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We assess the feasibility of conducting web-based eye-tracking experiments with children using two methods of webcam-based eye-tracking: automatic gaze estimation with the WebGazer.js algorithm and hand annotation of gaze direction from recorded webcam videos. Experiment 1 directly compares the two methods in a visual-world language task with five to six year-old children. Experiment 2 more precisely investigates WebGazer.js' spatiotemporal resolution with four to twelve year-old children in a visual-fixation task. We find that it is possible to conduct web-based eye-tracking experiments with children in both supervised (Experiment 1) and unsupervised (Experiment 2) settings - however, the webcam eye-tracking methods differ in their sensitivity and accuracy. Webcam video annotation is well-suited to detecting fine-grained looking effects relevant to child language researchers. In contrast, WebGazer.js gaze estimates appear noisier and less temporally precise. We discuss the advantages and disadvantages of each method and provide recommendations for researchers conducting child eye-tracking studies online.

Clearly, structural priming is a valuable tool for probing linguistic representation. But we don't think that the existing results provide strong support for Branigan & Pickering's (B&P's) model, largely because the priming effects are more confusing and diverse than their theory would suggest. Fortunately, there are a number of other experimental tools available, and linguists are increasingly making use of them.

Famously, dog bites man is trivia whereas man bites dog is news. This illustrates not just a fact about the world but about language: to know who did what to whom, we must correctly identify the mapping between semantic role and syntactic position. These mappings are typically predictable, and previous work demonstrates that young children are sensitive to these patterns and so could use them in acquisition. However, there is only limited and mixed evidence that children do use this information to guide acquisition outside of the laboratory. We find that children understand emotion verbs which follow the canonical CAUSE-VERB-PATIENT pattern (Mary frightened/delighted John) earlier than those which do not (Mary feared/liked John), despite the latter's higher frequency, suggesting children's generalization of the mapping between causativity and transitivity is broad and active in acquisition.

In many contexts, pronouns are interpreted as referring to the character mentioned first in the previous sentence, an effect called the 'first-mention bias'. While adults can rapidly use the first-mention bias to guide pronoun interpretation, it is unclear when this bias emerges during development. Curiously, experiments with children between two and three years old show successful use of order of mention, while experiments with older children (four to five years old) do not. While this could suggest U-shaped development, it could also reflect differences in the methodologies employed. We show that children can indeed use first-mention information, but do so too slowly to have been detected in previous work reporting null results. Comparison across the present and previously published studies suggests that the speed at which children deploy first-mention information increases greatly during the preschool years.

Recent work in adult psycholinguistics has demonstrated that activation of semantic representations begins long before phonological processing is complete. This incremental propagation of information across multiple levels of analysis is a hallmark of adult language processing but how does this ability develop? In two experiments, we elicit measures of incremental activation of semantic representations during word recognition in children. Five-year-olds were instructed to select a target (logs) while their eye-movements were measured to a competitor (key) that was semantically related to an absent phonological associate (lock). We found that, like adults, children made increased looks to competitors relative to unrelated control items. However, unlike adults, children continued to look at the competitor even after the target word was uniquely identified and were more likely to incorrectly select this item. Altogether, these results suggest that early lexical processing involves cascading activation but less efficient resolution of competing entries.