1,720,969 research outputs found
Quanti bambini con DSA? È possibile identificarli in modo attendibile?
No full textLa recente pubblicazione del DSM-5 suggerisce una riflessione sulle procedure diagnostiche in generale e su quelle relative ai disturbi dell’apprendimento in particolare. Su questo tema, il DSM 5 riporta novità importanti. Se i manuali precedenti avevano progressivamente enfatizzato il tema della specificità dei disturbi, nell’ultima versione vi è, su questo, un ripensamento e viene avanzata, viceversa, la proposta di una singola categoria diagnostica («specific learning disorder») anche se accompagnata da una serie di specificazioni. Il commentario analizza i motivi che hanno portato a questo cambiamento.The recent publication of the DSM-5 suggests a number of considerations on the diagnostic procedures in general and on those specific for learning disabilities more in particular. On this issue, the DSM-5 reports a number of new ideas. While previous manuals had progressively emphasized the theme of the specificity of the disturbances in the last version on this question there is an afterthought and the idea of a single diagnostic category is proposed ("specific learning disorder») even though accompanied by a series of specifications. The commentary analyzes the reasons that brought to this change
Analyzing global components in developmental dyscalculia and dyslexia
Full text linkThe study examined whether developmental deficits in reading and numerical skills could be expressed in terms of global factors by reference to the rate and amount (RAM) and difference engine (DEM) models. From a sample of 325 fifth grade children, we identified 5 children with dyslexia, 16 with dyscalculia, 7 with a “mixed pattern,” and 49 control children. Children were asked to read aloud words presented individually that varied for frequency and length and to respond (either vocally or manually) to a series of simple number tasks (addition, subtraction, number reading, and number comparisons). Reaction times were measured. Results indicated that the deficit of children with dyscalculia and children with a mixed pattern on numerical tasks could be explained by a single global factor, similarly to the reading deficit shown by children with dyslexia. As predicted by the DEM, increases in task difficulty were accompanied by a corresponding increase in inter-individual variability for both the reading and numerical tasks. These relationships were constant across the four groups of children but differed in terms of slope and intercept on the x-axis, indicating that two different general rules underlie performance in reading and numerical skills. The study shows for the first time that, as previously shown for reading, also numerical performance can be explained with reference to a global factor. The advantage of this approach is that it takes into account the over-additivity effect, i.e., the presence of larger group differences in the case of more difficult conditions over and above the characteristics of the experimental conditions. It is concluded that reference to models such as the RAM and DEM can be useful in delineating the characteristics of the dyscalculic deficit as well as in the description of co-morbid disturbances, as in the case of dyslexia and dyscalculi
Italian developmental dyslexic and proficient readers: Where are the differences?
No full textItalian dyslexic children are characterized by a pervasive reading speed deficit, with relatively preserved accuracy. This pattern has been associated with predominant use of the nonlexical reading procedure. However, there is no evidence of a deficit in the lexical route of Italian dyslexics. We investigated both lexical and nonlexical reading procedures in dyslexic children through two marker effects, namely, the word frequency effect and the effect of contextual grapheme-to-phoneme conversion rules. Although dyslexics were slower and less accurate than controls, they were affected by word frequency, grapheme contextuality, and their interaction in a similar manner as average readers. These results show the use of lexical reading in Italian dyslexics, and refute the claim of a deficit in whole-word processing with consequent over-reliance on the nonlexical route. (c) 2006 Elsevier Inc. All rights reserved
Sensory and Physico-Psychological Metaphor Comprehension in Children with ASD: A Preliminary Study on the Outcomes of a Treatment
Full text linkRecent research into difficulties in figurative language in children with ASD highlighted that it is possible to devise training interventions to overcome these difficulties by teaching specific strategies. This study describes how children with ASD can improve their capability to explain metaphors with a treatment. Two types of metaphors, in the “X is Y” form, were addressed: sensory and physico-psychological. To face the difficulties posed by these metaphors, the adult taught two strategies: inserting the connective “is like” between “X” and “Y”, which transforms the metaphor into a simile; comparing “X” and “Y” by means of thinking maps. Two tests of metaphor comprehension were used, one based on sensory and the other on physico-psychological metaphors. Sixteen 10 year-old children participated into the study, including an experimental group formed by 8 children with ASD (n = 4) which had received the treatment, and a control group (n = 4) which had not, and 8 typically-developing (TD) children. At the post-test, the experimental group significantly outperformed the controls in explaining both types of metaphors, but only in the sensory metaphors did their performances reach TD children’s levels. These results illuminate how clinical treatment can positively influence the developmental trajectories of metaphor comprehension
Lexicality and stimulus length effects in Italian dyslexics: Role of the overadditivity effect
No full textThe effect of lexicality and stimulus length was studied in 32 third- and fourth-grade Italian dyslexics and in 86 age-matched controls A visual lexical decision task was used As proposed by Faust et al. (1999), the results were analyzed in terms of raw reaction time (RT) data and using the z-score transformation to control for the presence of overadditivity effects. In terms of RTs, dyslexics showed a larger difference between words and nonwords (lexicality effect) and between short and long stimuli (length effect) than proficient readers. When data were transformed into z scores, only the group by length interaction remained significant while that with lexicality vanished. This pattern indicates that stimulus length has a specific role in Italian dyslexics' reading deficit; in contrast, slowness in responding to nonwords was not specific but was interpreted as one aspect of dyslexics' general inability to deal with alphabetical material (overadditivity effect)
The role of cognitive reserve on prefrontal and premotor cortical activity in visuo-motor response tasks in healthy old adults
No full text: Cognitive reserve (CR) is a key factor to mitigate the cognitive decline during the aging process. Here, we used event-related potentials to target the preparatory brain activities associated with different levels of CR during visuo-motor simple response tasks (SRTs) and discriminative response tasks (DRTs). EEG was recorded from 28 healthy old (Age: 72.2 ± 4.7 years) and 14 young (Age: 22.2 ± 2.4 years) individuals during an SRT and a DRT. Depending on the CR median score, old participants were divided into either a high (High-CR) or a low CR (Low-CR) group. Behavioral performance and electrophysiological data were compared across the 3 groups. Compared with the Low-CR, the High-CR group showed larger prestimulus prefrontal (prefrontal negativity) and premotor activity (Bereitschaftspotential-BP), in the SRT, and increased premotor readiness (BP), in the DRT. The High-CR was faster and more accurate than the Low-CR group in the DRT and SRT, respectively. The High-CR group revealed enhanced brain preparatory activities that, paralleled to their behavioral performance, might reflect neural compensation and maintenance effects possibly counteracting the age-related decline in cognitive functioning
Length effect in word naming in reading: Role of reading experience and reading deficit in Italian readers
No full textVocal reaction times (RTs) in naming 3- to 8-letter words were measured in proficient and dyslexic readers (Study 1). In proficient readers, RTs were independent of word length up to 5-letter words, indicating parallel processing. In the 5- to 8-letter range, RTs increased linearly, indicating sequential processing. Reading experience was associated with both faster discrimination of individual elements and parallel processing of increasingly large word parts. In dyslexics, RTs increased linearly with increasing length indicating reliance on sequential decoding. Individual analysis indicated 2 profiles of RTs (Types A and B). In Study 2, the distinction between A and B dyslexics was not associated with the use of different reading procedures. However, a more marked speed deficit characterized Type B dyslexics
Reading development in an orthographically regular language: effects of length, frequency, lexicality and global processing ability
No full textThe acquisition of reading skill was studied in 503 Italian children in first to eighth grade using a task that required reading of lists of words and non-words. Analysis of the metric characteristics of the measures indicated that reading speed but not accuracy was normally distributed across all ages considered. The role of specific effects (length, word frequency, and lexicality) versus global factors in reading speed was examined using the Rate-Amount Model (RAM). A global processing factor accounted for a large portion of the variance. Specific influences of length, frequency, and lexicality were detected in different periods of development over and above the global processing factor. Length modulated performance at early stages of learning and progressively less later on; in the case of non-words, the effect of length was large but did not change as a function of grade. The lexicality effect, present at all ages for high frequency words and by third grade for low frequency words increased with reading practice indicating a progressive differentiation in the ability to read words and non-words. Finally, the effect of word frequency was highest in third grade and then decreased. These findings are discussed in terms of their relevance for reading acquisition in a language with transparent orthography and their implications for evaluating developmental reading deficits. Overall, it is proposed that RAM is a useful tool for disentangling the role of specific versus global factors in reading development
Is developmental dyslexia modality specific? A visual-auditory comparison of Italian dyslexics
No full textAlthough developmental dyslexia is often referred to as a cross-modal disturbance, tests of different modalities using the same stimuli are lacking. We compared the performance of 23 children with dyslexia and 42 chronologically matched control readers on reading versus repetition tasks and visual versus auditory lexical decision using the same stimuli. With respect to control readers, children with dyslexia were impaired only on stimuli in the visual modality; they had no deficit on the repetition and auditory lexical decision tasks. By applying the rate-amount model (Faust et al., 1999), we showed that performance of children with dyslexia on visual (but not auditory) tasks was associated with that of control readers by a linear relationship (with a 1.78 slope), suggesting that a global factor accounts for visual (but not auditory) task performance. We conclude that the processing of linguistic stimuli in the visual and auditory modalities is carried Out by independent processes and that dyslexic children have a selective deficit in the visual modality. (C) 2011 Elsevier Ltd. All rights reserved
Rapid naming deficits in dyslexia: a stumbling block for the perceptual anchor theory of dyslexia.
No full textAccording to a recent theory of dyslexia, the perceptual anchor theory, children with dyslexia show deficits in classic auditory and phonological tasks not because they have auditory or phonological impairments but because they are unable to form a ‘perceptual anchor’ in tasks that rely on a small set of repeated stimuli. The theory makes the strong prediction that rapid naming deficits should only be present in small sets of repeated items, not in large sets of unrepeated items. The present research tested this prediction by comparing rapid naming performance of a small set of repeated items with that of a large set of unrepeated items. The results were unequivocal. Deficits were found both for small and large sets of objects and numbers. The deficit was actually bigger for large sets than for small sets, which is the opposite of the prediction made by the anchor theory. In conclusion, the perceptual anchor theory does not provide a satisfactory account of some of the major hallmark effects of developmental dyslexia
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