Brains that Scream

We communicate our feelings through multiple channels, verbal and non-verbal. According to researchers from the University of Zurich, we are also neurologically sensitive to the affective (emotional) information carried through different types of screams. 

The University of Zurich researchers argue that previous studies have focused primarily on screams communicating fearful emotions. However, humans can scream to communicate a variety of powerful emotions. According to experiments led by Prof. Dr. Sascha Frühholz and colleagues, human screams can indicate six distinct emotions: anger, sadness, joy, pain, fear, and pleasure. 

Frühholz and colleagues did a total of four experiments to investigate the neural processes underlying the different scream calls. First of all, the researchers asked 12 participants to vocalize six different types of screams conveying fear, pain, sadness, joy, anger, and pleasure. A neutral scream was also used in the study to act as a control variable. As the seventh scream, the participants produced an “intense vocalization of the vowel /a/.” 

While vocalizing the different types of scream calls, the participants were told to imagine themselves in scenarios where they were attacked by an armed stranger in a dark alley (e.g., fearful scream) or that their favorite team won the World Cup (e.g., joyful scream). The researchers report in their study that “although these screams were largely acted rather than spontaneously expressed, acted screams seem to be perceptually similar to natural screams.”

After the scream calls were recorded, the researchers asked 23 participants to rate the alarming quality of each scream – from not alarming at all to highly alarming. Then, Frühholz and colleagues asked another set of 26 participants to rate the emotional valence of the scream calls. Lastly, a total of 84 screams were selected from three female and three males speakers. 

While the participants rated the emotional valence of the scream calls, their brain activity was recorded using fMRI (Functional Magnetic Resonance Imaging) to monitor how they perceived and categorized the scream calls. Frühholz explains that “the frontal, auditory and limbic brain regions showed much more activity and neural connectivity when hearing non-alarm screams than when processing alarm scream calls.” 

These findings suggest that we are more sensitive to screams conveying joy and pleasure (i.e., non-alarming screams) than screams signaling danger. We hope that future studies will shed light on some of the reasons why this difference in neural processing exists in humans.