An official website of the United States government
We investigate the roles of linguistic and sensory experience in the early-produced visual, auditory, and abstract words of congenitally-blind toddlers, deaf toddlers, and typicallysighted/ hearing peers. We also assess the role of language access by comparing early word production in children learning English or American Sign Language (ASL) from birth, versus at a delay. Using parental report data on child word production from the MacArthur-Bates Communicative Development Inventory, we found evidence that while children produced words referring to imperceptible referents before age 2, such words were less likely to be produced relative to words with perceptible referents. For instance, blind (vs. sighted) children said fewer highly visual words like “blue” or “see”; deaf signing (vs. hearing) children produced fewer auditory signs like HEAR. Additionally, in spoken English and ASL, children who received delayed language access were less likely to produce words overall. These results demonstrate and begin to quantify how linguistic and sensory access may influence which words young children produce.
more »
« less
The role of vision in the acquisition of words: Vocabulary development in blind toddlers
What is vision's role in driving early word production? To answer this, we assessed parent-report vocabulary questionnaires administered to congenitally blind children (N = 40, Mean age = 24 months [R: 7–57 months]) and compared the size and contents of their productive vocabulary to those of a large normative sample of sighted children (N = 6574). We found that on average, blind children showed a roughly half-year vocabulary delay relative to sighted children, amid considerable variability. However, the content of blind and sighted children's vocabulary was statistically indistinguishable in word length, part of speech, semantic category, concreteness, interactiveness, and perceptual modality. At a finer-grained level, we also found that words’ perceptual properties intersect with children's perceptual abilities. Our findings suggest that while an absence of visual input may initially make vocabulary development more difficult, the content of the early productive vocabulary is largely resilient to differences in perceptual access. Research Highlights Infants and toddlers born blind (with no other diagnoses) show a 7.5 month productive vocabulary delay on average, with wide variability. Across the studied age range (7–57 months), vocabulary delays widened with age. Blind and sighted children's early vocabularies contain similar distributions of word lengths, parts of speech, semantic categories, and perceptual modalities. Blind children (but not sighted children) were more likely to say visual words which could also be experienced through other senses.
more »
« less
- Award ID(s):
- 2337766
- PAR ID:
- 10502525
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Developmental Science
- ISSN:
- 1363-755X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
We compared everyday language input to young congenitally-blind children with no addi- tional disabilities (N=15, 6–30 mo., M:16 mo.) and demographically-matched sighted peers (N=15, 6–31 mo., M:16 mo.). By studying whether the language input of blind children differs from their sighted peers, we aimed to determine whether, in principle, the language acquisition patterns observed in blind and sighted children could be explained by aspects of the speech they hear. Children wore LENA recorders to capture the auditory language environment in their homes. Speech in these recordings was then analyzed with a mix of automated and manually-transcribed measures across various subsets and dimensions of language input. These included measures of quantity (adult words), interaction (conversational turns and child-directed speech), linguistic properties (lexical diversity and mean length of utterance), and conceptual features (talk centered around the here-and-now; talk focused on visual referents that would be inaccessible to the blind but not sighted children). Overall, we found broad similarity across groups in speech quantitative, interactive, and linguistic properties. The only exception was that blind children’s language environments contained slightly but significantly more talk about past/future/hypothetical events than sighted children’s input; both groups received equiva- lent quantities of “visual” speech input. The findings challenge the notion that blind children’s lan- guage input diverges substantially from sighted children’s; while the input is highly variable across children, it is not systematically so across groups, across nearly all measures. The findings suggest instead that blind children and sighted children alike receive input that readily supports their language development, with open questions remaining regarding how this input may be differentially leveraged by language learners in early childhood.more » « less
-
Socioeconomic status (SES) has been repeatedly linked to the developmental trajectory of vocabulary acquisition in young children. However, the nature of this relationship remains underspecified. In particular, despite an extensive literature documenting young children's reliance on a host of skills and strategies to learn new words, little attention has been paid to whether and how these skills relate to measures of SES and vocabulary acquisition. To evaluate these relationships, we conducted two studies. In Study 1, 205 2.5‐ to 3.5‐year‐old children from widely varying socioeconomic backgrounds were tested on a broad range of word‐learning skills that tap their ability to resolve cases of ambiguous reference and to extend words appropriately. Children's executive functioning and phonological memory skills were also assessed. In Study 2, 77 of those children returned for a follow‐up session several months later, at which time two additional measures of vocabulary were obtained. Using Structural Equation Modeling (SEM) and multivariate regression, we provide evidence of the mediating role of word‐learning skills on the relationship between SES and vocabulary skill over the course of early development.more » « less
-
Intelligent tutoring systems (ITS) provide educational benefits through one-on-one tutoring by assessing children’s existing knowledge and providing tailored educational content. In the domain of language acquisition, several studies have shown that children often learn new words by forming semantic relationships with words they already know. In this paper, we present a model that uses word semantics (semantics-based model) to make inferences about a child’s vocabulary from partial information about their existing vocabulary knowledge. We show that the proposed semantics-based model outperforms models that do not use word semantics (semantics-free models) on average. A subject-level analysis of results reveals that different models perform well for different children, thus motivating the need to combine predictions. To this end, we use two methods to combine predictions from semantics-based and semantics-free models and show that these methods yield better predictions of a child’s vocabulary knowledge. Our results motivate the use of semantics-based models to assess children’s vocabulary knowledge and build ITS that maximizes children’s semantic understanding of words.more » « less
-
Occipital cortices of different sighted people contain analogous maps of visual information (e.g. foveal vs. peripheral). In congenital blindness, “visual” cortices respond to nonvisual stimuli. Do visual cortices of different blind people represent common informational maps? We leverage naturalistic stimuli and inter-subject pattern similarity analysis to address this question. Blindfolded sighted (n = 22) and congenitally blind (n = 22) participants listened to 6 sound clips (5–7 min each): 3 auditory excerpts from movies; a naturalistic spoken narrative; and matched degraded auditory stimuli (Backwards Speech, scrambled sentences), during functional magnetic resonance imaging scanning. We compared the spatial activity patterns evoked by each unique 10-s segment of the different auditory excerpts across blind and sighted people. Segments of meaningful naturalistic stimuli produced distinctive activity patterns in frontotemporal networks that were shared across blind and across sighted individuals. In the blind group only, segment-specific, cross-subject patterns emerged in visual cortex, but only for meaningful naturalistic stimuli and not Backwards Speech. Spatial patterns of activity within visual cortices are sensitive to time-varying information in meaningful naturalistic auditory stimuli in a broadly similar manner across blind individuals.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Journal Article:
- https://doi.org/10.1111/desc.13475
