Cascading and Multisensory Influences on Speech Perception Development

Abstract

Over the first weeks and months following birth, infants' initial, broad‐based perceptual sensitivities become honed to the characteristics of their native language. In this article, we review this process of emerging specialization within the context of a cascading “critical period” (CP) framework, in which periods of maximal openness to experience of different aspects of language occur at sequential, overlapping points in development. Importantly, as infants' experience of speech is not limited to auditory signals, but is informed by—for example—their experience of talking faces and their own oral motor movements, we review the trajectory of perceptual specialization in multisensory language processing. Throughout, we highlight the impact of increasing perceptual specialization on later language outcomes (e.g., word learning, foundations of syntax, literacy), and consider how the outcomes can be compromised if/when the timing of perceptual specialization has been perturbed.

Bridging ears and eyes when learning spoken words: On the effects of bilingual experience at 30 months

“…But there is the case of sequential bilinguals who are learning one language first and then another one later. The distinction between the two language experiences is of importance as there are maturational epochs in early childhood during which the developing brain is optimally more open to visual experiential influences (Birdsong, 2018; Choi, Black, & Werker, 2018). This is illustrated by adult studies who found that early childhood exposure is crucial for using relevant visual speech information to separate languages visually (Weikum et al., 2013) and boost non‐native phonetic discrimination (Burfin et al., 2014).…”

Korean Mothers Attune the Frequency and Acoustic Saliency of Sound Symbolic Words to the Linguistic Maturity of Their Children

“…Moreover, there is evidence showing that mothers’ touches are aligned with their speech in a systematic way, suggesting that tactile cues could assist infant word segmentation and word learning (Abu-Zhaya and Seidl, 2017). As such, infants seem to use multimodal cues in language learning in various perceptual domains such as visual-auditory and tactile-auditory, thus benefiting from sound symbolism which in most cases inherently encodes cross-modal information (see Choi et al, 2018 for a recent review on the effect of early multisensory signals on infants’ language ability). A future study directly testing the benefits of the acoustic saliency encoded in expressive lengthening for infants’ word learning would strengthen our understanding of word learning mechanisms in children.…”

The Case for Measuring and Reporting Bilingualism in Developmental Research

“…Historically, even in studies focusing on bilingualism, age of acquisition has been reported with relatively little precision, (e.g., terms such as "early bilinguals"). However, the precise timing of acquisition of each language can impact development, for example, the difference between learning a language from birth versus later in school (Choi, Black, & Werker, 2018;Sebastián-Gallés, Echeverría, & Bosch, 2005). Empirical and theoretical work points to the need to be as precise as possible when reporting acquisition onset, and whether it was interrupted at some point (e.g., exposure or use of a language stopped due to relocation).…”