Music makes people move and groove, often in surprisingly involuntary ways. As it turns out, we even blink in time to the beat, researchers report in PLOS Biology. "Our eyes — which we usually think of as purely visual organs — spontaneously dance to the rhythm of what we hear," says study co-author Du Yi, a cognitive neuroscientist at the Chinese Academy of Sciences in Beijing. Additional research showed certain songs cause a tendency toward either "bop" or "sway" movements.
Using a high-speed eye-tracking system, Du and her team were "stunned" to discover nonmusicians instinctively blinking in sync with the beat structure of Bach chorales (though not on every single beat, she notes, which would be "quite exhausting"). Du suspects the effect would persist for any music with a "strong groove," not just Bach.
Synchronized blinking faded when the researchers sped up the Bach chorales to 120 beats per minute. It also disappeared when the study's participants were asked to detect a red dot on a screen, implying that active listening is required. "It isn't that the music 'loses its magic' when we're distracted but rather that the brain reallocates its rhythmic resources to whatever we are focusing on most," Du says.
Blinking to the beat came as no surprise to Elizabeth Margulis, director of Princeton University's Music Cognition Lab and author of an upcoming book on "musical daydreams." After all, she notes, music activates the motor areas of the brain. Even if we're just sitting still — and not bopping our heads, tapping our feet or dancing — "there can often be this sense of motion," Margulis says. People tend to synchronize their steps to the beat at the gym and drive faster when listening to pulsing, absorbing songs, she notes. Those with Parkinson's disease, meanwhile, are known to walk more steadily when music is playing.
Even voluntary music response seems to have an instinctual aspect. Shimpei Ikegami, a music psychologist at Showa Women's University in Tokyo, asked four Japanese pop musicians to compose short musical excerpts, some designed to elicit vertical up-and-down bopping movements known as tate-nori and others designed to elicit horizontal side-to-side swaying movements called yoko-nori. Sure enough, when undergraduate nonmusicians listened to songs with a strong beat and abrupt changes in sound, they spontaneously felt like bopping. And songs characterized by a smooth timbre and mild sound changes made them want to sway.
To Ikegami, who presented his findings at a recent conference, this suggests that the music instructs us on how to move — and that runners and Parkinson's patients, for example, might get better results with vertical music, whereas horizontal music lends itself to stretching and yoga. In general, he says, our playlists could be "much more targeted" to take advantage of powerful innate reactions to pumping up the volume.