Over the last two decades, many studies have demonstrated that infant and adult learners are capable of tracking distributional properties of sensory input in order to infer the underlying structure of the environment. In the realm of language acquisition, statistical learning has been found to operate at many levels, including phonetic learning (e.g., Maye, Werker, & Gerken, 2002), speech segmentation (e.g., Saffran, Aslin, & Newport, 1996), word learning (e.g., Smith & Yu, 2008), and grammar learning (e.g., Reeder, Newport, & Aslin, 2013). Notably, the vast majority of research in this field to date has assumed, at least implicitly, that the task of the learner is to acquire a single pattern. That is, almost all studies of statistical learning, particularly with infants, have presented learners with a uniform structure such that sampling at any point during familiarization yields the same statistical information. In the real world, however, the underlying statistical distribution of the input varies meaningfully over time, for example when encountering different topics, dialects, or languages. The ability to cope with multiple statistical structures is thus particularly relevant for learners in bilingual environments, who must learn multiple underlying structures in order to acquire both of their languages.
Expectation is a powerful mechanism in native-language processing. Listeners – child and adult – use information from various sources to create expectations about what is likely to come next. A variety of recent studies have probed anticipatory effects by measuring comprehenders' referential expectations, i.e., their guess about who or what the speaker will mention next. That work has found evidence that comprehenders are sensitive to cues such as the lexical semantics of a verb, which can create expectations regarding an upcoming referent in the current or next sentence (Altmann & Kamide, 1999; Pyykkönen & Järvikivi, 2010). Similarly, there is evidence that comprehenders are sensitive to the morphosyntactic properties of determiners which restrict the possible nouns to follow (Dahan et al., 2000; DeLong et al., 2005; Lew-Williams & Fernald, 2007). Expectations like these are not only characteristic of language processing in native speaking adults, but also in children (Borovsky et al., 2012). It thus appears that the ability to narrow down the potentially infinite range of upcoming information through the generation of expectations is likely to be a critical factor in explaining how we process language at the speed and with the success we typically do, at least in our native language. * The use of expectations, however, is not present in all contexts across all populations. Recent work indicates a decline in expectation generation in older adults (Federmeier et al., 2002), suggesting that " predictive processing may not be the best – or even a viable – strategy for all individuals at all phases of the lifespan and/or in all processing situations " (Federmeier, 2007, p. 495). This is because predictive processing comes with the risk of failure, that is, the possibility that built-up expectations are not fulfilled. In such cases, the processor will have to react swiftly and flexibly, and it will require sufficient resources to do so and still keep up with the ongoing flow of information. This may not always be possible, as for older adults with lower working memory capacities (Federmeier et al., 2002). Non-native speakers may be another such case; recent work points to limits in their expectation-driven processing at and Mónica Vidal for assistance with data collection and annotation.
The use of visual and haptic measures as proxies for underlying cognitive abilities has a rich history in infant development research, and perhaps none more so than studies of early vocabulary comprehension. Although visual and haptic measures have displayed long-term predictive value, it remains unclear whether visual attention and haptic responses are analogous and substitutable measures of lexical knowledge. The goal of the current study was to assess the bidirectional relationship between vision and action, and to evaluate the underlying word representations that guide infants' visual and haptic responses. Two measures of visual attention, one macro-level (look accuracy) and one micro-level (proportion of gaze shifts), were measured concurrently with haptic performance during an intermodal word comprehension task. During the task, infants were presented with two images simultaneously on a touchscreen and asked to touch one of the images. Results revealed a somewhat discrepant view on how visual attention relates to haptic performance. Specifically, during trials where an incorrect haptic response was performed, looking-time was significantly greater to the incorrect visual referent, however infants displayed a more sophisticated visual attention style (greater proportion of gaze shifts) known to predict later intellectual functioning. Conversely, during trials where infants failed to perform a haptic response, looking-time to the target was significantly greater than chance however, infants performed significantly fewer gaze shifts. These results will help bridge the gap between literatures that use different response modalities and provide insight on the nature of children's developing knowledge about words.
The role of age of acquisition on ultimate linguistic attainment has been the object of much research on first (L1) and second (L2) language acquisition. Work on L1 acquisition (e.g., Curtiss, 1977; Lenneberg, 1967; Penfield & Roberts, 1959) has led to the proposal of the Critical Period Hypothesis, which states that there is a particular period of time early in life when the brain displays a superior predisposition to attend to certain experiences in the environment and learn from them. Language is considered one of these experiences. In other words, the brain can be easily influenced by those experiences, but only if they take place within a biologically specified time period (Ortega, 2009). Researchers in the L2 acquisition tradition have also focused on age effects, investigating whether adults can attain native-like competency in a second language (e.g., Hyltenstam & Abrahamsson, 2000; Birdsong, 2005; Long, 2005; Marinova-Todd, 2004; Singleton & Ryan, 2004). Some studies have reported important differences between native speakers and second language learners (e.g., Johnson, 1992; Johnson & Newport, 1989; Oyama, 1976; Patkowski, 1980, 1994) in favor of the notion of a fundamental difference between the mechanisms that subserve L1 and L2 acquisition. The idea of a fundamental difference between first and second language acquirers has also been recently proposed in the domain of language processing to explain purported qualitative differences between the performance of native and second language speakers (e.g., Clahsen & Felser, 2006). There is, however, some recent evidence arguing against a fundamental difference hypothesis between L1 and L2 speakers, at least in its strongest
The important role that pragmatics plays in the acquisition of morphology has been hardly studied. In this contribution we focus on the pragmatic strategies of adult caretakers in their reactions to children's early morphological productions in three different languages (French, German, Lithuanian).The most relevant distinction proposed is that between metadiscursive and conversational reactions, i.e, between reactions on linguistic form and on content. In contrast to the latter, the former represent interruptions of the flow of interaction. The distribution of these two types of reactions provides the child with abundant direct and indirect positive and negative evidence about whether his/her preceding morphological production has been well formed or in formed. Among these reactions. which may consist in reformulations, expansions, and others, we emphasize particularly repetitions and their pragmatic functions and show that they are partially specific to child-directed speech.A special type of young children's morphological productions are bare infinitives. In contrast to their grammar-theoretical accounts in generative studies, we follow a pragmatic approach, based on child-directed speech and caretakers' reactions, which evidences the caretakers' tolerance of ambiguity and thus the importance of inferential work in child-adult interactions. Despite great grammatical differences between French, German and Lithuanian, the pragmatic strategies used by caretakers are very similar in quality and quantity. (C) 2008 Elsevier B.V. All rights reserved.
The production of inflected word forms has been claimed to be influenced by a number of item-specific and subject-specific factors. The former include differences in word-form frequency and differences in the kinds of inflectional processes. Also, a participant’s working memory capacity has been proposed to affect the production of inflected word forms, in both children and adults (Clahsen, Hadler & Weyerts, 2004). The current study investigates the role of these factors in adults’ and children's spoken production of past participles in German (e.g. ge-frag-t ‘asked’[PART], ge-schlaf-en ‘slept’[PART]) using a speeded production task. 40 children (6;3-10;7 years) and 20 adults were asked to produce past participle forms for regular and irregular verbs of high and low frequency. Production latencies and error rates were analyzed. For irregularly inflected participles, a robust advantage of high over low-frequency forms was obtained for all age groups. For regulars, however, a significant disadvantage of high over low-frequency forms was found for children, but not for adults (taken as one group). Interestingly, however, when including independently measured working memory scores into the analysis, adults with low working memory were found to perform like children, also demonstrating a frequency advantage for high-frequency irregulars paired with a disadvantage for high-frequency regulars. We propose a dual-mechanism account for this unusual set of findings. 1. Background ∗
