Cross‐Linguistic Differences in Digit Memory Span

This study investigated whether the better performance of the Chinese in digit memory span tasks was due only to the shorter pronunciation duration of Chinese digit names, or to enhanced visuospatial sketchpad abilities, or to both. Results of the experiment showed that the Chinese outperformed their Malay counterparts in digit memory span tasks because Chinese digit names had shorter pronunciation durations than Malay digit names and not because the Chinese had better visuospatial sketchpad abilities than the Malays. The results thus support Baddeley's phonological loop hypothesis as an account for cross‐linguistic differences in digit memory spans. Because memory traces are subject to decay and the phonological store is temporally limited, the shorter the pronunciation duration of digit names in a language, the more digits one can rehearse within a limited time period, and therefore the larger is one's short‐term digit span in that language.     

Effect of age on forward and backward digit spans

Abstract

A number of studies has suggested that aging is characterized by a decline in the central executive while the automatic processes (in particular operations by the phonological loop) remain intact. According to interpretation, age differences should be minimal in verbal forward digit span while they should be more important in backward verbal digit span. A sample of 1,000 subjects with ages ranging from 16 years to 79 years was used to test this hypothesis. the results show no significant effect of age on the difference between digit span forward and backward. the theoretical implications of these results are discussed.     

6-9岁儿童工作记忆的发展研究

以Baddeley工作记忆模型为基础考察儿童语音环路、视觉空间模板、中央执行的发展及其与复杂广度的关系。225名6-9岁被试完成9个任务,分别测量听力广度及工作记忆三个子系统的功能。发现工作记忆各个子成分的功能在6-9岁期间发展速度不同;中央执行与语音环路和视觉空间模板的联系随年龄增长加强;结构方程模型分析发现中央执行和语音环路功能对儿童听力广度都有显著的直接影响,表明言语复杂广度任务既涉及中央执行功能也涉及语音环路的存贮功能。     

The phonological loop and memory for rhythms: an individual differences approach

The purpose of the current study was to examine the relationship between short-term memory for rhythm and the phonological loop in working memory. Results showed that digit span scores significantly correlated with the scores on the rhythmic memory task, and that the correlation between the two scores remained significant even after the common variance with reading speed was partialled out. Partial correlation and regression analyses indicated that the relation between memory for rhythm and digit span scores is mediated by the third component in the phonological loop, the component that is responsible for regulation of timing mechanisms in immediate memory tasks.     

A strict test of the phonological loop hypothesis with Libyan data

In Arabic, there are two ways, differing in length, of pronouncing each digit. This feature of word pairs that are conceptually identical but of different length allows for a stricter test of the phonological loop hypothesis than has been reported previously. Libyan schoolchildren, both boys and girls, of two grades took part in a quasi-experimental study in which shorter and longer digits and shorter and longer words were presented in recall and pronunciation tasks. The results confirmed the validity of the phonological loop model in that memory span was longer for shorter stimuli. Analysis of the data with structural equation modeling showed that only 17% of the individual-level variation in memory span could be explained by pronunciation speed. In an analysis of covariance, it was determined that pronunciation speed could account for a substantial proportion of the variation found across age (8-year-olds vs. 10-year-olds), stimulus modality (digits vs. words), and stimulus length (short vs. long), but not for gender differences.     

A developmental deficit in short-term phonological memory: Implications for language and reading

Abstract

QU, an eight-year-old boy, was identified from a large scale normative study on the basis of his greatly reduced digit span, combined with normal long-term memory and non-verbal intelligence. Further investigation indicated that his visual STM was normal, but that he was clearly impaired on two verbal STM tests, nonword repetition, and memory span for words. His span showed clear effects of phonological similarity and word-length, suggesting qualitatively normal functioning of the phonological loop component of working memory, despite a quantitative impairment in level of performance. This pattern resembles that found in an earlier study of children with a specific language disorder. We tested QU on measures of vocabulary, syntax, and reading, and found him to be substantially below the age norms on all three. The implications of these findings are discussed for the role of the phonological loop in language development.     

Speech Rate Estimates,Language of Schooling and Bilingual Digit Span

Bilinguals obtain larger digit spans in the language in which speech rate is fastest. This effect is generally interpreted as support for a central tenet of working memory theory, which proposes subvocal rehearsal rate as an influential determinant of memory span. Variation in the method of speech rate estimation, however, has been high, making comparison between studies difficult. In the present study, we compared the predictive power of three estimates of speech rate in relation to auditory digit span for two distinct bilingual types across nine school grades (1–9). One type spoke Swedish in the home and school (SS), the other spoke Finnish in the home and Swedish at school (FS). The results showed SS consistently obtained faster speech rates in Swedish, whereas FS obtained shorter articulation and numeral reading times in Swedish, as did grades 1–3 on a digit word reading task. However, FS grades 4–9 obtained equivalent digit word reading times between the languages. SS obtained a larger digit span in Swedish than Finnish, whereas FS obtained an equivalent digit span between the languages. Thus the results indicated that memory span was mediated by factors other than phonological loop functioning, as articulation time did not predict memory span performance for FS. The finding that FS obtained lower digit spans in Swedish relative to SS suggested that the former were disadvantaged in the processing of digits compared to native speakers of the language of schooling.     

Memory development in Libyan and Dutch school children

Cross-cultural similarities and differences in memory were examined in two studies with Libyan and Dutch school children of two different grades. The first study analysed effects of word length and pronunciation speed on recall. Baddeley's phonological loop hypothesis could fully account for the somewhat larger digit span of the Dutch children. The second study investigated effects of rehearsal training on recall. Experimental groups showed a higher performance increase after training than did control groups; Libyan children with the same pretest scores as Dutch children showed higher posttest scores, which could be a consequence of sample differences in age or test-wiseness. The studies demonstrated that current theories provide more precise explanations of cross-cultural differences in structural memory features than in control processes. Implications for instructional practice are discussed.     

The contribution of working memory to children's mathematical word problem solving

The study explored the contribution of working memory to mathematical word problem solving in children. A total of 69 children in grades 2, 3 and 4 were given measures of mathematical problem solving, reading, arithmetical calculation, fluid IQ and working memory. Multiple regression analyses showed that three measures associated with the central executive and one measure associated with the phonological loop contributed unique variance to mathematical problem solving when the influence of reading, age and IQ were controlled for in the analysis. In addition, the animal dual‐task, verbal fluency and digit span task continued to contribute unique variance when the effects of arithmetical calculation in addition to reading, fluid IQ, and age were controlled for. These findings demonstrate that the phonological loop and a number of central executive functions (shifting, co‐ordination of concurrent processing and storage of information, accessing information from long‐term memory) contribute to mathematical problem solving in children. Copyright © 2006 John Wiley & Sons, Ltd.     

数学学业不良初中生的工作记忆特点：领域普遍性还是特殊性?

研究选取上海111名(男生48名, 女生63名, 平均年龄11.97岁)初中学生(数学学业不良学生55名与数学学业优秀学生56名), 根据国家数学课程标准, 将数学划分为数与代数、空间与几何两部分, 又从空间与几何领域中选取初一数学学业知识点—— 轴对称和中心对称图形, 分析在不同内容知识领域的解答过程中所涉及的工作记忆成分。结果发现：(1)数与代数学习需要中央执行系统、视觉-空间模板、语音环路三个成分的共同作用; 空间与几何学习主要受到视觉-空间模板和中央执行系统的影响, 但不存在语音环路的影响。(2)对轴对称与中心对称图形任务的成绩影响最大的是视觉-空间模板, 其次是中央执行系统, 语音环路对该任务作用不明显。两个研究说明工作记忆在初中不同年级的各类数学学业任务中具有不同的作用, 中央执行系统和视觉-空间模板相对更具有普遍性作用, 语音环路具有特殊性作用, 并且随着年龄增高, 视觉－空间模板对数学学业任务的作用更为突显。     

How does the severity of a learning disability affect working memory performance?

Working memory performance was examined in children aged 11-12 years who had borderline, mild, and moderate learning disabilities. Comparisons with children of average abilities were used to determine whether those with more severe learning disabilities had greater impairments in working memory. Seven measures of working memory span were used to assess temporary phonological short-term storage (digit span, word span), temporary visuo-spatial short-term storage (pattern span, spatial span), and temporary short-term storage with additional processing, or central executive, demands (listening span, odd one out span, reverse digit span). Children with mild and moderate learning disabilities were impaired on all measures of working memory compared to children of average abilities. Children with borderline learning disabilities were just as good as children with average abilities on visuo-spatial and complex span tasks, but showed an impairment on phonological span tasks. Children with moderate learning disabilities were indistinguishable from children with mild learning disabilities on simple span tasks, but were significantly poorer than the mild group on the more demanding complex span tasks. For the group as a whole, working memory was strongly related to mental age.     

How does the severity of a learning disability affect working memory performance?

Working memory performance was examined in children aged 11-12 years who had borderline, mild, and moderate learning disabilities. Comparisons with children of average abilities were used to determine whether those with more severe learning disabilities had greater impairments in working memory. Seven measures of working memory span were used to assess temporary phonological short-term storage (digit span, word span), temporary visuo-spatial short-term storage (pattern span, spatial span), and temporary short-term storage with additional processing, or central executive, demands (listening span. odd one out span, reverse digit span). Children with mild and moderate learning disabilities were impaired on all measures of working memory compared to children of average abilities. Children with borderline learning disabilities were just as good as children with average abilities on visuo-spatial and complex span tasks, but showed an impairment on phonological span tasks. Children with moderate learning disabilities were indistinguishable from children with mild learning disabilities on simple span tasks, but were significantly poorer than the mild group on the more demanding complex span tasks. For the group as a whole, working memory was strongly related to mental age.     

Speech timing and working memory in profoundly deaf children after cochlear implantation

Thirty-seven profoundly deaf children between 8- and 9-years-old with cochlear implants and a comparison group of normal-hearing children were studied to measure speaking rates, digit spans, and speech timing during digit span recall. The deaf children displayed longer sentence durations and pauses during recall and shorter digit spans compared to the normal-hearing children. Articulation rates, measured from sentence durations, were strongly correlated with immediate memory span in both normal-hearing and deaf children, indicating that both slower subvocal rehearsal and scanning processes may be factors that contribute to the deaf children's shorter digit spans. These findings demonstrate that subvocal verbal rehearsal speed and memory scanning processes are not only dependent on chronological age as suggested in earlier research by. Instead, in this clinical population the absence of early auditory experience and phonological processing activities before implantation appears to produce measurable effects on the working memory processes that rely on verbal rehearsal and serial scanning of phonological information in short-term memory.     

Breaking a habit: A further role of the phonological loop in action control

Recent research has suggested that keeping track of a task goal in rapid task switching may depend on the phonological loop component of working memory. In this study, we investigated whether the phonological loop plays a similar role when a single switch extending over several trials is required after many trials on which one has performed a competing task. Participants were shown pairs of digits varying in numerical and physical size, and they were required to decide which digit was numerically or physically larger. An experimental cycle consisted of four blocks of 24 trials. In Experiment 1, participants in the task change groups performed the numerical-size judgment task during the first three blocks, and then changed to the physical-size judgment task in the fourth. Participants in the continuation groups performed only the physical-size judgment task throughout all four blocks. We found negative effects of articulatory suppression on the fourth block, but only in the task change groups. Experiment 2 was a replication, with the modification that both groups received identical instructions and practice. Experiment 3 was a further replication using numerical-size judgment as the target task. The results showed a pattern similar to that from Experiment 1, with negative effects of articulatory suppression found only in the task change group. The congruity of numerical and physical size had a reliable effect on performance in all three experiments, but unlike the task change, it did not reliably interact with articulatory suppression. The results suggest that in addition to its well-established role in rapid task switching, the phonological loop also contributes to active goal maintenance in longer-term action control.     

认知作业年老化的比较研究

用言语—操作和人机对话两种方式完成１２项认知作业年老化比较研究,被试２４２人,４６－７５岁。结果表明：（１）一些作业（符号数字、视觉数字广度、听觉数字广度、词对联想学习、图象自由回忆和无意图形再认）成绩随年老明显下降,另一些作业（图象分类、卡片分类、心算和矩阵填图）成绩不随年老明显降低;（２）再次验证心算、符号数字、数字鉴别和计数四项非词语性作业速度随年老进行性减慢。     

Reduced phonological similarity effects in patients with damage to the cerebellum

Ten cerebellar patients were compared to 10 control subjects on a verbal working memory task in which the phonological similarity of the words to be remembered and their modality of presentation were manipulated. Cerebellar patients demonstrated a reduction of the phonological similarity effect relative to controls. Further, this reduction did not depend systematically upon the presentation modality. These results first document that qualitative differences in verbal working memory may be observed following cerebellar damage, indicating altered cognitive processing, even though behavioral output as measured by the digit span may be within normal limits. However, the results also present problems for the hypothesis that the cerebellar role is specifically associated with articulatory rehearsal as conceptualized in the Baddeley-Hitch model of working memory.     

Subgroups of developmental language impairment

Nineteen children with developmental language impairments were given tests which measured syntactic and phonological skills in both comprehension and production conditions, semantic ability, syllable sequencing, and digit span. The results of discriminant function analysis show that the children could be divided into two groups. Group 1, expressive, was characterized primarily by deficits in the production of syntax and phonology. Group 2, expressive-receptive, was more impaired on measures of phonological discrimination, digit span, and semantic ability in addition to showing global syntactic deficits. An auditory-perceptual basis for the language impairments was not supported.     

Working memory contributions to reading comprehension components in middle childhood children

This study examined working memory contributions to reading comprehension subskills in Greek children (mean age 9 years, 1 month). The phonological loop of the Baddeley and Hitch working memory model was assessed with 3 recall tasks (words, nonwords, and digits) and a word list matching task. The central executive (CE) was assessed with 3 tasks (listening, counting, and backward digit recall). Participants were also given a receptive vocabulary task, a reading fluency task, and written stories accompanied by comprehension questions. Canonical correlation analyses showed that the comprehension variables were related to the CE rather than the phonological loop measures. CE functions were more strongly associated with elaborative inference generation (involving significant offline processing) and comprehension control (involving metacognitive monitoring). Smaller yet significant associations were observed between the CE and the necessary inference and literal comprehension measures, whereas a moderate relationship was found in the case of the simile comprehension variable. Among the CE variables, listening recall demonstrated the highest loading on the canonical function, followed by moderate yet significant counting and backward digit recall loadings. Vocabulary was found to fully mediate several associations between working memory and comprehension measures; however, the relationship between listening recall and elaborative inferences was partly mediated. Reading fluency and, on several occasions, Greek vocabulary knowledge did not mediate the relationships between CE measures and comprehension skills assessed. This study demonstrates the usefulness of CE measures for identifying young children's possible difficulties in carrying out specific reading comprehension processes.     

Contributions of linguistic,quantitative, and spatial attention skills to young children's math versus reading: Same,different, or both?

The study used Bayesian and Frequentist methods to investigate whether the roles of linguistic, quantitative, and spatial attention skills are distinct in children's acquisition of reading and math. A sample of 175 Chinese kindergarteners was tested with measures of linguistic skills (phonological awareness and phonological memory), quantitative knowledge (number line task, symbolic digit comparison, and non-symbolic number estimation), spatial attention skills (visual span, mental rotation, and visual search), word reading, and calculation. After statistically controlling for age and nonverbal intelligence, phonological awareness and digit comparison performance explained unique variance in both math and reading. Moreover, number line estimation was specifically important for math, while phonological memory was specifically essential for reading. These findings highlight the possibility of developing early screening tools with different cognitive measures for children at risk of learning disabilities in reading and/or math.     

数字工作记忆广度的毕生发展及其作用因素

以10~90岁的1993名自愿者为被试完成该实验研究。结果表明：（1）在最简单的心算加工负荷下,数字工作记忆广度约为6±2;（2）在10至90岁范围内,测验的最高成绩在16~19岁组（即高中生组）,回归分析表明数字工作记忆广度随年龄的对数呈抛物线变化;（3）教育因素对成年人数字工作记忆广度的随龄化过程有重要作用;（4）与我们过去的研究结果相比较,发现数字工作记忆广度受心算加工负荷的影响显著