When music plays, our bodies often respond instinctively—tapping feet, nodding heads, or swaying to the beat. Now, a study published in PLOS Biology reveals an even subtler form of synchronization: our eyes blink in time with musical rhythms, entirely without conscious effort.

Led by Dr.DU Yi from the Institute of Psychology, Chinese Academy of Sciences, and Dr. TENG Xiangbin from the Chinese University of Hong Kong, the research demonstrates that this involuntary behavior reflects a profound connection between auditory processing and oculomotor activity, driven by the brain’s internal timing mechanisms.

The study, involving four experiments with 123 young non-musicians, found that when participants listened to rhythmically stable Bach chorales, their spontaneous blinks consistently aligned with musical beats. This synchronization persisted even when melodic cues were removed, using tone sequences that retained only the temporal structure of the music. Electroencephalogram (EEG) recordings further revealed a dynamic correspondence between blink timing and neural activity tracking the beats.

"We discovered that people’s spontaneous eye blinks fall in step with the musical beat—even without being instructed to move—unveiling a hidden link between music processing and the oculomotor system," explained Dr. DU Yi.

The study also revealed that when participants’ attention was diverted by an unrelated visual task, blink synchronization disappeared, indicating that the phenomenon is not a mere reflex but depends on active auditory engagement. Moreover, individuals with stronger blink synchronization performed better at detecting pitch deviations aligned with the beat.

Beyond identifying blink synchronization as a novel form of auditory-motor coupling, the research linked it to structural differences in the brain. Diffusion MRI analysis showed that variations in white matter microstructure within the left posterior superior longitudinal fasciculus—a pathway connecting auditory and frontoparietal regions—were associated with individual differences in synchronization strength.

"What surprised us most was how reliably a small movement like blinking locks to the beat," added Dr. Du. "Because blinks are effortless to measure, this behavior offers a simple, implicit window into how we process rhythm and could potentially serve as a clinical screening tool for rhythm-related difficulties."

This study expands our understanding of how music interacts with unconscious bodily movements and opens new avenues for exploring rhythm processing mechanisms, with potential implications for understanding and addressing neurodevelopmental disorders.

This study was supported by the STI 2030—Major Projects, the National Natural Science Foundation of China, the Research Grants Council of the Hong Kong Special Administrative Region, China.