Natural languages come in two different modalities. The impact of modality on the grammatical structure and linguistic theory has been discussed at great length in the last 20 years. By contrast, the impact of modality on linguistic data elicitation and collection, corpus studies and experimental (psycholinguistic) studies is still underinvestigated (van Herreweghe/Vermeerbergen 2012; Orfanidou et al. 2015). In this paper, we address specific challenges that arise in judgement data elicitation and experimental studies of sign languages. These challenges are related (...) to the socio-linguistic status of the Deaf community and the larger variability across signers within the same community, to the social status of sign languages, to properties of ;he visual-gestural modality and its interface with gesture, to methodological aspects of handling sign language data, and to specific linguistic features of sign languages. While some of these challenges also pertain to (some varieties of) spoken languages, other challenges are more modality-specific. In addition, the special combination of the challenges discussed in this paper seems to be a specific facet empirical research on sign languages is faced with. In addition, we discuss the complementarity of theoretical approaches and experimental studies and show how the interaction of both approaches contributes to a better understanding of sign languages in particular and linguistic structures in general. (shrink)

Researchers in the fields of sign language and gesture studies frequently present their participants with video stimuli showing actors performing linguistic signs or co-speech gestures. Up to now, such video stimuli have been mostly controlled only for some of the technical aspects of the video material, leaving open the possibility that systematic differences in video stimulus materials may be concealed in the actual motion properties of the actor’s movements. Computer vision methods such as OpenPose enable the fitting of (...) body-pose models to the consecutive frames of a video clip and thereby make it possible to recover the movements performed by the actor in a particular video clip without the use of a point-based or markerless motion-tracking system during recording. The OpenPoseR package provides a straightforward and reproducible way of working with these body-pose model data extracted from video clips using OpenPose, allowing researchers in the fields of sign language and gesture studies to quantify the amount of motion pertaining only to the movements performed by the actor in a video clip. These quantitative measures can be used for controlling differences in the movements of an actor in stimulus video clips or, for example, between different conditions of an experiment. In addition, the package also provides a set of functions for generating plots for data visualization, as well as an easy-to-use way of automatically extracting metadata from large sets of video files. (shrink)

Associations between language and executive functions are well-established but previous work has often focused more on EFs than on language. To further clarify the language–EF relationship, we assessed several aspects of language and EFs in 431 Swedish children aged 4–6, including selective auditory attention which was measured in an event-related potential paradigm. We also investigated potential associations to age, socioeconomic status, bi-/multilingualism, sex and aspects of preschool attendance and quality. Language and EFs correlated weakly to (...) moderately, indicating that relying on measures of vocabulary alone may overestimate the strength of the language–EF relationship. Contrary to predictions, we found no correlations between selective attention and EFs. There were however correlations between morphosyntactic accuracy and selective auditory attention which is in line with previous work and suggests a specific link between morphosyntax and the ability to suppress irrelevant stimuli. In Sweden, socioeconomic differences are rather small and preschool is universally available, but nevertheless, aspects of parental SES predicted children’s performance on all measures. Bi-/multilingual children performed lower on language also when controlling for SES, highlighting the need for interventions to reduce inequalities in educational outcomes already in preschool. A female advantage was found for both language and EFs, whereas preschool attendance and quality were not significantly related to outcome measures. Future work should include longitudinal studies of language and EF development, include children from diverse SES backgrounds and contribute toward a theoretical framework that further clarifies the language–EF relationship. (shrink)

Since the beginning of signed language research, the linguistic units have been divided into conventional, standard and fixed signs, all of which were considered as the core of the language, and iconic and productive signs, put at the edge of language. In the present paper, we will review different models proposed by signed language researchers over the years to describe the signed lexicon, showing how to overcome the hierarchical division between standard and productive lexicon. Drawing from (...) the semiotic insights of Peirce we proposed to look at signs as a triadic construction built on symbolic, iconic, and indexical features. In our model, the different iconic, symbolic, and indexical features of signs are seen as the three sides of the same triangle, detectable in the single linguistic sign. The key aspect is that the dominance of the feature will determine the different use of the linguistic unit, as we will show with examples from different discourse types. (shrink)

The American Sign Language Sentence Reproduction Test (ASL-SRT) requires the precise reproduction of a series of ASL sentences increasing in complexity and length. Error analyses of such tasks provides insight into working memory and scaffolding processes. Data was collected from three groups expected to differ in fluency: deaf children, deaf adults and hearing adults, all users of ASL. Quantitative (correct/incorrect recall) and qualitative error analyses were performed. Percent correct on the reproduction task supports its sensitivity to fluency as (...) test performance clearly differed across the three groups studied. A linguistic analysis of errors further documented differing strategies and bias across groups. Subjects' recall projected the affordance and constraints of deep linguistic representations to differing degrees, with subjects resorting to alternate processing strategies when they failed to recall the sentence correctly. A qualitative error analysis allows us to capture generalizations about the relationship between error pattern and the cognitive scaffolding, which governs the sentence reproduction process. Highly fluent signers and less-fluent signers share common chokepoints on particular words in sentences. However, they diverge in heuristic strategy. Fluent signers, when they make an error, tend to preserve semantic details while altering morpho-syntactic domains. They produce syntactically correct sentences with equivalent meaning to the to-be-reproduced one, but these are not verbatim reproductions of the original sentence. In contrast, less-fluent signers tend to use a more linear strategy, preserving lexical status and word ordering while omitting local inflections, and occasionally resorting to visuo-motoric imitation. Thus, whereas fluent signers readily use top-down scaffolding in their working memory, less fluent signers fail to do so. Implications for current models of working memory across spoken and signed modalities are considered. (shrink)

There has long been interest in why languages are shaped the way they are, and in the relationship between sign language and gesture. In sign languages, entity classifiers are handshapes that encode how objects move, how they are located relative to one another, and how multiple objects of the same type are distributed in space. Previous studies have shown that hearing adults who are asked to use only manual gestures to describe how objects move in space will (...) use gestures that bear some similarities to classifiers. We investigated how accurately hearing adults, who had been learning British Sign Language for 1–3 years, produce and comprehend classifiers in locative and distributive constructions. In a production task, learners of BSL knew that they could use their hands to represent objects, but they had difficulty choosing the same, conventionalized, handshapes as native signers. They were, however, highly accurate at encoding location and orientation information. Learners therefore show the same pattern found in sign-naïve gesturers. In contrast, handshape, orientation, and location were comprehended with equal accuracy, and testing a group of sign-naïve adults showed that they too were able to understand classifiers with higher than chance accuracy. We conclude that adult learners of BSL bring their visuo-spatial knowledge and gestural abilities to the tasks of understanding and producing constructions that contain entity classifiers. We speculate that investigating the time course of adult sign language acquisition might shed light on how gesture became conventionalized during the genesis of sign languages. (shrink)

Sign languages exhibit all the complexities and evolutionary advantages of spoken languages. Consequently, sign languages are problematic for a theory of language evolution that assumes a gestural origin. There are no compelling arguments why the expanding spiral between protosign and protospeech proposed by Arbib would not have resulted in the evolutionary dominance of sign over speech.

Even the simplest narratives combine multiple strands of information, integrating different characters and their actions by expressing multiple perspectives of events. We examined the emergence of referential shift devices, which indicate changes among these perspectives, in Nicaraguan Sign Language (NSL). Sign languages, like spoken languages, mark referential shift grammatically with a shift in deictic perspective. In addition, sign languages can mark the shift with a point or a movement of the body to a specified spatial location (...) in the three-dimensional space in front of the signer, capitalizing on the spatial affordances of the manual modality. We asked whether the use of space to mark referential shift emerges early in a new sign language by comparing the first two age cohorts of deaf signers of NSL. Eight first-cohort signers and 10 second-cohort signers watched video vignettes and described them in NSL. Narratives were coded for lexical (use of words) and spatial (use of signing space) devices. Although the cohorts did not differ significantly in the number of perspectives represented, second-cohort signers used referential shift devices to explicitly mark a shift in perspective in more of their narratives. Furthermore, while there was no significant difference between cohorts in the use of non-spatial, lexical devices, there was a difference in spatial devices, with second-cohort signers using them in significantly more of their narratives. This suggests that spatial devices have only recently increased as systematic markers of referential shift. Spatial referential shift devices may have emerged more slowly because they depend on the establishment of fundamental spatial conventions in the language. While the modality of sign languages can ultimately engender the syntactic use of three-dimensional space, we propose that a language must first develop systematic spatial distinctions before harnessing space for grammatical functions. (shrink)

Name der Zeitschrift: Cognitive Linguistics Jahrgang: 26 Heft: 2 Seiten: 211-260.

We describe how a Community-Based Participatory Research (CBPR) process was used to develop a means of discussing end-of-life care needs of Deaf seniors. This process identified a variety of communication issues to be addressed in working with this special population. We overview the unique linguistic and cultural characteristics of this community and their implications for working with Deaf individuals to provide information for making informed decisions about end-of-life care, including completion of health care directives. Our research and our work with (...) members of the Deaf community strongly show that communication and presentation of information should be in American Sign Language, the language of Deaf citizens. (shrink)

The present study investigates the types of verb and symbolic representational strategies used by 10 deaf signing adults and 13 deaf signing children who described in Italian Sign Language 45 video clips representing nine action types generally communicated by five general verbs in spoken Italian. General verbs, in which the same sign was produced to refer to several different physical action types, were rarely used by either group of participants. Both signing children and adults usually produced specific (...) depicting predicates by incorporating, through a representational strategy, the object and/or the modality of the action into the sign. As for the different types of representational strategies, the adults used the hand-as-object strategy more frequently than the children, who, in turn, preferred to use the hand-as-hand strategy, suggesting that different degrees of cognitive complexity are involved in these two symbolic strategies. Addressing the symbolic iconic strategies underlying sign formation could provide new insight into the perceptual and cognitive processes of linguistic meaning construction. The findings reported here support two main assumptions of cognitive linguistics applied to sign languages: there is a strong continuity between gestures and language; lexical units and depicting constructions derive from the same iconic core mechanism of sign creation. (shrink)

The study of signed languages has inspired scientific' speculation regarding foundations of human language. Relationships between the acquisition of sign language in apes and man are discounted on logical grounds. Evidence from the differential hreakdown of sign language and manual pantomime places limits on the degree of overlap between language and nonlanguage motor systems. Evidence from functional magnetic resonance imaging reveals neural areas of convergence and divergence underlying signed and spoken languages.

The book represents a historical overview of the way the topic of gesture and sign language has been treated in the 18th century French philosophy. The texts treated are grouped into several categories based on the view they present of deafness and gesture. While some of those texts obviously view deafness and sign language in negative terms, i.e. as deficiency, others present deafness essentially as difference, i.e. as a set of competences that might provide some insights (...) into how spoken language works. One of the arguments of the book is that these two views of deafness and sign language still represent two dominant paradigms present in the current debates on the issue. The aim of the book, therefore, is not only to provide a historical overview but to trace what might be called a "history of the present". (shrink)

Name der Zeitschrift: Cognitive Linguistics Jahrgang: 27 Heft: 1 Seiten: 35-65.

Chomsky's “revolution” and the revolution in sign language linguistics began around the same time, but they did not directly affect each other for a while. This chapter focuses on Chomsky‐inspired research on sign language grammar and the ways that the study of sign languages connects to theories of innateness, the two main ways that Chomsky's impact has been felt in sign linguistics. Chomsky's linguistic legacy has two primary arms: one in theories of syntax, and (...) the other in theories of language acquisition. Chomsky's strong claim is that the input provided to young children acquiring their native language is too poor to constitute a complete inductive basis for general cognitive learning principles to succeed. Specifying the content of the “language acquisition device” has been a central concern of Chomskian linguistics. (shrink)

Harris proposes a new theory of communication, beginning with the premise that the mental life of an individual should be conceived of as a continuous attempt to integrate the present with the past and future.

This paper presents a study of modality in Iranian Sign Language (ZEI) from a cognitive perspective, aimed at analyzing two linguistic channels: facial and manual. While facial markers and their grammatical functions have been studied in some sign languages, we have few detailed analyses of the facial channel in comparison with the manual channel in conveying modal concepts. This study focuses on the interaction between manual and facial markers. A description of manual modal signs is offered. Three (...) facial markers and their modality values are also examined: squinted eyes, brow furrow, and downward movement of lip corners (horseshoe mouth). In addition to offering this first descriptive analysis of modality in ZEI, this paper also applies the Cognitive Grammar model of modality, the Control Cycle, and the Reality Model, classifying modals into two kinds, effective and epistemic. It is suggested that effective control, including effective modality, tends to be expressed on the hands, while facial markers play an important role in marking epistemic assessment, one manifestation of which is epistemic modality. ZEI, like some other sign languages, exhibits an asymmetry between the number of manual signs and facial markers expressing epistemic modality: while the face can be active in the expression of effective modality, it is commonly the only means of expressing epistemic modality. By positing an epistemic core in effective modality, Cognitive Grammar provides a theoretical basis for these findings. (shrink)

Here, a moral case is presented as to why sign languages such as Auslan should be made compulsory in general school curricula. Firstly, there are significant benefits that accrue to individuals from learning sign language. Secondly, sign language education is a matter of justice; the normalisation of sign language education and use would particularly benefit marginalised groups, such as those living with a communication disability. Finally, the integration of sign languages into the (...) curricula would enable the flourishing of Deaf culture and go some way to resolving the tensions that have arisen from the promotion of oralist education facilitated by technologies such as cochlear implants. There are important reasons to further pursue policy proposals regarding the prioritisation of sign language in school curricula. (shrink)

When naming certain hand-held, man-made tools, American Sign Language signers exhibit either of two iconic strategies: a handling strategy, where the hands show holding or grasping an imagined object in action, or an instrument strategy, where the hands represent the shape or a dimension of the object in a typical action. The same strategies are also observed in the gestures of hearing nonsigners identifying pictures of the same set of tools. In this paper, we compare spontaneously created gestures (...) from hearing nonsigning participants to commonly used lexical signs in ASL. Signers and gesturers were asked to respond to pictures of tools and to video vignettes of actions involving the same tools. Nonsigning gesturers overwhelmingly prefer the handling strategy for both the Picture and Video conditions. Nevertheless, they use more instrument forms when identifying tools in pictures, and more handling forms when identifying actions with tools. We found that ASL signers generally favor the instrument strategy when naming tools, but when describing tools being used by an actor, they are significantly more likely to use more handling forms. The finding that both gesturers and signers are more likely to alternate strategies when the stimuli are pictures or video suggests a common cognitive basis for differentiating objects from actions. Furthermore, the presence of a systematic handling/instrument iconic pattern in a sign language demonstrates that a conventionalized sign language exploits the distinction for grammatical purpose, to distinguish nouns and verbs related to tool use. (shrink)

This essay offers an interpretation and partial defense of Nietzsche's idea that moralities and moral judgments are “sign-languages” or “symptoms” of our affects, that is, of our emotions or feelings. According to Nietzsche, as I reconstruct his view, moral judgments result from the interaction of two kinds of affective responses: first, a “basic affect” of inclination toward or aversion from certain acts, and then a further affective response to that basic affect. I argue that Nietzsche views basic affects asnoncognitive, (...) that is, as identifiable solely by how they feel to the subject who experiences the affect. By contrast, I suggest that meta-affects sometimes incorporate acognitivecomponent like belief. After showing how this account of moral judgment comports with a reading of Nietzsche's moral philosophy that I have offered in previous work, I conclude by adducing philosophical and empirical psychological reasons for thinking that Nietzsche's account of moral judgment is correct. (shrink)

Metaphor abounds in both sign and spoken languages. However, in sign languages, languages in the visual-manual modality, metaphors work a bit differently than they do in spoken languages. In this paper we explore some of the ways in which metaphors in sign languages differ from metaphors in spoken languages. We address three differences: (a) Some metaphors are very common in spoken languages yet are infelicitous in sign languages; (b) Body-part terms are possible in very specific types (...) of metaphors in sign languages, but are not so restricted in spoken languages; (c) Similes in some sign languages are dispreferred in predicative positions in which metaphors are fine, in contrast to spoken languages where both can appear in these environments. We argue that these differences can be explained by two seemingly unrelated principles: the Double Mapping Constraint (Meir 2010), which accounts for the interaction between metaphor and iconicity in languages, and Croft's (2003) constraint regarding the autonomy and dependency of elements in metaphorical constructions. We further argue that the study of metaphor in the signed modality offers novel insights concerning the nature of metaphor in general, and the role of figurative speech in language. (shrink)

In contrast to scholars and signers in the nineteenth century, William Stokoe conceived of American Sign Language (ASL) as a unique linguistic tradition with roots in nineteenth-centurylangue des signes française, a conception that is apparent in his earliest scholarship on ASL. Stokoe thus contributed to the theoretical foundations upon which the field of sign language historical linguistics would later develop. This review focuses on the development of sign language historical linguistics since Stokoe, including the (...) field's significant progress and the theoretical and methodological problems that it still faces. The review examines the field's development through the lens of two related problems pertaining to how we understand sign language relationships and to our understanding of cognacy, as the term pertains to signs. It is suggested that the theoretical notions underlying these terms do not straightforwardly map onto the historical development of many sign languages. Recent approaches in sign language historical linguistics are highlighted and future directions for research are suggested to address the problems discussed in this review. (shrink)

Productivity—the hallmark of linguistic competence—is typically attributed to algebraic rules that support broad generalizations. Past research on spoken language has documented such generalizations in both adults and infants. But whether algebraic rules form part of the linguistic competence of signers remains unknown. To address this question, here we gauge the generalization afforded by American Sign Language (ASL). As a case study, we examine reduplication (X→XX)—a rule that, inter alia, generates ASL nouns from verbs. If signers encode this (...) rule, then they should freely extend it to novel syllables, including ones with features that are unattested in ASL. And since reduplicated disyllables are preferred in ASL, such rule should favor novel reduplicated signs. Novel reduplicated signs should thus be preferred to nonreduplicative controls (in rating), and consequently, such stimuli should also be harder to classify as nonsigns (in the lexical decision task). The results of four experiments support this prediction. These findings suggest that the phonological knowledge of signers includes powerful algebraic rules. The convergence between these conclusions and previous evidence for phonological rules in spoken language suggests that the architecture of the phonological mind is partly amodal. (shrink)

How does sign language compare with gesture, on the one hand, and spoken language on the other? Sign was once viewed as nothing more than a system of pictorial gestures without linguistic structure. More recently, researchers have argued that sign is no different from spoken language, with all of the same linguistic structures. The pendulum is currently swinging back toward the view that sign is gestural, or at least has gestural components. The goal (...) of this review is to elucidate the relationships among sign language, gesture, and spoken language. We do so by taking a close look not only at how sign has been studied over the past 50 years, but also at how the spontaneous gestures that accompany speech have been studied. We conclude that signers gesture just as speakers do. Both produce imagistic gestures along with more categorical signs or words. Because at present it is difficult to tell where sign stops and gesture begins, we suggest that sign should not be compared with speech alone but should be compared with speech-plus-gesture. Although it might be easier (and, in some cases, preferable) to blur the distinction between sign and gesture, we argue that distinguishing between sign (or speech) and gesture is essential to predict certain types of learning and allows us to understand the conditions under which gesture takes on properties of sign, and speech takes on properties of gesture. We end by calling for new technology that may help us better calibrate the borders between sign and gesture. (shrink)

Dr. Fouts began his lecture with the story of how he and his wife Deborah became involved with Washoe—the first non-human to acquire the signs of American Sign Language (ASL). Project Washoe began in 1966 with Drs. Allen and Beatrix Gardner in Reno, Nevada. There had been other experiments that attempted to get chimpanzees to speak. These experiments were not successful due to anatomical and neurological differences between humans and chimpanzees. (Fouts showed some video of the chimpanzee Vicki (...) trying to say the four words she had learned—mama, papa, up, cup.) Part of the issue is the construction of the chimpanzee’s vocal box while another part of the issue is that chimpanzee vocalizations are tied to their .. (shrink)

The ethical and philosophical issues of choosing disability accommodations, particularly regarding human service provider accommodations, have not received much attention in the academic literature. Signed language interpreting is an especially complex accommodation that requires assessment of the deaf person's language knowledge and facility in a society where the many varieties of deaf education have generated a continuum of American Sign Language and signed English. Signed language interpreters with variable levels of skill and proficiency flock to (...) work in locations with high demand for their services, sometimes with little regulation and consumer protection, due to laws that mandate the provision of... (shrink)

A universally acknowledged, core property of language is its complexity, at each level of structure – sounds, words, phrases, clauses, utterances, and higher levels of discourse. How does this complexity originate and develop in a language? We cannot fully answer this question from spoken languages, since they are all thousands of years old or descended from old languages. However, sign languages of deaf communities can arise at any time and provide empirical data for testing hypotheses related to (...) the emergence of language complexity. An added advantage of the signed modality is a direct correspondence between visible physical articulations and linguistic structures, providing a more transparent view of linguistic complexity and its emergence (Sandler 2012). These essential characteristics of sign languages allow us to address the issue of emerging complexity by documenting the use of the body for linguistic purposes. We look at three types of discourse relations of increasing complexity motivated by research on spoken languages – additive, symmetric and asymmetric (Mann and Thompson 1988; Sanders, Spooren, and Noordman 1992), Each relation type can connect units at two different levels: within propositions (simpler) and across propositions (more complex). We hypothesized that these relations provide a measure for charting the time course of emergence of complexity, from simplest to most complex, in a new sign language. We test this hypothesis on Israeli Sign Languages (ISL), a young language, some of whose earliest users are still available for recording. Taking advantage of the unique relation in sign languages between bodily articulations and linguistic form, we study fifteen ISL signers from three different generations, and demonstrate that the predictions indeed hold. We also find that younger signers tend to converge on more systematic marking of relations, that they use fewer articulators for a given linguistic function than older signers, and that the form of articulations becomes reduced, as the language matures. Mapping discourse relations to the bodily expression of linguistic components across age groups reveals how simpler, less constrained, and more gesture-like expressions, become language. (shrink)

We argue that the pictorial nature of certain constructions in signs and in gestures explains surprising properties of their syntax. In several sign languages, the standard word order (e.g. SVO) gets turned into SOV (with preverbal arguments) when the predicate is a classifier, a distinguished construction with highly iconic properties (e.g. Pavlič, 2016). In silent gestures, participants also prefer an SOV order in extensional constructions, irrespective of the word order of the language they speak (Goldin-Meadow et al., 2008). (...) But in silent gestures and in Brazilian Sign Language (Libras), intensional constructions can override these SOV preferences, yielding SVO instead (Schouwstra & de Swart, 2014; Napoli et al., 2017). This distinction was argued to be due to iconicity: arguments are expressed before the verb if they correspond to entities that are present before the action, otherwise they follow the verb. While agreeing with this intuition, we propose that the extensional/intensional distinction is neither empirically nor theoretically appropriate. In new data from American Sign Language, we replicate the distinction among extensional classifier predicates: for _x ate up the ball_, the ball is typically seen before the eating and a preposed object is preferred; but for _x spit out the ball_, the ball is typically seen after the spitting and a postposed object is preferred, although both _eat up_ and _spit out_ are used extensionally. We extend this finding to data involving pro-speech (= speech-replacing) gestures embedded in French sentences. We argue for a Visibility Generalization according to which arguments appear before the verb if their denotations are typically visible before the action, and we develop a new formal account within a pictorial semantics for visual animations (inspired by Greenberg and Abusch). It derives the observed word order preferences, it explains how the semantics of classifier predicates combines iconic and conventional properties, and it makes a more general point: sign language semantics combines logical semantics with pictorial semantics. (shrink)

Signed languages employ finely articulated facial and head displays to express grammatical meanings such as mood and modality, complex propositions, information structure, assertions, content and yes/no questions, imperatives, and miratives. In this paper we examine two facial displays: an upper face display in which the eyebrows are pulled together called brow furrow, and a lower face display in which the corners of the mouth are turned down into a distinctive configuration that resembles a frown or upside-down U-shape. Our analysis employs (...) Cognitive Grammar, specifically the control cycle and its manifestation in effective control and epistemic control. Our claim is that effective and epistemic control are associated with embodied actions. Prototypical physical effective control requires effortful activity and the forceful exertion of energy and is commonly correlated with upper face activity, often called the “face of effort.” The lower face display has been shown to be associated with epistemic indetermination, uncertainty, doubt, obviousness, and skepticism. We demonstrate that the control cycle unifies the diverse grammatical functions expressed by each facial display within a language, and that they express similar functions across a wide range of signed languages. (shrink)

For humans, the ability to communicate and use language is instantiated not only in the vocal modality but also in the visual modality. The main examples of this are sign languages and gestures. Sign languages, the natural languages of Deaf communities, use systematic and conventionalized movements of the hands, face, and body for linguistic expression. Co-speech gestures, though non-linguistic, are produced in tight semantic and temporal integration with speech and constitute an integral part of language together (...) with speech. The articles in this issue explore and document how gestures and sign languages are similar or different and how communicative expression in the visual modality can change from being gestural to grammatical in nature through processes of conventionalization. As such, this issue contributes to our understanding of how the visual modality shapes language and the emergence of linguistic structure in newly developing systems. Studying the relationship between signs and gestures provides a new window onto the human ability to recruit multiple levels of representation in the service of using or creating conventionalized communicative systems. (shrink)