The role of visual and auditory temporal processing in reading irregular and nonsense words.

In the present study, the role of rapid visual and auditory temporal processing in reading irregular and nonsense words was investigated with a group of normal readers. One hundred and five undergraduates participated in various visual and auditory temporal-processing tasks. Readers who primarily adopted the phonological route in reading (nonsense-word readers) showed a trend for better auditory temporal resolution but readers who primarily adopted sight word skills (irregular-word readers) did not exhibit better visual temporal resolution. Both the correlation and stepwise multiple-regression analyses, however, revealed a relationship between visual temporal processing and irregular-word reading as well as a relationship between auditory temporal processing and nonsense-word reading. The results support the involvement of visual and auditory processing in reading irregular and nonsense words respectively, and were discussed with respect to recent findings that only dyslexics with phonological impairment will display temporal deficits. Further, the temporal measures were not effective discriminants for the reading groups, suggesting a lack of association between reading ability and the choice of reading strategy.     

The contribution of rapid visual and auditory processing to the reading of irregular words and pseudowords presented singly and in contiguity

This study examined the relative involvement of rapid auditory and visual temporal resolution mechanisms in the reading of phonologically regular pseudowords and English irregular words presented both in isolation and in contiguity as a series of six words. Seventy-nine undergraduates participated in a range of reading, visual temporal, and auditory temporal tasks. The correlation analyses suggested a general timing mechanism across modalities. There were more significant correlations between the visual temporal measures and irregular word reading and between the auditory measures and pseudoword reading. Auditory gap detection predicted pseudoword reading accuracies. The low temporal frequency flicker contrast sensitivity measure predicted the accuracies of isolated irregular words and pseudowords presented in contiguity. However, when a combined speed-accuracy score was used, visible persistence at both low and high spatial frequencies and auditory gap detection were active in the reading of pseudowords presented in contiguity. Sensory processing skills in both visual and auditory modalities accounted for some of the variance in the reading performance of normal undergraduates, not just reading-impaired students.     

Impaired sensitivity to dynamic stimuli in poor readers of a regular orthography

The mappings from grapheme to phoneme are much less consistent in English than they are for most other languages. Therefore, the differences found between English-speaking dyslexics and controls on sensory measures of temporal processing might be related more to the irregularities of English orthography than to a general deficit affecting reading ability in all languages. However, here we show that poor readers of Norwegian, a language with a relatively regular orthography, are less sensitive than controls to dynamic visual and auditory stimuli. Consistent with results from previous studies of English-readers, detection thresholds for visual motion and auditory frequency modulation (FM) were significantly higher in 19 poor readers of Norwegian compared to 22 control readers of the same age. Over two-thirds (68.4%) of the children identified as poor readers were less sensitive than controls to either or both of the visual coherent motion or auditory 2Hz FM stimuli.     

The reading ability of good and poor temporal processors among a group of college students

In this study, we examined whether good auditory and good visual temporal processors were better than their poor counterparts on certain reading measures. Various visual and auditory temporal tasks were administered to 105 undergraduates. They read some phonologically regular pseudowords and irregular words that were presented sequentially in the same ("word" condition) and in different ("line" condition) locations. Results indicated that auditory temporal acuity was more relevant to reading, whereas visual temporal acuity was more relevant to spelling. Good auditory temporal processors did not have the advantage in processing pseudowords, even though pseudoword reading correlated significantly with auditory temporal processing. These results suggested that some higher cognitive or phonological processes mediated the relationship between auditory temporal processing and pseudoword reading. Good visual temporal processors did not have the advantage in processing irregular words. They also did not process the line condition more accurately than the word condition. The discrepancy might be attributed to the use of normal adults and the unnatural reading situation that did not fully capture the function of the visual temporal processes. The distributions of auditory and visual temporal processing abilities were co-occurring to some degree, but they maintained considerable independence. There was also a lack of a relationship between the type and severity of reading deficits and the type and number of temporal deficits.     

英语学习不良儿童语音能力与阅读理解的关系

探讨了英语学习不良儿童语音能力的发展状况,分析了这些儿童在英语学习中语音能力,句法意识及阅读理解能力间的关系。结果发现,除了在假词拼读能力上存在缺陷外,英语学习不良儿童在其他语音能力--英语语音意识、听觉言语工作记忆及视觉言语工作记忆上均不存在发展滞后现象;在对儿童的阅读理解能力进行预测时,假词拼读、语音意识、句法意识和听觉工作记忆是较好的预测效标。     

Speed of lower-level auditory and visual processing as a basic factor in dyslexia: electrophysiological evidence

This study investigated speed of processing (SOP) among college-level adult dyslexic and normal readers in nonlinguistic and sublexical linguistic auditory and visual oddball tasks, and a nonlinguistic cross-modal choice reaction task. Behavioral and electrophysiological (ERP) measures were obtained. The results revealed that between both groups, reaction times (RT) were longer and the latencies of P2 and P3 components occurred later in the visual as compared to auditory oddball tasks. RT and ERP latencies were longest in the cross-modal task. RT and ERP latencies were delayed among dyslexic as compared to normal readers across tasks. On the oddball tasks, group differences in brain activity were observed only when responding to low-probability targets. These differences were largest for the P3 component, and most pronounced in the case of phonemes. The gap between ERP latencies in the visual versus the auditory modalities for each component was larger among dyslexic as compared to normal readers, and was particularly evident at the linguistic level. A hypothesis is proposed that suggests an amodal, basic SOP deficit among dyslexic readers. The slower cross-modal SOP is attributed to slower information processing in general and to disproportionate "asynchrony" between SOP in the visual versus the auditory system. It is suggested that excessive asynchrony in the SOP of the two systems may be one of the underlying causes of dyslexics' impaired reading skills.     

The relationship between auditory temporal processing,phonemic awareness,and reading disability

Recent research suggests an auditory temporal deficit as a possible contributing factor to poor phonemic awareness skills. This study investigated the relationship between auditory temporal processing of nonspeech sounds and phonological awareness ability in children with a reading disability, aged 8-12 years, using Tallal's tone-order judgement task. Normal performance on the tone-order task was established for 36 normal readers. Forty-two children with developmental reading disability were then subdivided by their performance on the tone-order task. Average and poor tone-order subgroups were then compared on their ability to process speech sounds and visual symbols, and on phonological awareness and reading. The presence of a tone-order deficit did not relate to performance on the order processing of speech sounds, to poorer phonological awareness or to more severe reading difficulties. In particular, there was no evidence of a group by interstimulus interval interaction, as previously described in the literature, and thus little support for a general auditory temporal processing difficulty as an underlying problem in poor readers. In this study, deficient order judgement on a nonverbal auditory temporal order task (tone task) did not underlie phonological awareness or reading difficulties.     

Prosodic awareness and punctuation ability in adult readers

We examined the relationship between two metalinguistic tasks: prosodic awareness and punctuation ability. Specifically, we investigated whether adults' ability to punctuate was related to the degree to which they are aware of and able to manipulate prosody in spoken language. English-speaking adult readers (n = 115) were administered a receptive and a productive measure of prosodic awareness, a measure of their baseline knowledge of punctuation, and a productive measure of punctuation ability, in addition to control measures. Prosodic awareness emerged as a robust predictor of adults' ability to punctuate, over and above the influence of their punctuation knowledge, reading comprehension, and working memory.     

Visual information processing in relation to age and to reading ability.

Temporal aspects of early visual information processing were studied developmentally in good and in poor reading male subjects ranging in age from 7 to 13 years. Forced-choice temporal integration and backward masking tasks, respectively, were utilized to assess duration of visual persistence and of relative rate of visual information processing. The results did not reveal differences in either visual persistence or processing rate in relation to reading ability at any age level studied. However, processing rate was found to increase markedly with chronological age in both the good and the poor readers while visual persistence did not vary significantly. The findings were discussed in relation to earlier work and in relation to current theoretical formulations of visual information processing.     

Rapid alternating stimulus naming in the developmental dyslexias

A rapid, alternating stimulus (RAS) naming measure was designed to study the developing ability in dyslexic readers to direct attention to contextual patterns while performing a rapid serial naming task. The results from a 3-year longitudinal investigation of 98 children indicate three trends. RAS performances differentiate both average from impaired readers and dyslexic subgroups from each other. The largest, most impaired subgroup can not complete the RAS tasks in kindergarten; the smaller subgroups have little name access speed deficits. Early RAS performances are highly predictive of later reading, particularly at the single-word reading level. Implications for understanding the development of automaticity and the relationship between retrieval speed and reading are discussed.     

Visual word recognition without central attention: Evidence for greater automaticity with greater reading ability

The present study examined individual differences in the automaticity of visual word recognition. Specifically, we examined whether people can recognize words while central attention is devoted to another task and how this ability depends on reading skill. A lexical-decision Task 2 was combined with either an auditory or visual Task 1. Regardless of the Task 1 modality, Task 2 word recognition proceeded in parallel with Task 1 central operations for individuals with high Nelson-Denny reading scores, but not for individuals with low reading scores. We conclude that greater lexical skill leads to greater automaticity, allowing better readers to more efficiently perform lexical processes in parallel with other attention-demanding tasks.     

Visual temporal processing in dyslexia and the magnocellular deficit theory: the need for speed?

A controversial question in reading research is whether dyslexia is associated with impairments in the magnocellular system and, if so, how these low-level visual impairments might affect reading acquisition. This study used a novel chromatic flicker perception task to specifically explore temporal aspects of magnocellular functioning in 40 children with dyslexia and 42 age-matched controls (aged 7-11). The relationship between magnocellular temporal resolution and higher-level aspects of visual temporal processing including inspection time, single and dual-target (attentional blink) RSVP performance, go/no-go reaction time, and rapid naming was also assessed. The Dyslexia group exhibited significant deficits in magnocellular temporal resolution compared with controls, but the two groups did not differ in parvocellular temporal resolution. Despite the significant group differences, associations between magnocellular temporal resolution and reading ability were relatively weak, and links between low-level temporal resolution and reading ability did not appear specific to the magnocellular system. Factor analyses revealed that a collective Perceptual Speed factor, involving both low-level and higher-level visual temporal processing measures, accounted for unique variance in reading ability independently of phonological processing, rapid naming, and general ability.     

Skilled deaf readers have an enhanced perceptual span in reading

Recent evidence suggests that, compared with hearing people, deaf people have enhanced visual attention to simple stimuli viewed in the parafovea and periphery. Although a large part of reading involves processing the fixated words in foveal vision, readers also utilize information in parafoveal vision to preprocess upcoming words and decide where to look next. In the study reported here, we investigated whether auditory deprivation affects low-level visual processing during reading by comparing the perceptual span of deaf signers who were skilled and less-skilled readers with the perceptual span of skilled hearing readers. Compared with hearing readers, the two groups of deaf readers had a larger perceptual span than would be expected given their reading ability. These results provide the first evidence that deaf readers' enhanced attentional allocation to the parafovea is used during complex cognitive tasks, such as reading.     

Letter-specific processing in children and adults matched for reading level

Expert readers perform faster and more accurately during tasks that involve letters from the known language compared to tasks that involve unfamiliar letter-like forms (e.g., pseudoletters). Previous work with typically developing participants suggests that this letter-specific processing emerges as a consequence of increased reading ability, rather than increased age. In contrast, others have suggested that adults rely on visual information to a greater extent than children when reading, despite reading at similar less-than-expert levels, implying that adults may exhibit greater letter specificity than children. The present study aimed to discriminate between these possibilities by comparing the advantage for letters over pseudoletters in children and adults reading at the same less-than-expert (fourth grade) level. Results revealed greater letter specificity in adults than in children in both error rate and response time measures. Moreover, the magnitude of letter specificity did not vary with reading ability. Thus, results suggest that adults are more sensitive than children to the visual forms of letters, and that differences in letter specificity are not necessarily dependent on reading skill.     

Cross-modality temporal processing deficits in developmental phonological dyslexics

Neuroanatomical evidence suggests that poor readers may have abnormal lateral (LGN) and medial (MGN) geniculate nuclei responsible for temporal processing in visual and auditory domains respectively (Livingstone & Galaburda, 1993). Although behavioral evidence does support this neuroanatomical evidence in that poor readers have performed poorly on visual and auditory tasks thought to require the utilization of the LGN and MGN, respectively, appropriate examination of the coexistence of these behavioral abnormalities in the same population of poor readers has yet to take place. The present study examined correlations between visual and auditory temporal processing scores of all readers (collapsed groups), good readers, and poor readers who were isolated into phonological and surface dyslexic subtypes. The same subjects and data from Cestnick and Coltheart (1999) and Cestnick and Jerger (2000) were used to run the analyses. Results demonstrated a multitude of correlations between these tasks for the phonological dyslexic group only. It is contended that cross-modality temporal processing deficits may exist in poor nonlexical (phonological dyslexics) as opposed to poor lexical (surface dyslexics) readers. It is conceivable that phonological dyslexics may also have deficiencies within the LGN and MGN, or perhaps within systems related to these nuclei. The precise cause of these processing patterns and correlations is still unknown.     

发展性阅读障碍的视听时间敏感性缺陷及其脑神经机制

阅读是一个视听加工过程,阅读障碍的产生可能是过程中视听时间敏感性缺陷的结果。视听时间敏感性指个体对视觉和听觉刺激出现时间的感知能力,可通过同时性判断、时间顺序判断和视听整合考察。研究发现,阅读障碍者在这一能力上表现出行为和脑层面异常。而这些研究多是拼音文字背景,汉语文字下该领域研究相当少。未来需要丰富实验设计,扩大对汉语背景下视听时间敏感性研究,并以此开发干预手段,为阅读障碍的机制和治疗提供借鉴。     

Phonological and orthographic coding skills in adult readers

Although less skilled readers are handicapped by their poor phonological skills, this may not be true of their visual and orthographic coding skills. Because of an increasing reliance on visual-orthographic coding with reading experience, the author predicted that there would be smaller differences between skilled and less skilled adult readers on orthographic coding measures than on phonological coding measures. The orthographic and phonological coding measures involved, respectively, judgments of which looks more like a word, filv-fild, and which sounds like a real word, kake-dake? On the orthographic measure, reading groups did not differ in coding speed--although the less skilled readers made more errors, but far fewer than on the phonological coding measure. Differences between reading groups were substantial for both speed and errors on the phonological coding measure. Phonological variables accounted for most of the variance in word recognition, and this was especially true for men. The results suggest that in less skilled adult readers, phonological skills are a primary factor in their reading despite some evidence of visual-orthographic compensation.     

Individual differences in skilled adult readers reveal dissociable patterns of neural activity associated with component processes of reading

We used fMRI to examine patterns of brain activity associated with component processes of visual word recognition and their relationships to individual differences in reading skill. We manipulated both the judgments adults made on written stimuli and the characteristics of the stimuli. Phonological processing led to activation in left inferior frontal and temporal regions whereas semantic processing was associated with bilateral middle frontal activation. Individual differences in reading subskills were reflected in differences in the degree to which cortical regions were engaged during reading. Variation in sight word reading efficiency was associated with degree of activation in visual cortex. Increased phonological decoding skill was associated with greater activation in left temporo-parietal cortex. Greater reading comprehension ability was associated with decreased activation in anterior cingulate and temporal regions. Notably, associations between reading ability and neural activation indicate that brain/behavior relationships among skilled readers differ from patterns associated with dyslexia and reading development.     

Processing of identity and position information in normal and disabled readers

Processing of identity and position information was investigated in normal and disabled readers at two grade levels (third/fourth grade and sixth grade). Two partial-report tasks were used. The identity task consisted of visual presentation of a five-letter array, followed by a probe letter. Subjects responded yes for a match and no for a mismatch (identity response). The identity + position task was identical except that an additional response was required on correct yes trials: subjects reported the position of the probe letter in the array (position response). Both grade level and reading ability differences were found on the identity response measure, but not on the position response measure. Results were inconsistent with the hypothesis that disabled readers have difficulties in processing order information. Reader ability differences in identity processing attenuated somewhat with age. Serial position functions for both identity and position responses suggested the presence of a left-to-right scanning operation in both age and ability groups. Reader ability differences in processing letter identities were discussed in the context of current theories of reading acquisition.