Can’t tap to a tune? You might be ‘beat deaf’

"We found that these beat-deaf individuals were able to perceive different rhythms and tap a regular beat in the absence of sound," says Caroline Palmer. "Only when they had to move with the beat did we see a deficit." (Credit: tribehunter/Flickr)

Scientists have figured out why some people just can’t move to the beat.

Beat-deafness, though very rare, is a problem not simply of how people feel a pulse or move their bodies, but instead how people synchronize with sounds they hear.

“We examined beat tracking, the ability to find a regular pulse and move with it, in individuals who complained of difficulty following a beat in everyday activities like listening to music and dancing,” says Caroline Palmer, a psychology professor at McGill University.

Because beat deafness is so rare, the researchers compared two beat deaf individuals with 32 control participants of comparable age and educational level. Listeners were asked to tap evenly in the absence of any sound. The researchers found that all participants performed this task well, ruling out a general motor deficit.

“We found that these beat-deaf individuals were able to perceive different rhythms and tap a regular beat in the absence of sound, similarly to control group members,” says Palmer. “Only when they had to move with the beat did we see a deficit, compared with the control group.”

Can’t synch up

“Most people had no problem, but the beat-deaf individuals were quite variable in their tapping—sometimes missing the beat by a large amount,” says Palmer. “The most difficult test was to tap along with a metronome that suddenly became faster or slower.

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“The non-beat-deaf were able to adapt to the changes within a few beats, but interestingly the beat-deaf individuals were not able to synchronize with the new beat. The types of mistakes that beat-deaf individuals made indicated deficits in biological rhythms, including the natural frequencies or rates at which the internal oscillations pulsed, and how long it took them to respond to the new metronome tempo.”

Biological rhythms are behaviors that are periodic or cyclic, and can be slow like circadian day/night cycles or fast like heart rates. Common activities like walking, clapping, making music, and even speaking are all examples of rhythms.

Some rhythmic behaviors are driven by external cues, like a musical tempo that makes a jogger run faster, or a fast walker who slows down to match their partner’s pace.

“While most people can adapt their rhythms in response to an external cue, some people are less able to do that,” says Palmer. “We tested what makes beat-deaf individuals different by seeing how people whose biological rhythms may not respond normally to external cues adapt to an external beat.”

The Natural Sciences and Engineering Research Council of Canada (NSERC), Canada Research Chairs program, and Belgian FRS-FRNS supported the research, which will be published this week in the journal Philosophical Transactions: Biological Sciences. Researchers from the University of Montreal collaborated on the study.

Source: McGill University