Language as a multimodal phenomenon: implications for language learning,processing and evolution

Our understanding of the cognitive and neural underpinnings of language has traditionally been firmly based on spoken Indo-European languages and on language studied as speech or text. However, in face-to-face communication, language is multimodal: speech signals are invariably accompanied by visual information on the face and in manual gestures, and sign languages deploy multiple channels (hands, face and body) in utterance construction. Moreover, the narrow focus on spoken Indo-European languages has entrenched the assumption that language is comprised wholly by an arbitrary system of symbols and rules. However, iconicity (i.e. resemblance between aspects of communicative form and meaning) is also present: speakers use iconic gestures when they speak; many non-Indo-European spoken languages exhibit a substantial amount of iconicity in word forms and, finally, iconicity is the norm, rather than the exception in sign languages. This introduction provides the motivation for taking a multimodal approach to the study of language learning, processing and evolution, and discusses the broad implications of shifting our current dominant approaches and assumptions to encompass multimodal expression in both signed and spoken languages.     

Rich inflection and the production of finite verbs in child language

Children acquiring languages with rich inflection produce verbal morphology earlier in development than those learning languages with more impoverished inflection. In this paper, I present data from bilingual children acquiring Basque and Spanish, two null-subject languages with rich morphology which show a lead-lag pattern in the acquisition of inflection. Verbal inflection appears earlier in Spanish than in Basque, and although children produce few root infinitives in either language, they produce fewer in Spanish than in Basque. This is surprising, given that Basque has even “richer” verbal inflection than Spanish insofar as Basque has more obligatory morphological distinctions than Spanish does. These results lead me to propose that a combination of factors facilitate the early emergence of inflection in languages such as Spanish, including nominative/accusative case marking as well as morphological complexity, rather than solely the richness of the verbal paradigm.     

An fMRI Study of Grammatical Morpheme Processing Associated with Nouns and Verbs in Chinese

This study examined whether the degree of complexity of a grammatical component in a language would impact on its representation in the brain through identifying the neural correlates of grammatical morpheme processing associated with nouns and verbs in Chinese. In particular, the processing of Chinese nominal classifiers and verbal aspect markers were investigated in a sentence completion task and a grammaticality judgment task to look for converging evidence. The Chinese language constitutes a special case because it has no inflectional morphology per se and a larger classifier than aspect marker inventory, contrary to the pattern of greater verbal than nominal paradigmatic complexity in most European languages. The functional imaging results showed BA47 and left supplementary motor area and superior medial frontal gyrus more strongly activated for classifier processing, and the left posterior middle temporal gyrus more responsive to aspect marker processing. We attributed the activation in the left prefrontal cortex to greater processing complexity during classifier selection, analogous to the accounts put forth for European languages, and the left posterior middle temporal gyrus to more demanding verb semantic processing. The overall findings significantly contribute to cross-linguistic observations of neural substrates underlying processing of grammatical morphemes from an analytic and a classifier language, and thereby deepen our understanding of neurobiology of human language.     

Iconicity in English and Spanish and Its Relation to Lexical Category and Age of Acquisition

Signed languages exhibit iconicity (resemblance between form and meaning) across their vocabulary, and many non-Indo-European spoken languages feature sizable classes of iconic words known as ideophones. In comparison, Indo-European languages like English and Spanish are believed to be arbitrary outside of a small number of onomatopoeic words. In three experiments with English and two with Spanish, we asked native speakers to rate the iconicity of ~600 words from the English and Spanish MacArthur-Bates Communicative Developmental Inventories. We found that iconicity in the words of both languages varied in a theoretically meaningful way with lexical category. In both languages, adjectives were rated as more iconic than nouns and function words, and corresponding to typological differences between English and Spanish in verb semantics, English verbs were rated as relatively iconic compared to Spanish verbs. We also found that both languages exhibited a negative relationship between iconicity ratings and age of acquisition. Words learned earlier tended to be more iconic, suggesting that iconicity in early vocabulary may aid word learning. Altogether these findings show that iconicity is a graded quality that pervades vocabularies of even the most “arbitrary” spoken languages. The findings provide compelling evidence that iconicity is an important property of all languages, signed and spoken, including Indo-European languages.     

Syncretism in Dutch dialects

Dutch dialects show an enormous amount of variation with respect to the verbal inflectional paradigm. To wit, some dialects only have two forms in the present tense indicative to express all persons in singular and plural, whereas other dialects use three or even four different forms to do so. inflectional pattern is equally likely to occur; some patterns are found nowhere, whereas others are geographically widespread and stable over time. We will show that these recurring patterns of syncretism are also typologically well-attested. The recurring pattern involves neutralization of a morphosyntactic distinction in the marked half of the paradigm. More specifically, we see that plural and past tense are neutralizing contexts. We will show that a grammar that solely uses underspecification of affixes to account for the observed syncretisms, misses a generalization that can only be expressed by impoverishment rules or some paradigmatic means.     

Social scale and structural complexity in human languages

The complexity of different components of the grammars of human languages can be quantified. For example, languages vary greatly in the size of their phonological inventories, and in the degree to which they make use of inflectional morphology. Recent studies have shown that there are relationships between these types of grammatical complexity and the number of speakers a language has. Languages spoken by large populations have been found to have larger phonological inventories, but simpler morphology, than languages spoken by small populations. The results require further investigation, and, most importantly, the mechanism whereby the social context of learning and use affects the grammatical evolution of a language needs elucidation.     

Irregular past tense forms in English: how data from children with specific language impairment contribute to models of morphology

Two cognitive models of inflectional morphology are widely debated in the literature—the Words and Rules model, whereby irregular forms are stored in the lexicon but regular forms are created by rule, and Single Mechanism models, whereby both regulars and irregulars form an associative network, with no rules. A newer model, the Computational Grammatical Complexity (CGC) model, recognises the contribution of hierarchical complexity in three components of the grammar, syntax, morphology and phonology, to the construction of morphologically complex forms. This model has previously been tested for regular past tense inflection in English, and in this study we test its predictions for the English irregular past tense, in four groups of children: a group with Grammatical Specific Language Impairment (G-SLI; aged 9;8–17;8), and three groups of typically developing children (aged 5;4–8;5). Children with G-SLI provide an important test case for the CGC model because they have deficits in syntax, morphology and phonology. As predicted, children with G-SLI produced fewer tense-marked irregulars than expected for their age, and fewer over-regularisations than their language-matched controls. The effect of verb-end phonology on over-regularisation and null-marking errors was the same for all groups: both G-SLI and typically developing children were more likely to over-regularise verbs ending in a vowel, and more likely to null-mark verbs ending in an alveolar consonant. We interpret these results as providing further support for the CGC model.     

Borrowing contextual inflection: evidence from northern Australia

Gurindji Kriol is a north Australian mixed language which combines lexical and structural elements from Gurindji (Pama-Nyungan), and Kriol (English-lexifier). One of the more striking features of the grammar of Gurindji Kriol is the presence of the Gurindji case paradigm including ergative and dative case-markers within a Kriol verbal frame. Given the fragility of inflectional morphology in other language contact situations, particularly contextual inflections such as structural case markers, this situation bears closer scrunity. This paper argues that the presence of Gurindji case morphology is the result of pervasive code-switching practices which immediately preceded the genesis of the mixed language. As the code-switching stabilised into a mixed language, case-marking was integrated into predicate argument structure of Gurindji Kriol via nominal adjunct structures. Yet, these case markers were not absorbed unscathed. Although the Gurindji Kriol case paradigm bears a close resemblance to its Gurindji source in form, these case markers have not been perfectly replicated in function and distribution. Contact with Kriol functional equivalents such as prepositions and word order have altered the function and distribution of these case markers. The last part of this paper examines the shift that has occurred in Gurindji-derived case morphology in Gurindji Kriol.     

Fronto-temporal brain systems supporting spoken language comprehension

The research described here combines psycholinguistically well-motivated questions about different aspects of human language comprehension with behavioural and neuroimaging studies of normal performance, incorporating both subtractive analysis techniques and functional connectivity methods, and applying these tasks and techniques to the analysis of the functional and neural properties of brain-damaged patients with selective linguistic deficits in the relevant domains. The results of these investigations point to a set of partially dissociable sub-systems supporting three major aspects of spoken language comprehension, involving regular inflectional morphology, sentence-level syntactic analysis and sentence-level semantic interpretation. Differential patterns of fronto-temporal connectivity for these three domains confirm that the core aspects of language processing are carried out in a fronto-temporo-parietal language system which is modulated in different ways as a function of different linguistic processing requirements. No one region or sub-region holds the key to a specific language function; each requires the coordination of activity within a number of different regions. Functional connectivity analysis plays the critical role of indicating the regions which directly participate in a given sub-process, by virtue of their joint time-dependent activity. By revealing these codependencies, connectivity analysis sharpens the pattern of structure-function relations underlying specific aspects of language performance.     

Language Structure Is Partly Determined by Social Structure

Background

Languages differ greatly both in their syntactic and morphological systems and in the social environments in which they exist. We challenge the view that language grammars are unrelated to social environments in which they are learned and used.

Methodology/Principal Findings

We conducted a statistical analysis of >2,000 languages using a combination of demographic sources and the World Atlas of Language Structures— a database of structural language properties. We found strong relationships between linguistic factors related to morphological complexity, and demographic/socio-historical factors such as the number of language users, geographic spread, and degree of language contact. The analyses suggest that languages spoken by large groups have simpler inflectional morphology than languages spoken by smaller groups as measured on a variety of factors such as case systems and complexity of conjugations. Additionally, languages spoken by large groups are much more likely to use lexical strategies in place of inflectional morphology to encode evidentiality, negation, aspect, and possession. Our findings indicate that just as biological organisms are shaped by ecological niches, language structures appear to adapt to the environment (niche) in which they are being learned and used. As adults learn a language, features that are difficult for them to acquire, are less likely to be passed on to subsequent learners. Languages used for communication in large groups that include adult learners appear to have been subjected to such selection. Conversely, the morphological complexity common to languages used in small groups increases redundancy which may facilitate language learning by infants.

Conclusions/Significance

We hypothesize that language structures are subjected to different evolutionary pressures in different social environments. Just as biological organisms are shaped by ecological niches, language structures appear to adapt to the environment (niche) in which they are being learned and used. The proposed Linguistic Niche Hypothesis has implications for answering the broad question of why languages differ in the way they do and makes empirical predictions regarding language acquisition capacities of children versus adults.     

Wordhood and the interplay of linguistic levels in synthetic languages. An empirical study on Wichi (Mataguayan,Gran Chaco)

On the basis of data from the synthetic and agglutinative South American language Wichi (Mataguayan, Argentina/Bolivia), I argue in favor of regarding interface phenomena as typological variables. In particular, in this paper I discuss what type of interactions these are, arguing that they do not affect wordhood but do contribute to its formation. I will defend the hypothesis that linguistic level interactions within the word are of two types and different in nature: overlapping on the one hand and conditioning and alteration on the other. Conditioning only takes place in morphophonological and morphosemantic interactions and it follows the wordhood requirements of the language. Conversely, the interaction of morphology with all linguistic levels shows overlapping of units: the phonological word and the grammatical word in the morphophonological relation; the word and the simple clause or nominal phrase in the morphosyntactic relation; and the word and the semantic unit in the morphosemantic relation. This explains why the word is generally defined by phonological, morphological, syntactic and semantic criteria. It is to be hoped that the conclusions arrived at in this paper would contribute to deepen our knowledge of the notion of wordhood in synthetic languages in South America as well as our understanding of language structure and functioning.     

Abstractive morphological learning with a recurrent neural network

In traditional word-and-paradigm models of morphology, an inflectional system is represented via a set of exemplary paradigms. Novel wordforms are produced by analogy with previously encountered forms. This paper describes a recurrent neural network which can use this strategy to learn the paradigms of a morphologically complex language based on incomplete and randomized input. Results are given which show good performance for a range of typologically diverse languages.     

Comparison of maternal lineage and biogeographic analyses of ancient and modern Hungarian populations

The Hungarian language belongs to the Finno-Ugric branch of the Uralic family, but Hungarian speakers have been living in Central Europe for more than 1000 years, surrounded by speakers of unrelated Indo-European languages. In order to study the continuity in maternal lineage between ancient and modern Hungarian populations, polymorphisms in the HVSI and protein coding regions of mitochondrial DNA sequences of 27 ancient samples (10th-11th centuries), 101 modern Hungarian, and 76 modern Hungarian-speaking Sekler samples from Transylvania were analyzed. The data were compared with sequences derived from 57 European and Asian populations, including Finno-Ugric populations, and statistical analyses were performed to investigate their genetic relationships. Only 2 of 27 ancient Hungarian samples are unambiguously Asian: the rest belong to one of the western Eurasian haplogroups, but some Asian affinities, and the genetic effect of populations who came into contact with ancient Hungarians during their migrations are seen. Strong differences appear when the ancient Hungarian samples are analyzed according to apparent social status, as judged by grave goods. Commoners show a predominance of mtDNA haplotypes and haplogroups (H, R, T), common in west Eurasia, while high-status individuals, presumably conquering Hungarians, show a more heterogeneous haplogroup distribution, with haplogroups (N1a, X) which are present at very low frequencies in modern worldwide populations and are absent in recent Hungarian and Sekler populations. Modern Hungarian-speaking populations seem to be specifically European. Our findings demonstrate that significant genetic differences exist between the ancient and recent Hungarian-speaking populations, and no genetic continuity is seen.     

Morphology, language and the brain: the decompositional substrate for language comprehension

This paper outlines a neurocognitive approach to human language, focusing on inflectional morphology and grammatical function in English. Taking as a starting point the selective deficits for regular inflectional morphology of a group of non-fluent patients with left hemisphere damage, we argue for a core decompositional network linking left inferior frontal cortex with superior and middle temporal cortex, connected via the arcuate fasciculus. This network handles the processing of regularly inflected words (such as joined or treats), which are argued not to be stored as whole forms and which require morpho-phonological parsing in order to segment complex forms into stems and inflectional affixes. This parsing process operates early and automatically upon all potential inflected forms and is triggered by their surface phonological properties. The predictions of this model were confirmed in a further neuroimaging study, using event-related functional magnetic resonance imaging (fMRI), on unimpaired young adults. The salience of grammatical morphemes for the language system is highlighted by new research showing that similarly early and blind segmentation also operates for derivationally complex forms (such as darkness or rider). These findings are interpreted as evidence for a hidden decompositional substrate to human language processing and related to a functional architecture derived from non-human primate models.     

Networks uncover hidden lexical borrowing in Indo-European language evolution

Language evolution is traditionally described in terms of family trees with ancestral languages splitting into descendent languages. However, it has long been recognized that language evolution also entails horizontal components, most commonly through lexical borrowing. For example, the English language was heavily influenced by Old Norse and Old French; eight per cent of its basic vocabulary is borrowed. Borrowing is a distinctly non-tree-like process--akin to horizontal gene transfer in genome evolution--that cannot be recovered by phylogenetic trees. Here, we infer the frequency of hidden borrowing among 2346 cognates (etymologically related words) of basic vocabulary distributed across 84 Indo-European languages. The dataset includes 124 (5%) known borrowings. Applying the uniformitarian principle to inventory dynamics in past and present basic vocabularies, we find that 1373 (61%) of the cognates have been affected by borrowing during their history. Our approach correctly identified 117 (94%) known borrowings. Reconstructed phylogenetic networks that capture both vertical and horizontal components of evolutionary history reveal that, on average, eight per cent of the words of basic vocabulary in each Indo-European language were involved in borrowing during evolution. Basic vocabulary is often assumed to be relatively resistant to borrowing. Our results indicate that the impact of borrowing is far more widespread than previously thought.     

Defining ‘periphrasis’: key notions

We examine the notion of ??(inflectional) periphrasis?? within the framework of Canonical Typology, and argue that the canonical approach allows us to define a logically coherent notion of periphrasis. We propose a set of canonical criteria for inflectional morphology and a set of canonical criteria for functional syntax, that is, syntactic constructions which include functional elements and which express grammatical features. We argue that canonical periphrasis is exemplified in our theoretical space of possibilities whenever a cell in a (canonically morphological) inflectional paradigm (??feature intersection??) is expressed by a multiword construction which respects the canonical properties of functional syntax. We compare our canonically-based approach with the approach of other authors, notably, Ackerman & Stump (2004), who argue for three sufficient conditions for a construction to be regarded as periphrastic: feature intersection, non-compositionality and distributed exponence. We argue that non-compositionality and distributed exponence, while sometimes diagnostic of periphrasis on a language-particular basis, do not constitute canonical properties of periphrasis. We also examine crucial but neglected syntactic aspects of periphrastic constructions: recursion of periphrases and headedness of periphrastic constructions. The approach we propose allows us to distinguish between constructions in actual languages which approximate the ideal of canonical periphrasis to various degrees without committing us to a categorical distinction between periphrastic and non-periphrastic constructions. At the same time we can capture the intuition that there is in some languages a distinct identifiable set of multiword constructions whose principal role is to realize grammatical features.     

On the way from morphology to phonology: German linking elements and the role of the phonological word

German linking elements are sometimes classified as inflectional affixes, sometimes as derivational affixes, and in any case as morphological units with at least seven realisations (e.g. -s-, -es-, -(e)n-, -e-). This article seeks to show that linking elements are hybrid elements situated between morphology and phonology. On the one hand, they have a clear morphological status since they occur only within compounds (and before a very small set of suffixes) and support the listener in decoding them. On the other hand, they also have to be analysed on the phonological level, as will be shown in this article. Thus, they are marginal morphological units on the pathway to phonology (including prosodics). Although some alloforms can sometimes be considered former inflectional endings and in some cases even continue to demonstrate some inflectional behaviour (such as relatedness to gender and inflection class), they are on their way to becoming markers of ill-formed phonological words. In fact, linking elements, above all the linking -s-, which is extremely productive, help the listener decode compounds containing a bad phonological word as their first constituent, such as Geburt+s+tag ‘birthday’ or Religion+s+unterricht ‘religious education’. By marking the end of a first constituent that differs from an unmarked monopedal phonological word, the linking element aids the listener in correctly decoding and analysing the compound. German compounds are known for their length and complexity, both of which have increased over time—along with the occurrence of linking elements, especially -s-. Thus, a profound instance of language change can be observed in contemporary German, one indicating its typological shift from syllable language to word language.     

How do we use language? Shared patterns in the frequency of word use across 17 world languages

We present data from 17 languages on the frequency with which a common set of words is used in everyday language. The languages are drawn from six language families representing 65 per cent of the world's 7000 languages. Our data were collected from linguistic corpora that record frequencies of use for the 200 meanings in the widely used Swadesh fundamental vocabulary. Our interest is to assess evidence for shared patterns of language use around the world, and for the relationship of language use to rates of lexical replacement, defined as the replacement of a word by a new unrelated or non-cognate word. Frequencies of use for words in the Swadesh list range from just a few per million words of speech to 191 000 or more. The average inter-correlation among languages in the frequency of use across the 200 words is 0.73 (p < 0.0001). The first principal component of these data accounts for 70 per cent of the variance in frequency of use. Elsewhere, we have shown that frequently used words in the Indo-European languages tend to be more conserved, and that this relationship holds separately for different parts of speech. A regression model combining the principal factor loadings derived from the worldwide sample along with their part of speech predicts 46 per cent of the variance in the rates of lexical replacement in the Indo-European languages. This suggests that Indo-European lexical replacement rates might be broadly representative of worldwide rates of change. Evidence for this speculation comes from using the same factor loadings and part-of-speech categories to predict a word's position in a list of 110 words ranked from slowest to most rapidly evolving among 14 of the world's language families. This regression model accounts for 30 per cent of the variance. Our results point to a remarkable regularity in the way that human speakers use language, and hint that the words for a shared set of meanings have been slowly evolving and others more rapidly evolving throughout human history.