Working behind the scenes instead of at, or in front of, the camera, these are the creators of the soundtracks which engage and
manipulate our emotions and can dramatically affect how we feel. Take John Williams’ instantly recognizable theme, for example,
which turns a shaky video of a rather peaceful coral reef into a nail-biting introduction to the horror classic, Jaws.
But why does music affect our emotions this drastically? How can a few seconds of a soundtrack send a shiver down our spines,
make our blood run cold, and help us completely forget we are being taken in by an illusion? The answer, of course, must lie in our
brains, and now a team of neuroscientists at the University of Montreal may be able to throw some light on a crucial piece of the
puzzle.
“We know music is very effective at communicating and evoking emotions,” said Dr William Aubé, who worked on the team. “We
wanted to find out why it is so effective from measuring the brain’s responses to music.” Part of the challenge here is that it is
unclear what (if any) function music could play in the brain, making it difficult to know where to start looking for clues. But what if,
the neuroscientists wondered, our brain was in fact sometimes treating music like another, more ‘informative’ sort of sound, the
human voice? “Our brains are predicting machines that help us adapt to the environment,” Aubé continued. “We’re very efficient at
taking information and developing anticipations and expectations to predict what’s going to happen next.”
To test their theory, the team brought in 47 participants and a functional magnetic resonance imaging (fMRI) scanner for an
experimental study. Participants individually lay down inside the scanner and were presented with a randomly ordered series of
sounds and pictures from three different groups. The first group contained specially composed, five-second musical excerpts that
had previously been classified by an audience as ‘fearful, ‘happy’, ‘sad’ or ‘neutral’. The second group was made up of more fivesecond ‘vocalisations’ – wordless sounds made by actors expressing the same four categories (think dramatic screams, chuckles,
sobs etc). The last group contained only pictures of faces displaying expressions in each category. During the whole experiment,
the scanner measured the level of activity occurring in different areas of the brain.
The resulting images of brain activity revealed exactly the sort of pattern the neuroscientists had been looking for: two regions of
the brain showed remarkably similar increases in activity when people were listening either to clips of fearful vocalisations or to
frightening music (as compared to neutral clips), but not when they were looking at fearful facial expressions. Both of these regions
are already known to be involved in processing emotions from other people’s voices, faces and body language. The first region is
called the insula, a large folded section of the brain that plays a role in your level of self-awareness as well as what happens when
you fall in love. The second, the amygdala, consists of two small, almond-shaped groups of neurons involved in everything from
how aggressive you are to how much ‘personal space’ you like to have between you and other people.
According to this study, the fact that the increase in activity in these two areas was correlated for vocalisations and music suggests
that some of our ability to perceive emotions in music – at least, fear – does indeed lie in some of the same circuits that the brain
usually uses to recognise emotions in other people’s voices. Or in Aubé’s words, “it provides some support for the idea that music
could ‘invade’ regions in the brain related to voice processing, which could explain why it is so powerful in communicating emotion.
Music is like a ‘super-expressive’ voice.”
By using only five-second clips that the participants hadn’t heard before, the neuroscientists deliberately measured only the brain’s
immediate responses to unfamiliar music and vocalizations. Listening to music for a longer time, says Aubé, particularly if it is
familiar, engages all sorts of other pathways in the brain, including those associated with memories - making some music
emotionally significant for some people and relatively meaningless to others.
Additionally, the fact that brains only showed a correlated response to vocalizations and music expressing fear, even though
people reported recognizing both happiness and sadness in other excerpts, could suggest that fear is fundamentally more
recognizable in music, compared to other emotions. It could also imply that there are other circuits involved in processing different
emotions that the neuroscientists did not observe in this experiment.
Although this study didn’t itself test what specifically made a piece of music ‘frightening’ or ‘happy’, musicologists studying the
properties of emotional music have come up with a number of characteristics that can affect how certain pieces sound to us. For
example, music that spends a lot of time in ‘extreme registers’ – that is, contains mostly very high or very low notes – can cause
stress, as does music that is fast and sounds agitated. Various types of ‘dissonance’, or notes that don’t sound pleasant together,
can also be unsettling. Meanwhile, slow music in a minor key is often associated with sadness, and fast, high-pitched music in a
major key is more likely to be identified as ‘happy’. Exactly how music ‘expresses’ these emotions, and to what degree we are
culturally influenced in our responses to different types of music, though, remain a bit of a mystery