A recent study that’s published in the journal Social, Cognitive and Affective Neuroscience says that we notice angry or aggressive voices much faster than the voices that are normal or happy. This happens to enable the brain to correctly recognise the location of a potential threat.
Researchers from the University of Geneva (UNIGE) in Switzerland showed how our brain works and uses the disposable sources when it senses danger. Although sight and hearing both allow human beings to detect a threatening situation, it is the sense of hearing that gives us a 360-degree coverage of the surroundings.
To conduct the experiment, 35 participants were exposed to 22 short human voices in neutral utterances, anger and joy.The brain’s responses were recorded using an electroencephalogram (EEG).
"Each participant heard two sounds simultaneously: two neutral voices, one neutral and one angry voice, or one neutral and one happy voice. When they perceived anger or joy, they had to respond by pressing a key on a keyboard as accurately and quickly as possible," said Leonardo Ceravolo, researcher at UNIGE.
The intensity of the brain activity was measured when the attention was focused on the different sounds, as well as the duration of the focus, before it returned to the basic state.
The EEG’s data helped the researchers examine the appearance of a cerebral marker of auditory attention called N2ac. When the brain perceives anger, the N2ac activity is amplified and lasts longer as compared to neutral utterances.
"Anger can signal a potential threat, which is why the brain analyses these kinds of stimuli for a longer time," said Ceravolo.
Thus, the study helped demonstrate for the first time that the human brain is more sensitive to the presence of angry voices.