Perception of speech and nonspeech stimuli by children with and without reading disability and attention deficit hyperactivity disorder

The auditory temporal deficit hypothesis predicts that children with reading disability (RD) will exhibit deficits in the perception of speech and nonspeech acoustic stimuli in discrimination and temporal ordering tasks when the interstimulus interval (ISI) is short. Initial studies testing this hypothesis did not account for the potential presence of attention deficit hyperactivity disorder (ADHD). Temporal order judgment and discrimination tasks were administered to children with (1) RD/no-ADHD (n=38), (2) ADHD (n=29), (3) RD and ADHD (RD/ADHD; n=32), and (4) no impairment (NI; n=43). Contrary to predictions, children with RD showed no specific sensitivity to ISI and performed worse relative to children without RD on speech but not nonspeech tasks. Relationships between perceptual tasks and phonological processing measures were stronger and more consistent for speech than nonspeech stimuli. These results were independent of the presence of ADHD and suggest that children with RD have a deficit in phoneme perception that correlates with reading and phonological processing ability. (c) 2002 Elsevier Science (USA).     

Discrimination of speech sounds by children with dyslexia: comparisons with chronological age and reading level controls

Previous studies have shown that children suffering from developmental dyslexia have a deficit in categorical perception of speech sounds. The aim of the current study was to better understand the nature of this categorical perception deficit. In this study, categorical perception skills of children with dyslexia were compared with those of chronological age and reading level controls. Children identified and discriminated /do-to/ syllables along a voice onset time (VOT) continuum. Results showed that children with dyslexia discriminated among phonemically contrastive pairs less accurately than did chronological age and reading level controls and also showed higher sensitivity in the discrimination of allophonic contrasts. These results suggest that children with dyslexia perceive speech with allophonic units rather than phonemic units. The origin of allophonic perception in the course of perceptual development and its implication for reading acquisition are discussed.     

The relationship between phonological skills and word decoding

Word decoding ability is a critical factor in reading performance. In the present study, we examined the relationship between word decoding ability and three different phonological skills; phonemic awareness, verbal short-term memory (V-STM), and rapid automatic naming (RAN) in 1007 Scandinavian third- and fifth-graders. In the first part of the study, we sought to investigate the influence of the three phonological skills on word decoding ability. Using multiple regression analysis, our result clearly demonstrated that phonemic awareness was the most powerful phonological skill explaining variance in word decoding ability among average decoders. Among children with poor decoding skills, however, RAN was the most important factor in Grade 3, whereas V-STM was the main contributor to decoding ability among children in Grade 5. In the second part of the research, we examined the relationship between poor phonological skills and word decoding ability. Interestingly, our result revealed that approximately one half of the children with phonological difficulties, still performed within the average range with regard to word decoding ability. However, our analyses confirmed earlier research concerning the severe word decoding difficulties children with both poor phonemic awareness and restricted V-STM, experience.     

A comparison of the cognitive deficits in reading disability and attention-deficit/hyperactivity disorder

This study used a nonreferred sample of twins to contrast the performance of individuals with reading disability (RD; n = 93), attention-deficit/hyperactivity disorder (ADHD; n = 52), RD and ADHD (n = 48), and neither RD nor ADHD (n = 121) on measures of phoneme awareness (PA) and executive functioning (EF). Exploratory factor analysis of the EF measures yielded underlying factors of working memory, inhibition, and set shifting. Results revealed that ADHD was associated with inhibition deficits, whereas RD was associated with significant deficits on measures of PA and verbal working memory. The RD + ADHD group was most impaired on virtually all measures, providing evidence against the phenocopy hypothesis as an explanation for comorbidity between RD and ADHD.     

Emergent literacy skills and training time uniquely predict variability in responses to phonemic awareness training in disadvantaged kindergartners

The factors that predicted variability in responses to phonemic awareness training were investigated in kindergartners who live in poverty. Treatment children (n=42) received both analytic and synthetic phonemic awareness computer-assisted instruction, while controls (n=34) received no special training. Mean age of participants was approximately 5 years 7 months. Pretests included initial phonemic awareness, letter knowledge, word-level reading, invented spelling, vocabulary knowledge, and print concepts. Spelling skills emerged as the best consistent predictor of variability in phonemic awareness in response to instruction. We propose that relations between phonemic awareness and spelling skills are bidirectional: Spelling influenced growth in phonemic awareness and phonemic awareness contributed to growth in spelling skills. The amount of exposure that children had to the treatment intervention contributed uniquely to individual differences in posttest levels of phonemic awareness and spelling.     

四种语音意识干预模式对小学生英文单词朗读作用的比较

采用前-后测对比组的准实验设计,将84名小学三年级学生分配到四种语音意识干预组,即:单纯的音素意识训练组、字母-音素意识二合一训练组、字母-音标-音素意识三合一训练组和字母-音标-反切意识三合一训练组,旨在比较四种语音意识干预模式对于小学三年级学生英语语音意识和英文单词朗读技能的作用。结果表明:(1)就音素合成与音素替换技能的训练而言,字母-音标-反切意识三合一训练模式,都会产生一定的优势;(2)四种语音意识干预模式,不仅能够显著地提高小学三年级学生的英文单词朗读技能,而且能够使他们将经过干预而获得的朗读技能迁移到陌生词的朗读之中;(3)虽然四种语音意识干预模式都能够显著地促进小学三年级学生的英文单词朗读技能,但是,字母-音素意识二合一训练模式的促进作用最大。     

“热”执行对注意缺陷多动障碍和阅读障碍儿童言语工作记忆的影响

ADHD儿童在与背外侧前额叶(DLPFC)相关的"冷"执行功能上的缺陷已大量证实,但在与眼眶和中前额叶皮层(OMPFC)相关的"热"执行功能上,ADHD儿童是否存在缺陷则未可知。与儿童赌博任务实验范式(该任务中"热"启动对"冷"执行起到抑制作用)不同,本研究考察趣味言语N-back任务是否对ADHD和阅读障碍儿童的成绩有促进作用。枯燥N-back任务考察的是言语工作记忆的纯认知特征,而趣味任务则卷入了"热"执行对"冷"执行的影响。结果表明,在枯燥任务上,ADHD和阅读障碍儿童的成绩均明显低于正常儿童,二者之间差异不显著,在趣味任务成绩上,ADHD儿童与正常儿童的成绩没有显著差异,而阅读障碍儿童成绩落后于正常控制组和ADHD组,在成绩变化的趋势上,ADHD儿童在趣味任务上成绩明显提高,而阅读障碍儿童则无明显改善。结果说明ADHD和阅读障碍儿童的言语工作记忆均存在明显的缺陷,但是机制不同,"热"执行对提高ADHD的言语工作记忆有明显的促进作用,ADHD的"冷"执行缺陷能够通过"热"执行的调节得到改善。     

Does the Conners' Continuous Performance Test Aid in ADHD Diagnosis?

The performance of clinic-referred children aged 6–11 (N = 100) was examined using the Conners' Continuous Performance Test (CPT) and measures of auditory attention (Auditory Continuous Performance Test; ACPT), phonological awareness, visual processing speed, and visual-motor competence. The Conners' CPT overall index was unrelated to measures of visual processing speed or visual-motor competence. Although the Conners' CPT converged with the ACPT, the latter demonstrated age and order effects. Significant variance in Conners' CPT parameters was predicted by phonological awareness measures, suggesting that Reading Disordered (RD) children could be false positives on the Conners' CPT. The Conners' CPT overall index, phonological awareness, and visual-motor measures were submitted to a 2×2 MANCOVA (ADHD vs. RD, covarying for age and socieoeconomic status): a main effect for RD status was found. Children with ADHD did not have higher Conners' CPT scores than did clinical controls; however, children with Reading Disorders did. Phonological measures distinguished RD children from ADHD children and other clinical controls. ADHD children who failed the Conners' CPT were rated by teachers as more hyperactive. Despite the strengths of the Conners' CPT, its utility for differential diagnosis of ADHD is questioned.     

Time Perception: Does It Distinguish ADHD and RD Children in a Clinical Sample?

This study used a double-dissociation design to evaluate whether children with ADHD demonstrated specific deficits relative to children with Reading Disorders. Recent theory suggests that ADHD children have deficits in time perception and working memory, whereas RD children have deficits in phonological decoding. The performance of 113 clinic-referred children aged 6-11 was examined using measures of working memory, phonological processing, and time perception. Respondents completed two time production tasks in which they were to judge when 30-s had elapsed, and another in which they were asked to estimate the duration of the Conners' CPT (CCPT). Time Perception and phonological processing variables were submitted to a 2 x 2 ANCOVA (ADHD vs. RD), covarying for age, SES, IQ, and working memory. Children with ADHD were more likely to overestimate the time taken for the CCPT than children without ADHD, but no group differences were found on the 30-s estimation tasks. Children with RD did not display deficits in time estimation, but showed deficits in auditory phonological processing. The lack of interaction effects supported an "etiological subtype" over the "phenocopy" model of ADHD and RD. No group differences were detected using the CCPT. Although our previous studies did not find an order effect for the Conners' CPT in a 1-hr battery, a fatigue effect was evident with a 1.5-hr battery. The implications for Barkley's behavioral inhibition theories (R. Barkley, 1997) are discussed.     

The relationship between phonological processing and arithmetic in children with learning disabilities

Phonological processing skills have not only been shown to be important for reading skills, but also for arithmetic skills. Specifically, previous research in typically developing children has suggested that phonological processing skills may be more closely related to arithmetic problems that are solved through fact retrieval (e.g., remembering the solution from memory) than procedural computation (e.g., counting). However, the relationship between phonological processing and arithmetic in children with learning disabilities (LDs) has not been investigated. Yet, understanding these relationships in children with LDs is especially important because it can help elucidate the cognitive underpinnings of math difficulties, explain why reading and math disabilities frequently co-occur, and provide information on which cognitive skills to target for interventions. In 63 children with LDs, we examined the relationship between different phonological processing skills (phonemic awareness, phonological memory, and rapid serial naming) and arithmetic. We distinguished between arithmetic problems that tend to be solved with fact retrieval versus procedural computation to determine whether phonological processing skills are differentially related to these two arithmetic processes. We found that phonemic awareness, but not phonological memory or rapid serial naming, was related to arithmetic fact retrieval. We also found no association between any phonological processing skills and procedural computation. These results converge with prior research in typically developing children and suggest that phonemic awareness is also related to arithmetic fact retrieval in children with LD. These results raise the possibility that phonemic awareness training might improve both reading and arithmetic fact retrieval skills.

Research Highlights

• Relationships between phonological processing and various arithmetic skills were investigated in children with learning disabilities (LDs) for the first time.
• We found phonemic awareness was related to arithmetic involving fact retrieval, but not to arithmetic involving procedural computation in LDs.
• The results suggest that phonemic awareness is not only important to skilled reading, but also to some aspects of arithmetic.
• These results raise the question of whether intervention in phonemic awareness might improve arithmetic fact retrieval skills.

     

Co-occurring disorders: a possible key to visual perceptual deficits in children with developmental coordination disorder?

A study was conducted to examine how visual perceptual functioning in children with DCD may be influenced by co-occurring learning problems such as reading disabilities (RD) and/or attention deficit hyperactivity disorder (ADHD). Participants included seven groups of children: 27 children with DCD only, 11 with ADHD only, 14 with RD only, 63 with DCD and at least one other disorder (i.e., DCD + ADHD, DCD + RD, DCD + ADHD + RD), and 73 typically developing controls. Visual perceptual skills were assessed using the Test of Visual Perceptual Skills (TVPS) and the Rey Osterreith Complex Figure (ROCF; copy and delayed recall). Children with DCD and at least one other disorder were found to have impairments on the TVPS compared to children with DCD only, ADHD only, and typically developing controls, particularly on subtests assessing visual memory. On the ROCF, children with DCD and at least one other disorder scored significantly lower than children with ADHD only or RD only. Children with DCD plus one other disorder were then subdivided into three groups: DCD + ADHD, DCD + RD, and DCD + ADHD + RD and compared to children with DCD only, ADHD only, and RD only. Results indicated that children with DCD + ADHD + RD had significant impairments on the TVPS compared to children with DCD only and children with ADHD only. On the ROCF, children with DCD + ADHD + RD scored significantly lower than all of the groups, except the DCD+RD group. These findings suggest that DCD on its own is not associated with visual perceptual problems; rather, it is the presence of co-occurring disorders that is a possible key to visual perceptual deficits in children with DCD. The number of co-occurring disorders present with DCD is associated with the severity of the visual perceptual dysfunction. Deficits in visual memory skills appear to be a specific area of difficulty for children with DCD and co-occurring RD and/or ADHD.     

阅读障碍与注意缺陷多动障碍儿童的语言加工和反应抑制

阅读障碍与注意缺陷多动障碍(ADHD)高度共病,以往研究结果显示两种障碍在语言加工、执行功能等领域的缺陷既相似又不同。本研究采用语音意识测验、快速命名测验、语素意识测验和停止信号任务,以及阅读广度测验,分别考察四组被试（阅读障碍组、ADHD组、双重障碍组、正常控制组）的基础语言加工、反应抑制和言语工作记忆能力,结果发现：阅读障碍组和双重障碍组在语言加工任务上的成绩均显著差于ADHD组和正常组;ADHD组和双重障碍组在停止信号任务上的成绩显著差于阅读障碍组和正常组;所有障碍组在阅读广度测验上的成绩显著差于正常组。表明阅读障碍的特异性缺陷体现在语言加工过程上,而注意缺陷多动障碍的特异性缺陷体现在反应抑制上。这对于今后单一障碍的研究及临床诊断和干预具有重要的参考价值。     

Relations between enabling skills and reading comprehension: a follow-up study of Latvian students from first to second grade

In order to examine the relationships among various phonological skills and reading comprehension, Latvian children were followed from grade 1 to grade 2 and were tested with a battery of phonological, word reading, and reading comprehension tasks. A principal component analysis of the phonological tasks revealed three salient factors: a phonemic awareness factor, a rapid naming factor, and a short-term memory factor. In order to analyze the relationship between various phonological skills and reading comprehension, a structural modeling analysis was performed. Phonemic awareness and rapid naming explained approximately the same amount of unique variance in reading comprehension, but phonemic awareness had most predictive power indirectly via word decoding. Only rapid naming had a significant direct impact on reading comprehension.     

Adaptation of the relative onset time of two-component tones

The results of three selective adaptation experiments employing nonspeech signals that differed in temporal onset are reported. In one experiment, adaptation effects were observed when both the adapting and test stimuli were selected from the same nonspeech test continuum. This result was interpreted as evidence for selective processing of temporal order information in nonspeech signals. Two additional experiments tested for the presence of cross-series adaptation effects from speech to nonspeech and then from nonspeech to speech. Both experiments failed to show any evidence of cross-series adaptation effects, implying a possible dissociation between perceptual classes of speech and nonspeech signals in processing temporal order information. Despite the absence of cross-series effects, it is argued that the ability of the auditory system to process temporal order information may still provide a possible basis for explaining the perception of voicing in stops that differ in VOT. The results of the present experiments, taken together with earlier findings on the perception of temporal onset in nonspeech signals, were viewed as an example of the way spoken language has exploited the basic sensory capabilities of the auditory system to signal phonetic differences.     

Naming Speed Performance and Stimulant Effects Indicate Effortful, Semantic Processing Deficits in Attention-Deficit/Hyperactivity Disorder

This study investigated rapid automatized naming and effects of stimulant medication in school-age children with attention-deficit/hyperactivity disorder (ADHD) with and without concurrent reading disorder (RD). Two ADHD groups (67 ADHD only; 21 ADHD + RD) and a control group of 27 healthy age-matched peers were compared on four variables: color naming speed, letter naming speed, phonologic decoding, and arithmetic computation. Discriminant function analysis (DFA) was conducted to predict group membership. The four variables loaded onto two discriminant functions with good specificity: phonologic decoding, letter naming speed, and arithmetic defined the first function; color naming speed defined the second function. Both ADHD groups were significantly slower in color naming than controls, but did not differ from one another. DFA correctly classified 96% of the control group, 91% of ADHD + RD, and 82% of ADHD only. A subset of children in the ADHD groups participated subsequently in an acute, randomized, placebo-controlled, crossover trial with three single doses (10, 25, 20 mg) of methylphenidate. Methylphenidate selectively improved color-naming speed but had no effect on the speed of naming letters or digits. These findings challenge the tenet that naming speed deficits are specific to RD and implicate naming speed deficits associated with effortful semantic processing in ADHD, which are improved but not normalized by stimulant medication.     

Phonemic restorations based on subsequent context

Earlier experiments have shown that when one or more speech sounds in a sentence are replaced by a noise meeting certain criteria, the listener mislocalizes the extraneous sound and believes he hears the missing phoneme(s) clearly. The present study confirms and extends these earlier reports of phonemic restorations under a variety of novel conditions. All stimuli had some of the context necessary for the appropriate phonemic restoration following the missing sound, and all sentences had the missing phoneme deliberately mispronounced before electronic deletion (so that the neighboring phonemes could not provide acoustic cues to aid phonemic restorations). The results are interpreted in terms of mechanisms normally aiding veridical perception of speech and nonspeech sounds.     

Effects of computer-assisted practice on reading and spelling in children with learning disabilities

The main purpose of this study was to analyze the effects of computer-assisted practice on reading and spelling in children with learning disabilities (LD). We compared three practice conditions, one with reading and two with spelling, in order to test whether computer-based reading and spelling practice has an influence on the development of reading and spelling ability in children with LD. A sample was selected of 85 children with LD, with age range between 8 years and 10 years (age, M=111.02, SD=9.6), whose spelling performance was two years below grade level. The participants were randomly assigned to one of four groups: 1) Copy the target word from the computer screen (n=22), 2) Memorize the target word and write it from memory (n=21), 3) Word reading (n=21), and 4) the untrained control group (n=21). We administered measures of pseudoword reading, phonological awareness, phonological word decoding and orthographical word decoding tasks. We examined the learning effects and transfer effects on words classified as a function of length, consistency, and complexity of syllable structure. Overall, the results showed that reading training did not improve spelling; however, the children who participated in the copy training condition improved their spelling skills.     

Conditions on rate normalization in speech perception

Recent work by Summerfield (1975) and others indicates that a listener’s phonemic judgments may vary with the utterance rate of prior context. In particular, if a phonemic distinction is signaled by a temporal cue such as voice onset time (VOT), faster utterance rates tend to shift the phoneme boundary toward smaller values of that cue. The listener thus appears to “normalize” temporal cues according to utterance rate. In the present experiment, subjects identified syllables varying in VOT ([ga]-[k^ha]) following either a slow or a fast version of the phrase “Teddy hears_ _ _ _ .” Typical normalization effects were observed when the precursor phrase and target syllable had formant frequencies corresponding to an adult male vocal tract. However, a reversal of the typical pattern (i.e., a shift in the perceived voicing boundary towardlarger values of VOT with an increased utterance rate) occurred when the precursor and target had formant frequencies corresponding to an adult female vocal tract. Both normalization and “reverse” normalization effects were reduced or eliminated under several conditions of source change between precursor and target. These conditions included a change in fundamental frequency, a change in implied vocal-tract size (as reflected in an upward or downward scaling of formant frequencies), or both.     

Dissociating the performance of cortical and subcortical patients on phonemic tasks

To assess cortical and subcortical contributions to phonemic processing, patients with left frontal, temporal-parietal, or cerebellar lesions as well as those with Parkinson's disease were tested on phonemic identification and production tasks. In Experiment 1, patients and controls were asked to identify syllables on both a voicing and place of articulation continuum. Subcortical patients were relatively unimpaired at this task whereas cortical patients were less accurate at identifying the endpoints of both continua and exhibited little evidence of categorical perception. For Experiment 2, controls and patients were asked to produce syllables. Subcortical patients were able to produce contrastive voice onset times (VOTs) for voicing cognates although VOT of the voiceless phoneme was more variable for cerebellar patients. Cortical patients showed greater overlap in the production of both VOT and formant transition intervals. These results are discussed in terms of the type of computations hypothesized to originate from each neural area.     

PHONEMIC PROCESSING OF CHILDREN WITH LANGUAGE DEFICITS; WHICH TASKS BEST DISCRIMINATE CHILDREN WITH LEARNING DISABILITIES FROM AVERAGE READERS?

ABSTRACT

This comparative study investigated the levels of phonemic awareness that accounted for differences between children with learning disabilities (LD) and children of average reading ability of the same chronological age level (CA) and younger children of average reading ability at the same reading age level (RA). Two planned comparisons were implemented. All three groups were assessed on three levels of phonemic awareness represented as a hierarchical set: awareness of onset and rime, simple phonemic awareness, and compound phonemic awareness. Compared to the RA group, the LD group performed significantly worse only on the first level of phonemic awareness, the awareness of onset and rime. Results of a stepdown analysis revealed that compared with the CA matched group, the LD group performed significantly worse on compound phonemic awareness with all preceding variables partialled from the analysis. Implications for diagnosis and remediation of learning disabilities is explicated.