Pubmed: La dislessia

La dislessia è un disturbo specifico dell'apprendimento, che si manifesta con difficoltà nella decodifica di un testo scritto; in parole povere, il soggetto legge in modo molto incerto, perchè fatica a legare i suoni e le sillabe, confonde alcune lettere o le inverte. Il mio interesse per la dislessia si spiega in diversi modi. Innanzitutto mia mamma è un'insegnante elementare e ho potuto osservare che i casi di dislessia sono in aumento, soprattutto perchè, in passato, c'era scarsa conoscenza di questo disturbo che oggi, invece, è diagnosticato facilmente. La dislessia è molto diffusa nei paesi anglosassoni, perchè nella lingua Inglese, ma non solo, non c'è corrispondenza tra grafema e fonema, come ho potuto constatare io stessa nel corso dei miei studi. Infine, un libro di Roald Dahl, "Il vicario, cari voi" ha contribuito ad attirare la mia attenzione. Ecco perchè ho utilizzato pubmed per avere informazioni!
Guardate un po' cosa ho trovato....
Motor sequence learning and developmental dyslexia.
Beyond the reading-related deficits typical of developmental dyslexia (DD), recent evidence suggests that individuals afflicted with this condition also show difficulties in motor sequence learning. To date, however, little is known with respect to the characteristics of the learning impairments, nor to the neural correlates associated with this type of procedural deficit in DD patients.
Impaired serial visual search in children with developmental dyslexia.
In order to test the hypothesis of attentional deficits in dyslexia, we investigated the performance of children with developmental dyslexia on a number of visual search tasks. When tested with conjunction tasks for orientation and form using complex, letter-like material, dyslexic children showed an increased number of errors accompanied by faster reaction times in comparison to control children matched to the dyslexics on age, gender, and intelligence. On conjunction tasks for orientation and color, dyslexic children were also less accurate, but showed slower reaction times than the age-matched control children. These differences between the two groups decreased with increasing age. In contrast to these differences, the performance of dyslexic children in feature search tasks was similar to that of control children. These results suggest that children with developmental dyslexia present selective deficits in complex serial visual search tasks, implying impairment in goal-directed, sustained visual attention.
The effect of word length and other sublexical, lexical, and semantic variables on developmental reading deficits.
BACKGROUND: Previous studies indicated the role of word length in transparent orthographies. However, several factors that may interact with word length were not controlled for. METHODS: Seventeen impaired and 34 skilled sixth-grade readers were presented words of different lengths, matched for initial phoneme, bigram frequency, word frequency, age of acquisition, and imageability. Participants were asked to read aloud, as quickly and as accurately as possible. Reaction times at the onset of pronunciation and mispronunciations were recorded. RESULTS: Impaired readers' reaction times indicated a marked effect of word length; in skilled readers, there was no length effect for short words but, rather, a monotonic increase from 6-letter words on. Regression analyses confirmed the role of word length and indicated the influence of word frequency (similar in impaired and skilled readers). No other variables predicted reading latencies. CONCLUSIONS: Word length differentially influenced word recognition in impaired versus skilled readers, irrespective of the action of (potentially interfering) sublexical, lexical, and semantic variables. It is proposed that the locus of the length effect is at a perceptual level of analysis. The independent influence of word frequency on the reading performance of both groups of participants indicates the sparing of lexical activation in impaired readers.