Why does the human brain respond more to sounds than language?
It takes just one-tenth of a second for our brains to begin to recognize emotions conveyed by vocalizations, according to researchers from McGill. It doesn't matter whether the non-verbal sounds are growls of anger, the laughter of happiness or cries of sadness. More importantly, the researchers have also discovered that we pay more attention when an emotion (such as happiness, sadness or anger) is expressed through vocalizations than we do when the same emotion is expressed in speech.
The researchers believe that the speed with which the brain 'tags' these vocalizations and the preference given to them compared to language, is due to the potentially crucial role that decoding vocal sounds has played in human survival.
"The identification of emotional vocalizations depends on systems in the brain that are older in evolutionary terms," says Marc Pell, Director of McGill's School of Communication Sciences and Disorders and the lead author on the study that was recently published in Biological Psychology. "Understanding emotions expressed in spoken language, on the other hand, involves more recent brain systems that have evolved as human language developed."
Of nonsense speech and growls
The researchers were interested in finding out whether the brain responded differently when emotions were expressed through vocalizations (sounds such as growls, laughter or sobbing, where no words are used) or through language. They focused on three basic emotions: anger, sadness and happiness and tested 24 participants by playing a random mix of vocalizations and nonsense speech, e.g. The dirms are in the cindabal, spoken with different emotional intent. (The researchers used nonsense phrases in order to avoid any linguistic cues about emotions.) They asked participants to identify which emotions the speakers were trying to convey and used an EEG to record how quickly and in what ways the brain responded as the participants heard the different types of emotional vocal sounds.
Man spewing letters image via Shutterstock.
Read more at EurekAlert.