Do different components of working memory underlie different subgroups of reading disabilities?

The purpose of this study was to determine the components of working memory (WM) that underlie less skilled readers' comprehension and word recognition difficulties. Performance of 3 less skilled reading subgroups---children with reading disabilities (RD) in both word recognition and comprehension; children with comprehension deficits only; and children with low verbal IQ, word recognition, and comprehension (poor readers)--was compared to that of skilled readers on WM, short-term memory (STM), processing speed, executive, and phonological processing measures. Ability group comparisons showed that (a) skilled readers outperformed all less skilled readers on measures of WM, updating, and processing speed; (b) children with comprehension deficits only outperformed children with RD on measures of WM, STM, phonological processing, and processing speed; and (c) children with RD outperformed poor readers on WM and phonological processing measures. A hierarchical regression analysis showed that (a) subgroup differences on WM tasks among less skilled readers were moderated by a storage system not specific to phonological skills, and (b) STM and updating contributed significant variance to WM beyond what was contributed by reading group classification. The latter finding suggested that some differences in storage and executive processing emerged between skilled and less skilled readers that were not specific to reading.     

Evaluation of the double-deficit hypothesis subtype classification of readers in Spanish

The double-deficit hypothesis acknowledges both phonological processing deficits and serial naming speed deficits as two dimensions associated with reading disabilities. The purpose of this study was to examine these two dimensions of reading as they were related to the reading skills of 29 Spanish average readers and poor readers (mean age 9 years 7 months) who met the criteria for either single phonological deficit (PD), double deficit (DD), or no deficit. DD children were the slowest readers and had the weakest orthography processing skills. No significant differences were found between PD and DD groups on word and pseudoword reading. Word reading and reading comprehension skills were average or above average in the three studied groups. As in previous studies in transparent orthographies, word reading was not a salient problem for Spanish poor readers, whereas for the DD group, reading speed and orthographic recognition skills were significantly affected.     

Lexical and nonlexical routes: a comparison between normally achieving and poor readers.

This study investigated qualitative differences in poor readers relative to normally achieving readers of the same reading level. Thirty-eight 9-year-old poor readers and forty 7- and 8-year-old reading-age-matched normally achieving readers from the United Kingdom were matched in phonemic processing and then given tests of memory span and visual discrimination of letter-like characters, were required to read different word types (regular, exception, and pseudoword), and were asked to complete a homophonic pseudoword test. The poor readers were worse at reading pseudowords compared to the controls, but this difference was unrelated to phonemic length of number of letters, or to the ease of producing analogies for the pseudowords. The results suggest that although there are no differences with reading-age controls in phonological processing, poor readers have worse grapheme-phoneme conversion skills and greater reluctance to relinquish the lexical route when appropriate. The results also showed that poor readers were slightly better at visual discrimination but had poorer memory spans.     

Brain Activity During Performance of Naming Tasks: Comparison Between Dyslexic and Regular Readers

This research was aimed at contributing to the current understanding of the underlying factors of naming speed and the causes of naming speed deficits. Forty regular readers and 40 dyslexic university students participated in the study. Electrophysiological (Event-Related Potentials [ERPs]) and behavioral measures were employed. Behavioral baseline tasks assessed general ability, reading skills, reading-related cognitive abilities, and standard Rapid Automatized Naming (RAN) and Rapid Alternating Stimulus tests. ERP tasks included letter and object naming tasks adapted for electrophysiological research presentation. The dyslexics were significantly slower and less accurate than the controls on most of the baseline measures. On all the naming tasks, the peak ERP latencies were elicited later, reaction times were longer, and the P300 latency width was wider among the dyslexics as compared to the regular readers. On the choice reaction time naming tasks, accuracy for both groups was almost perfect. When naming presentation time was controlled by the experiment, the dyslexics were significantly less accurate than the controls. Our data indicated that effective naming speed was related to an earlier P200 latency peak among regular readers and to an earlier P300 latency peak and narrower area component activation in the dyslexic group. The results from this study suggest that effective RAN speed among regular readers might be a result of efficient processing of RAN information at the input stage of stimulis perception and evaluation as well as of updating and processing the information in short-term memory among dyslexics.     

Performance of good and poor readers at two grade levels on an Auditory Cognitive Style Task

Sixty-four good and poor readers at first and third grades were administered a task measuring cognitive style in the auditory modality. They were also administered the Peabody Picture Vocabulary Test-Revised (PPVT-R) to obtain a measure of IQ. Poor readers committed significantly more errors and exhibited shorter response latencies on the Auditory Cognitive Style Task than did good readers. More importantly, poor readers demonstrated inefficient strategies for successful performance. It was suggested that good reading skills, as well as successful performance on the auditory task, require a certain degree of planfulness and self-monitoring activity on the part of the child which was apparently absent in the poor reader. Furthermore, it was proposed that the cognitive style variable, conceptual tempo, may be better viewed within the framework of the concept of metacognition.     

初一英语语音意识、句法意识、工作记忆与英语阅读的关系

通过使用音素定位、句法更正、句子尾词记忆.单词阅读、句子理解和短文理解任务探查了初一学生英语语音意识,句法意识和工作记忆与单词阅读、句子阅读和短文阅读等不同层次阅读的关系,以及阅读水平高低不同学生在元语言意识的差异.结果发现,英语阅读水平高低两组学生在英语语音意识、句法意识和工作记忆方面有显著差异.回归分析发现,英语句法意识对不同层次阅读都具有最显著的预测作用,但英语语音意识只对短文阅读理解有显著预测作用,工作记忆对不同层次阅读的预测都不显著,表明英语句法意识是初一学生英语阅读的重要预测变量.     

Development of Poor and Better Readers During the Elementary School

The goal of this longitudinal study was to describe the average development of word recognition, reading comprehension, vocabulary and spelling of poor and better readers during the elementary school period and to determine whether the differences between these readers increase over a period of 6 years of elementary education. Poor and better readers were defined to belong to the lowest 30% and to the higher 70% of a longitudinal sample, respectively. It appeared that for word recognition the developmental curves for the groups were very distinct and followed similar patterns. For reading comprehension, vocabulary and spelling, the developmental curves showed similar patterns with decreasing differences across grades, however. Clear seasonal effects were found for reading comprehension, vocabulary and spelling, while the seasonal effect for word recognition was restricted to the early grades. It appeared that students with initially poor abilities in word recognition and reading comprehension showed greater improvement over time on reading comprehension, vocabulary and spelling than students with initially better abilities in word recognition and reading comprehension. These findings contradict the existence of a Matthew effect for these skills. For word recognition, a clear differential effect could not be found: the groups did not differ systematically in mean development. The gap between the poor and better decoders did not widen over time for this skill; so a Matthew effect for word recognition was not supported.     

Children's memory for phonemically confusable and nonconfusable letters: changes with age and reading ability

This experiment focused on differences that occur with age and reading skill in the use of phonemic codes in short-term retention tasks where stimuli were presented visually. In 1 condition, individuals recalled 6-letter strings composed of rhyming and nonrhyming letters after a 15-sec delay under conditions that permitted phonemic coding and rehearsal. 2 other conditions were designed to suppress (a) rehearsal of certain types of phonemic codes in the delay interval and (b) both phonemic coding at stimulus presentation and rehearsal. Subjects were grade 2 average readers matched in reading skill with grade 4 disabled readers, grade 4 average matched with grade 6 disabled, and grade 6 average matched with grade 4 superior readers. Average readers showed a decrease in errors with age in all 3 conditions, although performance was always better in the nonsuppression condition. In the latter, memory for nonrhyming letters was always better than memory for rhyming letters. Differential use of phonemic codes by good and poor readers in grades 4 and 6 was less than that found in previous research with younger children. Finally, by comparing the performances of grade 2 average with grade 4 disabled readers and grade 4 average with grade 6 disabled readers, the developmental lag hypothesis of reading disability was examined. Problems with testing the hypothesis are discussed.     

Reading ability and memory span: Long-term memory contributions to span for good and poor readers

A number of studies have shown that childrenwith reading difficulties perform poorly ontests of verbal memory span. The extent towhich differences in memory span for good andpoor readers can be explained by differences ina long-term memory component to span as well asby differences in short-term memory processeswas investigated in this study. Memory spanand rehearsal rate were measured for high andlow frequency words and nonwords. Althoughmemory span performance for high frequencywords was comparable for all reading abilitygroups, good readers had better memory spanperformance for low frequency words. This wasattributable to differences in both short-termand long-term memory contributions to spanperformance. Differences between readingability groups also emerged when memory spanfor nonwords was measured. In this case,differences between groups also appeared to bethe result of difficulties which poor readersencountered in learning newphonologically-based materials (i.e. nonwords). The nature of the inter-relationships betweenmemory span, reading and measures ofphonological awareness are discussed in thelight of these findings.     

Phonemic awareness,naming, visual symbol processing,and reading

This study examined differences between adequate and poor readers in phonemic awareness, rapid continuous and confrontation naming, and visual symbol processing. It also investigated which of these skills make independent contributions to word recognition, pseudoword reading, and reading comprehension. Subjects were 170 school referrals of average intelligence, aged 6 to 10 years. The strongest differentiators of adequate and poor readers, with IQ and reading experience controlled, were phonemic awareness, naming speed for letters and pictured objects, and visual symbol processing. Letter naming speed made the largest independent contribution to word recognition, phonemic awareness to pseudoword reading, and object naming speed to reading comprehension. Confrontation picture naming accounted for minimal variance in reading skills, when IQ was controlled. It was concluded that tasks of naming speed, phonemic awareness, and visual symbol processing are valuable components of a diagnostic battery when testing children with possible reading disability.     

An evaluation of the discrepancy definition of dyslexia.

The purpose of this study was to determine whether children with dyslexia, that is, children whose reading levels were significantly lower than would be predicted by their IQ scores, constituted a distinctive group when compared with poor readers, that is, children whose reading scores were consistent with their IQ scores. The performance of children with dyslexia, poor readers, and normally achieving readers was compared on a variety of reading, spelling, phonological processing, language, and memory tasks. Although the children with dyslexia had significantly higher IQ scores than the poor readers, these two groups did not differ in their performance on reading, spelling, phonological processing, or most of the language and memory tasks. In all cases, the performance of both reading disabled groups was significantly below that of nondisabled readers. The findings were similar whether absolute difference or regression scores were used. Reading disabled children, whether or not their reading is significantly below the level predicted by their IQ scores, experience significant problems in phonological processing, short-term and working memory, and syntactic awareness. On the basis of these data, there does not seem to be a need to differentiate between individuals with dyslexia and poor readers. Both of these groups are reading disabled and have deficits in phonological processing, verbal memory, and syntactic awareness.     

Tracing symbol naming speed's unique contributions to reading disabilities over time

The contributions of naming speed measured on both serial-list and various discrete-trial formats to several reading subskills were examined longitudinally to determine their impact independent of other reading-related skills on reading disabilities. Tests of symbol naming speed, phonological awareness, vocabulary, memory span and coding speed were given to 38 poor and average readers when they were in Grades 2, 3 and 4. Grade 4 poor readers were discriminated from moderately poor or good readers on serial-list and discrete-trial naming speed tests in all grades. In addition, phonological awareness and vocabulary, but not memory span or coding speed, discriminated groups. These variables in Grade 2 contributed unique variance to reading scores in Grade 4 in differing patterns. Hypotheses about the nature of the reading — naming speed relationship are discussed.     

Subtypes of developmental dyslexia: The influence of definitional variables

The purpose of this study was to investigate the hypothesis that the manner in which a reading disability is defined will influence the conclusions that are made about the characteristics of the disability. To test this hypothesis, learning disabled and normally achieving children, aged 6 to 14, were administered tasks measuring grammatical, shortterm memory, phonological, reading, and visual-spatial skills. The poor readers were divided into groups of poor readers with

Qualitative and quantitative differences among dyslexic,normal, and nondyslexic poor readers

This study tested the hypothesis that when a stringent criterion of normal IQ is applied in the selection of dyslexic readers, and when dyslexics, nondyslexic poor readers, and normal readers are matched on reading comprehension — rather than word reading — significant differences among these groups can be demonstrated. Two groups of poor readers from primary grades, one with normal IQ (dyslexics) and the other with below-average IQ (nonspecific reading disabled, NSRD) were matched for reading comprehension with a group of younger normal readers. The dyslexic group was found to be inferior to the other two groups in tests of decoding and spelling. The dyslexic readers were more context-dependent for word recognition than the other two groups. The NSRD group did not differ from the normal readers in these aspects but had the worst performance on a test of inferential comprehension. It was concluded that dyslexics differ from normal readers and low-IQ poor readers in word and nonword reading skills and context-dependency for reading. A group of six adult dyslexics were also found to be deficient in decoding skills. A lack of unanimity in the use of certain terminology, a substantial age difference between low-IQ poor readers and normals, and the difference in the criteria used for matching the different groups could be factors that can explain the disagreements seen between the findings of the present study and those reported by some other studies. Potential problems associated with reading-age matched experimental design are discussed.     

Subgrouping poor readers on the basis of individual differences in reading-related abilities

The present study investigated the use of the Reading Component Model to subgroup poor readers. A large sample of poor readers was identified in second grade and subgrouped on the basis of relative strengths and weaknesses in word recognition and listening comprehension. Although homogeneous subgroups were not identified, poor readers could be classified into four subgroups that differed significantly in reading-related abilities. Further analyses showed that poor readers' strengths and weaknesses in listening comprehension, and to a lesser extent in word recognition, were foreshadowed by their abilities on related kindergarten measures. Follow-up testing in the fourth grade indicated that poor readers' individual differences in word recognition and listening comprehension were consistent and that subgroups were moderately stable. The implications of these results for the assessment and remediation of reading disabilities are discussed.     

Learning to read Chinese: Semantic,syntactic, phonological and working memory skills in normally achieving and poor Chinese readers

Whereas many studies point to a positive relationship between phonological skills and reading in English, little is known about these relationships for children learning to read in a morphemic orthography such as Chinese. The aim of this study was to examine the relationships among reading ability, phonological, semantic and syntactic skills in Chinese. The participants were 196 grade 1 to grade 4 Chinese children in Hong Kong. A word recognition task in Chinese was developed and children who scored in the lowest quartile were classified as poor readers. The children were administered phonological tasks (tone and rhyming discrimination), semantic tasks (choosing similar words and sentences meanings), a syntactic task (oral cloze), and a working memory task. The results showed that word recognition was highly correlated with phonological skills and semantic processing, and was only moderately related to syntactic knowledge and working memory. Poor readers showed a significant lag in the development of these skills with the most significant problems at the phonological and semantic levels. Phonological skills are important to the acquisition of reading skills in both Chinese and English.     

Relationships of naming skills to reading,memory, and receptive vocabulary: Evidence for imprecise phonological representations of words by poor readers

The main hypotheses addressed in the research were (1) whether imprecision in the phonological representations of lexical items underlies the impaired expressive naming abilities of disabled readers, and (2) whether weak verbal memory might mediate the relationship between naming and reading skills. From samples of 93 first graders and 67 fourth graders, extreme groups of good and poor readers were identified and compared on measures of receptive vocabulary, expressive naming, acceptability judgments for variants of object names, imitation and correction of naming errors by another speaker, pseudoword repetition, and long-term memory. Performance was generally better by older than younger students and by good than poor readers at each age, with little interaction between grade and reader group. The results indicated that for both good and poor readers, imprecise phonological knowledge, especially about long words, contributed to children’s difficulties on all naming tasks. Memory differences, however, appeared to play only a minor role in explaining the strong association between naming and reading.     

The effect of modifying the cognitive tempo of reading disabled children on reading comprehension

The present investigation was concerned with teaching poor readers to use a reflective cognitive style. It was hypothesized that such a strategy would facilitate the reading ability of poor readers. To test this hypothesis, approximately half the poor readers and half the average readers were divided into experimental and control groups. The experimental group of children was taught to delay their responses and to use more efficient search and scanning techniques. All groups were tested before and after training on the Matching Familiar Figures test and the Gates-MacGinitie Reading Test. Poor readers' vocabulary and comprehension scores and level of reflectivity improved following training. It was concluded that imposing slow reading strategies on impulsive children is an important factor in developing educational programs for children with reading disabilities and that teaching poor readers a reflective cognitive strategy may have important consequences on the child's reading performance.     

Reading comprehension and lateral preference in normal readers

The effect of lateral preference on passage comprehension and short-term memory function was examined for 48 normal fourth-grade males. Scores on a self-report measure of lateral preference were used to divide the children into groups who differed in their laterality. The subjects were tested for basic comprehension on written and aurally presented prose in standard and nonstandard phrase form. Consistently lateralized readers recalled more information under the auditory than under the written conditions, while bilateral readers showed no preference for mode of presentation. Between-group comparisons showed bilateral readers to comprehend significantly more in the written conditions than did the other group. Groups did not differ on recall of auditorily presented material or on short-term digit memory. These results may be interpreted as demonstrating that bilateral preference need not be tied to reading difficulty.     

The effects of phonological transparency on reading derived words

The purpose of this study was to determine whether poor readers have more pronounced problems than average-reading peers reading derived words the base forms of which undergo a phonological shift when a suffix is added (i.e., shift relations as in “natural”), as compared to derived words whose forms are phonologically and orthographically transparent (i.e., stable relations, as in “cultural”). Two computer-based word recognition tasks (Naming and Lexical Decision) were administered to children with reading disability (RD), peers with average reading ability, and adults. Across tasks, there was an effect for transparency (i.e., better performance on stable than shift words) for both child groups and the adults. For the children, a significant interaction was found between group and word type. Specifically, on the naming task, there was an advantage for the stable words, and this was most noteworthy for the children with RD. On the lexical decision task, trade-offs of speed and accuracy were evident for the child reader groups. Performances on the nonwords showed the poor readers to be comparable to the average readers in distinguishing legal and illegal nonwords; further analyses suggested that poor readers carried out deeper processing of derived words than their average reading peers. Additional study is needed to explore the relation of orthographic and phonological processing on poor readers’ memory for and processing of derived words.