Spoken Language: A Metronome for Reading?
When we read, our eyes move in a particular pattern as we follow the text. This pattern is surprisingly similar to the rhythm of spoken language, as an international research team, including scientists from the Max Planck Institute for Empirical Aesthetics, has just discovered. Their findings have now been published in the journal Nature Human Behavior.
Reading a text involves letting our eyes wander over it, but not just any which way. In fact, our eyes move according to a distinctive temporal rhythm. Using eye-movement experiments and a meta-study involving 14 different languages, the team of scientists discovered that the temporal structure of reading is almost identical to the dominant rhythm of spoken language. This suggests that we process written and spoken language in ways far more similar than previously thought.
The other institutions participating in the study were Goethe University Frankfurt am Main, the University of Vienna, the Ernst Strüngmann Institute Frankfurt am Main, New York University, and the University of Salzburg.
Spoken languages and writing systems are key elements of human communication. For millennia, writing systems have enabled us to go beyond sharing information face to face; the materiality of writing allows information to be stored and made available over longer periods of time.
“Reading is one of humankind’s most fascinating cultural achievements,” explains first author Benjamin Gagl of the University of Vienna. “Spoken language also influences reading. But until now little has been known about the underlying mechanisms shared by reading and speech."
Under the direction of Christian Fiebach of Goethe University, the research team transferred methods of frequency analysis, which are already widely used in the study of phonetic speech signal, to the study of eye movements. In addition to manifesting similar rhythms of reading and speaking, less experienced readers showed a direct temporal coupling of reading and speech processes. More experienced readers, on the other hand, read faster and were able to extract more information from the text between any two eye movements.
Additionally, the authors conducted a meta-study of all eye-movement studies of reading published in scientific journals from 2006 to 2016. They estimated the temporal rhythm of reading for 14 languages and multiple writing systems used in these studies, and found that the rhythm of reading is slower for character-based writing systems (such as Chinese), which can be explained by the more intensive visual analysis that more complex characters require.
“Our findings show connections between spoken and written language in a novel and previously uncharted way,” Fiebach reports. “The language processing systems of the human brain came to be specialized, in the course of evolution, in temporally processing spoken language. The results of this study lead us to hypothesize that these language systems serve as a kind of ‘metronome’ for the eyes during reading, allowing the eyes to send the read information to the brain in an optimal temporal rhythm, thus facilitating further analysis. This hypothesis can now be investigated in greater depth using the methodological approach presented here.”
Gagl, B., Gregorova, K., Golch, J., Hawelka, S., Sassenhagen, J., Tavano, A., Poeppel, D. & Fiebach, C. J. (2021). Eye movements during text reading align with the rate of speech production. Nature Human Behaviour. Advance online publication. doi:10.1038/s41562-021-01215-4