No abstract

Dyslexia is a specific learning disability characterized by difficulties with accurate and/or fluent word recognition and by poor spelling abilities. The absence of other high level cognitive deficits in the dyslexic population has led some authors to propose that non-strategical processes like implicit learning could be impaired in this population. Most studies have addressed this issue by using sequence learning tasks, but so far the results have not been conclusive. We test this hypothesis by comparing the performance of dyslexic children and good readers in both implicit and explicit versions of the sequence learning task, as well as in another implicit learning task not involving sequential information. The results showed that dyslexic children failed to learn the sequence when they were not informed about its presence (implicit condition). In contrast, they learned without significant differences in relation to the good readers group when they were encouraged to discover the sequence and to use it in order to improve their performance (explicit condition). Moreover, we observed that this implicit learning deficit was not extended to other forms of non-sequential, implicit learning such as contextual cueing. In this case, both groups showed similar implicit learning about the information provided by the visual context. These results help to clarify previous contradictory data, and they are discussed in relation to how the implicit sequence learning deficit could contribute to the understanding of dyslexia.

Some research on literacy acquisition suggests that implicit learning processes may be related to reading and writing proficiency in English, which is a deep orthography. However, little research has been done to determine if the same is true in shallow orthographies. Here, we investigated whether the implicit learning ability of third grade Spanish speaking children was related to their reading and writing abilities. Twenty eight children viewed pseudowords which all adhered to untaught graphotactic rules and were later assessed to determine their implicit learning of these rules. The children's reading and writing abilities were also assessed using standardized tests. No correlations were found between the participants' level of implicit learning and their performance on reading tasks or on a pseudoword writing task, suggesting that implicit learning is not strongly related to the acquisition of phonological regularities in a shallow orthography. A correlation was found between recognition of previously seen exemplars and the ability to spell inconsistent words which require word specific knowledge to resolve the spelling inconsistencies. This result suggests that implicit learning mechanisms may play a role in the acquisition of lexical knowledge and thus, in writing proficiency.

One of the hallmarks of dyslexia is the failure to automatise written patterns despite repeated exposure to print. Although many explanations have been proposed to explain this problem, researchers have recently begun to explore the possibility that an underlying implicit learning deficit may play a role in dyslexia. This hypothesis has been investigated through non-linguistic tasks exploring implicit learning in a general domain. In this study, we examined the abilities of children with dyslexia to implicitly acquire positional regularities embedded in both non-linguistic and linguistic stimuli. In experiment 1, 42 children (21 with dyslexia and 21 typically developing) were exposed to rule-governed shape sequences; whereas in experiment 2, a new group of 42 children were exposed to rule-governed letter strings. Implicit learning was assessed in both experiments via a forced-choice task. Experiments 1 and 2 showed a similar pattern of results. ANOVA analyses revealed no significant differences between the dyslexic and the typically developing group, indicating that children with dyslexia are not impaired in the acquisition of simple positional regularities, regardless of the nature of the stimuli. However, within group t-tests suggested that children from the dyslexic group could not transfer the underlying positional rules to novel instances as efficiently as typically developing children.

Background: Detecting reading comprehension difficulties is challenging because many factors are involved in comprehension ability. Various reading comprehension tests can be used to detect difficulties but often do not yield the same results. Method: Our aim was to analyse the agreement between three commonly used standardised reading comprehension tests (ECOMPLEC, ACL and PROLEC-R) in the detection of reading comprehension difficulties in Spanish. A total of 139 children (72 fifth graders and 67 sixth graders) at the same public-sector school participated in this study. The three reading comprehension tests were administered, together with word and nonword reading, vocabulary and nonverbal intelligence measures. Results: Modest intercorrelations among the tests were found. The consistency of classification for each reading profile across the three reading comprehension tests was low. The results show different reading comprehension profiles depending on the test used. Conclusions: It is important to use more than one instrument to diagnose reading comprehension difficulties, due to the complexity involved. Furthermore, knowledge of the characteristics of each reading comprehension test is essential to the choice of test. The educational implications of children being wrongly diagnosed are discussed.