Publications

Abstract

We used a multi-method approach to investigate how children avoid (or retreat from) argument structure overgeneralisation errors (e.g., *You giggled me). Experiment 1 investigated how semantic and statistical constraints (preemption and entrenchment) influence children’s and adults’ judgments of the grammatical acceptability of 120 verbs in transitive and intransitive sentences. Experiment 2 used syntactic priming to elicit overgeneralisation errors from children (aged 5–6) to investigate whether the same constraints operate in production. For judgments, the data showed effects of preemption, entrenchment, and semantics for all ages. For production, only an effect of preemption was observed, and only for transitivisation errors with intransitive-only verbs (e.g., *The man laughed the girl). We conclude that preemption, entrenchment, and semantic effects are real, but are obscured by particular features of the present production task.

Abstract

Eye gaze is a ubiquitous cue in child-caregiver interactions and infants are highly attentive to eye gaze from very early on. However, the question of why infants show gaze-sensitive behavior, and what role this sensitivity to gaze plays in their language development, is not yet well-understood. To gain a better understanding of the role of eye gaze in infants’ language learning, we conducted a broad systematic review of the developmental literature for all studies that investigate the role of eye gaze in infants’ language development. Across 77 peer-reviewed articles containing data from typically-developing human infants (0-24 months) in the domain of language development we identified two broad themes. The first tracked the effect of eye gaze on four developmental domains: (1) vocabulary development, (2) word-object mapping, (3) object processing, and (4) speech processing. Overall, there is considerable evidence that infants learn more about objects and are more likely to form word-object mappings in the presence of eye gaze cues, both of which are necessary for learning words. In addition, there is good evidence for longitudinal relationships between infants’ gaze following abilities and later receptive and expressive vocabulary. However, many domains (e.g. speech processing) are understudied; further work is needed to decide whether gaze effects are specific to tasks such as word-object mapping, or whether they reflect a general learning enhancement mechanism. The second theme explored the reasons why eye gaze might be facilitative for learning, addressing the question of whether eye gaze is treated by infants as a specialized socio-cognitive cue. We concluded that the balance of evidence supports the idea that eye gaze facilitates infants’ learning by enhancing their arousal, memory and attentional capacities to a greater extent than other low-level attentional cues. However, as yet, there are too few studies that directly compare the effect of eye gaze cues and non-social, attentional cues for strong conclusions to be drawn. We also suggest there might be a developmental effect, with eye gaze, over the course of the first two years of life, developing into a truly ostensive cue that enhances language learning across the board.

Abstract

In the previous decade, dozens of studies involving thousands of children across several research disciplines have made use of a combined daylong audio-recorder and automated algorithmic analysis called the LENAⓇ system, which aims to assess children’s language environment. While the system’s prevalence in the language acquisition domain is steadily growing, there are only scattered validation efforts on only some of its key characteristics. Here, we assess the LENAⓇ system’s accuracy across all of its key measures: speaker classification, Child Vocalization Counts (CVC), Conversational Turn Counts (CTC), and Adult Word Counts (AWC). Our assessment is based on manual annotation of clips that have been randomly or periodically sampled out of daylong recordings, collected from (a) populations similar to the system’s original training data (North American English-learning children aged 3-36 months), (b) children learning another dialect of English (UK), and (c) slightly older children growing up in a different linguistic and socio-cultural setting (Tsimane’ learners in rural Bolivia). We find reasonably high accuracy in some measures (AWC, CVC), with more problematic levels of performance in others (CTC, precision of male adults and other children). Statistical analyses do not support the view that performance is worse for children who are dissimilar from the LENAⓇ original training set. Whether LENAⓇ results are accurate enough for a given research, educational, or clinical application depends largely on the specifics at hand. We therefore conclude with a set of recommendations to help researchers make this determination for their goals.

Abstract

Understanding the mechanisms that drive variation in children’s language acquisition requires large, population-representative datasets of children’s word learning across development. Parent report measures such as the MacArthur-Bates Communicative Development Inventories (CDI) are commonly used to collect such data, but the traditional paper-based forms make the curation of large datasets logistically challenging. Many CDI datasets are thus gathered using convenience samples, often recruited from communities in proximity to major research institutions. Here, we introduce Web-CDI, a web-based tool which allows researchers to collect CDI data online. Web-CDI contains functionality to collect and manage longitudinal data, share links to test administrations, and download vocabulary scores. To date, over 3,500 valid Web-CDI administrations have been completed. General trends found in past norming studies of the CDI are present in data collected from Web-CDI: scores of children’s productive vocabulary grow with age, female children show a slightly faster rate of vocabulary growth, and participants with higher levels of educational attainment report slightly higher vocabulary production scores than those with lower levels of education attainment. We also report results from an effort to oversample non-white, lower-education participants via online recruitment (N = 241). These data showed similar demographic trends to the full sample but this effort resulted in a high exclusion rate. We conclude by discussing implications and challenges for the collection of large, population-representative datasets.

Abstract

By the end of their first year, infants can interpret many different types of complex dynamic visual events, such as caused-motion, chasing, and goal-directed action. Infants of this age are also in the early stages of vocabulary development, producing their first words at around 12 months. The present work examined whether there are meaningful individual differences in infants’ ability to represent dynamic causal events in visual scenes, and whether these differences influence vocabulary development. As part of the longitudinal Language 0–5 Project, 78 10-month-old infants were tested on their ability to interpret three dynamic motion events, involving (a) caused-motion, (b) chasing behaviour, and (c) goal-directed movement. Planned analyses found that infants showed evidence of understanding the first two event types, but not the third. Looking behaviour in each task was not meaningfully related to vocabulary development, nor were there any correlations between the tasks. The results of additional exploratory analyses and simulations suggested that the infants’ understanding of each event may not be predictive of their vocabulary development, and that looking times in these tasks may not be reliably capturing any meaningful individual differences in their knowledge. This raises questions about how to convert experimental group designs to individual differences measures, and how to interpret infant looking time behaviour.

Abstract

A key omission from many accounts of children’s early word learning is the linguistic knowledge that the child has acquired up to the point when learning occurs. We simulate this knowledge using a computational model that learns phoneme and word sequence knowledge from naturalistic language corpora. We show how this simple model is able to account for effects of word length, word frequency, neighborhood density and phonotactic probability on children’s early word learning. Moreover, we show how effects of neighborhood density and phonotactic probability on word learning are largely influenced by word length, with our model being able to capture all effects. We then use predictions from the model to show how the ease by which a child learns a new word from maternal input is directly influenced by the phonological knowledge that the child has acquired from other words up to the point of encountering the new word. There are major implications of this work: models and theories of early word learning need to incorporate existing sublexical and lexical knowledge in explaining developmental change while well-established indices of word learning are rejected in favor of phonological knowledge of varying grain sizes.

Abstract

The purpose of this project was to investigate the effectiveness of a language-focused professional development programme on the knowledge and behaviour of preschool practitioners (sometimes called early years practitioners) in the UK. In Study 1 we determined whether the training received by practitioners is effective in improving their knowledge of how to support children’s language and communicative development. In Study 2 we tested whether trained practitioners, and practitioners from centres with embedded Language Champions, were able to implement the techniques they had been taught. For this, we video-recorded practitioners interacting, one to one, with 2- and 3–4-year-old children in their centres. We conclude that (1) practitioners retain the knowledge they have been taught, both about how children learn and about how to promote this learning, and that (2), in some respects, this knowledge translates well into practice; practitioners in centres with embedded Language Champions and trained practitioners used language-enriching behaviours when interacting with children more often than did untrained practitioners. We discuss how the translation of some techniques into overt behaviour could be made more effective

Abstract

Language users encounter words in at least two different modalities. Arguably, the most frequent encounters are in spoken or written form. Previous research has shown that – compared to the spoken modality – written language features more difficult words. Thus, frequent reading might have effects on word recognition. In the present study, we investigated 1) whether input modality (spoken, written, or bimodal) has an effect on word recognition accuracy, 2) whether this modality effect interacts with word difficulty, 3) whether the interaction of word difficulty and reading experience impacts word recognition accuracy, and 4) whether this interaction is influenced by input modality. To do so, we re-analysed a dataset that was collected in the context of a vocabulary test development to assess in which modality test words should be presented. Participants had carried out a word recognition task, where non-words and words of varying difficulty were presented in auditory, visual and audio-visual modalities. In addition to this main experiment, participants had completed a receptive vocabulary and an author recognition test to measure their reading experience. Our re-analyses did not reveal evidence for an effect of input modality on word recognition accuracy, nor for interactions with word difficulty or language experience. Word difficulty interacted with reading experience in that frequent readers were more accurate in recognizing difficult words than individuals who read less frequently. Practical implications are discussed.

Abstract

Continuous vector word representations (or
word embeddings) have shown success in cap-turing semantic relations between words, as evidenced by evaluation against behavioral data of adult performance on semantic tasks (Pereira et al., 2016). Adult semantic knowl-edge is the endpoint of a language acquisition process; thus, a relevant question is whether these models can also capture emerging word
representations of young language learners. However, the data for children’s semantic knowledge across development is scarce. In this paper, we propose to bridge this gap by using Age of Acquisition norms to evaluate word embeddings learnt from child-directed input. We present two methods that evaluate word embeddings in terms of (a) the semantic neighbourhood density of learnt words, and (b) con-
vergence to adult word associations. We apply our methods to bag-of-words models, and find that (1) children acquire words with fewer semantic neighbours earlier, and (2) young learners only attend to very local context. These findings provide converging evidence for validity of our methods in understanding the prerequisite features for a distributional model of word learning.

Abstract

A central question in language acquisition is how children master sentence types that they have seldom, if ever, heard. Here we report the findings of a pre-registered, randomised, single-blind intervention study designed to test the prediction that, for one such sentence type, complex questions (e.g., Is the crocodile who’s hot eating?), children could combine schemas learned, on the basis of the input, for complex noun phrases (the [THING] who’s [PROPERTY]) and simple questions (Is [THING] [ACTION]ing?) to yield a complex-question schema (Is [the [THING] who’s [PROPERTY]] ACTIONing?). Children aged 4;2 to 6;8 (M = 5;6, SD = 7.7 months) were trained on simple questions (e.g., Is the bird cleaning?) and either (Experimental group, N = 61) complex noun phrases (e.g., the bird who’s sad) or (Control group, N = 61) matched simple noun phrases (e.g., the sad bird). In general, the two groups did not differ on their ability to produce novel complex questions at test. However, the Experimental group did show (a) some evidence of generalising a particular complex NP schema (the [THING] who’s [PROPERTY] as opposed to the [THING] that’s [PROPERTY]) from training to test, (b) a lower rate of auxiliary-doubling errors (e.g., *Is the crocodile who’s hot is eating?), and (c) a greater ability to produce complex questions on the first test trial. We end by suggesting some different methods – specifically artificial language learning and syntactic priming – that could potentially be used to better test the present account.

Abstract

All accounts of language acquisition agree that, by around age 4, children’s knowledge of grammatical constructions is abstract, rather than tied solely to individual lexical items. The aim of the present research was to investigate, focusing on the passive, whether children’s and adults’ performance is additionally semantically constrained, varying according to the distance between the semantics of the verb and those of the construction. In a forced‐choice pointing study (Experiment 1), both 4‐ to 6‐year olds (N = 60) and adults (N = 60) showed support for the prediction of this semantic construction prototype account of an interaction such that the observed disadvantage for passives as compared to actives (i.e., fewer correct points/longer reaction time) was greater for experiencer‐theme verbs than for agent‐patient and theme‐experiencer verbs (e.g., Bob was seen/hit/frightened by Wendy). Similarly, in a production/priming study (Experiment 2), both 4‐ to 6‐year olds (N = 60) and adults (N = 60) produced fewer passives for experiencer‐theme verbs than for agent‐patient/theme‐experiencer verbs. We conclude that these findings are difficult to explain under accounts based on the notion of A(rgument) movement or of a monostratal, semantics‐free, level of syntax, and instead necessitate some form of semantic construction prototype account.

Abstract

The ability to make inferences is essential for effective language comprehension. While inferencing training benefits reading comprehension in school-aged children (see Elleman, 2017, for a review), we do not yet know whether it is beneficial to support the development of these skills prior to school entry. In a pre-registered randomised controlled trial, we evaluated the efficacy of a parent-delivered intervention intended to promote four-year-olds’ oral inferencing skills during shared book-reading. One hundred children from socioeconomically diverse backgrounds were randomly assigned to inferencing training or an active control condition of daily maths activities. The training was found to have no effect on inferencing. However, inferencing measures were highly correlated with children's baseline language ability. This suggests that a more effective approach to scaffolding inferencing in the preschool years might be to focus on promoting vocabulary to develop richer and stronger semantic networks.

Abstract

Visual reaction times to target pictures after naming events are an informative measurement in language acquisition research, because gaze shifts measured in looking-while-listening paradigms are an indicator of infants’ lexical speed of processing. This measure is very useful, as it can be applied from a young age onwards and has been linked to later language development. However, to obtain valid reaction times, the infant is required to switch the fixation of their eyes from a distractor to a target object. This means that usually at least half the trials have to be discarded—those where the participant is already fixating the target at the onset of the target word—so that no reaction time can be measured. With few trials, reliability suffers, which is especially problematic when studying individual differences. In order to solve this problem, we developed a gaze-triggered looking-while-listening paradigm. The trials do not differ from the original paradigm apart from the fact that the target object is chosen depending on the infant’s eye fixation before naming. The object the infant is looking at becomes the distractor and the other object is used as the target, requiring a fixation switch, and thus providing a reaction time. We tested our paradigm with forty-three 18-month-old infants, comparing the results to those from the original paradigm. The Gaze-triggered paradigm yielded more valid reaction time trials, as anticipated. The results of a ranked correlation between the conditions confirmed that the manipulated paradigm measures the same concept as the original paradigm.

Abstract

Error-based theories of language acquisition suggest that children, like adults, continuously make and evaluate predictions in order to reach an adult-like state of language use. However, while these theories have become extremely influential, their central claim - that unpredictable
input leads to higher rates of lasting change in linguistic representations – has scarcely been
tested. We designed a prime surprisal-based intervention study to assess this claim.
As predicted, both 5- to 6-year-old children (n=72) and adults (n=72) showed a pre- to post-test shift towards producing the dative syntactic structure they were exposed to in surprising sentences. The effect was significant in both age groups together, and in the child group separately when participants with ceiling performance in the pre-test were excluded. Secondary
predictions were not upheld: we found no verb-based learning effects and there was only reliable evidence for immediate prime surprisal effects in the adult, but not in the child group. To our knowledge this is the first published study demonstrating enhanced learning rates for the same syntactic structure when it appeared in surprising as opposed to predictable contexts, thus
providing crucial support for error-based theories of language acquisition.

Abstract

To acquire language, infants must learn how to identify words and linguistic structure in speech. Statistical learning has been suggested to assist both of these tasks. However, infants’ capacity to use statistics to discover words and structure together remains unclear. Further, it is not yet known how infants’ statistical learning ability relates to their language development. We trained 17-month-old infants on an artificial language comprising non-adjacent dependencies, and examined their looking times on tasks assessing sensitivity to words and structure using an eye-tracked head-turn-preference paradigm. We measured infants’ vocabulary size using a Communicative Development Inventory (CDI) concurrently and at 19, 21, 24, 25, 27, and 30 months to relate performance to language development. Infants could segment the words from speech, demonstrated by a significant difference in looking times to words versus part-words. Infants’ segmentation performance was significantly related to their vocabulary size (receptive and expressive) both currently, and over time (receptive until 24 months, expressive until 30 months), but was not related to the rate of vocabulary growth. The data also suggest infants may have developed sensitivity to generalised structure, indicating similar statistical learning mechanisms may contribute to the discovery of words and structure in speech, but this was not related to vocabulary size.

Abstract

Much of Lieven’s pioneering work has helped move the study of individual differences to the centre of child language research. The goal of the present chapter is to illustrate how the study of individual differences provides crucial insights into the language acquisition process. In part one, we summarise some of the evidence showing how pervasive individual differences are across the whole of the language system; from gestures to morphosyntax. In part two, we describe three causal factors implicated in explaining individual differences, which, we argue, must be built into any theory of language acquisition (intrinsic differences in the neurocognitive learning mechanisms, the child’s communicative environment, and developmental cascades in which each new linguistic skill that the child has to acquire depends critically on the prior acquisition of foundational abilities). In part three, we present an example study on the role of the speed of linguistic processing on vocabulary development, which illustrates our approach to individual differences. The results show evidence of a changing relationship between lexical processing speed and vocabulary over developmental time, perhaps as a result of the changing nature of the structure of the lexicon. The study thus highlights the benefits of an individual differences approach in building, testing, and constraining theories of language acquisition.

Abstract

The fact that many sub-populations do not take part in research, especially participants fromlower socioeconomic (SES) backgrounds, is a serious problem in education research. Toincrease the participation of such groups we must discover what social, economic andpractical factors prevent participation, and how to overcome these barriers. In the currentpaper, we review the literature on this topic, before describing a case study that demonstratesfour potential solutions to four barriers to participation in a shared reading intervention forfamilies from lower SES backgrounds. We discuss the implications of our findings forfamily-based interventions more generally, and the difficulty of balancing strategies toencourage participation with adhering to the methodological integrity of a research study

Abstract

Background: Shared reading interventions can impact positively on preschool children’s
language development and on their caregiver’s attitudes/behaviours towards
reading. However, a number of barriers may discourage families from engaging with
these interventions, particularly families from lower socio-economic status (SES)
backgrounds. We investigated how families from such backgrounds responded to an
intervention designed explicitly to overcome these barriers.
Methods: In a preregistered cluster randomised controlled trial, 85 lower SES families
and their 3-year-old to 4-year-old children from 10 different preschools were randomly
allocated to take part in The Reader’s Shared Reading programme
(intervention) or an existing ‘Story Time’ group at a library (control) once a week
for 8 weeks. Three outcome measures were assessed at baseline and post intervention:
(1) attendance, (2) enjoyment of the reading groups and (3) caregivers’ knowledge of,
attitudes and behaviours towards reading. A fourth children’s vocabulary – was
assessed at baseline and 4 weeks post intervention.
Results: Families were significantly more likely to attend the intervention group and
rated it more favourably, compared with the control group. However, there were no
significant effects on caregivers’ knowledge, attitudes and behaviours or on children’s
language.
Conclusion: The intervention was only successful in engaging families from disadvantaged
backgrounds in shared reading. Implications for the use, duration and intensity
of shared reading interventions are discussed.

Abstract

This study aimed to examine the influence of the complexity of the story-book on caregiver extra-textual talk (i.e., interactions beyond text reading) during shared reading with preschool-age children. Fifty-three mother–child dyads (3;00–4;11) were video-recorded sharing two ostensibly similar picture-books: a simple story (containing no false belief) and a complex story (containing a false belief central to the plot, which provided content that was more challenging for preschoolers to understand). Book-reading interactions were transcribed and coded. Results showed that the complex stories facilitated more extra-textual talk from mothers, and a higher quality of extra-textual talk (as indexed by linguistic richness and level of abstraction). Although the type of story did not affect the number of questions mothers posed, more elaborative follow-ups on children's responses were provided by mothers when sharing complex stories. Complex stories may facilitate more and linguistically richer caregiver extra-textual talk, having implications for preschoolers’ developing language abilities.

Abstract

Purpose: Research has indicated that interactive shared
book reading can support a wide range of early language
skills and that children who are read to regularly in the early
years learn language faster, enter school with a larger
vocabulary, and become more successful readers at school.
Despite the large volume of research suggesting interactive
shared reading is beneficial for language development, two
fundamental issues remain outstanding: whether shared
book reading interventions are equally effective (a) for children
from all socioeconomic backgrounds and (b) for a range of
language skills.
Method: To address these issues, we conducted a
randomized controlled trial to investigate the effects of two
6-week interactive shared reading interventions on a
range of language skills in children across the socioeconomic
spectrum. One hundred and fifty children aged between
2;6 and 3;0 (years;months) were randomly assigned to one

of three conditions: a pause reading, a dialogic reading, or
an active shared reading control condition.
Results: The findings indicated that the interventions were
effective at changing caregiver reading behaviors. However,
the interventions did not boost children’s language skills
over and above the effect of an active reading control
condition. There were also no effects of socioeconomic status.
Conclusion: This randomized controlled trial showed
that caregivers from all socioeconomic backgrounds
successfully adopted an interactive shared reading style.
However, while the interventions were effective at increasing
caregivers’ use of interactive shared book reading behaviors,
this did not have a significant impact on the children’s
language skills. The findings are discussed in terms of
practical implications and future research.

Abstract

In recent years the field has seen an increasing realisation that the full complexity of language acquisition demands theories that (a) explain how children integrate information from multiple sources in the environment, (b) build linguistic representations at a number of different levels, and (c) learn how to combine these representations in order to communicate effectively. These new findings have stimulated new theoretical perspectives that are more centered on explaining learning as a complex dynamic interaction between the child and her environment. This book is the first attempt to bring some of these new perspectives together in one place. It is a collection of essays written by a group of researchers who all take an approach centered on child-environment interaction, and all of whom have been influenced by the work of Elena Lieven, to whom this collection is dedicated.

Abstract

This paper introduces a new CLARIN Knowledge Center which is the K-Centre for Atypical Communication Expertise (ACE for short) which has been established at the Centre for Language and Speech Technology (CLST) at Radboud University. Atypical communication is an umbrella term used here to denote language use by second language learners, people with language disorders or those suffering from language disabilities, but also more broadly by bilinguals and users of sign languages. It involves multiple modalities (text, speech, sign, gesture) and encompasses different developmental stages. ACE closely collaborates with The Language Archive (TLA) at the Max Planck Institute for Psycholinguistics in order to safeguard GDPR-compliant data storage and access. We explain the mission of ACE and show its potential on a number of showcases and a use case.

Abstract

Shared book reading is thought to have a positive impact on young children's language development, with shared reading interventions often run in an attempt to boost children's language skills. However, despite the volume of research in this area, a number of issues remain outstanding. The current meta-analysis explored whether shared reading interventions are equally effective (a) across a range of study designs; (b) across a range of different outcome variables; and (c) for children from different SES groups. It also explored the potentially moderating effects of intervention duration, child age, use of dialogic reading techniques, person delivering the intervention and mode of intervention delivery.

Our results show that, while there is an effect of shared reading on language development, this effect is smaller than reported in previous meta-analyses (
 = 0.194, p = .002). They also show that this effect is moderated by the type of control group used and is negligible in studies with active control groups (  = 0.028, p = .703). Finally, they show no significant effects of differences in outcome variable (ps ≥ .286), socio-economic status (p = .658), or any of our other potential moderators (ps ≥ .077), and non-significant effects for studies with follow-ups (  = 0.139, p = .200). On the basis of these results, we make a number of recommendations for researchers and educators about the design and implementation of future shared reading interventions.

Abstract

A long‐standing question in child language research concerns how children achieve mature syntactic knowledge in the face of a complex linguistic environment. A widely accepted view is that this process involves extracting distributional regularities from the environment in a manner that is incidental and happens, for the most part, without the learner's awareness. In this way, the debate speaks to two associated but separate literatures in language acquisition: statistical learning and implicit learning. Both fields have explored this issue in some depth but, at present, neither the results from the infant studies used by the statistical learning literature nor the artificial grammar learning tasks studies from the implicit learning literature can be used to fully explain how children's syntax becomes adult‐like. In this work, we consider an alternative explanation—that children use error‐based learning to become mature syntax users. We discuss this proposal in the light of the behavioral findings from structural priming studies and the computational findings from Chang, Dell, and Bock's (2006) dual‐path model, which incorporates properties from both statistical and implicit learning, and offers an explanation for syntax learning and structural priming using a common error‐based learning mechanism. We then turn our attention to future directions for the field, here suggesting how structural priming might inform the statistical learning and implicit learning literature on the nature of the learning mechanism.

Abstract

It is becoming increasingly clear that the way that children acquire cognitive representations
depends critically on how their processing system is developing. In particular, recent studies
suggest that individual differences in language processing speed play an important role in explaining
the speed with which children acquire language. Inconsistencies across studies, however,
mean that it is not clear whether this relationship is causal or correlational, whether it is
present right across development, or whether it extends beyond word learning to affect other
aspects of language learning, like syntax acquisition. To address these issues, the current study
used the looking-while-listening paradigm devised by Fernald, Swingley, and Pinto (2001) to test
the speed with which a large longitudinal cohort of children (the Language 0–5 Project) processed
language at 19, 25, and 31 months of age, and took multiple measures of vocabulary (UKCDI,
Lincoln CDI, CDI-III) and syntax (Lincoln CDI) between 8 and 37 months of age. Processing
speed correlated with vocabulary size - though this relationship changed over time, and was
observed only when there was variation in how well the items used in the looking-while-listening
task were known. Fast processing speed was a positive predictor of subsequent vocabulary
growth, but only for children with smaller vocabularies. Faster processing speed did, however,
predict faster syntactic growth across the whole sample, even when controlling for concurrent
vocabulary. The results indicate a relatively direct relationship between processing speed and
syntactic development, but point to a more complex interaction between processing speed, vocabulary
size and subsequent vocabulary growth.

Abstract

It is unknown whether modality affects the efficiency with which humans learn novel word forms and their meanings, with previous studies reporting both written and auditory advantages. The current study implements controls whose absence in previous work likely offers explanation for such contradictory findings. In two novel word learning experiments, participants were trained and tested on pseudoword - novel object pairs, with controls on: modality of test, modality of meaning, duration of exposure and transparency of word form. In both experiments word forms were presented in either their written or spoken form, each paired with a pictorial meaning (novel object). Following a 20-minute filler task, participants were tested on their ability to identify the picture-word form pairs on which they were trained. A between subjects design generated four participant groups per experiment 1) written training, written test; 2) written training, spoken test; 3) spoken training, written test; 4) spoken training, spoken test. In Experiment 1 the written stimulus was presented for a time period equal to the duration of the spoken form. Results showed that when the duration of exposure was equal, participants displayed a written training benefit. Given words can be read faster than the time taken for the spoken form to unfold, in Experiment 2 the written form was presented for 300 ms, sufficient time to read the word yet 65% shorter than the duration of the spoken form. No modality effect was observed under these conditions, when exposure to the word form was equivalent. These results demonstrate, at least for proficient readers, that when exposure to the word form is controlled across modalities the efficiency with which word form-meaning associations are learnt does not differ. Our results therefore suggest that, although we typically begin as aural-only word learners, we ultimately converge on developing learning mechanisms that learn equally efficiently from both written and spoken materials.