Changing the mood with music can change the brain’s response to our heartbeats, study suggests

Music has played a central role in human cultures for thousands of years. For most of us, music is emotional. It moves us.

It’s known that stimulating music and low-energy music have different effects on the brain, but how does music affect the connection between our head (ie. the brain) and the heart, the popular seat of emotion? And how does that impact on emotions? To try and find out, researchers from Goldsmiths, University of London have been exploring how the brain responds to our heartbeat while listening to music.

Dr Caroline Di Bernardi Luft and Professor Joydeep Bhattacharya (Department of Psychology) induced different moods in healthy adults by playing music. A high arousal mood was induced with stimulating music - Bizet’s Carmen Overture and Mozart’s Sonata for two pianos in D major K - and a low-arousal mood was induced by playing Barber’s Adagio for Strings and Albinoni, Adagio in G minor.

The researchers monitored the electrical responses of the brain to each heartbeat while playing high-arousal music for five minutes and again with five minutes of the low-arousal music, while also measuring the interval between volunteers' heartbeats.

They were especially interested in studying the communication between the brain and the heart, as indexed by the heartbeat evoked potential (HEP): the way the brain processes the heartbeat. 

Despite the absence of heart rate differences between the two induced mood conditions of low or high arousal, the researchers found a robust difference in how the brain processes the heartbeats between these two moods.

When listening to higher-arousal music, participants had a higher HEP. Importantly, it was also found that specific brain rhythms - alpha oscillations - predicted the brain responses to heartbeats.

Participants with higher alpha power showed a higher increase in the HEP in response to the high-arousal music, compared to the low arousal music. Essentially, the higher the alpha power, the more the HEP changed when different moods were induced.

The researchers say that the study suggests different types of music can change how the brain is tuned to the heart and that individual differences in alpha oscillations may mediate this effect. 

So why is it important?

Dr Luft explains: “There are certain pathological conditions such as depression where people have a lower ‘heartbeat evoked potential’. The way our brain processes the heartbeat is also sensitive to a range of psychological factors, including motivation, attention and pain.

“Generally, the HEP increases by training cardiac awareness: we could argue that how well the brain responds to the heart is a marker of how ‘in-tune’ you are to your body. But if we can manipulate the HEP – in this case by playing different mood-inducing music – could this be used therapeutically?

“Demonstrating the way the brain processes heartbeats is important in understanding emotion and mood, in this case, implicit emotions in the brain not ‘feelings’ or behaviour. Our study provides a mechanism for explaining individual differences: the way our brains are linked to our hearts are different, so we can say that the way we process emotions seems to be too.”

More than 2500 years ago, Confucius remarked that "music produces a kind of pleasure which human nature cannot do without". The current study shows how music indeed brings together two of our most vital organs. 

'Aroused with heart: Modulation of heartbeat evoked potential by arousal induction and its oscillatory correlates' by Caroline Di Bernardi Luft and Joydeep Bhattacharya was published in Scientific Reports on Tuesday 27 October 2015.