- Examining the neuroscience of lying
APRIL FOOL’S Day is the one day of the year when people are allowed to lie without feeling any guilt. What actually happens to the brain when people lie? In a new field of the neuroscience on lying, scientists have been trying to figure out how different parts of the brain and the body react to lying. Believe it or not, many parts of the human body become active even with trivial lies.
Lying: psychology or science?
Though previously thought only as a field of psychology, telling lies actually involves a great amount of activity in the brain as well as chemical and physical reactions in the human body. One of the most popular tests proving such is the mock theft paradigm conducted by Kebbell and Daniels in 2006. In the experiment, each volunteer was told to take one of the two given items and hide it in a locker. He or she was then instructed to deny having either of the items during the ‘questioning’ period of the experiment. Meanwhile, the participants had electrodes placed on their scalps that helped the scientists observe brain activity through electrical signals. Consequently, whenever the participants lied, different parts of the brain such as the prefrontal cortex* and amygdala** became active. The experiment was far from perfect, however. Since the test only measured superficial brain activities and the activity of large brain regions, it failed to identify the exact brain areas involved when telling a lie. Still, it was a great opportunity to discover the fact that lying involves an aspect of science as well as psychology.
How the brain reacts
With the development of science, researchers started to use the functional Magnetic Resonance Imaging (fMRI). It is a functional neuroimaging procedure using MRI technology that measures brain activity by detecting changes associated with blood flow, in order to study the neuroscience of lying. The resulting images of fMRI allow researchers to point out specific regions of the brain that are particularly active during the process of lying.
In his interview with Kyunghyang Newspaper, Kim Sung-Ju (Prof., College of Medicine, SungKyunKwan Univ.) stated that the prefrontal cortex gets actived when a person lies. The cortex is situated just behind the forehead and works as an executive control of the brain that distinguishes between what is right and what is wrong. Hence, the prefrontal cortex is the central control system that guides people to act rationally in certain situations. When people first lie, the prefrontal cortex becomes active, and they feel guilty in response. But as they continue to lie, the cortex gradually becomes less active, making people feel less guilty about lying. Hence, lying gets easier and more addictive each time.
In October 2016, a research team by Charlotte Tally (Prof., Dept. of Psychology, London Univ.) conducted an experiment to measure the reaction of the brain during the process of lying. Under the so-called lie-reward game, 80 participants from ages 18 to 65 were each shown a bottle with coins inside and were asked to call out to their partners the number of coins in the bottle. When both participants shouted out the same number, they were both rewarded with the total amount of money they called out. As the experiment repeated itself several times, the participants started to lie about the number of coins in order to get more money in the end. Moreover, the participants started to call out a greater amount of money each time, up to a maximum of eight British pounds. Meanwhile, the fMRI images showed that the prefrontal cortex became less active each time the participants lied.
How our physical body reacts
In the fairy tale Pinocchio, the nose of a wooden doll named Pinocchio grows longer whenever Pinocchio lies. This story is no longer mere fiction. When people lie, they experience the “Pinocchio Effect,” in which a person’s nose becomes swollen in response to telling lies. According to a study by the Department of Experimental Psychology in the University of Granada in December 2012, the amount of catecholamine, a chemical substance in the brain, increases in the orbital muscle at the inner corner of the eye when a person lies. Also, people face small anxiety attacks as they lie, and their facial temperature rises. In response to the extension of muscle around the nose, a person’s nose gets a little swollen. Although it is a very trivial change, the study still shows that the human body reacts to lying, just like Pinocchio’s nose.
Furthermore, since the lie detector was first invented in 20th century, scientists have observed numerous changes in the human body. A lie detector is a machine that detects lies by measuring several changes of involuntary responses such as blood pressure, breathing rate, pulse and perspiration. These irregularities are measured through six sensors attached to or wrapped around the body in the form of electrical wires. There is a polygraph attached to the lie detector that shows a stable horizontal line. When a person lies, the line fluctuates. Through several experiments using the lie detector, scientists have observed that people who lie tend to roll their eyes to the right and have their mouths dry as they felt anxious. In addition, there were some internal changes detected, such as fluctuations in blood pressures and electro-dermal activity.
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Lying is not simply a field of ethics and psychology. It is deeply related to neuroscience, and scientists continue to carry out experiments to figure out the exact relationship between the human body and the process of lying. Pinocchio does not seem fictional anymore.
*Prefrontal cortex: the gray matter of the anterior part of the frontal lobe that is highly developed in humans and plays a role in the regulation of complex cognitive, emotional, and behavioral functioning.
**Amygdala: a roughly almond-shaped mass of gray matter inside each cerebral hemisphere, involved with the experiencing of emotions.
Lee Sun-joo firstname.lastname@example.org
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