Modality of language shapes working memory: evidence from digit span and spatial span in ASL signers

Deaf children who are native users of American Sign Language (ASL) and hearing children who are native English speakers performed three working memory tasks. Results indicate that language modality shapes the architecture of working memory. Digit span with forward and backward report, performed by each group in their native language, suggests that the language rehearsal mechanisms for spoken language and for sign language differ in their processing constraints. Unlike hearing children, deaf children who are native signers of ASL were as good at backward recall of digits as at forward recall, suggesting that serial order information for ASL is stored in a form that does not have a preferred directionality. Data from a group of deaf children who were not native signers of ASL rule out explanations in terms of a floor effect or a nonlinguistic visual strategy. Further, deaf children who were native signers outperformed hearing children on a nonlinguistic spatial memory task, suggesting that language expertise in a particular modality exerts an influence on nonlinguistic working memory within that modality. Thus, language modality has consequences for the structure of working memory, both within and outside the linguistic domain.     

Using immediate recall to assess language proficiency in deaf students.

We used an immediate recall paradigm to study the effects of list organization and semantic and grammatical features of printed stimuli on working memory capacity in deaf students with differing English language abilities. Thirty lists of five organizational types (random words, semantically related words, semantically paired words, scrambled sentences, and grammatical sentences) were presented to two groups of deaf students who differed in their proficiency in the English language. The students were required to recall the lists in writing. The results indicate that, overall, the students with higher levels of English language proficiency recalled significantly more than those with lower levels. Additionally, semantic and syntactic organization of the lists had different effects on the two groups of students. Semantic pairing aided the low-level group significantly more than the high-level group, whereas the syntactic organization of the grammatical sentences aided the high-level group significantly more. Implications for assessing language ability in deaf students are discussed.     

Working memory for sign language: a window into the architecture of the working memory system

Traditionally, working memory has been divided into two major domains: verbal and visuo-spatial. The verbal domain of working memory can be characterized either by its relationship to language or by its grounding in auditory processing. Because of this ambiguity, languages that are not auditory and vocal (i.e., signed languages) pose a challenge to this conception of working memory. We describe several experiments with deaf users of American Sign Language (ASL) that explore the extent to which the architecture of working memory is determined by the constraints of auditory and visual processing and the extent to which it is determined by the characteristics of language. Various working memory effects were investigated: phonological similarity, word length, and articulatory suppression. The pattern of evidence strongly supports the existence of a sign-based 'rehearsal loop' mechanism parallel to the speech-based rehearsal loop. However, we also discuss evidence pointing to differences between the speech loop and the sign loop from forward and backward digit span tasks with deaf and hearing subjects. Despite their similarities based on linguistic properties, the speech loop and the sign loop appear to diverge due to the differing processing demands of audition and vision. Overall, the results suggest that the architecture of working memory is shaped both by the properties of language structure and by the constraints imposed by sensorimotor modality.     

Intrusion errors in working memory tasks: Are they related to reading comprehension ability?

The purpose of the present research was to investigate whether inefficient suppression mechanisms cause overload and interference in working memory and, consequently, influence reading comprehension. Two groups of children, matched for intelligence but differing in inferential comprehension ability, were compared on measures of short-term (passive storage) and working memory (maintenance and processing) and memory for relevant and irrelevant information after reading a passage. Poor comprehenders produced more intrusion errors in a working memory task and recalled more irrelevant information from the passage. The presence of irrelevant information in recall suggests that poor comprehenders are less efficient in reducing the activation (suppression) of information, which is no longer relevant. A year-long longitudinal study was conducted to investigate the influence of suppression efficiency in reading comprehension. Intrusion errors were shown to be a good predictor of comprehension performance 1 year later. Suppression mechanisms seem to play an important role in working memory by reducing interference and improving the processing and maintenance of relevant information in order to build a coherent representation during reading comprehension.     

The role of sentence recall in reading and language skills of children with learning difficulties

The present study explores the relationship between sentence recall and reading and language skills in a group of 7–11-year-old children with learning difficulties. While recent studies have found that performance on sentence recall tasks plays a role in learning, it is possible that this contribution is a reflection of shared resources with working memory. In order to investigate whether sentence recall was uniquely associated with reading and language skills, differences associated with IQ and working memory capacity were statistically controlled. A sample of 72 children was tested on measures of verbal complex memory, verbal short-term memory, sentence recall, expressive vocabulary, verbal and performance IQ, reading and language skills. Both sentence recall and verbal complex memory shared unique links with reading skill, and sentence recall was uniquely associated with language skills. This finding indicates that resources in long-term memory also play an important diagnostic role in reading and language abilities. The implications for educational practice are discussed.     

Role of Mimeticism and Spatiality in Textual Recall

Four experiments were conducted to investigate the role of map spatiality and icon mimeticism in facilitating text recall. A secondary goal was to explore an assumption of the conjoint retention hypothesis, that the visuospatial component of working memory is involved in retrieving map information. We manipulated display conditions to evaluate the separate and combined effects of map spatiality and icon mimeticism on text recall. We also utilized a concurrent task paradigm to assess both the recognition of spatial displays and the recall of map feature information. The results of all four experiments point to the mimeticism of icons as the key attribute of maps for facilitating recall, rather than the spatial layout of the map when visual displays and text are presented simultaneously during encoding. We also found no evidence indicating that maps are processed in a more spatial manner than are lists. Copyright 2000 Academic Press.     

The Role of Attention in the Development of Short-Term Memory: Age Differences in the Verbal Span of Apprehension

In previous studies of memory span, participants have attended to the stimuli while they were presented, and therefore have had the opportunity to use a variety of mnemonic strategies. In the main portion of the present study, participants (first- and fourth-grade children, and adults; 24 per age group) carried out a visual task while hearing lists of spoken digits and received a post-list digit recall cue only occasionally, for some lists. Under these conditions, list information presumably must be extracted from a passively held store such as auditory sensory memory. The results suggest that each individual has a core memory capacity limit that can be observed clearly in circumstances in which it cannot be supplemented by mnemonic strategies, and that the capacity limit appears to increase with age during childhood. Other, attention-demanding processes also contribute to memory for attended lists.     

Memory for everyday information in students with learning disabilities

This study compared students with and without learning disabilities (LD) on their recall of academic information and information encountered in the students' everyday lives. The academic recall measures included a sentence listening span test, a rhyming words working memory test, and a visual matrix working memory task. Students' cued recall of all the tasks was also measured. The everyday working memory tasks included a dance episode event recall test; a library procedure recall test; and recall tests of commonly found objects, such as a coin, a telephone, and a McDonald's sign. Compared to students without LD, students with LD performed poorly on both the academic recall tasks and the everyday recall tasks. These results support the notion that some students with LD may have working memory problems that affect their performance on tasks other than reading. The results of the cued recall showed that the availability of cues significantly decreased the ability group differences on many of the academic and everyday tasks. This result replicates prior research findings that students with LD do not use retrieval strategies effectively and that some students with LD may have a production deficiency that affects their retrieval of previously encoded information.     

The relationships between reading processes and English skills of deaf college students

This research project investigated the relationships between various working memory (WM) recoding processes and English language skills in a sample of 86 prelingually deaf college students from varied educational backgrounds. Part 1 reports the results of a short-term memory (STM) experiment and a Recoding Strategies questionnaire. The STM results suggested that, for most deaf students, neither the speech, sign, or visual codes are as efficient as the speech code of hearing persons for the purpose of maintaining English linguistic information in WM. However, the ability to use speech-based recoding processes was positively correlated with WM capacity, and the use of sign recoding was found to decrease as the ability to make efficient use of a speech recoding strategy increased. In addition, the questionnaire data suggested that neither the speech nor sign recoding systems provide the majority of students with a complete internal representation of English surface structure grammatical information in WM. There was no evidence that the use of sign language in education interfered with the ability to develop a speech recoding strategy, or that knowledge of American Sign Language (ASL) negatively influenced the acquisition of English skills. The overall pattern of results suggested that WM processes and recoding strategies may be influencing grammatical processes, and the acquisition of English skills, in distinctive ways.     

Another look at the STM capacity of prelingually deafened individuals and its relation to reading comprehension

The study investigated the short-term recall of serially presented verbal(izable) information by prelingually deafened individuals and hearing individuals, and reconsidered how short-term memory (STM) is linked with their reading skills and their memory coding strategies. A computer-controlled paradigm calling for written ordered recall of 12 lists of 8 consecutively displayed Hebrew nouns was used to assess STM capacity. Forty-nine students with prelingual deafness (mean grade 6.9) and 39 hearing students (mean grade 6.5) participated in the experiment. Twenty-seven of the participants with deafness were raised according to an oral philosophy. The remaining 22 participants from the deaf group used sign language as their preferred communication code. In general, the findings suggest that neither discrepancy in the ordered short-term recall of verbal materials nor discrepancies in reading comprehension are directly assignable to differences in the memory coding strategies of prelingually deafened and hearing individuals. If such functional discrepancies develop, they reflect absent or insufficiently internalized knowledge.     

Language codes and sense-making among deaf schoolchildren

There are at least two languages (American Sign Language [ASL], English) and three modalities (sign, speech, print) in most deaf individuals' lives. Mixing of ASL and English in utterances of deaf adults has been described in various ways (pidgins, diglossia, language contact, bilingualism), but children's mixing usually is treated as the 'fault' of poor input language. Alternatively, how might language mixing serve their communication goals? This article describes code variations and adaptations to particular situations. Deaf children were seen to exhibit a wide variety of linguistic structures mixing ASL, English, Spanish, signing, and speaking. Formal lessons supported a recoding of English print as sign and speech, but the children who communicated English speech were the two who could hear speech. The children who communicated ASL were those who had deaf parents communicating ASL or who identified with deaf houseparents communicating ASL. Most language produced by the teacher and children in this study was mixed in code and mode. While some mixing was related to acquisition and proficiency, mixing, a strategy of many deaf individuals, uniquely adapts linguistic resources to communication needs. Investigating deaf children's language by comparing it to standard English or ASL overlooks the rich strategies of mixing that are central to their communication experience.     

Dyslexia: Symbol processing difficulty in the Kannada language

The purpose of this study was to investigate whether among children who speak Kannada, a Dravidian language from South India, there are those who show the same pattern of specific dyslexia as has been found to occur in children who speak European languages. The performances of 14 dyslexic children, aged between 8 and 10 years, whose native language was Kannada, were compared on a variety of tasks with fourteen normal readers and fourteen non-dyslexic poor readers. There were no significant differences between the three groups on tests of visual discrimination, visual recognition, visual recall, memory for shapes in sequence, or auditory discrimination. There were differences, however, between the dyslexics and the normal readers on tests of recall of auditorily presented digits, word analysis, word synthesis, and on two tests of visual-verbal association. The non-dyslexic poor readers were more similar to the dyslexics on recall of auditorily presented digits and word synthesis but more similar to the normal readers on word analysis and on the two tests of visual-verbal association. It is argued that these results are evidence of a consistent pattern in specific dyslexia which does not depend on any one writing system or geographical location.     

Developmentally invariant dissociations in children's true and false memories: not all relatedness is created equal

The role of categorical versus associative relations in 5-, 7-, and 11-year-old children's true and false memories was examined using the Deese-Roediger-McDermott (DRM) paradigm and categorized lists of pictures or words with or without category labels as primes. For true items, recall increased with age and categorized lists were better recalled than DRM lists. For false items, recall increased with age except for picture lists, there were no differences between categorized and DRM lists and no effect of priming, and there were fewer false memories for pictures than words. Like adults, children's false memories are based on associative not thematic relations, whereas their veridical memories depend on both. This new, developmentally invariant dissociation is consistent with knowledge- and resource-based models of memory development.     

Is graphic activity cognitively costly? A developmental approach

The present experiment was carried out to test the hypothesis that the use of the written mode increases the working memory load. Second and fourth graders were orally presented with series of unrelated words which they were required to recall in sequence. Each subject had to recall five different lists in the following conditions: oral alone, written, oral with a concurrent task (tapping, categorization, drawing). Participants recalled more words in the oral condition than in either the written mode or the `oral and categorization' conditions. Moreover, second graders performed better in the oral mode than in the `oral and drawing condition'. This trend was not significant with older children. Finally, the tapping task did not affect children's performance. The results are consistent with our cognitive load hypothesis.     

The role of vowel signs in Hebrew: Beyond word recognition

After third grade of elementary school, native Hebrew speakers in Israel gradually become expert in reading two kinds of writing systems: the one they start with that contains signs for every phoneme of the spoken language, and another, to which they are steadily introduced, beginning with the second grade, which omits most vowels, together with few consonantal distinctions. Earlier studies indicate that single voweled words are read faster than unvoweled words, particularly in a naming task. This study examined another possible contribution of vowel signs in reading Hebrew: Its effect on memory and comprehension. It was assumed that if subvocalization facilitates memory of words while reading, and if vowel signs facilitate phonological processing, as is perhaps the case in naming tasks, then vowelization may intensify the processing of the articulatory loop and this should improve memory and comprehension. Our first two experiments assessed the contribution of vowel signs to the memory of word lists in either recognition memory or word recall tasks. The third experiment examined the contribution of vowel signs to the reading of connected texts. We found that vowel signs speeded up recognition memory of words in third graders, and improved the recall of words printed in the context of mixed lists in sixth graders. We also found that vowelization improved memory and comprehension of some prose texts.     

Incidental word learning in a hearing child of deaf adults

It is unclear how children develop the ability to learn words incidentally (i.e., without direct instruction or numerous exposures). This investigation examined the early achievement of this skill by longitudinally tracking the expressive vocabulary and incidental word-learning capacities of a hearing child of Deaf adults who was natively learning American Sign Language (ASL) and spoken English. Despite receiving only 20% of language input in spoken English, the child's expressive vocabularies at 16 and 20 months of age, in each language, were similar to those of monolingual age-matched peers. At 16 months of age, the child showed signs of greater proficiency in the incidental learning of novel ASL signs than she did for spoken English words. At 20 months of age, the child was skilled at incidental word learning in both languages. These results support the methodology as it applies to examining theoretical models of incidental word learning. They also suggest that bilingual children can achieve typical vocabulary levels (even with minimal input in one of the languages) and that the development of incidental word learning follows a similar trajectory in ASL and spoken English.     

Reading? ... pah! (I got it!). Innovative Reading Technique For Successful Deaf Readers

A reading program utilizing five components--a shortcut to phonemic awareness, Adapted Dolch words, Bridge lists and the Bridging process, reading comprehension, and American Sign Language development/language experience stories--was administered to 48 elementary school students at a residential school for the deaf. Data analyses reveal dramatic gains in students' reading levels and academic behavior, teachers' growth in reflective sign skills, and students' and teachers' overall growth in ASL skills, resulting in a more organized, consistent approach to linguistic input and usage.     

The Effect of External Representations on Compare Word Problems: Supporting Mental Model Construction

This study explored the effectiveness of external representations presented together with compare word problems, and whether such effectiveness was moderated by working memory. Participants were 49 secondary school students. Each participant solved 48 problems presented in 4 presentation types that included 2 difficulty treatments (number of steps and language consistency). Data from errors and response times indicated that adding a graph to compare word problems helped accuracy (d =.60) and response time (d =.44). This effect was larger for difficult and cognitively demanding problems. Findings suggest that external representations might help problem-solvers build a mental model of the described problem situation. In addition, working memory was not found to moderate the effectiveness of external representations.