Impact of Language Experience on Attention to Faces in Infancy: Evidence From Unimodal and Bimodal Bilingual Infants

Abstract

Faces capture and maintain infants’ attention more than other visual stimuli. The present study addresses the impact of early language experience on attention to faces in infancy. It was hypothesized that infants learning two spoken languages (unimodal bilinguals) and hearing infants of Deaf mothers learning British Sign Language and spoken English (bimodal bilinguals) would show enhanced attention to faces compared to monolinguals. The comparison between unimodal and bimodal bilinguals allowed differentiation of the effects of learning two languages, from the effects of increased visual communication in hearing infants of Deaf mothers. Data are presented for two independent samples of infants: Sample 1 included 49 infants between 7 and 10 months (26 monolinguals and 23 unimodal bilinguals), and Sample 2 included 87 infants between 4 and 8 months (32 monolinguals, 25 unimodal bilinguals, and 30 bimodal bilingual infants with a Deaf mother). Eye-tracking was used to analyze infants’ visual scanning of complex arrays including a face and four other stimulus categories. Infants from 4 to 10 months (all groups combined) directed their attention to faces faster than to non-face stimuli (i.e., attention capture), directed more fixations to, and looked longer at faces than non-face stimuli (i.e., attention maintenance). Unimodal bilinguals demonstrated increased attention capture and attention maintenance by faces compared to monolinguals. Contrary to predictions, bimodal bilinguals did not differ from monolinguals in attention capture and maintenance by face stimuli. These results are discussed in relation to the language experience of each group and the close association between face processing and language development in social communication.

Language Experience Impacts Brain Activation for Spoken and Signed Language in Infancy: Insights From Unimodal and Bimodal Bilinguals

“…When this group of 60 infants was considered as a whole, we found activation in response to audiovisual infantdirected spoken language in a wide bilateral network, which included the posterior temporal and the inferior frontal areas. This pattern of activation is similar to the network involved in spoken language processing in adults (Price, 2010) and also to that previously reported in infants (Altvater-Mackensen & Grossmann, 2016;Dehaene-Lambertz et al, 2002, 2010May et al, 2018;Minagawa-Kawai et al, 2010;Pena et al, 2003;Perani et al, 2011;Sato et al, 2012;Shultz et al, 2014;Vannasing et al, 2016). Sign language elicited activation in a few channels located in the right temporoparietal area.…”

“…Areas of the frontal and temporal cortex are crucial to language processing in adulthood. These regions are already activated in response to spoken language in the first few days or weeks of life (Altvater-Mackensen & Grossmann, 2016;Dehaene-Lambertz, Dehaene, & Hertz-Pannier, 2002;Dehaene-Lambertz et al, 2006, 2010May, Gervain, Carreiras, & Werker, 2018;Minagawa-Kawai et al, 2010;Pena et al, 2003;Perani et al, 2011;Sato et al, 2012;Shultz, Vouloumanos, Bennett, & Pelphrey, 2014;Vannasing et al, 2016). As in adults, brain responses to speech in infants are often found to be greater in amplitude in the left than in the right hemisphere (Altvater-Mackensen & Grossmann, 2016;Dehaene-Lambertz et al, 2002, 2010Minagawa-Kawai et al, 2010;Pena et al, 2003;Shultz et al, 2014;Vannasing et al, 2016), but this left lateralization is not always observed in infants (Dehaene-Lambertz et al, 2006;May, Byers-Heinlein, Gervain, & Werker, 2011;May et al, 2018;Perani et al, 2011).…”

“…Despite this early neural specialization for language, there is also a clear role of experience in shaping the neural substrate of language. In newborns and in older infants, brain activation for the familiar language has been shown to be larger in amplitude (Fava, Hull, & Bortfeld, 2014;May et al, 2011;Minagawa-Kawai et al, 2010;Sato et al, 2012) and more left lateralized (Sato et al, 2012;Vannasing et al, 2016) than for an unfamiliar language. Moreover, in the left temporal and temporoparietal cortex of newborns, forward speech elicits more activation than backward speech for a familiar language, whereas this difference is not observed for an unfamiliar language (May et al, 2018;Sato et al, 2012; but see also May et al, 2011).…”

“…To address this we use functional near-infrared spectroscopy (fNIRS). A technique that has been used successfully to study brain representation for language in infants (Altvater-Mackensen & Grossmann, 2016;Fava et al, 2014;May et al, 2011May et al, , 2018Minagawa-Kawai et al, 2010;Pena et al, 2003;Sato et al, 2012;Vannasing et al, 2016), fNIRS measures hemodynamic responses elicited by neuronal activation. This technique offers a balance of spatial and temporal resolution, is relatively robust to movement artifacts, and requires less infant tolerance than does fMRI or MEG (Lloyd-Fox, Blasi, & Elwell, 2010).…”

The Use of Eye Tracking as a Biomarker of Treatment Outcome in a Pilot Randomized Clinical Trial for Young Children with Autism

“…This criterion was chosen in order to minimize loss of data while also providing sufficient looking data necessary to reflect a clear fixation and systematic scanning, especially in the case of static images which do not hold attention as well as dynamic stimuli. This criterion is similar to other studies utilizing similar types of static stimuli [Elsabbagh et al, ; Mercure et al, ; Oakes & Ellis, ]. Of note, modifying this valid looking criterion to 200 ms and 1000 ms did not impact the results of the study as they are described below.…”