Morten H Christiansen

Cornell University | CU · Department of Psychology

It is generally assumed that hierarchical phrase structure plays a central role in human language. However, considerations of simplicity and evolutionary continuity suggest that hierarchical structure should not be invoked too hastily. Indeed, recent neurophysiological, behavioural and computational studies show that sequential sentence structure h...

Recent research suggests that language evolution is a process of cultural change, in which linguistic structures are shaped through repeated cycles of learning and use by domain-general mechanisms. This paper draws out the implications of this viewpoint for understanding the problem of language acquisition, which is cast in a new, and much more tra...

Recent research has demonstrated that systematic mappings between phonological word forms and their meanings can facilitate language learning (e.g., in the form of sound symbolism or cues to grammatical categories). Yet, paradoxically from a learning viewpoint, most words have an arbitrary form-meaning mapping. We hypothesized that this paradox may...

Mastering how to convey meanings using language is perhaps the main challenge facing any language learner. However, satisfactory accounts of how this is achieved, and even of what it is for a linguistic item to have meaning, are hard to come by. Nick Chater was one of the pioneers involved in the early development of one of the most successful meth...

In language learning, learners engage with their environment, incorporating cues from different sources. However, in lab‐based experiments, using artificial languages, many of the cues and features that are part of real‐world language learning are stripped away. In three experiments, we investigated the role of positive, negative, and mixed feedbac...

Establishing and maintaining mutual understanding in everyday conversations is crucial. To do so, people employ a variety of conversational devices, such as backchannels, repair, and linguistic entrainment. Here, we explore whether the use of conversational devices might be influenced by cross‐linguistic differences in the speakers’ native language...

Rapid individual cognitive phenotyping holds the potential to revolutionize domains as wide-ranging as personalized learning, employment practices, and precision psychiatry. Going beyond limitations imposed by traditional lab-based experiments, new efforts have been underway towards greater ecological validity and participant diversity to capture t...

This study compared the acoustic properties of 26 (100% female, 100% monolingual) Danish caregivers' spontaneous speech addressed to their 11- to 24-month-old infants (infant-directed speech, IDS) and an adult experimenter (adult-directed speech, ADS). The data were collected between 2016 and 2018 in Aarhus, Denmark. Prosodic properties of Danish I...

In conversation, individuals work together to achieve communicative goals, complementing and aligning language and body with each other. An important emerging question is whether interlocutors entrain with one another equally across linguistic levels (e.g., lexical, syntactic, and semantic) and modalities (i.e., speech and gesture), or whether ther...

Rapid individual cognitive phenotyping holds the potential to revolutionize domains as wide-ranging as personalized learning, employment practices, and precision psychiatry. Going beyond limitations imposed by traditional lab-based experiments, new efforts have been underway toward greater ecological validity and participant diversity to capture th...

To what degree can language be acquired from linguistic input alone? This question has vexed scholars for millennia and is still a major focus of debate in the cognitive science of language. The complexity of human language has hampered progress because studies of language–especially those involving computational modeling–have only been able to dea...

We agree with Heintz & Scott-Phillips that pragmatics does not supplement, but is prior to and underpins, language. Indeed, human non-linguistic communication is astonishingly rich, flexible, and subtle, as we illustrate through the game of charades, where people improvise communicative signals when linguistic channels are blocked. The route from n...

Humans readily engage in idle chat and heated discussions and negotiate tough joint decisions without ever having to think twice about how to keep the conversation grounded in mutual understanding. However, current attempts at identifying and assessing the conversational devices that make this possible are fragmented across disciplines and investig...

In conversation, individuals work together to achieve communicative goals, complementing and aligning language and body with each other. However, there is no consensus as to whether interlocutors entrain with one another equally across levels (e.g., lexical, syntactic, semantic) and modalities (i.e., speech, gesture), or whether there are complemen...

Statistical learning is a key concept in our understanding of language acquisition. Ample work has highlighted its role in numerous linguistic functions—yet statistical learning is not a unitary construct, and its consistency across different language properties remains unclear. In a meta‐analysis of auditory‐linguistic statistical learning researc...

Statistical learning (SL) is considered a cornerstone of cognition. While decades of research have unveiled the remarkable breadth of structures that participants can learn from statistical patterns in experimental contexts, how this ability interfaces with real-world cognitive phenomena remains inconclusive. These mixed results may arise from the...

The study by Kidd and Garcia is long overdue. Their analyses of published research on language acquisition highlight the lack of typological diversity in studies of how children acquire their native tongue. We concur with their conclusion that more research on understudied languages is urgently needed. However, we argue that what the field needs is...

How individuals learn complex regularities in the environment and generalize them to new instances is a key question in cognitive science. Although previous investigations have advocated the idea that learning and generalizing depend upon separate processes, the same basic learning mechanisms may account for both. In language learning experiments,...

Establishing and maintaining mutual understanding in everyday conversations is crucial. To do so people employ a variety of conversational devices, such as backchannels, repair and linguistic entrainment. Here we explore whether speakers of different languages use conversational devices in the same way, or whether their use might be modulated by di...

Recent publications have lamented the dominance of psychology in cognitive science. However, this relies on a limited definition of collaboration between fields. We call for a renewed conception of interdisciplinarity as a "mixture of expertise." We describe an information-theoretic measure of interdisciplinarity and apply it to multiauthored publi...

The phonological peculiarities of spoken Danish have been argued to reduce the salience of cues that allow infant listeners to extract linguistic information from the speech stream. To assess whether caregivers adjust their infant-directed speech to accommodate these processing challenges, this study compares the acoustic properties of 26 Danish ca...

The key to explaining the many mysteries of language is to think of it as a game, say cognitive scientists Morten H. Christiansen and Nick Chater

The world’s languages vary in almost every conceivable way, yet children readily learn their native language. Understanding how children can acquire such a diversity of different languages has been a long-standing goal for psychological science, yet current acquisition research is dominated by studies of children learning one particular language: E...

A growing body of research investigates individual differences in the learning of statistical structure, tying them to variability in cognitive (dis)abilities. This approach views statistical learning (SL) as a general individual ability that underlies performance across a range of cognitive domains. But is there a general SL capacity that can sort...

The ability to produce and understand an unlimited number of different sentences is a hallmark of human language. Linguists have sought to define the essence of this generative capacity using formal grammars that describe the syntactic dependencies between constituents, independent of the computational limitations of the human brain. Here, we evalu...

Danish language technology has been hindered by a lack of broad-coverage corpora at the scale modern NLP prefers. This paper describes the Danish Gigaword Corpus, the result of a focused effort to provide a diverse and freely-available one billion word corpus of Danish text. The Danish Giga-word corpus covers a wide array of time periods , domains,...

It is often assumed that all languages are fundamentally the same. This assumption has been challenged by research in linguistic typology and language evolution, but questions of language learning and use have largely been left aside. Here we review recent work on Danish that provides new insights into these questions. Unlike closely related langua...

High frequency words play a key role in language acquisition, with recent work suggesting they may serve both speech segmentation and lexical categorisation. However, it is not yet known whether infants can detect novel high frequency words in continuous speech, nor whether they can use them to help learning for segmentation and categorisation at t...

Over the last two decades statistical learning (SL) has evolved into a key explanatory mechanism underlying the incidental learning of regularities across different domains of cognition, such as language, visual and auditory perception, and memory. Yet SL has mainly been investigated as an independent research area, separated from the primary study...

Statistical learning (SL) has been a prominent focus of research in developmental and adult populations, guided by the assumption that it is a fundamental component of learning underlying higher-order cognition. In developmental populations, however, there have been recent concerns regarding the degree to which many current tasks reliably measure S...

A large body of research over the past two decades has demonstrated that children and adults are equipped with statistical learning mechanisms that facilitate their language processing and boost their acquisition. However, this research has been conducted primarily using artificial languages that are highly simplified relative to real language inpu...

Humans readily engage in idle chat, heated discussions, and negotiate tough joint decisions without ever having to think twice about the different mechanisms they use to keep the conversation grounded in mutual understanding. However, current attempts at identifying and assessing the grounding mechanisms that make this possible are fragmented acros...

Whereas a growing bulk of work has demonstrated that both adults and children are sensitive to frequently occurring word sequences, little is known about the potential role of meaning in the processing of such multiword chunks. Here, we take a first step toward assessing the contribution of meaningfulness in the processing of multiword sequences, u...

Are all languages processed in the same way, or might typological variation cause systematic differences between languages? We explore this question through a cross-linguistic comparison of categorical perception in two closely related languages, Danish and Norwegian. We employ drift diffusion models to reveal cross-linguistic differences in the ro...

Prior investigations have demonstrated that people tend to link pseudowords such as bouba to rounded shapes and kiki to spiky shapes, but the cognitive processes underlying this matching bias have remained controversial. Here, we present three experiments underscoring the fundamental role of emotional mediation in this sound–shape mapping. Using st...

The computations involved in statistical learning have long been debated. Here, we build on work suggesting that a basic memory process, chunking, may account for the processing of statistical regularities into larger units. Drawing on methods from the memory literature, we developed a novel paradigm to test statistical learning by leveraging a rob...

Danish is a North Germanic/Scandinavian language spoken primarily in Denmark, a country with a tradition of technological and scientific innovation. However, from a technological perspective, the Danish language has received relatively little attention and, as a result, Danish language technology is hard to develop, in part due to a lack of large o...

Obtaining quick and reliable evidence regarding the proficiency of learners is a perennial issue in second language (L2) learning research. In this study, we examined naturalistic utterance recall as a measure of L2 learning proficiency that can be easily extracted from videos and automatically scored using the video's captions. In our recall task,...

Research has suggested that Danish-learning children lag behind in early language acquisition. The phenomenon has been attributed to the opaque phonetic structure of Danish, which features an unusually large number of non-consonantal sounds (i.e., vowels and semivowels/glides). The large number of vocalic sounds in speech is thought to provide fewe...

Research has suggested that Danish-learning children lag behind in early language acquisition. The phenomenon has been attributed to the opaque phonetic structure of Danish, which features an unusually large number of non-consonantal sounds (i.e., vowels and semivowels/glides). The large amount of vocalic sounds in speech is thought to provide fewe...

Research has suggested that Danish-learning children lag behind in early language acquisition. The phenomenon has been attributed to the opaque phonetic structure of Danish, which features an unusually large number of non-consonantal sounds (i.e., vowels and semivowels/glides). The large amount of vocalic sounds in speech is thought to provide fewe...

Recent evidence suggests that while native language (L1) learning relies on the extraction of multiword units (MWUs) for the acquisition of grammatical knowledge, adult speakers have difficulty extracting frequently co-occurring MWUs when learning a second language (L2) [1,2]. Thus, differences between child L1 and adult L2 acquisition may be due i...

Statistical learning (SL) involving sensitivity to distributional regularities in the environment has been suggested to be an important factor in many aspects of cognition, including language. However, the degree to which statistically-learned information is retained over time is not well understood. To establish whether or not learners are able to...

Statistical learning (SL) is involved in a wide range of basic and higher-order cognitive functions and is taken to be an important building block of virtually all current theories of information processing. In the last 2 decades, a large and continuously growing research community has therefore focused on the ability to extract embedded patterns o...

Artificial grammar learning (AGL) has become an important tool used to understand aspects of human language learning and whether the abilities underlying learning may be unique to humans or found in other species. Successful learning is typically assumed when human or animal participants are able to distinguish stimuli generated by the grammar from...

The ability to produce and understand an unlimited number of different sentences is a hallmark of human language. Linguists have sought to define the essence of this generative capacity using formal grammars that describe the syntactic dependencies between constituents, independent of the computational limitations of the human brain. Here, we evalu...

A central question for cognitive science is whether children's linguistic productivity can be captured by item-based learning, or whether the learner must be guided by abstract, system-wide principles governed by innate constraints. Here, we present a computational model of early language acquisition which learns to discover and use lexically-based...

Achieving linguistic proficiency requires identifying words from speech, and discovering the constraints that govern the way those words are used. In a recent study of non-adjacent dependency learning, Frost and Monaghan (2016) demonstrated that learners may perform these tasks together, using similar statistical processes-contrary to prior suggest...

A substantial body of research has highlighted the central role of statistical learning (SL) in the acquisition of language in children and adults. This research has predominantly been conducted using artificial language learning (ALL) paradigms. However, it remains unclear to what extent such SL generalizes to a natural learning context. In contra...

Speech input is often noisy and ambiguous. Yet listenersusually do not have difficulties understanding it. A keyhypothesis is that in speech processing acoustic-phoneticbottom-up processing is complemented by top-downcontextual information. This context effect is larger when theambiguous word is only separated from a disambiguating word by a few sy...

A substantial body of research has demonstrated that children and adults (both native and non-native speakers) are sensitive to the statistics of multiword sequences (MWS) and rely on knowledge of such statistics to facilitate their language processing and boost their acquisition. However, this research was primarily aimed at determining whether an...

Statistical learning (SL), sensitivity to probabilistic regularities in sensory input, has been widely implicated in cognitive and perceptual development. Little is known, however, about the underlying mechanisms of SL and whether they undergo developmental change. One way to approach these questions is to compare SL across perceptual modalities. W...

Do people adjust their conversational strategies to the specific contextual demands of a given situation? Prior studies have yielded conflicting results, making it unclear how strategies vary with demands. We combine insights from qualitative and quantitative approaches in a within-participant experimental design involving two different contexts: s...

Language processing depends on the integration of bottom-up information with top-down cues from several different sources—primarily our knowledge of the real world, of discourse contexts, and of how language works. Previous studies have shown that factors pertaining to both the sender and the receiver of the message affect the relative weighting of...

Research has shown that contoids (phonetically defined consonants) may provide more robust and reliable cues to syllable and word boundaries than vocoids (phonetically defined vowels). Recent studies of Danish, a language characterized by frequent long sequences of vocoids in speech, have suggested that the reduced occurrence of contoids may make s...

High frequency words have been suggested to benefit both speech segmentation and grammatical categorisation of the words around them. Despite utilising similar information, these tasks are usually investigated separately in studies examining learning. We determined whether including high frequency words in continuous speech could support categorisa...

While usage-based approaches to language development enjoy considerable support from computational studies, there have been few attempts to answer a key computational challenge posed by usage-based theory: the successful modeling of language learning as language use. We present a usage-based computational model of language acquisition which learns...

New linguistic information must be integrated into our existing language system. Using a novel experimental task that incorporates a syntactic priming paradigm into artificial language learning, we investigated how new grammatical regularities and words are learned. This innovation allowed us to control the language input the learner received, whil...

It has been suggested that external and/or internal limitations paradoxically may lead to superior learning, that is, the concepts of starting small and less is more (Elman, 1993; Newport, 1990). In this paper, we explore the type of incremental ordering during training that might help learning, and what mechanism explains this facilitation. We rep...

A common assumption in the cognitive sciences is that artificial and natural language learning rely on shared mechanisms. However, attempts to bridge the two have yielded ambiguous results. We suggest that an empirical disconnect between the computations employed during learning and the methods employed at test may explain these mixed results. Furt...

Structured sequence processing tasks inform us about statistical learning abilities that are relevant to many areas of cognition, including language. Despite the ubiquity of these abilities across different tasks and cognitive domains, recent research in humans has demonstrated that these cognitive capacities do not represent a single, domain-gener...

Language acquisition researchers have often viewed children as ‘mini-linguists,’ attempting to infer abstract knowledge of language from exposure to their native language. From this perspective, the challenge of acquisition can seem so formidable that meeting it would appear to require that much of this knowledge must be built-in, as a language ins...

Humans and nonhuman primates can learn about the organization of stimuli in the environment using implicit sequential pattern learning capabilities. However, most previous artificial grammar learning studies with nonhuman primates have involved relatively simple grammars and short input sequences. The goal in the current experiments was to assess t...

Ding et al. (2017) contrast their view that language processing is based on hierarchical syntactic structures, to a view that relies on word-level input statistics. In this response to their paper, we clarify how, exactly, the two views differ (and how they do not), and make a case for the importance of sequential, as opposed to hierarchical, struc...

Languages with many speakers tend to be structurally simple while small communities sometimes develop languages with great structural complexity. Paradoxically, the opposite pattern appears to be observed for non-structural properties of language such as vocabulary size. These apparently opposite patterns pose a challenge for theories of language c...

Humans differ in innumerable ways, with considerable variation observable at every level of description, from the molecular to the social. Traditionally, linguistic and psycholinguistic theory has downplayed the possibility of meaningful differences in language across individuals. However, it is becoming increasingly evident that there is significa...

Previous research has shown that Danish-learning children lag behind in early lexical acquisition compared with children learning a number of other languages. This delay has been ascribed to the opaque phonetic structure of Danish, which appears to have fewer reliable segmentation cues than other closely related languages. In support of this hypoth...

Several recent empirical findings have reinforced the notion that a basic learning and memory skill—chunking—plays a fundamental role in language processing. Here, we provide evidence that chunking shapes sentence processing at multiple levels of linguistic abstraction, consistent with a recent theoretical proposal by Christiansen and Chater (2016)...

Why are children better language learners than adults despite being worse at a range of other cognitive tasks? Here, we explore the role of multiword sequences in explaining L1-L2 differences in learning. In particular, we propose that children and adults differ in their reliance on such multiword units (MWUs) in learning, and that this difference...

Attempts to connect individual differences in statistical learning with broader aspects of cognition have received considerable attention, but have yielded mixed results. A possible explanation is that statistical learning is typically tested using the two-alternative forced choice (2AFC) task. As a meta-cognitive task relying on explicit familiari...

The ability to convey our thoughts using an infinite number of linguistic expressions is one of the hallmarks of human language. Understanding the nature of the psychological mechanisms and representations that give rise to this unique productivity is a fundamental goal for the cognitive sciences. A long-standing hypothesis is that single words and...

Implicit learning and statistical learning are two contemporary approaches to the long‐standing question in psychology and cognitive science of how organisms pick up on patterned regularities in their environment. Although both approaches focus on the learner's ability to use distributional properties to discover patterns in the input, the relevant...

Human language is composed of sequences of reusable elements. The origins of the sequential structure of language is a hotly debated topic in evolutionary linguistics. In this paper, we show that sets of sequences with language-like statistical properties can emerge from a process of cultural evolution under pressure from chunk-based memory constra...

Supporting Material: String Length-Connectivity Scaling. (DOCX)