"Feeling" music

The chorus of “Gangnam Style” makes us promptly break into a dance!  Adele’s “Someone Like You” brings tears to our eyes.  An electrifying rock concert brings shivers down our spines!

How do we feel music when, in reality, we’re only listening to it?

Music is one of the most blissful experiences we have as humans.  As my childhood music instructor said, “It is the language of the soul.”  Still, the phenomenon of how our brain perceives, appreciates, and enjoys music is poorly understood.  What is essentially just a combination of melodies, beats, rhythms, and tones can have a tremendous effect on the human brain.  When an all-time favorite song plays on the radio, we find ourselves tapping our feet, clicking our fingers, swaying to the beats, and going back to memories related to the song.  Now, let’s put on our neuroscience goggles and look at all of this: our favorite song, which is an auditory stimulus, is capable of activating our motor cortex (tapping feet, swaying body), our somatosensory cortex (clicking fingers) and our hippocampus (memories)!  How incredible is that?

There are two integral parts to music: melody (raag) and beats (meter or taal).  Melody (raag), the main tune of a song, has the ability to activate the brain’s limbic system, which is a group of brain structures responsible for our emotions.  Several studies have shown that while listening to music pieces that trigger happiness or sadness or even fear, the same brain regions are activated as with feeling happy, sad or afraid in response to real situations or words!  This explains why we tend to choose different genres of music depending on our mood.

A team at Johns Hopkins University recently published their study about the perception of the beats component of music.  They addressed a very fascinating question: in feeling the rhythm of a song, do our ears process the beats, or does tactile information (clicking fingers, clapping, tapping feet) contribute to our ability to recognize beats?

In their study, they recruited 12 professional musicians and asked them to discriminate between dual-beat (1-2-1-2, march-like) and triple-beat (1-2-3-1-2-3, waltz-like) rhythms.  These rhythms were given to the participants either via headphones to their left ear (auditory) or by the touch of a small contact tip on their left index finger (tactile).  The participants’ left hands were placed inside an entry hole such that the tactile stimulus was neither visible nor audible but only ‘felt’ by the finger.

When rhythms were given to the ear alone or the finger alone, the participants perceived the beats with equal accuracy of 70-85%.  These dual- and triple-beat rhythms were then given via both auditory and tactile stimulation.  When the beats at the ear and at the finger were simultaneous and synchronous, the participants were able to perceive the beats with an even greater accuracy of about 90%.  Interestingly, when the ear and the finger received incongruent inputs, the auditory perception dominated over the tactile perception.

These experiments showed that the brain sends information of music beats (taal) to the auditory cortex along a common central pathway, with inputs coming from both the sound and touch systems.  But in the situation of conflicting inputs, the brain’s auditory center possibly gives dominance to the inputs from the ears.

Isn’t the science of music perception amazing?  We often take our brain’s boundless abilities for granted when, in reality, even accurately head banging to the beats at a rock concert is a big feat in itself!