Neuropsychology

Scare me, maestro!

Without the music, the shark attacks in Jaws and the shower scene in Psycho would be quite banal. John Williams’ nervy chords and Bernard Herrmann’s strident violins are what make the hair stand up on the back of your neck. “Everyone knows that music conveys emotion, and film-makers have understood that for a very long time. But the link between the brain and musical emotion is very difficult to measure scientifically,” explains neuropsychologist Nathalie Gosselin, who recently completed her doctoral thesis at the Université de Montréal on this very topic.

Gosselin set up an experiment involving 32 research subjects, half of whom had had a median excision of the temporal lobe of the brain, enabling her to identify an area, the amygdala, that plays a role in musical emotion, especially when the emotion is fear. “People who lack this structure but have a normal appreciation of joyful music suddenly become unable to recognize scary music,” Gosselin explains.

Gosselin’s experiment was designed to find out how this “emotional illiteracy” could be expressed. Working with Bernard Bouchard, a composer and research agent at the joint UdeM-McGill Brain, Music and Sound Lab (BRAMS), she selected a pool of 150 tunes played on the piano – happy, sad, peaceful, or frightening. Designed as movie soundtracks based on tested parameters (a quick tempo for happy tunes, minor chords for sad tunes, etc.), the melodies, lasting from six to 10 seconds, were evaluated by the subjects on a scale from 0 (no emotion) to 9 (high emotion). “Our findings clearly show that musical emotions linked to fear are attached to the amygdala, because people who have had the medial temporal lobe excised are deprived of that emotion, even if they are able to recognize other tunes without any problem,” says the researcher.

Could humans’ ability to recognize the frightening nature of music be based on biology?  Gosselin believes the answer is yes. Fear stimuli are some of the most significant stimuli in our repertoire of sounds because they’re a signal for dangerous events, Gosselin explained in an article that appeared in the February 2005 issue of Brain (co-authored by Isabelle Peretz, Marion Noulhiane, Dominique Hasboun, Christine Beckett, Michel Baulac, and Séverine Samson). Compared to less “urgent” feelings like joy, fear – which elicits an immediate reaction from the individual – appears to be more specialized in the brain. Music, an extremely complex form of language, has been used for thousands of years to alert primitive peoples to danger or to repel bad spirits. But from Paleolithic times to 2006, learning has always begun very early in life. Babies in arms can recognize disapproval in their mother’s voice. Whether acquired or innate, the ability to perceive danger in music – and associated structures like the amygdala – have important biological functions, the authors pointed out in the Brain article. The musical sound of the human voice could be a pre-language medium for communicating emotions between baby and mother.