A new study suggests that screams of joy are easier to understand by our brains than screams of fear. The results add an astonishing new layer to scientists ’long-held idea that our brains are connected to quickly recognize and respond to fearful cries as a survival mechanism (SN: 16/07/15).
The study looked at different types of screams and how listeners perceive them. For example, the team asked participants to imagine that “you are being attacked by a stranger armed in a dark alley” and to scream in fear and “your favorite team wins the World Cup” and shout for joy. Each of the 12 participants produced seven different types of screams: six emotional screams (pain, anger, fear, pleasure, sadness, and joy) and a neutral scream where the volunteer just shouted loudly the vowel & # 39; a & # 39 ;.
Separate sets of study participants were then tasked with classifying and distinguishing between the different types of screams. In one task, 33 volunteers were asked to hear screams and were given three seconds to classify them into one of seven different screams. In another task, 35 different volunteers were presented with two screams, one at a time, and asked to categorize the screams as quickly as possible as they tried to make an accurate decision about what type of scream it was, or alarming screams of pain. , anger or fear or non-alarming cries of pleasure, sadness, or joy. Participants took longer to complete the task when they involved fear and other alarming cries, and those cries were not as easily recognizable as non-alarming cries like joy, researchers reported online on April 13 in PLOS Biology.
In another experiment, 30 different volunteers underwent a functional MRI, or MRI, while listening to the screams. The team found that less alarming screams caused more activity in the auditory and frontal brain regions than more alarming screams, although it is not yet clear why we responded that way.
The study shows that communication between screams and the ways we understand vocalization is diverse in humans, compared to other mammals whose screams are often associated with alarming situations such as danger, says Sascha Frühholz, a psychologist at the University of Zurich. His team’s work challenges the dominant view in neuroscience that the human brain is primarily tuned to detect negative threats, he said.
Although the results are limited to experiments and do not reflect how humans would respond to real-world cries, the rigor of the study methods provides high confidence in the results, says Adeen Flinker, a neuroscientist at New York University School of Medicine. Drug not involved in the study.
The difference that appeared between alarming and non-alarming cries provides a “deeper understanding of this important vocalization,” says NYU psychologist David Poeppel, who also did not participate in the study. The range of experiments, from acoustic analysis to magnetic resonance imaging, also offers “a good step in developing a more methodical and mechanistic understanding of how we process screams,” he says.