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The connectionist triangle model of reading aloud proposes that semantic activation of phonology is particularly important for correct pronunciation of low-frequency exception words. Our consideration of this issue (Woollams, Lambon Ralph, Plant, & Patterson, 2007) reported computational simulations demonstrating that reduction and disruption of this semantic activation resulted in the marked deficit in low-frequency exception word reading that is characteristic of surface dyslexia. We then presented 100 observations of reading aloud from 51 patients with semantic dementia (SD) demonstrating a universal decline into surface dyslexia, a phenomenon we termed 'SD-squared.' Coltheart, Tree, and Saunders (2010) have more recently provided a simulation of the SD-squared data within the dual route cascaded (DRC) model, achieved by varying the amount of damage to components of the lexical and nonlexical pathways. Although they suggested that these simulations provide a closer fit to the SD patients' reading data than our own, we demonstrate here that this is not the case. Moreover, we argue that the connectionist triangle model account has substantially greater explanatory and predictive power than the DRC account. Keywords: surface dyslexia, semantic memory, reading aloud, frequency, regularity DOI: 10.1037/a0017641

Developmental dyslexia is a specific learning disability characterized by difficulties in reading and writing despite adequate intelligence, cognitive abilities, and learning environments (Shaywitz et al., 1998; Snowling, 2000). Over the [...], Purpose: This study investigated whether adults with dyslexia show evidence of a consistent speech perception deficit by testing phoneme categorization and word perception in noise. Method: Seventeen adults with dyslexia and 20 average readers underwent a test battery including standardized reading, language and phonological awareness tests, and tests of speech perception. Categorization of a pea/bee voicing contrast was evaluated using adaptive identification and discrimination tasks, presented in quiet and in noise, and a fixed-step discrimination task. Two further tests of word perception in noise were presented. Results: There were no significant group differences for categorization in quiet or noise, across- and within-category discrimination as measured adaptively, or word perception, but average readers showed better across- and within-category discrimination in the fixed-step discrimination task. Individuals did not show consistent poor performance across related tasks. Conclusions: The small number of group differences, and lack of consistent poor individual performance, suggests weak support for a speech perception deficit in dyslexia. It seems likely that at least some poor performances are attributable to nonsensory factors like attention. It may also be that some individuals with dyslexia have speech perceptual acuity that is at the lower end of the normal range and exacerbated by nonsensory factors. KEY WORDS: speech perception, dyslexia, speech perception in noise, adults

The goal of this review is to evaluate the literature on binocular coordination during reading and non-reading tasks in adult, child, and dyslexic populations. The review begins with a description of the basic characteristics of eye movements during reading. Then, reading and non-reading studies investigating binocular coordination are evaluated. Areas of future research in the field are identified and discussed. Finally, some general conclusions are made regarding binocular coordination. The review demonstrates that findings from traditionally independent areas of research are largely consistent and complementary. Throughout the review, theoretical and methodological commonalities are identified and clarified in order to advance current understanding of this fundamental aspect of human visual processing. Keywords: binocular coordination, fixation disparity, oculomotor control, dyslexia

Developmental dyslexia is a neurobiologically based disorder that affects [approximately equal to] 5-17% of school children and is characterized by a severe impairment in reading skill acquisition. For readers of alphabetic (e.g., English) languages, recent neuroimaging studies have demonstrated that dyslexia is associated with weak reading-related activity in left temporoparietal and occipitotemporal regions, and this activity difference may reflect reductions in gray matter volume in these areas. Here, we find different structural and functional abnormalities in dyslexic readers of Chinese, a non-alphabetic language. Compared with normally developing controls, children with impaired reading in logographic Chinese exhibited reduced gray matter volume in a left middle frontal gyrus region previously shown to be important for Chinese reading and writing. Using functional MRI to study language-related activation of cortical regions in dyslexics, we found reduced activation in this same left middle frontal gyrus region in Chinese dyslexics versus controls, and there was a significant correlation between gray matter volume and activation in the language task in this same area. By contrast, Chinese dyslexics did not show functional or structural (i.e., volumetric gray matter) differences from normal subjects in the more posterior brain systems that have been shown to be abnormal in alphabetic-language dyslexics. The results suggest that the structural and functional basis for dyslexia varies between alphabetic and nonalphabetic languages. brain function | Chinese language | culture | reading disorder | neuroimaging

The double-deficit hypothesis (DDH) of developmental dyslexia was investigated in seven to twelve year old Spanish children. It was observed that the double deficit (DD) group had the greatest difficulty with reading.

A study was conducted to determine whether the measures used to identify native English speakers who are at risk for reading difficulties could also be used for identifying English learners who were at a similar risk. Additionally it was investigated whether English learners should be assessed in the language of instruction, English, or in their home language, Spanish.

The conversational timing patterns of three year old children who were at a high familial risk for dyslexia were examined in the course of their interaction with adults. Findings indicated that previously documented differences in speech timing surface as subtle differences in spontaneous child-adult conversation as early as three years of age.

Two studies investigating the cognitive phenotype of dyslexia are described. Study 1 compared three groups of English and Italian children on speed of processing tasks: (a) children with dyslexia, (b) generally delayed poor readers and (c) CA-controls. In tests of simple and choice reaction time and two visual scanning tasks, children with dyslexia performed like controls and significantly faster than generally delayed poor readers. A second prospective longitudinal investigation of children at family risk of dyslexia showed that problems of literacy development were less circumscribed, with affected children showing phonological deficits in the context of more general oral language difficulties. An important finding was that the risk of dyslexia was continuous in this sample; among at-risk children with normal literacy development, mild impairments of phonological skills were apparent early in development, and subtle difficulties with reading fluency and spelling emerged in early adolescence. A case series extended these findings to show that phonological deficits alone are insufficient to explain literacy difficulties, and it is children with multiple deficits (including language problems) that are more likely to succumb to reading failure.

This case study of an adolescent with dyslexia suggests some ways that all teachers can become more supportive of such students' strengths and mindful of their additional needs. A little [...]

Within the connectionist triangle model of reading aloud, interaction between semantic and phonological representations occurs for all words but is particularly important for correct pronunciation of lower frequency exception words. This framework therefore predicts that (a) semantic dementia, which compromises semantic knowledge, should be accompanied by surface dyslexia, a frequency-modulated deficit in exception word reading, and (b) there should be a significant relationship between the severity of semantic degradation and the severity of surface dyslexia. The authors evaluated these claims with reference to 100 observations of reading data from 51 cases of semantic dementia. Surface dyslexia was rampant, and a simple composite semantic measure accounted for half of the variance in low-frequency exception word reading. Although in 3 cases initial testing revealed a moderate semantic impairment but normal exception word reading, all of these became surface dyslexic as their semantic knowledge deteriorated further. The connectionist account attributes such cases to premorbid individual variation in semantic reliance for accurate exception word reading. These results provide a striking demonstration of the association between semantic dementia and surface dyslexia, a phenomenon that the authors have dubbed SD-squared. Keywords: surface dyslexia, semantic memory, reading aloud, frequency, regularity

LEARNING TO READ and write is a challenge for most deaf children due to their limited experiences with, and access to, spoken language. In the case of deaf students who have difficulty processing visual print, literacy becomes an even greater challenge. The study piloted an intervention procedure that incorporated the principles of automaticity, repetition, functional vocabulary, and a positive teacher-student relationship as recommended in programs for struggling readers and adapted them to the needs of two deaf high school students with dyslexia in an American Sign Language-English bilingual program. The P findings reveal gains in reading ability on the formal measures, though not more than would be expected over a 6-month period simply due to development. The real improvements were noted in the students' attitudes toward literacy, improved social interaction, and increased self-confidence.

In functional neuroimaging studies, individuals with dyslexia frequently exhibit both hypoactivation, often in the left parietotemporal cortex, and hyperactivation, often in the left inferior frontal cortex, but there has been no evidence to suggest how to interpret the differential relations of hypoactivation and hyperactivation to dyslexia. To address this question, we measured brain activation by functional MRI during visual word rhyme judgment compared with visual cross-hair fixation rest, and we measured gray matter morphology by voxel-based morphometry in dyslexic adolescents in comparison with (i) an age-matched group, and (ii) a reading-matched group younger than the dyslexic group but equal to the dyslexic group in reading performance. Relative to the age-matched group (n = 19; mean 14.4 years), the dyslexic group (n = 19; mean 14.4 years) exhibited hypoactivation in left parietal and bilateral fusiform cortices and hyperactivation in left inferior and middle frontal gyri, caudate, and thalamus. Relative to the reading-matched group (n = 12; mean 9.8 years), the dyslexic group (n = 12; mean 14.5 years) also exhibited hypoactivation in left parietal and fusiform regions but equal activation in all four areas that had exhibited hyperactivation relative to age-matched controls as well. in regions that exhibited atypical activation in the dyslexic group, only the left parietal region exhibited reduced gray matter volume relative to both control groups. Thus, areas of hyperactivation in dyslexia reflected processes related to the level of current reading ability independent of dyslexia. In contrast, areas of hypoactivation in dyslexia reflected functional atypicalities related to dyslexia itself, independent of current reading ability, and related to atypical brain morphology in dyslexia. inferior frontal region | inferior parietal lobule | voxel-based morphometry | functional MRI | compensation

Some visual processing deficits in developmental dyslexia have been attributed to abnormalities in the subcortical M stream and/or the cortical dorsal stream of the visual pathways. The nature of the relationship between these visual deficits and reading is unknown. The purpose of the present article was to characterize reading-related perceptual processes that may link the visual deficits to reading problems. We identified contrast sensitivity, position encoding, oculomotor control, visual attention, parafoveal/foveal interactions, and saccadic suppression as potential reading-related dorsal stream processes. We then evaluated the role of each process in reading and the status of each process in dyslexia. In theory, a number of dorsal stream processes (e.g., oculomotor control and visual attention) might contribute to reading problems in developmental dyslexia. More work is needed to demonstrate the connection empirically. Keywords: dyslexia, reading, visual deficits, M stream, dorsal stream

We report the case of a patient V.E.M. who exhibits the infrequently described syndrome of visual dyslexia. V.E.M. read many single words accurately and rapidly; however, when words were read inaccurately, the majority of responses were alternate real words beating a strong visual relationship to the target items. A series of observational and experimental investigations of her reading skills revealed that response accuracy was strongly affected by word frequency and mildly affected by concreteness but not influenced by word length, orthographic neighbourhood size, or semantic priming. It is argued that V.E.M.'s visual dyslexia results from a deficit of the visual word form system. More specifically, we propose that this deficit has an 'access' quality, with visual word form representations remaining relatively intact despite an impairment in the processes by which these representations are activated. Taking the results of this study together with previous reports of dyslexic patients who make a high proportion of visual paralexic errors, we also suggest that visual dyslexia represents a multicomponent dyslexic syndrome for which phonological impairment and not semantic impairment may be a necessary condition.

This work examines the association between symbols and their representation in adult developmental dyscalculia and dyslexia. Experiment l used comparative judgment of numerals, and it was found that in physical comparisons (e.g., 3-5 vs. 3-5) the dyscalculia group showed a significantly smaller congruity effect than did the dyslexia and the control groups. Experiment 2 used Navon figures (D. Navon, 1977) in Hebrew, and participants were asked to name the large or the small letters. Phoneme similarity modulated performance of the control and the dyscalculia groups and showed a very small effect in the dyslexia group. This suggests that the dyscalculia population has difficulties in automatically associating numerals with magnitudes but no problems in associating letters with phonemes, whereas the dyslexia population shows the opposite pattern. Keywords: developmental dyslexia, developmental dyscalculia, phonemes, quantities

The authors examined the developmental trajectories of children's early letter knowledge in relation to measures spanning and encompassing their prior language-related and cognitive measures and environmental factors and their subsequent Grade 1 reading achievement. Letter knowledge was assessed longitudinally at ages 4.5, 5.0, 5.5, and 6.5 years; earlier language skills and environmental factors were assessed at ages 3.5 and 4.5 years; and reading achievement was assessed at the beginning and end of Grade 1. The analyses were conducted on a longitudinal data set involving children with and without familial risk for dyslexia. Emerging from the trajectory analysis of letter knowledge were 3 separate clusters: delayed (n = 63), linearly growing (n = 73), and precocious (n = 51). The members of the delayed cluster were predominantly children with familial risk for dyslexia, and the members of the precocious cluster were predominantly control group children. Phonological sensitivity, phonological memory, and rapid naming skills predicted delayed letter knowledge. Environmental predictors included level of maternal education and the amount of letter name teaching. Familial risk for dyslexia made a significant contribution to the predictive relations. Membership in the delayed cluster predicted poor reading performance at Grade 1. Keywords: letter knowledge development, home environment, language skills, familial dyslexia risk, beginning reading

Abstract The purpose of this research was to ascertain if teachers with dyslexia and dyscalculia perceive that their learning disabilities have affected their adult lives, including their teaching. It was [...]

Abstract This case study considers inclusive practice in learning and teaching in the context of session design and delivery in the foreign language classroom, focusing on a dyslexic student. It [...]

In recent years, there has been considerable interest in the relationship between developmental disorders of oral and written language (Bishop & Snowling, 2004; Catts & Kamhi, 2005). The most widely [...], Purpose: The purpose of this study was to determine whether specific language impairment (SLI) and dyslexia are distinct developmental disorders. Method: Study 1 investigated the overlap between SLI identified in kindergarten and dyslexia identified in 2nd, 4th, or 8th grades in a representative sample of 527 children. Study 2 examined phonological processing in a subsample of participants, including 21 children with dyslexia only, 43 children with SLI only, 18 children with SLI and dyslexia, and 165 children with typical language/reading development. Measures of phonological awareness and nonword repetition were considered. Results: Study 1 showed limited but statistically significant overlap between SLI and dyslexia. Study 2 found that children with dyslexia or a combination of dyslexia and SLI performed significantly less well on measures of phonological processing than did children with SLI only and those with typical development. Children with SLI only showed only mild deficits in phonological processing compared with typical children. Conclusions: These results support the view that SLI and dyslexia are distinct but potentially comorbid developmental language disorders. A deficit in phonological processing is closely associated with dyslexia but not with SLI when it occurs in the absence of dyslexia. KEY WORDS: specific language impairment, dyslexia, phonological processing, phonological awareness, nonward repetition

Numerous studies indicate that dyslexic and nondyslexic individuals exhibit different patterns of sensitivity to spatial frequency. However, the extension of this effect to normal (nondyslexic) adults of good and poor reading abilities and the role played by different spatial frequencies in word perception have yet to be determined. In this study, using normal (nondyslexic) adults, we assessed reading ability, spatial frequency sensitivity, and perception of spatially filtered words and nonwords (using a two-alternative forced choice paradigm to avoid artifactual influences of nonperceptual guesswork). Good and poor readers showed different patterns of spatial frequency sensitivity. However, no differences in accuracy of word and nonword perception were found between good and poor readers, despite their differences in spatial frequency sensitivity. Indeed, both reading abilities showed the same superior perceptibility for spatially filtered words over nonwords across different spatial frequency bands. These findings indicate that spatial frequency sensitivity differences extend to normal (nondyslexic) adult readers and that a range of spatial frequencies can be used for word perception by good and poor readers. However, spatial frequency sensitivity may not accurately reveal an individual's ability to perceive words.

Dyslexic students may be disadvantaged in their use of written language, impeding academic achievement, and requiring remediation and concessions. A proximal analysis assessed the operations of the 3 major pathways (orthography to semantics, orthography to phonology, and phonology to orthography) within models of reading and spelling through lexical decision, reading aloud, and spelling aloud. No dyslexic individual exactly matched the group outcomes on all of the indicators, and no 2 dyslexic individuals presented identical profiles. A multicomponent mosaic model is supported whereby dyslexic difficulties relate to functions that require manipulation of orthographic and phonological units. A documented history and cognitive indicators of orthographic processing may offer a viable approach to the diagnosis, remediation, and concession of adult dyslexia in higher education.

A group of 39 persons (20 male and 19 female, 11.0 to 32.5 yr.) with developmental dyslexia and 42 controls (21 male and 21 female, 11.2 to 32.3 years) were compared on computerized tests of sight word reading, nonword decoding, and spelling recognition. The subjects with developmental dyslexia performed significantly slower and less accurately than controls on all tasks. Further, the effect size of the group differences was larger for the older group. Within-group analyses showed a significant difference by age group on accuracy. Only the control group showed a significant age difference between groups on response time. Mean accuracy and response times for the reading-disabled subjects resembled shifted versions of the control group means. These results agree with previous reports that phonological deficits persist for reading-disabled adults and suggest a test of whether the discrepancy between reading-disabled and typically achieving readers may actually increase across age groups.