WASHINGTON — The human brain can predict the future, at least when it comes to music. Researchers with the Association for Psychological Science report that when a “musical phrase” has an unresolved or uncertain quality, our minds instinctually and automatically predict how the tune will end. Simply put, your brain fills in the blanks missing from a song.
Prior research on neural patterns while hearing music reveals that the brain perceives musical phrases largely by looking back, not forward. This latest study, however, takes things a step further. Yes, the mind looks back when we hear a song, but only to help it anticipate what is coming next from the melody.
“The brain is constantly one step ahead and matches expectations to what is about to happen,” says co-lead study author Niels Chr. Hansen, a fellow at the Aarhus Institute of Advanced Studies, in a media release. “This finding challenges previous assumptions that musical phrases feel finished only after the next phrase has begun.”
Much of this research revolves around “musical phrases,” which refers to any sequence or pattern of sounds that constitute a distinct musical “thought” within a melody. Just like a sentence within a paragraph, a musical phrase is a small aspect of a greater “musical whole.”
Many musical phrases, though, end with some uncertainty regarding what is coming next within the melody. These findings indicate that in those moments of musical uncertainty our minds predict what will happen next.
“We only know a little about how the brain determines when things start and end,” Hansen explains. “Here, music provides a perfect domain to measure something that is otherwise difficult to measure—namely, uncertainty.”
Name that (future) tune
Researchers instructed 38 volunteers to listen, note by note, to chorale melodies by Bach. Participants were free to stop, start, and rewind the tunes throughout the experiment. Everyone was told they’d be tested on the music afterward. This way, researchers were able to use the amount of time each participant dwelled on each tone as an indirect indication of their understanding of musical phrasing.
Next, a group of 31 other volunteers listened to the very same musical phrases and assessed in their opinion how complete they sounded. Melodies that ended on an uncertain tone were judged to be more complete by subjects, who tended to linger on such melodies for longer periods of time.
“We were able to show that people have a tendency to experience high-entropy tones as musical-phrase endings. This is basic research that makes us more aware of how the human brain acquires new knowledge not just from music, but also when it comes to language, movements, or other things that take place over time,” says study co-leader Haley Kragness, a postdoctoral researcher at the University of Toronto-Scarborough.
Study authors hope their work can help improve communications between people and perhaps help us better understand how artists are able to tease or trick their audiences.
“This study shows that humans harness the statistical properties of the world around them not only to predict what is likely to happen next, but also to parse streams of complex, continuous input into smaller, more manageable segments of information,” Hansen concludes.
The findings appear in the journal Psychological Science.