Facial gestures may well be common across human cultures. As the researchers reported on August 19 in Science Advances, people can accurately decipher facial expressions depicted in ancient sculptures. In the first part of the research, the participants looked at pictures of sculptures created by ancient Mexican and Central American civilisations. The photos were cropped to display only the faces, so that the participants could not rely on contextual cues to infer emotional expressions.
According to a recent study from the Centers for Disease Control and Prevention, more than three in ten teenagers vape daily. The study is part of the CDC’s Youth Risk Activity Monitoring System, an annual survey that tracks adolescent health behaviors.
In the 1970s, anthropologist Paul Ekman suggested that people should feel six basic emotions: rage, fear, surprise, disgust, joy, and sadness. Since then, scientists have debated the exact number of human emotions—some scholars maintain that there are only four, while others list as many as 27. And scientists are also discussing whether they are common to all human cultures and whether we are born with them or learn from them through experience. Even the concept of emotion is a matter of debate. Three brain structures are most closely related to emotions: the amygdala, the insular or insular cortex, and the periaqueductal gray structure in the mid-brain.
A paired, almond-shaped structure deep inside the brain, the amygdala integrates emotion, emotional actions and motivation. It interprets fear, helps to differentiate between friends and foes, and describes social rewards and how to obtain them. Amygdala is also essential for the style of learning that is called classical conditioning. Russian physiologist Ivan Pavlov first identified classical conditioning, which through repeated exposure, induces a specific response in his dog digestion studies. The dogs were salivated when the lab technician gave them food. Over time, Pavlov noted the dogs also began to salivate at the mere sight of the technician, even if he was empty-handed.
Though emotions are subjective and difficult to describe—even for scientists—they serve important functions, allowing us to understand, initiate action, and live.