Phonological and Surface Subtypes among University Students with Dyslexia

Phonological dyslexics (Ph-DYS) are characterized by a phonological deficit, while surface dyslexics (S-DYS) are characterized by an orthographic deficit. Four issues were addressed in this study. First, we determined the proportion of Ph-DYS and S-DYS in a population of French dyslexics by applying Castles and Coltheart's (1993) regression method to two previously unused diagnostic measures: pseudo-word and irregular-word processing time. Thirty-one dyslexics were matched to 19 average readers of the same age (10 years, CA controls) and to 19 younger children of the same reading level (8 years, RL controls). Compared to CA controls, there were more Ph-DYS than S-DYS. Compared to RL controls, there were still a high number of Ph-DYS; however, the S-DYS profile almost disappeared. Next, we examined the reliability of these subtypes across different measures of phonological and orthographic skills. Compared to RL controls, both groups of dyslexics were found to be impaired only in phonological skills, either in processing time (Ph-DYS) or in accuracy (S-DYS). Then we assessed the moment at which the two dissociated profiles emerged in the course of cognitive development. In order to do so, we examined earlier longitudinal data, collected when the children were 7 and 8 years old, and found that only the S-DYS's orthographic deficit increased with development. Last, we looked at whether the Ph-DYS and S-DYS profiles were associated with other specific cognitive deficits. Specific deficits in phonemic awareness and in phonological short-term memory were found for both Ph-DYS and S-DYS. These data suggest that developmental dyslexia could be largely accounted for by an underlying phonological impairment.

Cortical and behavioral correlates of alexia in primary progressive aphasia and Alzheimer's disease.

Two ways of subtyping in dyslexia will be examined, namely visual/auditory (or ‘dyseidetic’/‘dysphonetic’) and phonological/surface. The conventional view is that phonological dyslexics have difficulty with non-words but are relatively stronger at real words, whereas the surface dyslexic can manage non-words but has difficulty with irregular words. When errors were classified into ‘visual’ and ‘auditory’, it was found in the case of 68 dyslexic children that after a 2-year period of tuition there was a change in the ratio of ‘visual’ errors to ‘auditory’ errors—the proportion of ‘auditory’ errors decreasing markedly. Also, when suitable regular words, non-words and irregular words were given to 58 dyslexic children and to 58 younger children matched for reading age, in neither group did the pattern of results give any significant support for classifying dyslexic children into ‘phonological dyslexics’ or ‘surface dyslexics’. A more economical hypothesis, which explains both sets of results, is that the observed changes reflect the instruction which the children had received. The alternative hypothesis, namely that there is some kind of ‘cognitive substrate’ which remains unchanged whatever the kind of teaching, was not supported by the data. Copyright © 1999 John Wiley & Sons, Ltd

The current study aimed to investigate in a group of nine Greek children with dyslexia (mean age 9.9 years) whether the surface and phonological dyslexia subtypes could be identified. A simple regression was conducted using printed word naming latencies and nonword reading accuracy for 33 typically developing readers. Ninety per cent confidence intervals were established and dyslexic children with datapoints lying outside the confidence intervals were identified. Using this regression-based method three children with the characteristic of phonological dyslexia (poor nonword reading), two with surface dyslexia (slow word naming latencies) and four with a mixed profile (poor nonword reading accuracy and slow word naming latencies) were identified. The children were also assessed in spelling to dictation, phonological ability, rapid naming, visual memory and multi-character processing (letter report). Results revealed that the phonological dyslexia subtype children had difficulties in tasks of phonological ability, and the surface subtype children had difficulties in tasks of multi-character simultaneous processing ability. Dyslexic children with a mixed profile showed deficits in both phonological abilities and multi-character processing. In addition, one child with a mixed profile showed a rapid naming deficit and another showed a difficulty in visual memory for abstract designs. Overall the results confirm that the surface and phonological subtypes of developmental dyslexia can be found in Greek-speaking children. They also indicate that different subtypes are associated with different underlying disorders.

A computational exploration of double dissociations: modes of processing instead of components of processing

Sensitivity to voicing similarity in printed stimuli: effect of a training programme in dyslexic children

Varieties of Developmental Reading Disorder: Genetic and Environmental Influences

The present study examined whether equivalents of surface and phonological subtypes of developmental dyslexia could be found among a sample of 84 poor readers aged 9–12 years in Greece. Word reading latency was used as a measure of lexical skill, and nonword reading accuracy was used as a measure of nonlexical skill. A simple regression of word reading latencies on nonword reading accuracy scores was performed for 42 developing readers. A total of 2 poor readers with accurate nonword reading plus slow word reading relative to controls (equivalents of surface dyslexia) and 2 poor readers with inaccurate nonword reading plus fast accurate word reading relative to controls (equivalents of phonological dyslexia) were identified from amongst the sample of poor readers. Further testing of these 4 cases on measures of irregular-word and nonword spelling revealed additional evidence of a dissociation between lexical and nonlexical impairments. These results support the notion that dual-route models can be used to explore individual differences among dyslexic readers in transparent orthographic systems such as Greek. An attempt is also made to interpret the results in terms of a double deficit theory of dyslexia (Wimmer, Mayringer, & Landerl, 2000; Wolf & Bowers, 1999).

Impaired activation of the phonological lexicon: Effects upon oral reading

Dyslexia is often assessed using categorical diagnoses, and subtypes of dyslexia are also recognized in a categorical fashion. Children may meet the criteria for dyslexia, and they may more specifically meet the criteria for a subtype of it, and thus get a diagnosis. This approach to diagnosis clashes with the actual distribution of reading performance in children (which is normal and continuous), and it has received criticism. This article offers a conceptual framework for conciliating these two positions. In short, the proposal is to use a set of multicomponent continuous assessments of reading, rather than thresholds. The proposal is explained using original data obtained from a sample of 30 children (age 7 to 11), tested in the United Kingdom. Using an assessment based on categorical-thresholds, only five children in our sample qualify for extra assistance, and only one may get a diagnosis of dyslexia, while with the mixed system proposed, a few additional children in the gray area would receive attention. This approach would not discard previous categorical approaches such as those distinguishing between surface and phonological dyslexia, but it would rather see these subtypes of dyslexia as the instance of a lower score on the continuum obtained on a single component of the multicomponent assessment.

Neuropsychological and developmental differences in reading have long informed visual word recognition theories. For instance, identification of whole-word readers (i.e., phonological dyslexics, Chinese-style readers) and part-word readers (i.e., surface dyslexics, Phoenician-style readers) has constrained visual word recognition theories. The influence of variability in normal readers’ cognitive abilities on visual word recognition is yet to be explored. Differences in visual and attentional processes, long- and short-term memory, verbal and nonverbal cognitive ability, and auditory and phonological processing could influence lexical processing, which should constrain such theories. We describe the Warwick Oral Reading Differences project, which seeks to relate these factors to the strength of lexical effects on the response times typically observed in normal adult naming experiments (i.e., word frequency, length, neighborhood size, regularity, and consistency) to further constrain the interpretation of these effects and, thus, model development. Findings from the project are presented.

Dysfunctional hemispheric asymmetry of theta and beta EEG activity during linguistic tasks in developmental dyslexia

We reviewed five studies that relied on the same methodologies to determine the prevalence of Phonological, Surface and Double-Deficit-Subtypes in developmental dyslexia. The proportion of these subtypes was found to vary according to the method (classical method or regression method), the measure (accuracy or processing time), the dyslexics’ language (English or French) and their chronological age. Only two results appeared consistently across the studies. First, with the classical method, and as compared to chronological age controls, most of the dyslexics appeared to suffer from a double deficit. Second, with the regression method, and as compared to reading level controls, the surface profile, though not the phonological profile, almost disappeared, thus suggesting that only the latter corresponds to a developmental deviance. In addition, in the sole study in which both accuracy and processing time were taken into account, in the comparison with reading level controls, only the phonological skills of both the phonological and the surface dyslexics were found to be impaired, either in accuracy or in processing time. These results are more in line with the hypothesis that a phonological deficit is at the core of developmental dyslexia, than with the idea that a clear dissociation exists between surface and phonological profiles.

Electronic screening and brief intervention for risky drinking in Swedish university students — A randomized controlled trial

The left-behind experience as an adverse childhood experience has a negative impact on the mental health of university students. Psychological inflexibility mediated the relationship between adverse childhood experiences and mental disorders, but no similar findings were drawn in psychological flexibility (PF). More research is needed to understand the relationship between PF and mental health of university students with left-behind experience. To investigate the relationship between PF profiles and mental health and sleep quality of university students with left-behind experience based on latent profile analysis. A sample of 1988 Chinese university students with left-behind experience were recruited to complete an online survey. Participants provided demographic information and completed validated measures of PF and mental health. Latent profile analysis was used to identify patterns of PF, and logistic regression analysis was used to examine the relationships among these variables. We found four PF profiles among participants, with the largest number being the moderately flexible profile (n = 808, 40.6%). The level of PF was positively correlated with mental health and sleep quality (all P < 0.001). Females, being left behind at a young age and for a long time, and having little contact with parents were associated with low PF (all P < 0.05). Our study highlights the importance of focusing on the PF of university students with left-behind experience and left-behind children, and the need for interventions to improve their PF and thus their mental health.