NEEDLE & GLOBE

Via Telegraph:

Fear of spiders, sharks, snakes, heights and other phobias could be cured by a simple injection which prevents people from learning to be afraid, claim scientists.

A team of researchers have found that the brain may be able to be ‘re-programmed’ to overcome some of our most basic fears. Scientists claim that because fear is a learned habit, they could be able to switch off the part of the brain that generates those emotions with a simple jab. Early tests showed that goldfish given a dose of the drug lidocaine were unable to be scared.

Researchers in Japan say the findings, published in BioMed Central’s open access journal, Behavioural and Brain Functions, would be a relief for people who suffer chronic phobias that affect their everyday lives.

Prof Masayuki Yoshida, of the University of Hiroshima, said the results of his research were exciting. “One day, our irrational phobias could become a thing of the past,” he said. “Imagine if your fear of spiders, heights or flying could be cured with a simple injection – our research suggests that one day this could be a reality.”

Prof Yoshida studied the cerebellum, which was thought to be involved with the development of fears, in goldfish and humans. Using classical conditioning, Prof Masayuki Yoshida taught goldfish to become afraid of a light flashed in their eyes. Prof Yoshida said: “By administering a low voltage electric shock every time a light was shone, the fish were taught to associate the light with being shocked, which slowed their hearts the typical fish reaction to a fright.

“As you would expect, the goldfish we used in our study soon became afraid of the flash of light because, whether or not we actually gave them a shock, they had quickly learned to expect one. “Fear was demonstrated by their heart beats decreasing, in a similar way to how our heart rate increases when someone gives us a fright.” The researchers then injected the goldfish with a common local anaesthetic called lidocaine and repeated the tests again.

Prof Yoshida said that when the fish were given a dose of the drug they did not show the same fear when a light was shone in their eyes. “We discovered that fish that had first been injected in the cerebellum with lidocaine had stable heart rates and showed no fear when the light was shone they were unable to learn to become afraid,” he said. Prof Yoshida said that because the brains of goldfish were similar to those of mammals, including humans, it was hoped that with further study it may soon be possible to understand more about the biological and chemical processes that cause us to become afraid.

For the goldfish, the effect of lidocaine was only temporary fearless fish return to being frightened fish as soon as the anaesthetic has worn off. Nevertheless, one day, our irrational phobias could become a thing of the past, he said. Prof Yoshida said humans can also be “trained” to become afraid, and in fact, simple classical conditioning rooted in our childhood and early development can explain many of our behaviours.

Via PhysOrg:

MIT neuroscientists have shown they can influence people’s moral judgments by disrupting a specific brain region — a finding that helps reveal how the brain constructs morality.

To make moral judgments about other people, we often need to infer their intentions — an ability known as “theory of mind.” For example, if a hunter shoots his friend while on a hunting trip, we need to know what the hunter was thinking: Was he secretly jealous, or did he mistake his friend for a duck?

Previous studies have shown that a brain region known as the right temporo-parietal junction (TPJ) is highly active when we think about other people’s intentions, thoughts and beliefs. In the new study, the researchers disrupted activity in the right TPJ by inducing a current in the brain using a magnetic field applied to the scalp. They found that the subjects’ ability to make moral judgments that require an understanding of other people’s intentions — for example, a failed murder attempt — was impaired.

The researchers, led by Rebecca Saxe, MIT assistant professor of brain and cognitive sciences, report their findings in the Proceedings of the National Academy of Sciences the week of March 29.

The study offers “striking evidence” that the right TPJ, located at the brain’s surface above and behind the right ear, is critical for making moral judgments, says Liane Young, lead author of the paper. It’s also startling, since under normal circumstances people are very confident and consistent in these kinds of moral judgments, says Young, a postdoctoral associate in MIT’s Department of Brain and Cognitive Sciences.

“You think of morality as being a really high-level behavior,” she says. “To be able to apply (a magnetic field) to a specific brain region and change people’s moral judgments is really astonishing.”

The researchers used a non-invasive technique known as transcranial magnetic stimulation (TMS) to selectively interfere with brain activity in the right TPJ. A magnetic field applied to a small area of the skull creates weak electric currents that impede nearby brain cells’ ability to fire normally, but the effect is only temporary.

In one experiment, volunteers were exposed to TMS for 25 minutes before taking a test in which they read a series of scenarios and made moral judgments of characters’ actions on a scale of 1 (absolutely forbidden) to 7 (absolutely permissible).

In a second experiment, TMS was applied in 500-milisecond bursts at the moment when the subject was asked to make a moral judgment. For example, subjects were asked to judge how permissible it is for someone to let his girlfriend walk across a bridge he knows to be unsafe, even if she ends up making it across safely. In such cases, a judgment based solely on the outcome would hold the perpetrator morally blameless, even though it appears he intended to do harm.

In both experiments, the researchers found that when the right TPJ was disrupted, subjects were more likely to judge failed attempts to harm as morally permissible. Therefore, the researchers believe that TMS interfered with subjects’ ability to interpret others’ intentions, forcing them to rely more on outcome information to make their judgments.

Young is now doing a study on the role of the right TPJ in judgments of people who are morally lucky or unlucky. For example, a drunk driver who hits and kills a pedestrian is unlucky, compared to an equally drunk driver who makes it home safely, but the unlucky homicidal driver tends to be judged more morally blameworthy.

More information: “Disruption of the right temporo-parietal junction with transcranial magnetic stimulation reduces the role of beliefs in moral judgments,” Liane Young, Joan Albert Camprodon, Marc Hauser, Alvaro Pascual-Leone, Rebecca Saxe. Proceedings of the National Academy of Sciences, week of March 29, 2010.

Provided by Massachusetts Institute of Technology.