Ability to Consolidate Instances as a Proxy for the Association Among Reading, Spelling, and Math Learning Skill

Learning skills (as well as disorders) tend to be associated; however, cognitive models typically focus either on reading, spelling or maths providing no clear basis for interpreting this phenomenon. A recent new model of learning cognitive skills proposes that the association among learning skills (and potentially the comorbidity of learning disorders) depends in part from the individual ability to consolidate instances (taken as a measure of rate of learning). We examined the performance of typically developing fifth graders over the acquisition of a novel paper-and-pencil task that could be solved based on an algorithm or, with practice, with reference to specific instances. Our aim was to establish a measure of individual rate of learning using parameters envisaged by the instance theory of automatization by Logan and correlate it to tasks requiring knowledge of individual items (e.g., spelling words with an ambiguous transcription) or tasks requiring the application of a rule or an algorithm (e.g., spelling non-words). The paper-and-pencil procedure yielded acquisition curves consistent with the predictions of the instance theory of automatization (i.e., they followed a power function fit) both at a group and an individual level. Performance in tasks requiring knowledge of individual items (such as doing tables or the retrieval of lexical representations) but not in tasks requiring the application of rules or algorithms (such as judging numerosity or spelling through sublexical mapping) was significantly predicted by the learning parameters of the individual power fits. The results support the hypothesis that an individual dimension of “ability to consolidate instances” contributes to learning skills such as reading, spelling, and maths, providing an interesting heuristic for understanding the comorbidity across learning disorders

Editorial: Understanding developmental dyslexia: linking perceptual and cognitive deficits to reading processes

The problem of causation has proven particularly elusive in the case of developmental dyslexia (DD). The field has been dominated by very general hypotheses, such as the idea that DD is caused by a phonological deficit and/or an impairment of the magnocellular pathway. Results are contrasting and causal unidirectional links have not been persuasively demonstrated. Some studies in the Research Topic (RT) re-examine these general hypotheses from the critical perspective of more selective predictions. Others focus on less general deficit hypotheses and stay closer to reading by investigating specific aspects of the reading process such as orthographic learning ability or the ability to deal with multiple-stimulus displays. Studies benefit from new research paradigms as well as new information from research areas such as neuroimaging or genetics. Below, we sketch the general questions tackled by these studies

Rehabilitation treatments for adults with behavioral and psychosocial disorders following acquired brain injury: a systematic review.

This review was aimed at systematically investigating the treatment efficacy and clinical effectiveness of neurobehavioral rehabilitation programs for adults with acquired brain injury and making evidence-based recommendations for the adoption of these rehabilitation trainings. Using a variety of search procedures, 63 studies were identified and reviewed using a set of questions about research methods, treatments, results and outcomes for the 1,094 participants. The 63 studies included treatments falling into three general categories: approaches based on applied behavior analysis, interventions based on cognitive-behavior therapy (CBT), and comprehensive-holistic rehabilitation programs (CHRPs). Considerable heterogeneity exists in the reviewed literature among treatment methods and within reported sample subjects. Despite the variety of methodological concerns, results indicate that the greatest overall improvement in psychosocial functioning is achieved by CHRP that can be considered a treatment standard for adults with behavioral and psychosocial disorders following acquired brain injury. Both approaches based on applied behavior analysis and CBT can be said to be evidence-based treatment options. However, findings raise questions about the role of uncontrolled factors in determining treatment effects and suggest the need for rigorous inclusion/exclusion criteria, with greater specification of theoretical basis, design, and contents of treatments for both interdisciplinary-comprehensive approaches and single-case methodologies

Il contributo di James Hinshelwood alla comprensione dei disturbi acquisiti ed evolutivi di lettura

Riassunto: Viene descritta l’opera di James Hinshelwood, un chirurgo oculista inglese il quale, a cavallo della fine del XIX secolo analizza prima una serie ampia di casi dislessia acquisita e successivamente una serie di casi con disturbi di tipo evolutivo. La proposta interpretativa di Hinshelwood accomuna il disturbo evolutivo per tipologia (anche se non per gravità) a quello mostrato da pazienti con alessia pura senza agrafia o word blindness. Nel corso del ventesimo secolo, tuttavia, l’idea di una base visiva del disturbo evolutivo viene progressivamente messa da parte a favore di interpretazioni che enfatizzano la perturbazione di processi centrali di tipo fonologico e/o lessicale. Viene qui proposto che l’intuizione di Hinshelwood di una continuità tra disturbi evolutivi e word blindness debba essere riconsiderata alla luce sia di dati comportamentali sia di recenti studi di neuroimmagine funzionale.Parole chiave: Dislessia acquisita; Dislessia evolutiva; Disgarfia acquisita; Alessia pura; James Hinshelwood. The Contribution of James Hinshelwood to the Comprehension of Acquired and Developmental Reading Disturbance Abstract: This paper describes the work of James Hinshelwood, a British ocular surgeon at the turn of the 19th Century who analyzed a large number of cases of acquired dyslexia and then of developmental disturbances. Hinshelwood’s theoretical framework associates the developmental disorder for type (if not severity) with that shown by patients with pure alexia without agraphia or word blindness. During the 20th century, the notion that the developmental disorder has a visual basis progressively lost ground in favour of interpretations emphasizing the perturbation of both phonological and lexical central processes. Here we propose that Hinshelwood’s hypothesis of continuity between developmental dyslexia and word blindness deficits should be reconsidered on the basis of behavioural and recent functional neuroimaging data.Keywords: Acquired Dyslexia; Evolutive Dyslexia; Acquired Dygraphia, Pure Alexia; James Hishelwood

Lexical stress assignment in Italian developmental dyslexia.

Stress assignment to Italian polysyllabic words is unpredictable, because stress is neither marked nor predicted by rule. Stress assignment, especially to low frequency words, has been reported to be a function of stress dominance and stress neighbourhood. Two experiments investigate stress assignment in sixth-grade, skilled and dyslexic, readers. In Experiment 1, skilled readers were not affected by stress dominance. Dyslexic children, although affected by word frequency, made more stress regularisation errors on low frequency words. In Experiment 2, stress neighbourhood affected low frequency word reading irrespective of stress dominance for both skilled and dyslexic readers. Words with many stress friends were read more accurately than words with many stress enemies. It is concluded that, in assigning stress, typically developing and developmental dyslexic Italian readers are sensitive to the distributional properties of the language

Discrete versus multiple word displays: A re-analysis of studies comparing dyslexic and typically developing children

The study examines whether impairments in reading a text can be explained by a deficit in word decoding or an additional deficit in the processes governing the integration of reading subcomponents (including eye movement programming and pronunciation) should also be postulated. We report a re-analysis of data from eleven previous experiments conducted in our lab where the reading performance on single, discrete word displays as well multiple displays (texts, and in few cases also word lists) was investigated in groups of dyslexic children and typically developing readers. The analysis focuses on measures of time and not accuracy. Across experiments, dyslexic children are slower and more variable than typically developing readers in reading texts as well as vocal RTs to singly presented words; the dis-homogeneity in variability between groups points to the inappropriateness of standard measures of size effect (such as Cohen’s d), and suggests the use of the ratio between groups’ performance. The mean ratio for text reading is 1.95 across experiments. Mean ratio for vocal RTs for singly presented words is considerably smaller (1.52). Furthermore, this latter value is probably an overestimation as considering total reading times (i.e., a measure including also the pronunciation component) considerably reduces the group difference in vocal RTs (1.19 according to Martelli et al., 2014). The ratio difference between single and multiple displays does not depend upon the presence of a semantic context in the case of texts as large ratios are also observed with lists of unrelated words (though studies testing this aspect were few). We conclude that, if care is taken in using appropriate comparisons, the deficit in reading texts or lists of words is appreciably greater than that revealed with discrete word presentations. Thus, reading multiple stimuli present a specific, additional challenge to dyslexic children indicating that models of reading should incorporate this aspect

Does pronounceability modulate the letter string deficit of children with dyslexia? A study with the rate and amount model

The locus of the deficit of children with dyslexia in dealing with strings of letters may be a deficit at a pre-lexical graphemic level or an inability to bind orthographic and phonological information. We evaluate these alternative hypotheses in two experiments by examining the role of stimulus pronounceability in a lexical decision task (LDT) and in a forced-choice letter discrimination task (Reicher-Wheeler paradigm). Seventeen fourth grade children with dyslexia and 24 peer control readers participated to two experiments. In the LDT children were presented with high-, low-frequency words, pronounceable pseudowords (such as DASU) and unpronounceable non-words (such as RNGM) of 4-, 5-, or 6- letters. No sign of group by pronounceability interaction was found when over-additivity was taken into account. Children with dyslexia were impaired when they had to process strings, not only of pronounceable stimuli but also of unpronounceable stimuli, a deficit well accounted for by a single global factor. Complementary results were obtained with the Reicher-Wheeler paradigm: both groups of children gained in accuracy in letter discrimination in the context of pronounceable primes (words and pseudowords) compared to unpronounceable primes (non-words). No global factor was detected in this task which requires the discrimination between a target letter and a competitor but does not involve simultaneous letter string processing. Overall, children with dyslexia show a selective difficulty in simultaneously processing a letter string as a whole, independent of its pronounceability; however, when the task involves isolated letter processing, also these children can make use of the ortho-phono-tactic information derived from a previously seen letter string. This pattern of findings is in keeping with the idea that an impairment in pre-lexical graphemic analysis may be a core deficit in developmental dyslexia

The ability to learn new written words is modulated by language orthographic consistency

Introduction It is well known that a difficulty in forming lexical representations is a strong predictor of reading and spelling difficulties even after controlling for the effects of other cognitive skills. Our study had two main interrelated aims. First, we wanted to examine whether the ability to learn new written words (lexical learning) varies as a function of the orthographic consistency of the language of the learner. Second, we wanted to evaluate the cognitive abilities involved in orthographic lexical learning and whether they differed as a function of language consistency. Method 163 Italian children and 128 English children performed a lexical learning task as well as tasks assessing several cognitive skills potentially related to the ability to establish orthographic representations. Results We found that children learning an orthographic inconsistent orthography (English) were better able to learn novel written words presented in association with pictures than children learning a consistent orthography (Italian). This was true for both younger and older primary school children and also when children were matched for school grade. Lexical learning may be better in English children because the many irregularities of this language promote storing in memory whole-word representations and processing larger orthographic units. In Italian, instead, reading can be accomplished successfully on the basis of grapheme-phoneme conversion rules and on processing smaller orthographic units. This interpretation was supported by the pattern of cognitive skills associated with lexical learning skills in the two languages. Variations in lexical learning were explained by spatial visual memory and phonological awareness tasks in both languages, but phonological STM explained further variance in Italian, while a task tapping visuo-attentional capacity explained further variance in English. Conclusion Learning a language with inconsistent orthography is associated with better lexical learning skills in children at different stages of primary school; the pattern of cognitive skills associated with lexical learning skills is also partially modulated by orthographic consistency

Measuring fixation disparity with infrared eye-trackers.

Fixation disparity, that is, misalignment of the gaze direction of both eyes, may be observed in static conditions (through standard optometric evaluation) and dynamic conditions (through eye movement recording). A computation method is presented to determine vergence angles and fixation disparity from gaze positions as commonly recorded by infrared eye-trackers when a participant looks at a personal computer (PC) screen. Eye-tracking devices provide gaze position in coordinates relative to the bidimensional screen surface. From these data, vergence angles can be calculated by trigonometric triangulations; fixation disparity is then calculated from the vergence angles. The application of the procedure to the recordings of one participant is described. To control for the effective alignment of the two eyes on the target during binocular calibration, a procedure based on the dichoptic presentation of nonius lines was used. The recordings confirm that computation and the dichoptic calibration procedures ensure reliable measures of vergence and fixation disparity. The usefulness of this approach with infrared recording of eye position is discussed

List context manipulation reveals orthographic deficits in Italian readers with developmental dyslexia.

We tested the influence of list context on word frequency and length effects on the reading aloud of Italian developmental dyslexics and skilled peers. The stimuli were presented either in mixed blocks (alternating words and non-words) or in pure blocks. The analyses based on the rate-and-amount-model (Faust et al., 1999) indicated that group differences in reaction times between dyslexic and skilled readers: a) were well accounted for in terms of global components and b) were modulated by context in the case of words but not in the case of non-words. ANOVAs on z-transformed reaction time data further indicated the influence of stimulus length. Importantly, the frequency effect interacted with context: controls showed a list context effect for high and low frequency words, while dyslexics showed a list context effect only for high frequency words. The effect of length on reading times remained unaffected by context manipulation. It is proposed that this pattern of results may be accounted for by hypothesizing two separate deficits: An early graphemic impairment affecting performance independently of context and a later inefficiency in activating entries in the orthographic lexicon as a function of context demands