John Everatt

Visual Processing and Dyslexia

Magnocellular-pathway deficits have been hypothesised to be responsible for the problems experienced by dyslexic individuals in reading. However, research has yet to provide a detailed account of the consequences of these deficits or to identify the behavioural link between them and reading disabilities. The aim of the present study was to determine the potential consequences of the magnocellular-pathway deficits for dyslexics in a comprehensive range of visual tasks. Dyslexics and nondyslexics were compared on their ability to (i) perform vernier-acuity and orientation-acuity tasks; (ii) perceive motion by using a range of measures common in the psychophysical literature (Dmin, Dmax, and global coherence); and (iii) perceive shapes presented in random-dot stereograms at a range of disparity pedestals, thereby dissociating stereopsis from vergence control. The results indicated no significant differences in performance between the dyslexic and nondyslexic subjects in terms of the visual-acuity measures. In general, dyslexics performed relatively poorly on measures of motion perception and stereopsis, although when considered individually some of the dyslexics performed better than some of the controls. The poor performance of the dyslexics in the stereogram tasks was attributable to a subgroup of dyslexics who also appeared to have severe difficulty with the motion-coherence task. These data are consistent with previous evidence that some dyslexics may have deficits within the magnocellular visual pathway.

An eye for the unusual: creative thinking in dyslexics

This article describes a series of studies investigating the relationship between developmental dyslexia and creative talents. Tasks performed by the subjects included: finding alternative uses for objects, producing drawn objects from basic shapes, completing a self-report inventory which assessed innovative styles of thinking, and the solving of problems which required some form of insightful thinking. The data indicated both differences between dyslexics and non-dyslexics and differences across age groups. Compared with non-dyslexics, dyslexic adults presented consistent evidence of greater creativity in tasks requiring novelty or insight and more innovative styles of thinking; in contrast, dyslexic primary and secondary school children performed on a level with their non-dyslexic peers on a test which involved making drawings from a number of different shapes (figural creativity). Little evidence was found for an association between creativity and enhanced visuo-spatial skills or between creativity and handedness. Despite evidence being provided for the hypothesized creative talents of dyslexics, it was not possible to confirm that these talents were constitutional in nature or that they were associated with enhanced functioning of the right hemisphere. Copyright

Predictors of word-level literacy amongst Grade 3 children in five diverse languages

Groups of Grade 3 children were tested on measures of word-level literacy and undertook tasks that required the ability to associate sounds with letter sequences and that involved visual, auditory and phonological-processing skills. These groups came from different language backgrounds in which the language of instruction was Arabic, Chinese, English, Hungarian or Portuguese. Similar measures were used across the groups, with tests being adapted to be appropriate for the language of the children. Findings indicated that measures of decoding and phonological-processing skills were good predictors of word reading and spelling among Arabic- and English-speaking children, but were less able to predict variability in these same early literacy skills among Chinese- and Hungarian-speaking children, and were better at predicting variability in Portuguese word reading than spelling. Results were discussed with reference to the relative transparency of the script and issues of dyslexia assessment across languages. Overall, the findings argue for the need to take account of features of the orthography used to represent a language when developing assessment procedures for a particular language and that assessment of word-level literacy skills and a phonological perspective of dyslexia may not be universally applicable across all language contexts.

Dyslexia screening measures and bilingualism

A series of measures used in a number of dyslexia screening tests was administered to groups of 7-8-year old English monolinguals and Sylheti/English bilinguals. Within these groups a subgroup of children was distinguished by poor spelling and reading in the absence of general ability, sensory, emotional or behavioural problems, i.e. specific literacy difficulties (SpLD). General ability (assessed by Ravens matrices), chronological age, male/female ratio and mono/bilingualism were controlled between SpLD and control groups. Screening measures assessed phonological skills, rapid naming, the ability to recite or repeat sequences of verbal and non-verbal stimuli, and visual and motor skills. Sample sizes were small owing to the selection criteria used and the small number of bilingual SpLD children identified. However, the results were encouraging in differentiating SpLD bilinguals from their peers, with the phonological measures in particular presenting consistent findings across bilingual and monolingual groupings. Those differences found between bilinguals and monolinguals are discussed in terms of a bilingual influence on the skills assessed or the reduced reliability of the measure.

Orthographic processing and reading comprehension among Arabic speaking mainstream and LD children.

Two cohorts of mainstream children (grades 2-5) and one cohort of children with learning disabilities (LD; grades 3-5), all Arabic speaking children in Kuwait, were given measures of reading comprehension fluency and orthographic discrimination to assess the relationship between the two. Additional measures of phonological processing (decoding and awareness), speed of processing (rapid naming) and memory (visual as well as phonological/verbal tasks) were included either because these have been found to be predictive of Arabic literacy or to provide an assessment of alternative interpretations of any influence of the orthographic task. The findings indicated that the orthographic measure predicted variability in the comprehension fluency over-and-above that predicted by the other measures in the study. This was significant in the older mainstream children (grades 4 and 5) when controlling for phonological processing, but was not in the younger grades (2 and 3) where experience text that incorporating short vowel markers is dominant. The LD group showed little evidence of an influence of phonological processing but did of orthographic processing. The findings are discussed in terms of the skills required to process Arabic literacy and potential causes of literacy learning difficulties among Arabic children.

The Role of Morphological Awareness in Reading Comprehension Among Typical and Learning Disabled Native Arabic Speakers

This work examines the role of morphological awareness in contrast to phonological processing in reading comprehension amongst two groups of native Arabic children: a group with learning disabilities (LD) and a mainstream group who were matched to the LD group in age or reading level. Measures of reading comprehension fluency, phonological skills, and morphological ability were given to both groups in addition to tests of nonverbal ability. For the mainstream children, unique variability in comprehension was predicted by the morphological measures over that of the measures of phonological skills and general nonverbal ability. In contrast, for the LD data, variability in comprehension was not predicted by morphological ability even though the children with LD performed the morphology task as well as their typically developing peers did. These findings are discussed in terms of theories of reading acquisition across languages as well as recommendations for literacy teaching and LD intervention in Arabic.

Cognitive Functioning and Work Success in Adults with Dyslexia

Dyslexic adults completed questionnaires designed to investigate relationships between cognitive functioning, especially executive aspects, and work success. The study was designed to determine whether quantitative support could be provided for the model of adult dyslexic success derived from the work of Gerber and his colleagues (Gerber, Ginsberg, & Reiff, 1992). A planning/metacognitive awareness scale and a cognitive failures scale were used as measures of cognitive skill. Personal success was assessed with job satisfaction and work-based self-efficacy scales, and societal success was determined by assessing the salary level, promotion in the current profession and academic qualifications. Correlational analyses indicated that people with dyslexia with higher levels of planning and metacognition reported higher levels of job satisfaction and self-efficacy. However, these measures were not related to societal success. The findings are discussed in terms of avenues for further investigation of factors leading to more positive outcomes for dyslexic individuals and ways to increase the likelihood of dyslexic adults achieving success in the workplace.

Individual Differences in Reading and Eye Movement Control

This chapter explores the effects of reading ability upon eye movement control. In terms of linguistic influences, it presents evidence for initial fixations within words being affected by the informativeness /distinctiveness of sections within those words. It further explores evidence of a relationship between the initial fixation location effect and reading ability in able readers. Such relationships are investigated by comparing eye movement control with reading disabled subjects and matched control subjects. These data suggest that a number of individuals diagnosed as dyslexic show less influence of informativeness/distinctiveness ahead of fixation, and this is related to lower levels of reading ability within these subjects. In conclusion, the study draws a relationship between reading deficits and the initial fixation location effect. Collected data indicates that the initial fixation location effect can be found within a wide range of different situations and, to some extent, is affected by variables commonly found to influence reading performance. Of the two factors which this study investigates, the initial fixation location effect seems to be more affected by the skill of the reader than the semantic context within which informative beginning/ending words appear.

Reflexive Shifts of Covert Attention Operate in an Egocentric Coordinate Frame

Covert shifts of attention have been shown to improve detection and discrimination thresholds for a range of visual stimuli. Although there is some evidence to suggest that the allocation of attention to a particular region of interest occurs in a retinotopic frame of reference, the importance of an allocentric, or object-based, framework has gained widespread empirical support. The current experiment investigates the nature of the spatial representation in which covert shifts of attention occur in response to a reflexive prime. Primes and targets were presented in four conditions designed to vary systematically the validity of the spatial relationship between the prime and target in egocentric or allocentric coordinate frameworks. A significant advantage, in terms of reaction time and correct identification, was found for targets located in positions previously primed in an egocentric (but not allocentric) framework whereas there was no advantage for locations primed in an allocentric (but not egocentric) framework. These results suggest that the allocation of covert spatial attention within an egocentric framework may be more important than previously thought.

Supporting Teachers in Inclusive Practices: Collaboration Between Special and Mainstream Schools in Kuwait

The authors discuss a project aimed at improving Kuwaiti mainstream teachers’ attitudes, knowledge, and teaching practice related to learning disabilities and inclusion. The project involved special school staff providing mainstream primary school teachers with first-hand experiences of inclusive practices that could be implemented in their own schools. Despite the projects relatively short duration, and the large number of teachers involved, there was evidence of improvements in teachers’ self-reported attitudes and views toward children with learning disabilities, as well as improved practice indicators, in the majority of schools. Overall, the value of this project has been that it showed how a special school can become the focus of inclusion work within an educational context in which inclusion is a relatively new and poorly understood concept.