Infants' lexical comprehension and lexical anticipation abilities are closely linked in early language development.

Theories across cognitive domains propose that anticipating upcoming sensory input supports information processing. In line with this view, prior findings indicate that adults and children anticipate upcoming words during real-time language processing, via such processes as prediction and priming. However, it is unclear if anticipatory processes are strictly an outcome of prior language development or are more entwined with language learning and development. We operationalized this theoretical question as whether developmental emergence of comprehension of lexical items occurs before or concurrently with the anticipation of these lexical items. To this end, we tested infants of ages 12, 15, 18, and 24 months (N = 67) on their abilities to comprehend and anticipate familiar nouns. In an eye-tracking task, infants viewed pairs of images and heard sentences with either informative words (e.g., eat) that allowed them to anticipate an upcoming noun (e.g., cookie), or uninformative words (e.g., see). Findings indicated that infants' comprehension and anticipation abilities are closely linked over developmental time and within individuals. Importantly, we do not find evidence for lexical comprehension in the absence of lexical anticipation. Thus, anticipatory processes are present early in infants' second year, suggesting they are a part of language development rather than solely an outcome of it.

Look at that: Spatial deixis reveals experience-related differences in prediction.

Prediction-based theories posit that interlocutors use prediction to process language efficiently and to coordinate dialogue. The present study evaluated whether listeners can use spatial deixis (i.e., this, that, these, and those) to predict the plurality and proximity of a speaker's upcoming referent. In two eye-tracking experiments with varying referential complexity (N = 168), native English-speaking adults, native English-learning 5-year-olds, and non-native English-learning adults viewed images while listening to sentences with or without informative deictic determiners, e.g., Look at the/this/that/these/those wonderful cookie(s). Results showed that all groups successfully exploited plurality information. However, they varied in using deixis to anticipate the proximity of the referent; specifically, L1 adults showed more robust prediction than L2 adults, and L1 children did not show evidence of prediction. By evaluating listeners with varied language experiences, this investigation helps refine proposed mechanisms of prediction, and suggests that linguistic experience is key to the development of such mechanisms.

Predictive language processing in young autistic children.

Recent theories propose that domain-general deficits in prediction (i.e., the ability to anticipate upcoming information) underlie the behavioral characteristics associated with autism spectrum disorder (ASD). If these theories are correct, autistic children might be expected to demonstrate difficulties on linguistic tasks that rely on predictive processing. Previous research has largely focused on older autistic children and adolescents with average language and cognition. The present study used an eye-gaze task to evaluate predictive language processing among 3- to 4-year-old autistic children (n = 34) and 1.5- to 3-year-old, language-matched neurotypical (NT) children (n = 34). Children viewed images (e.g., a cake and a ball) and heard sentences with informative verbs (e.g., Eat the cake) or neutral verbs (e.g., Find the cake). Analyses of children's looking behaviors indicated that young autistic children, like their language-matched NT peers, engaged in predictive language processing. Regression results revealed a significant effect of diagnostic group, when statistically controlling for age differences. The NT group displayed larger difference scores between the informative and neutral verb conditions (in looks to target nouns) compared to the ASD group. Receptive language measures were predictive of looking behavior across time for both groups, such that children with stronger language skills were more efficient in making use of informative verbs to process upcoming information. Taken together, these results suggest that young autistic children can engage in predictive processing though further research is warranted to explore the developmental trajectory relative to NT development. LAY SUMMARY: This study found that 3- to 4-year-old autistic children and younger, language-matched neurotypical (NT) children both used verbs to predict upcoming nouns in sentences like "Eat the cake." For both autistic and NT children, those with stronger language skills were able to predict upcoming nouns more quickly.

Adults and children predict in complex and variable referential contexts.

Prior research suggests that prediction supports language processing and learning. However, the ecological validity of such findings is unclear because experiments usually include constrained stimuli. While theoretically suggestive, previous conclusions will be largely irrelevant if listeners cannot generate predictions in response to complex and variable perceptual input. Taking a step toward addressing this limitation, three eye-tracking experiments evaluated how adults (N = 72) and 4- and 5-year-old children (N = 72) generated predictions in contexts with complex visual stimuli (Experiment 1), variable speech stimuli (Experiment 2), and both concurrently (Experiment 3). Results indicated that listeners generated predictions in contexts with complex visual stimuli or variable speech stimuli. When both were more naturalistic, listeners used informative verbs to generate predictions, but not adjectives or number markings. This investigation provides a test for theories claiming that prediction is a central learning mechanism, and calls for further evaluations of prediction in naturalistic settings.

Predict and redirect: Prediction errors support children's word learning.

According to prediction-based learning theories, erroneous predictions support learning. However, empirical evidence for a relation between prediction error and children's language learning is currently lacking. Here we investigated whether and how prediction errors influence children's learning of novel words. We hypothesized that word learning would vary as a function of 2 factors: the extent to which children generate predictions, and the extent to which children redirect attention in response to errors. Children were tested in a novel word learning task, which used eye tracking to measure (a) real-time semantic predictions to familiar referents, (b) attention redirection following prediction errors, and (c) learning of novel referents. Results indicated that predictions and prediction errors interdependently supported novel word learning, via children's efficient redirection of attention. This study provides a developmental evaluation of prediction-based theories and suggests that erroneous predictions play a mechanistic role in children's language learning. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Individual differences in nonverbal prediction and vocabulary size in infancy.

Children who generate and update verbal predictions have larger vocabularies, suggesting that prediction may be a mechanism that supports language learning. We hypothesize that this relation is not confined to the domain of language, but instead signals a broader individual difference in information processing. To investigate this possibility, we tested infants (n = 50) in the early stages of vocabulary development (12-24 months) on their ability to generate and update nonverbal, visual predictions. In an eye-tracking task, a central fixation reliably preceded a peripheral target. Then, halfway through the experiment, the peripheral target began appearing on the opposite side. We assessed infants' proficiency in initiating anticipatory eye movements before and after the switch, and found that infants with larger vocabularies did not generate more predictions overall, but were more efficient in updating predictions to the new target side. These findings establish a link between nonverbal prediction and vocabulary in infancy, and suggest a promising means of addressing whether or not prediction abilities are causally related to language learning.

Getting to No: Pragmatic and Semantic Factors in Two- and Three-Year-Olds' Understanding of Negation.

Although infants say "no" early, older children have difficulty understanding its truth-functional meaning. Two experiments investigate whether this difficulty stems from the infelicity of negative sentences out of the blue. In Experiment 1, given supportive discourse, 3-year-olds (N = 16) understood both affirmative and negative sentences. However, with sentence types randomized, 2-year-olds (N = 28) still failed. In Experiment 2, affirmative and negative sentences were blocked. Two-year-olds (N = 28) now succeeded, but only when affirmatives were presented first. Thus, although discourse felicity seems the primary bottleneck for 3-year-olds' understanding of negation, 2-year-olds struggle with its semantic processing. Contrary to accounts where negatives are understood via affirmatives, both sentence types were processed equally quickly, suggesting previously reported asymmetries are due to pragmatic accommodation, not semantic processing.