When I first heard about this study, I was in the middle of writing up my MA thesis on the effects of video for learning new speech sounds. I was washing the dishes and listening to the Science Friday podcast—I’m a huge podcast listener. I heard an interview with one of the authors, David Lewkowicz, and I had to immediately drop what I was doing and start taking notes. Thankfully, the plate survived!
The study, “Bilingualism modulates infants’ selective attention to the mouth of a talking face”, seems to have gotten a fair bit of attention in popular media. It’s one of those rare studies that is straightforward in its approach, unambiguous in its findings, and relevant to a whole bunch of fields. And it’s succinct! 8 pages, including graphs and references. This is the kind of thing I want to publish one day.
Ferran, Bosch and Lewkowicz used eye tracking to measure where infants were looking, and for how long, while watching videos of people speaking their language as well as a foreign language. They found that monolingual children go through two shifts in attention: first, they predominantly watch the eyes at 4 months, then the mouth at 8 months, and back to the eyes at 12 months. Bilingual children, on the other hand, watch the eyes and mouth equally at 4 months, and watch the mouth predominantly at 8 and 12 months.
The finding for monolingual children duplicates a previous finding from another of Lewkowicz’s studies. American infants go through the same shifts: eyes at 4 months, mouth at 8, then back to the eyes at 12. It seems to me that the timing of this shift is no accident. Patricia Kuhl and others have found that infants solidify their speech sound system between 6 and 12 months of age, learning to attend to the sounds of the languages around them more rapidly and ignoring distinctions not found in those languages. It makes sense, then, that infants would be engaged in watching the mouth more closely at this age.
Bilingual children show a different pattern, though, and that’s really a fascinating discovery. Even before the ‘golden age’ for sound distinctions, bilingual kids are engaged and paying attention to speech in different ways, and they continue to attend to the mouth even after that window shuts for most infants. Are they listening more carefully? Making more connections between the mouth gestures and the acoustic signal? I can’t say for sure, but it seems like they’re doing something along those lines.
What does all this mean for adult language learners? It indicates that watching the mouth may be helpful for learning. Navarra and Soto-Faraco found that visual information does help learners perceive L2 sounds. My own MA thesis was aimed at determining whether video helps students learn new sounds, but unfortunately the results weren’t as promising as I had hoped. I think learners need to have some level of explicit knowledge of the sounds before video training can really be helpful; they need to know that /r/ is usually accompanied by lip rounding, for example. That’s the topic of my next big research project: giving Japanese students explicit instruction, and then seeing if video is helpful.
For my next post, I’ll dig into Navarra and Soto-Faraco’s study on visual cues and second language speech perception. Thanks for reading!
 Pons, Ferran; Bosch, Laura; Lewkowicz, David J. (2015). Bilingualism modulates infants’ selective attention to the mouth of a talking face. Psychological Science, April 2015; vol. 26, 4: 490-498
 Lewkowicz, D.J., & Hansen-Tift, A.M. (2012). Infants deploy selective attention to the mouth of a talking face when learning speech. Proceedings of the National Academy of Sciences, USA, 109, 1431-1436.
 Navarra, J., & Soto-Faraco, S. (2007). Hearing lips in a second language: Visual articulatory information enables the perception of second language sounds. Psychological Research, 71, 4-12.