Intergenerational influence and ontogenetic development in the emergence of spatial grammar in Nicaraguan Sign Language

The recent emergence of a new sign language among deaf children and adolescents in Nicaragua provides an opportunity to study how grammatical features of a language arise and spread, and how new language environments are constructed. The grammatical regularities that underlie language use reside largely outside the domain of explicit awareness. Nevertheless, knowledge of these regularities must be transmitted from one generation to the next to survive as part of the language. During this transmission, language form and use is shaped by both the characteristics of ontogenetic development within individual users and by historical changes in patterns of interaction between users. To capture this process, the present study follows the emergence of spatial modulations in Nicaraguan Sign Language (NSL). A comprehension task examining interpretations of spatially modulated verbs reveals that new form-function mappings arise among children who functionally differentiate previously equivalent forms. The new mappings are then acquired by their age peers (who are also children), and by subsequent generations of children who learn the language, but not by adult contemporaries. As a result, language emergence is characterized by a convergence on form within each age cohort, and a mismatch in form from one age cohort to the cohort that follows. In this way, each age cohort, in sequence, transforms the language environment for the next, enabling each new cohort of learners to develop further than its predecessors.     

Interactions of language and memory in deaf children and adults

This article reviews theoretical and empirical issues concerning the relations of language and memory in deaf children and adults. An integration of previous studies, together with the presentation of new findings, suggests that there is an intimate relation between spoken language and memory. Either spoken language or sign language can serve as a natural mode of communication for young children (deaf or hearing), leading to normal language, social, and cognitive development. Nevertheless, variation in spoken language abilities can be shown to have a direct impact on memory span. Although the ways in which memory span can effect other cognitive processes and academic achievement are not considered in depth here, several variables that can have direct impact on the language-memory interaction are considered. These findings have clear implications for the education of deaf children.     

Tactile Enumeration and Embodied Numerosity Among the Deaf

Representations of the fingers are embodied in our cognition and influence performance in enumeration tasks. Among deaf signers, the fingers also serve as a tool for communication in sign language. Previous studies in normal hearing (NH) participants showed effects of embodiment (i.e., embodied numerosity) on tactile enumeration using the fingers of one hand. In this research, we examined the influence of extensive visuo-manual use on tactile enumeration among the deaf. We carried out four enumeration task experiments, using 1–5 stimuli, on a profoundly deaf group (n = 16) and a matching NH group (n = 15): (a) tactile enumeration using one hand, (b) tactile enumeration using two hands, (c) visual enumeration of finger signs, and (d) visual enumeration of dots. In the tactile tasks, we found salient embodied effects in the deaf group compared to the NH group. In the visual enumeration of finger signs task, we controlled the meanings of the stimuli presentation type (e.g., finger-counting habit, fingerspelled letters, both or neither). Interestingly, when comparing fingerspelled letters to neutrals (i.e., not letters or numerical finger-counting signs), an inhibition pattern was observed among the deaf. The findings uncover the influence of rich visuo-manual experiences and language on embodied representations. In addition, we propose that these influences can partially account for the lag in mathematical competencies in the deaf compared to NH peers. Lastly, we further discuss how our findings support a contemporary model for mental numerical representations and finger-counting habits.     

Brain activations associated with sign production using word and picture inputs in deaf signers

Effective literacy education in deaf students calls for psycholinguistic research revealing the cognitive and neural mechanisms underlying their written language processing. When learning a written language, deaf students are often instructed to sign out printed text. The present fMRI study was intended to reveal the neural substrates associated with word signing by comparing it with picture signing. Native deaf signers were asked to overtly sign in Chinese Sign Language (CSL) common objects indicated with written words or presented as pictures. Except in left inferior frontal gyrus and inferior parietal lobule where word signing elicited greater activation than picture signing, the two tasks engaged a highly overlapping set of brain regions previously implicated in sign production. The results suggest that word signing in the deaf signers relies on meaning activation from printed visual forms, followed by similar production processes from meaning to signs as in picture signing. The present study also documents the basic brain activation pattern for sign production in CSL and supports the notion of a universal core neural network for sign production across different sign languages.     

The onset and mastery of spatial language in children acquiring British Sign Language

In the course of language development children must solve arbitrary form-to-meaning mappings, in which semantic components are encoded onto linguistic labels. Because sign languages describe motion and location of entities through iconic movements and placement of the hands in space, child signers may find spatial semantics-to-language mapping easier to learn than child speakers. This hypothesis was tested in two studies: a longitudinal analysis of a native signing child's use of British Sign Language to describe motion and location events between the ages 1–10 and 3–0, and performance of 18 native signing children between the ages of 3–0 and 4–11 on a motion and location sentence comprehension task. The results from both studies argue against a developmental advantage for sign language learners for the acquisition of motion and location forms. Early forms point towards gesture and embodied actions followed by protracted mastery of the use of signs in representational space. The understanding of relative spatial relations continues to be difficult, despite the iconicity of these forms in the language, beyond 5 years of age.     

Number as a cognitive technology: evidence from Pirahã language and cognition

Does speaking a language without number words change the way speakers of that language perceive exact quantities? The Pirah? are an Amazonian tribe who have been previously studied for their limited numerical system [Gordon, P. (2004). Numerical cognition without words: Evidence from Amazonia. Science 306, 496-499]. We show that the Pirah? have no linguistic method whatsoever for expressing exact quantity, not even "one." Despite this lack, when retested on the matching tasks used by Gordon, Pirah? speakers were able to perform exact matches with large numbers of objects perfectly but, as previously reported, they were inaccurate on matching tasks involving memory. These results suggest that language for exact number is a cultural invention rather than a linguistic universal, and that number words do not change our underlying representations of number but instead are a cognitive technology for keeping track of the cardinality of large sets across time, space, and changes in modality.     

Acquiring English as a second language via print: The task for deaf children

Only a minority of profoundly deaf children read at age-level. We contend this reflects cognitive and linguistic impediments from lack of exposure to a natural language in early childhood, as well as the inherent difficulty of learning English only through the written modality. Yet some deaf children do acquire English via print. The current paper describes a theoretical model of how children could, in principle, acquire a language via reading and writing. The model describes stages of learning which represent successive, conceptual insights necessary for second/foreign language learning via print. Our model highlights the logical difficulties present when one cannot practice a language outside of reading/writing, such as the necessity of translating to a first language, the need for explicit instruction, and difficulty that many deaf children experience in understanding figurative language. Our model explains why learning to read is often a protracted process for deaf children and why many fail to make progress after some initial success. Because language acquisition is thought to require social interaction, with meaning cued by extralinguistic context, the ability of some deaf individuals to acquire language through print represents an overlooked human achievement worthy of greater attention by cognitive scientists.     

Baby hands that move to the rhythm of language: hearing babies acquiring sign languages babble silently on the hands

The "ba, ba, ba" sound universal to babies' babbling around 7 months captures scientific attention because it provides insights into the mechanisms underlying language acquisition and vestiges of its evolutionary origins. Yet the prevailing mystery is what is the biological basis of babbling, with one hypothesis being that it is a non-linguistic motoric activity driven largely by the baby's emerging control over the mouth and jaw, and another being that it is a linguistic activity reflecting the babies' early sensitivity to specific phonetic-syllabic patterns. Two groups of hearing babies were studied over time (ages 6, 10, and 12 months), equal in all developmental respects except for the modality of language input (mouth versus hand): three hearing babies acquiring spoken language (group 1: "speech-exposed") and a rare group of three hearing babies acquiring sign language only, not speech (group 2: "sign-exposed"). Despite this latter group's exposure to sign, the motoric hypothesis would predict similar hand activity to that seen in speech-exposed hearing babies because language acquisition in sign-exposed babies does not involve the mouth. Using innovative quantitative Optotrak 3-D motion-tracking technology, applied here for the first time to study infant language acquisition, we obtained physical measurements similar to a speech spectrogram, but for the hands. Here we discovered that the specific rhythmic frequencies of the hands of the sign-exposed hearing babies differed depending on whether they were producing linguistic activity, which they produced at a low frequency of approximately 1 Hz, versus non-linguistic activity, which they produced at a higher frequency of approximately 2.5 Hz - the identical class of hand activity that the speech-exposed hearing babies produced nearly exclusively. Surprisingly, without benefit of the mouth, hearing sign-exposed babies alone babbled systematically on their hands. We conclude that babbling is fundamentally a linguistic activity and explain why the differentiation between linguistic and non-linguistic hand activity in a single manual modality (one distinct from the human mouth) could only have resulted if all babies are born with a sensitivity to specific rhythmic patterns at the heart of human language and the capacity to use them.     

Time,number and length: Similarities and differences in discrimination in adults and children

The aim of this study was to focus on similarities in the discrimination of three different quantities—time, number, and line length—using a bisection task involving children aged 5 and 8 years and adults, when number and length were presented nonsequentially (Experiment 1) and sequentially (Experiment 2). In the nonsequential condition, for all age groups, although to a greater extent in the younger children, the psychophysical functions were flatter, and the Weber ratio higher for time than for number and length. Number and length yielded similar psychophysical functions. Thus, sensitivity to time was lower than that to the other quantities, whether continuous or not. However, when number and length were presented sequentially (Experiment 2), the differences in discrimination performance between time, number, and length disappeared. Furthermore, the Weber ratio values as well as the bisection points for all quantities presented sequentially appeared to be close to that found for duration in the nonsequential condition. The results are discussed within the framework of recent theories suggesting a common mechanism for all analogical quantities.     

The semantics and acquisition of number words: integrating linguistic and developmental perspectives

This article brings together two independent lines of research on numerally quantified expressions, e.g. two girls. One stems from work in linguistic theory and asks what truth conditional contributions such expressions make to the utterances in which they are used--in other words, what do numerals mean? The other comes from the study of language development and asks when and how children learn the meaning of such expressions. My goal is to show that when integrated, these two perspectives can both constrain and enrich each other in ways hitherto not considered. Specifically, work in linguistic theory suggests that in addition to their 'exactly n' interpretation, numerally quantified NPs such as two hoops can also receive an 'at least n' and an 'at most n' interpretation, e.g. you need to put two hoops on the pole to win (i.e. at least two hoops) and you can miss two shots and still win (i.e. at most two shots). I demonstrate here through the results of three sets of experiments that by the age of 5 children have implicit knowledge of the fact that expressions like two N can be interpreted as 'at least two N' and 'at most two N' while they do not yet know the meaning of corresponding expressions such as at least/most two N which convey these senses explicitly. I show that these results have important implications for theories of the semantics of numerals and that they raise new questions for developmental accounts of the number vocabulary.     

Knowledge of Language Transfers From Speech to Sign: Evidence From Doubling

Does knowledge of language transfer across language modalities? For example, can speakers who have had no sign language experience spontaneously project grammatical principles of English to American Sign Language (ASL) signs? To address this question, here, we explore a grammatical illusion. Using spoken language, we first show that a single word with doubling (e.g., trafraf) can elicit conflicting linguistic responses, depending on the level of linguistic analysis (phonology vs. morphology). We next show that speakers with no command of a sign language extend these same principles to novel ASL signs. Remarkably, the morphological analysis of ASL signs depends on the morphology of participants' spoken language. Speakers of Malayalam (a language with rich reduplicative morphology) prefer XX signs when doubling signals morphological plurality, whereas no such preference is seen in speakers of Mandarin (a language with no productive plural morphology). Our conclusions open up the possibility that some linguistic principles are amodal and abstract.     

How grammar can cope with limited short-term memory: simultaneity and seriality in sign languages

It is known that in American Sign Language (ASL) span is shorter than in English, but this discrepancy has never been systematically investigated using other pairs of signed and spoken languages. This finding is at odds with results showing that short-term memory (STM) for signs has an internal organization similar to STM for words. Moreover, some methodological questions remain open. Thus, we measured span of deaf and matched hearing participants for Italian Sign Language (LIS) and Italian, respectively, controlling for all the possible variables that might be responsible for the discrepancy: yet, a difference in span between deaf signers and hearing speakers was found. However, the advantage of hearing subjects was removed in a visuo-spatial STM task. We attribute the source of the lower span to the internal structure of signs: indeed, unlike English (or Italian) words, signs contain both simultaneous and sequential components. Nonetheless, sign languages are fully-fledged grammatical systems, probably because the overall architecture of the grammar of signed languages reduces the STM load. Our hypothesis is that the faculty of language is dependent on STM, being however flexible enough to develop even in a relatively hostile environment.     

The relation between teachers' math talk and the acquisition of number sense within kindergarten classrooms

The aim of the present study was to investigate the relation between teachers' math talk and the acquisition of number sense within kindergarten classrooms. The mathematical language input provided by 35 kindergarten teachers was examined with 9 different input categories. The results of this study indicate that the role of each of these math talk categories is not as straightforward as was hypothesized. Although significant positive relations were found for math talk categories such as cardinality and conventional nominatives, the relations between the categories' calculation and number symbols and children's score on specific number sense tasks were negative. Moreover, a large diversity in math talk was negatively related to kindergartners' number sense acquisition. These results suggest that teachers should be careful and selective with the amount of math talk that they offer to young children.     

Language as gesture

Language can be understood as an embodied system, expressible as gestures. Perception of these gestures depends on the “mirror system,” first discovered in monkeys, in which the same neural elements respond both when the animal makes a movement and when it perceives the same movement made by others. This system allows gestures to be understood in terms of how they are produced, as in the so-called motor theory of speech perception. I argue that human speech evolved from manual gestures, with vocal gestures being gradually incorporated into the mirror system in the course of hominin evolution. Speech may have become the dominant mode only with the emergence of Homo sapiens some 170,100 years ago, although language as a relatively complex syntactic system probably emerged over the past 2 million years, initially as a predominantly manual system. Despite the present-day dominance of speech, manual gestures accompany speech, and visuomanual forms of language persist in signed languages of the deaf, in handwriting, and even in such forms as texting.     

Find the picture of eight turtles: a link between children's counting and their knowledge of number word semantics

An essential part of understanding number words (e.g., eight) is understanding that all number words refer to the dimension of experience we call numerosity. Knowledge of this general principle may be separable from knowledge of individual number word meanings. That is, children may learn the meanings of at least a few individual number words before realizing that all number words refer to numerosity. Alternatively, knowledge of this general principle may form relatively early and proceed to guide and constrain the acquisition of individual number word meanings. The current article describes two experiments in which 116 children (2½- to 4-year-olds) were given a Word Extension task as well as a standard Give-N task. Results show that only children who understood the cardinality principle of counting successfully extended number words from one set to another based on numerosity—with evidence that a developing understanding of this concept emerges as children approach the cardinality principle induction. These findings support the view that children do not use a broad understanding of number words to initially connect number words to numerosity but rather make this connection around the time that they figure out the cardinality principle of counting.     

Genetic counseling for deaf adults: Communication/language and cultural considerations

It has been estimated that at least 50% of congenital or early onset deafness loss has a genetic etiology. Genetic services have traditionally been utilized by hearing parents of deaf children. Deaf adults could also greatly benefit from genetic counseling services. However, many deaf adults do not seek genetic services due in part to the communication/language and cultural differences of this group. Deaf people communicate in various ways including the use of sign language, oral communication, writing, or a combination of these modes. Also, while some deaf individuals are part of the hearing culture, others are part of the Deaf culture which has its own language, values, and traditions. Culturally Deaf individuals do not see themselves as handicapped or disabled. The genetic professional's awareness of the communication/language and cultural needs of this group, as well as their agency's responsibilities under section 504 of the Rehabilitation Act of 1973, may increase the accessibility of genetic services and contribute to the provision of successful genetic counseling for deaf adults.Throughout this paper, the term deaf will be used to denote a person who audiologically has a hearing loss which may range from mild to profound and may be sensorineural, conductive, or mixed. However, the term Deaf is used to denote cultural deafness.     

Ordered short-term memory differs in signers and speakers: implications for models of short-term memory

Capacity limits in linguistic short-term memory (STM) are typically measured with forward span tasks in which participants are asked to recall lists of words in the order presented. Using such tasks, native signers of American Sign Language (ASL) exhibit smaller spans than native speakers ([Boutla, M., Supalla, T., Newport, E. L., & Bavelier, D. (2004). Short-term memory span: Insights from sign language. Nature Neuroscience, 7(9), 997-1002]). Here, we test the hypothesis that this population difference reflects differences in the way speakers and signers maintain temporal order information in short-term memory. We show that native signers differ from speakers on measures of short-term memory that require maintenance of temporal order of the tested materials, but not on those in which temporal order is not required. In addition, we show that, in a recall task with free order, bilingual subjects are more likely to recall in temporal order when using English than ASL. We conclude that speakers and signers do share common short-term memory processes. However, whereas short-term memory for spoken English is predominantly organized in terms of temporal order, we argue that this dimension does not play as great a role in signers' short-term memory. Other factors that may affect STM processes in signers are discussed.     

Synesthesia and number cognition in children

Grapheme-color synesthesia, when achromatic digits evoke an experience of a specific color (photisms), has been shown to be consistent, involuntary, and linked with number concept in adults, yet there have been no comparable investigations with children. We present a systematic study of grapheme-color synesthesia in children aged between 7 and 15 years. Here we show that such children (but not children with phoneme-color synesthesia) experience involuntary difficulties in numerical tasks when digits are presented in colors incongruent with their photisms. Synesthesia in children may thus have important consequences for certain aspects of numerical cognition.     

Six does not just mean a lot: preschoolers see number words as specific

This paper examines what children believe about unmapped number words - those number words whose exact meanings children have not yet learned. In Study 1, 31 children (ages 2-10 to 4-2) judged that the application of five and six changes when numerosity changes, although they did not know that equal sets must have the same number word. In Study 2, 15 children (ages 2-5 to 3-6) judged that six plus more is no longer six, but that a lot plus more is still a lot. Findings support the hypothesis that children treat number words as referring to specific, unique numerosities even before they know exactly which numerosity each word refers to.