A recent study published in PLOS Biology, a peer-reviewed journal, evaluated the potential association between involuntary eye blinking and listening to music.
Let’s start with some background on this.
It all begins with a neurological process called auditory-motor synchronization.
Considered a universal human behavior, this form of unconscious synchronization refers to the "coordination of body movements with auditory rhythms.”
- Examples of these include clapping, dancing, or tapping your fingers or feet to a musical beat.
And the ophthalmic tie-in?
These so-called “synchronized” behaviors may also extend to more subtle, involuntary (spontaneous) eye movements.
Case in point: Previous research has investigated various potential correlations between pupil dynamics and saccadic eye movements with rhythmic structures and auditory rhythmic synchronizations, respectively.
- However: The relationship between eye blinking (an oculomotor activity) and musical rhythms has not undergone any clinical exploration—which brings us to this new study.
Real quick: Why focus on blinking?
As researchers noted: “The spontaneous blink rate has long been recognized as a vital indicator of cognitive and neural functions.”
For instance: Recent investigations have found a reduced blink rate to be indicative of increased attention and cognitive load during a task, and a higher blink rate indicating either mental fatigue or a potential neurological condition.
Got it. Now tell me about this research.
Investigators from the Chinese Academy of Sciences evaluated eye blink synchronization with musical beats via three forms of analysis: behavioral, neurophysiological, and neuroimaging.
- The participants: 123 non-musician individuals (aged 18 to 34; 57% women) with normal hearing (thresholds ≤20 dB SPL from 125 to 8,000 Hz)
- The setup: Individuals participated in four separate hearing experiments (with around 30 in each) listening to various classical musical pieces with even tempos by Johann Sebastian Bach.
- To ensure participants’ blinks weren’t responding to potentially familiar music, the songs were also played backwards
What was measured?
Participants’ spontaneous blinks were tracked via the Eyelink Portable Duo system (by SR Research), with a sampling rate of 500 Hz.
- Electroencephalogram (EEG) responses were also recorded to identify how musical structures were encoded in the brain and their association with blink activity.
And the findings?
In general: Investigators found that participants’ blinks—and brainwaves—synced up with the musical beats during active listening sessions, regardless of whether songs were played backwards.
- Those beats in question: Ranged from 66 to 86 beats per minute.
Was this true for all musical beats?
No … there wasn’t a significant synchronization between the blink rate and musical beat when the tempo was at 120 beats per minute—implying a rate limit similar to that observed in prior evaluation of other forms of auditory-motor synchronization.
The researchers’ input on this: They noted that further research is required to determine the optimal tempo range for robust blink synchronization to musical beats.
Expand on the brain wave synchronization.
Based on EEG results, some participants’ brain waves synced up with both their eye blinks and the musical beat—a form of that aforementioned auditory-motor synchronization.
Based on this: The study authors noted that such synchronization occurs unconsciously as a person hears music with a steady (this is key) tempo.
Were there any exceptions to this?
The only disruption to this synchronization throughout all four experiments occurred when participants were given an unrelated visual task to complete while listening to the music.
- During that time, their eye blinks went off-beat of the musical tempo—suggesting that the visual task itself interfered and diverted the eye blinks’ attention from maintaining synchronization with the beat.
Interesting … and what did the authors have to say about the data?
The findings not only establish a direct link between eye blinks and musical beat perception, but also introduce a novel type of “spontaneous music-synchronizing behavior,” they wrote in the study’s discussion.
Study investigator Yi Du further noted that, because blinks are effortless to measure, “This behavior offers a simple, implicit window into how we process rhythm—and could one day support clinical screening for rhythm-related difficulties."