.

The experiment involved six subjects (grouped into three pairs) who had to play a game involving shooting down rockets that were trying to invade a city. The catch was that only one member of the pair (called the sender) could see the screen, and the receiver, located in a different building, had access to the controller.

To shoot down a rocket, the sender imagined moving his or her right hand. This brain activity was picked up by the EEG and sent to the part of the receiver’s brain that controlled motion via TMS, causing the receiver’s hand to jerk up.

The pairs’ success in the game varied wildly, from one pair that shot down 83 per cent of rockets to another whose hit rate was only 25 per cent. Upon analysis, poor performance was linked not to the brain-to-brain interface being unreliable, but rather to the sender not playing the game very well.

The researchers point out the potential to extend these results to sending information from one person’s brain to multiple people, although they emphasize that current technology is still a long ways away from the mind-control rays of science fiction.