Infants Have an Innate Perception of Musical Patterns
Post by Leanna Kalinowski
The takeaway
Infants can perceive recurring patterns in music (called “meter”), regardless of whether the patterns are marked by obvious tones, in a similar manner to adults.
What's the science?
Across different cultures, music has several universal features that often cause humans to bob their heads or tap their feet in time with it. Within a given song, there is a small set of recurring patterns and accents, called “meter”, that allows humans to synchronize their perception of music and move along to it together. Sometimes, meter is made obvious by including tones that indicate its pulse, but other times, meter is much more implicit and marked by periods of silence. While we know that the adult brain can perceive both obvious and more implicit meter, less is known about how early this perceptual ability develops in infants. Recently in Developmental Science, Lenc and colleagues recorded brain activity in infants that were exposed to rhythms that are known to induce the perception of meter in adults.
How did they do it?
The researchers recruited 20 infants between five and six months old to participate in this study, during which they were exposed to two rhythms: a “strongly-periodic” rhythm and a “weakly-periodic” rhythm. The two rhythms typically produce the same perceived meter in adults, but the tones in the strongly-periodic rhythm matched the pulse of the typically perceived meter, while the tones in the weakly-periodic rhythm did not. The infants were played each rhythm twice -- once with a high-pitched tone, and once with a low-pitched tone – for a total of four sound clips. Brain activity while listening to each sound clip was measured using electroencephalography (EEG).
What did they find?
The researchers found that listening to both rhythms induced brain activity in infants that matched the frequency of the meter in a similar pattern to what is seen in adults. This brain activity was present not only for the rhythm with beats that matched the meter (i.e., strongly periodic) but also for the rhythm that did not have beats that matched the meter (i.e., weakly periodic). They also found that meter-related brain activity of both rhythm types was enhanced when the rhythm was produced by bass sounds (i.e., low-pitched tones) as compared to high-pitched tones. Together, these results suggest that high-level neural processes that facilitate music perception are already present soon after birth.
What's the impact?
Results from this study show that infants are able to perceive musical patterns shortly after birth – even when these patterns are not marked by obvious tones – well before infants even develop the motor ability to bob along to the music. These findings may help pave the way for developing age-appropriate interventions for developmental disorders that rely on auditory stimulation and rhythm perception.