Classical music pulls at the heartstrings of people in a vegetative state as well as those of healthy listeners. If you play music to vegetative patients, their heart rate changes in the same way as that of healthy controls, suggesting that music can affect the neural systems of emotion even when conscious thought is impossible.
Francesco Riganello at the Santa Anna Institute in Crotone, Italy, and colleagues played four pieces of classical music to 16 healthy volunteers while measuring their heartbeats. The team then repeated the experiment with nine people who were in a vegetative state. In addition, they asked the healthy volunteers to describe the emotions they had felt while listening.
The pieces, each 3 minutes long and by different composers, were chosen because they have different tempos and rhythms 鈥� factors previously shown to elicit positive and negative emotions.
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Riganello found that the music affected the heart rates of both groups in the same way. Pieces rated as 鈥減ositive鈥� by healthy volunteers, such as the minuet from Boccherini鈥檚 string quintet in E, slowed heart rate, while 鈥渘egative鈥� pieces like Tchaikovsky鈥檚 sixth symphony increased heart rate.
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People are medically defined as vegetative when they have no recognisable behavioural responses to external stimuli, says Riganello. 鈥淕enerally it is thought that vegetative patients are isolated from the external world, but maybe this is incorrect.鈥�
Interestingly, heartbeat patterns detected in people listening to Boccherini鈥檚 music indicated that the listeners were becoming relaxed. Riganello suggests that listening to music may have caused 鈥渟ome relaxation鈥� in the vegetative patients.
He believes this reaction originates from the lower regions of the brain, such as the limbic and paralimbic system. These are known to control emotion and autonomic responses and 鈥渕ay remain active after extensive brain damage鈥�.
鈥淚t鈥檚 a nice paper,鈥� says , a rehabilitation neuroscientist at the University of Sydney, Australia, who was not involved in the study. He points out, however, that it doesn鈥檛 show the vegetative people feel emotions as healthy people do. Although their basic, automatic brain functions are working, 鈥渢hat鈥檚 very different鈥� from the higher cognitive processes required to be conscious and feel emotions, he says.
at the University of Western Australia in Crawley agrees, but finds it very interesting that 鈥渕usic has this way of affecting neural systems that process emotion even in the absence of conscious thought鈥�.
Journal reference: , DOI: 10.1016/j.clinph.2010.05.010
