Prediction error boosts retention of novel words in adults but not in children

Zipfian distributions facilitate children's learning of novel word-referent mappings

The word-frequency distributions children hear during language learning are highly skewed (Zipfian). Previous studies suggest that such skewed environments confer a learnability advantage in tasks that require the learner to discover the units that have to be learned, as in word-segmentation or cross-situational learning. This facilitative effect has been attributed to contextual facilitation from high frequency items in learning lower frequency items, and to better learning under the increased predictability (lower entropy) of skewed distributions. Here, we ask whether Zipfian distributions facilitate learning beyond the discovery of units, as expected under the predictability account. We tested children's learning of novel word-referent mappings in a learning task where each mapping was presented in isolation during training, and did not need to be dicovered. We compared learning in a uniform environment to two skewed environments with different entropy levels. Children's learning was overall better in the two skewed environments, even for low frequency items. These results extend the facilitative effect of Zipfian distributions to additional learning tasks and show they can facilitate language learning beyond the discovery of units.

Error-based Implicit Learning in Language: The Effect of Sentence Context and Constraint in a Repetition Paradigm

Prediction errors drive implicit learning in language, but the specific mechanisms underlying these effects remain debated. This issue was addressed in an EEG study manipulating the context of a repeated unpredictable word (repetition of the complete sentence or repetition of the word in a new sentence context) and sentence constraint. For the manipulation of sentence constraint, unexpected words were presented either in high-constraint (eliciting a precise prediction) or low-constraint sentences (not eliciting any specific prediction). Repetition-induced reduction of N400 amplitudes and of power in the alpha/beta frequency band was larger for words repeated with their sentence context as compared with words repeated in a new low-constraint context, suggesting that implicit learning happens not only at the level of individual items but additionally improves sentence-based predictions. These processing benefits for repeated sentences did not differ between constraint conditions, suggesting that sentence-based prediction update might be proportional to the amount of unpredicted semantic information, rather than to the precision of the prediction that was violated. In addition, the consequences of high-constraint prediction violations, as reflected in a frontal positivity and increased theta band power, were reduced with repetition. Overall, our findings suggest a powerful and specific adaptation mechanism that allows the language system to quickly adapt its predictions when unexpected semantic information is processed, irrespective of sentence constraint, and to reduce potential costs of strong predictions that were violated.

Prediction error and memory across the lifespan

The influence of Prediction Errors (PEs) on episodic memory has generated growing empirical and theoretical interest. This review explores how the relationship between PE and memory may evolve throughout lifespan. Drawing upon the predictive processing framework and the Predictive, Interactive Multiple Memory System (PIMMS) model in particular, the paper highlights the hierarchical organization of memory systems and the interaction between top-down predictions and bottom-up sensory input, proposing that PEs promote synaptic change and improve encoding and consolidation processes. We discuss the neuroscientific mechanisms underlying PE-driven memory enhancement, focusing on the involvement of the hippocampus, the entorhinal cortex-hippocampus pathway, and the noradrenergic sympathetic system. Recognizing the divergent trajectories of episodic and semantic memory across the lifespan is crucial when examining the effects of PEs on memory. This review underscores the heterogeneity of memory processes and neurocognitive mechanisms underlying PE-driven memory enhancement across age. Future research is suggested to directly compare neural networks involved in learning from PEs across different age groups and to contribute to a deeper understanding of PE-driven learning across age.

What is the next structure? Guessing enhances L2 syntactic learning in a syntactic priming task

Previous psycholinguistic research has shown that Second Language (L2) speakers could learn from engaging in prediction. Few works have directly examined the relationship between prediction and L2 syntactic learning. Further, relatively limited attention has been paid to the effects of two linguistic factors in this area: structure type and L2 proficiency. Using a mixed experimental design, 147 L2 Arabic speakers with varying L2 proficiency levels completed two syntactic priming experiments, each targeting a different structure: (a) the dative and (b) Temporal Phrases (TP). The experimental conditions required participants to predict what the upcoming sentence's structure would be. The experimental conditions differed in the degree of engagement in prediction error. Results suggested that Arabic L2 speakers at different proficiency levels showed enhanced priming and short-term learning for two syntactic structures (PO, fronted TP) when (a) instructed to guess only (constrained condition) as well as when (b) instructed to guess and compute the prediction error (unconstrained condition), relative to the controls. These results imply a guessing benefit for priming and short-term learning. Participants also experienced different priming effects by structure type, but there was no significant effect for proficiency. The theoretical and practical implications of these findings are discussed.

Drivers of Lexical Processing and Implications for Early Learning

Understanding words in unfolding speech requires the coordination of many skills to support successful and rapid comprehension of word meanings. This multifaceted ability emerges before our first birthday, matures over a protracted period of development, varies widely between individuals, forecasts future learning outcomes, and is influenced by immediate context, prior knowledge, and lifetime experience. This article highlights drivers of early lexical processing abilities while exploring questions regarding how learners begin to acquire, represent, and activate meaning in language. The review additionally explores how lexical processing and representation are connected while reflecting on how network science approaches can support richly detailed insights into this connection in young learners. Future research avenues are considered that focus on addressing how language processing and other cognitive skills are connected.

Age-related differences in expectation-based novel word learning

Adult language users can infer the meaning of a previously unfamiliar word from a single exposure to this word in a semantically and thematically constrained context, henceforth, predictive context (Borovsky et al., 2010 Cognition, 116(2), 289-296; Borovsky et al., 2012 Language Learning and Development, 8(3), 278-302). Children use predictive contexts to anticipate upcoming stimuli (Borovsky et al., 2012 Language Learning and Development, 8(3), 278-302; Mani & Huettig, 2012 Journal of Experimental Psychology: Human Perception and Performance, 38(4), 843-847), but the extent to which they rely on prediction to learn novel word forms is unclear (Gambi et al., 2021 Cognition, 211, 104650). Here, we examine children's one-shot learning from predictive contexts using a modified version of the one-shot learning ERP paradigm for children aged 7-13 years. In a first learning phase, we presented audio recordings of expected words and unexpected novel pseudowords in strongly and weakly constraining sentence contexts. In the following priming phase, the same recorded words and pseudowords were used as primes to identical/synonymous, related, and unrelated target words. We measured N400 modulations to the word and pseudoword continuations in the learning phase and to the identical/synonymous, related, or unrelated target words in the priming phase. When initially presented in strongly constraining sentences, novel pseudowords primed synonymous targets equally well as word primes of the same intended meaning. This pattern was particularly pronounced in older children. Our findings suggest that, around early adolescence, children can use single exposures to constraining contexts to infer the meaning of novel words and to integrate these novel words in their lexicons.

The N400 ERP component reflects an error-based implicit learning signal during language comprehension

The functional significance of the N400 evoked-response component is still actively debated. An increasing amount of theoretical and computational modelling work is built on the interpretation of the N400 as a prediction error. In neural network modelling work, it was proposed that the N400 component can be interpreted as the change in a probabilistic representation of meaning that drives the continuous adaptation of an internal model of the statistics of the environment. These results imply that increased N400 amplitudes should correspond to greater adaptation, which can be measured via implicit memory. To investigate this model derived hypothesis, the current study manipulated expectancy in a sentence reading task to influence N400 amplitudes and subsequently presented the previously expected vs. unexpected words in a perceptual identification task to measure implicit memory. As predicted, reaction times in the perceptual identification task were significantly faster for previously unexpected words that induced larger N400 amplitudes in the previous sentence reading task. Additionally, it could be demonstrated that this adaptation seems to specifically depend on the process underlying N400 amplitudes, as participants with larger N400 differences during sentence reading also exhibited a larger implicit memory benefit in the perceptual identification task. These findings support the interpretation of the N400 as an implicit learning signal driving adaptation in language processing.