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What is the connection between the cultural evolution of a language and the rapid processing response to that language in the brains of individual learners? In an iterated communication study that was conducted previously, participants were asked to communicate temporal concepts such as "tomorrow," "day after," "year," and "past" using vertical movements recorded on a touch screen. Over time, participants developed simple artificial 'languages' that used space metaphorically to communicate in nuanced ways about time. Some conventions appeared rapidly and universally (e.g., using larger vertical movements to convey greater temporal durations). Other conventions required extensive social interaction and exhibited idiosyncratic variation (e.g., using vertical location to convey past or future). Here we investigate whether the brain's response during acquisition of such a language reflects the process by which the language's conventions originally evolved. We recorded participants' EEG as they learned one of these artificial space-time languages. Overall, the brain response to this artificial communication system was language-like, with, for instance, violations to the system's conventions eliciting an N400-like component. Over the course of learning, participants' brain responses developed in ways that paralleled the process by which the language had originally evolved, with early neural sensitivity to violations of a rapidly-evolving universal convention, and slowly developing neural sensitivity to an idiosyncratic convention that required slow social negotiation to emerge. This study opens up exciting avenues of future work to disentangle how neural biases influence learning and transmission in the emergence of structure in language. [ABSTRACT FROM AUTHOR]

According to the competitive exclusion principle (Gause, 1934), competition for the same niche must eventually lead one competitor to extinction or the occupation of a new niche. This principle applies in both biology and the cultural evolution of language, where different words and structures compete for the same function or meaning (Aronoff, 2016). Across languages, for example, word order trades off with case marking as a means of indicating who did what to whom in a sentence. Previous experimental work has shed light on how such trade-offs come about as languages adapt to human biases through learning and production, with biases becoming amplified through iterated learning over generations. At the same time, a large body of work has documented the impact of social biases on language change. However, little work has investigated how social biases interact with learning and production biases. In particular, the social dimension of language may provide alternative niches for otherwise redundant forms, preventing or slowing their extinction. We tested this hypothesis in an iterated-learning experiment in which participants were exposed to a language with two dialects, both of which had fixed word order, but differed in whether they employed case markers. In one condition, we biased participants socially towards speakers of the dialect that employed case; in other conditions we provided no bias, or biased participants for or against the dialect without case. As expected under our hypothesis, the use of case markers declined over time in all conditions, but the social bias in favor of case-dialect speakers slowed the decline. [ABSTRACT FROM AUTHOR]

While variation occurs in both phonology and morphosyntax, phonological variation also includes phonetic variation motivated by articulatory or perceptual factors. While learning in both domains is subject to cognitive biases, phonological learning may also be biased by physical factors, which may enhance learnability of phonetically motivated alternations. This study aims to identify whether learning differs when children are exposed to phonological or morphosyntactic patterns with equal complexity. Cantonese-speaking children learned an artificial language involving rounding harmony, where unround [e] or round [o] harmonizes with the following noun, or gender agreement, with feminine and masculine allomorphs lo ~ le. Patterns applied variably in 67% of training items, or categorically. Children were tested on generalization to novel stems. In the categorical learning conditions, participants showed comparable rates of harmony/agreement. In the variable phonological learning conditions, application of harmony exceeded the rate of exposure in training, suggesting the influence of a bias toward phonetically grounded rounding harmony. In the variable morphosyntactic condition, participants applied agreement below the rate of exposure. This finding points to a qualitative difference between learning in the two domains, with phonological (but not morphosyntactic) learning influenced by substantive grounding. [ABSTRACT FROM AUTHOR]

How do people learn to use language in creative but constrained ways? Experiment 1 investigates linguistic creativity by exposing adult participants to two novel word order constructions that differ in terms of their semantics: One construction exclusively describes actions that have a strong effect; the other construction describes actions with a weaker but otherwise similar effect. One group of participants witnessed novel verbs only appearing in one construction or the other, while another group witnessed a minority of verbs alternating between constructions. Subsequent production and judgment results demonstrate that participants in both conditions extended and accepted verbs in whichever construction best described the intended message. Unlike related previous work, this finding is not naturally attributable to prior knowledge of the likely division of labor between verbs and constructions or to a difference in cue validity. In order to investigate how speakers learn to constrain generalizations, Experiment 2 includes one verb (out of 6) that was witnessed in a single construction to describe both strong and weak effects, essentially statistically preempting the use of the other construction. In this case, participants were much more lexically conservative with this verb and other verbs, while they nonetheless displayed an appreciation of the distinct semantics of the constructions with new novel verbs. Results indicate that the need to better express an intended message encourages generalization, while statistical preemption constrains generalization by providing evidence that verbs are restricted in their distribution. [ABSTRACT FROM AUTHOR]

The linguist George Kingsley Zipf made a now classic observation about the relationship between a word's length and its frequency; the more frequent a word is, the shorter it tends to be. He claimed that this "Law of Abbreviation" is a universal structural property of language. The Law of Abbreviation has since been documented in a wide range of human languages, and extended to animal communication systems and even computer programming languages. Zipf hypothesised that this universal design feature arises as a result of individuals optimising form-meaning mappings under competing pressures to communicate accurately but also efficiently-his famous Principle of Least Effort. In this study, we use a miniature artificial language learning paradigm to provide direct experimental evidence for this explanatory hypothesis. We show that language users optimise form-meaning mappings only when pressures for accuracy and efficiency both operate during a communicative task, supporting Zipf's conjecture that the Principle of Least Effort can explain this universal feature of word length distributions. [ABSTRACT FROM AUTHOR]

Linguists from across sub-disciplines have noted that congruence (i.e., form-function mapping) across languages in contact seems to affect acquisition and play a role in language emergence (e.g. Creole genesis). However, because congruence is often confounded with other variables (e.g., frequency, language type, speakers' proficiency levels, perceptual salience, semantic transparency), it remains unclear whether congruence per se benefits learners. In this paper, we provide an experimental test of the effects of congruence on acquisition through an artificial language-learning experiment involving English (L1) and two artificial languages (Flugerdu and Zamperese). English-speakers who identified as "native" (i.e., first-language) speakers (N = 163) were randomly assigned to one of four conditions, varying which of the three languages expressed negation with congruent forms: all three languages; only Flugerdu and Zamperese; only English and Flugerdu; or none. Our findings show that participants better acquired the negation morpheme when the form was congruent with negation in English but not when the two artificial languages alone shared a congruent form. We likewise found unanticipated spillover effects in which participants better acquired the vocabulary and grammar of the artificial languages when all three languages had congruent negation forms. These findings provide insight into the effects of congruence on language acquisition in multilingual environments and Creole language formation. [ABSTRACT FROM AUTHOR]

A fundamental question for cognitive science concerns the ways in which languages are shaped by the biases of language learners. Recent research using laboratory language learning paradigms, primarily with adults, has shown that structures or rules that are common in the languages of the world are learned or processed more easily than patterns that are rare or unattested. Here we target child learners , investigating a set of biases for word order learning in the noun phrase studied by Culbertson, Smolensky, and Legendre (2012) in college-age adults. We provide the first evidence that child learners exhibit a preference for typologically common harmonic word order patterns—those which preserve the order of the head with respect to its complements—validating the psychological reality of a principle formalized in many different linguistic theories. We also discuss important differences between child and adult learners in terms of both the strength and content of the biases at play during language learning. In particular, the bias favoring harmonic patterns is markedly stronger in children than adults, and children (unlike adults) acquire adjective ordering more readily than numeral ordering. The results point to the importance of investigating learning biases across development in order to understand how these biases may shape the history and structure of natural languages. [ABSTRACT FROM AUTHOR]

The prevalence of redundancy in the world languages has long puzzled language researchers. It is especially surprising in light of the growing evidence on speakers' tendency to avoid redundant elements in production (omitting or reducing more predictable elements). Here, we propose that redundancy can be functional for learning. In particular, we argue that redundant cues can facilitate learning, even when they make the language system more complicated. This prediction is further motivated by the Linguistic Niche Hypothesis (Lupyan & Dale, 2010), which suggests that morphological complexity can arise due to the advantage redundancy might confer for child learners. We test these hypotheses in an artificial language learning study with children and adults, where either word order alone or both word order and case marking serve as cues for thematic assignment in a novel construction. We predict, and find, that children learning the redundant language learn to produce it, and show better comprehension of the novel thematic assignment than children learning the non-redundant language, despite having to learn an additional morpheme. Children in both conditions were similarly accurate in producing the novel word order, suggesting redundancy might have a differential effect on comprehension and production. Adults did not show better learning in the redundant condition, most likely because they were at ceiling in both conditions. We discuss implications for theories of language learning and language change. [ABSTRACT FROM AUTHOR]

Abstract: How recurrent typological patterns, or universals, emerge from the extensive diversity found across the world’s languages constitutes a central question for linguistics and cognitive science. Recent challenges to a fundamental assumption of generative linguistics—that universal properties of the human language acquisition faculty constrain the types of grammatical systems which can occur—suggest the need for new types of empirical evidence connecting typology to biases of learners. Using an artificial language learning paradigm in which adult subjects are exposed to a mix of grammatical systems (similar to a period of linguistic change), we show that learners’ biases mirror a word-order universal, first proposed by Joseph Greenberg, which constrains typological patterns of adjective, numeral, and noun ordering. We briefly summarize the results of a probabilistic model of the hypothesized biases and their effect on learning, and discuss the broader implications of the results for current theories of the origins of cross-linguistic word-order preferences. [Copyright &y& Elsevier]

Abstract: Children learning the inflections of their native language show the ability to generalize beyond the perceptual particulars of the examples they are exposed to. The phenomenon of “rule learning”—quick learning of abstract regularities from exposure to a limited set of stimuli—has become an important model system for understanding generalization in infancy. Experiments with adults and children have revealed differences in performance across domains and types of rules. To understand the representational and inferential assumptions necessary to capture this broad set of results, we introduce three ideal observer models for rule learning. Each model builds on the next, allowing us to test the consequences of individual assumptions. Model 1 learns a single rule, Model 2 learns a single rule from noisy input, and Model 3 learns multiple rules from noisy input. These models capture a wide range of experimental results—including several that have been used to argue for domain-specificity or limits on the kinds of generalizations learners can make—suggesting that these ideal observers may be a useful baseline for future work on rule learning. [Copyright &y& Elsevier]

Abstract: A study combining artificial grammar and sentence comprehension methods investigated the learning and online use of probabilistic, nonadjacent combinatorial constraints. Participants learned a small artificial language describing cartoon monsters acting on objects. Self-paced reading of sentences in the artificial language revealed comprehenders’ sensitivity to nonadjacent combinatorial constraints, without explicit awareness of the probabilities embedded in the language. These results show that even newly-learned constraints have an identifiable effect on online sentence processing. The rapidity of learning in this paradigm relative to others has implications for theories of implicit learning and its role in language acquisition. [Copyright &y& Elsevier]

Abstract: This study combined artificial language learning (ALL) with conventional experimental techniques to test whether statistical speech segmentation outputs are integrated into adult listeners’ mental lexicon. Lexicalization was assessed through inhibitory effects of novel neighbors (created by the parsing process) on auditory lexical decisions to real words. Both immediately after familiarization and post-one week, ALL outputs were lexicalized only when the cues available during familiarization (transitional probabilities and wordlikeness) suggested the same parsing (Experiments 1 and 3). No lexicalization effect occurred with incongruent cues (Experiments 2 and 4). Yet, ALL differed from chance, suggesting a dissociation between item knowledge and lexicalization. Similarly contrasted results were found when frequency of occurrence of the stimuli was equated during familiarization (Experiments 3 and 4). Our findings thus indicate that ALL outputs may be lexicalized as far as the segmentation cues are congruent, and that this process cannot be accounted for by raw frequency. [Copyright &y& Elsevier]

Abstract: Variation set structure – partial overlap of successive utterances in child-directed speech – has been shown to correlate with progress in children’s acquisition of syntax. We demonstrate the benefits of variation set structure directly: in miniature artificial languages, arranging a certain proportion of utterances in a training corpus in variation sets facilitated word and phrase constituent learning in adults. Our findings have implications for understanding the mechanisms of L1 acquisition by children, and for the development of more efficient algorithms for automatic language acquisition, as well as better methods for L2 instruction. [Copyright &y& Elsevier]

Language learning involves exposure to inconsistent systems - that is, systems where multiple patterns or methods exist to mark some meaning. Inconsistent systems often change to be more regular over time - they become systematized. However, some recent studies have reported that learners tend to reproduce inconsistency in the input, leading to models in which the language learning mechanism is basically preservatory. We ran an artificial language learning experiment using a novel paradigm to extend our understanding of systematizing versus preservatory mechanisms in language learning. Participants were taught two number marking systems, either completely consistently (the probability P of the system is 1.00) or inconsistently (with P = 0.875 for one system and P = 0.125 for the other, and so on for P = 0.75 and P = 0.625). One marking system was a plural-marking system. The other was a typologically rare singulative-marking system. When generalizing to novel items, participants produced more regular output patterns overall for more consistent input conditions than for less consistent ones, and more for the plural-marking conditions than for the singulative-marking conditions. For the singulative-marking conditions, the inter-participant variation was much greater than for the plural-marking ones; some individuals systematized towards the more familiar pattern, some systematized towards the less familiar pattern and some were not significantly different from probability-matching. We analyze the variation in relation to current statistical learning models, showing that preservatory learning models, as well as all models with a single free parameter, fail to capture our results. We show how a model with two free parameters in which individuals can vary in their propensity to systematize in any given situation is more successful. We also discuss implications for the theory of language change. [ABSTRACT FROM AUTHOR]

Word order harmony describes the tendency, found across the world's languages, to consistently order syntactic heads relative to dependents. It is one of the most well-known and well-studied typological universals. Almost since it was first noted by Greenberg (1963), there has been disagreement about what role, if any, the cognitive system plays in driving harmony. Recently, a series of studies using artificial language learning experiments reported that harmonic noun phrase word orders were preferred over non-harmonic orders by English-speaking adults and children (Culbertson et al., 2012; Culbertson & Newport, 2015, 2017). However, this evidence is potentially confounded by the fact that English is itself a harmonic language (Goldberg, 2013). Here we sought to extend the results from these studies by exploring whether learners who have substantial experience with a non-harmonic language still showed a bias for harmonic patterns during learning. We found that monolingual French- and Hebrew-speaking children, whose language has a non-harmonic noun phrase order (N Adj, Num N) nevertheless preferred harmonic patterns when learning an artificial language. We also found evidence for a harmony bias across several populations of adult learners, although this interacted in complex ways with their L2 experience. Our results suggest that transfer from the L1 cannot explain the preference for harmony found in previous studies. Moreover, they provide the strongest evidence yet that a cognitive bias for harmony is a plausible candidate for shaping linguistic typology. [ABSTRACT FROM AUTHOR]

It is often assumed that cross-linguistically more prevalent distinctions are easier to learn (Typological Prevalence Hypothesis; TPH). Prior work supports this idea in phonology, morphology and syntax but has not addressed semantics. Using Artificial Language Learning experiments with adults, we test predictions made by the TPH about the relative learnability of semantic distinctions in the domain of evidentiality, i.e., the linguistic encoding of information source. As the TPH predicted, when exposed to miniature evidential morphological systems, adult speakers of English whose language does not encode evidentiality grammatically learned the typologically most prevalent system (marking indirect, reportative information) better compared to less-attested systems (Experiments 1-2). Similar patterns were observed when non-linguistic symbols were used to encode evidential distinctions (Experiment 3). Our data support the conjecture that some semantic distinctions are marked preferentially and acquired more easily compared to others in both language and other symbolic systems. [ABSTRACT FROM AUTHOR]