Fluidez en la lectura y procesamiento morfolexical: estudios de desarrollo en Italia / Reading fluency and morpho-lexical processing: developmental studies in Italian

Se ha sugerido que, al aprender a leer, los lectores de ortografías transparentes se basan en unidades de lectura de reducido tamaño, como grafemas y fonemas. El presente artículo muestra que los lectores en desarrollo en Italia utilizan la lectura lexical y morfolexical desde los primeros grados elementales. Asimismo, se revisan varios estudios que documentan la presencia de efectos lexicales y morfolexicales en disléxicos evolutivos italianos. Se sostiene que, incluso en ortografías transparentes, las unidades de lectura de amplio tamaño, como morfemas y palabras completas, son necesarias para adquirir fluidez en la lectura

It has been suggested that readers of transparent orthographies rely on small-size reading units, such as graphemes and phonemes, in learning to read. The present paper shows that lexical and morpholexical reading is used by developing readers of Italian since the first elementary grades. Several studies that report the presence of lexical and morpholexical effects in Italian developmental dyslexics are also reviewed. It is argued that large-size reading units such as morphemes and whole-words are necessary, even in a transparent orthography, in order to attain reading fluency

Supercalifragilisticexpialidocious: how the brain learns words never heard before.

Vocabulary acquisition is such a major aspect of language learning in children, but also in adults when learning a foreign language, that a dedicated vocabulary learning device may exist within the language organ. To identify the relevant brain systems, we performed regional cerebral blood flow measurements in normal subjects while they were learning a list of neologisms or a list of word-nonword pairs. Structures implicated in phonological short-term memory (Broca's area, left temporo-parietal junction) were steadily activated during nonwords learning, while the left temporal lobe neocortical and paralimbic structures (parahippocampal region), associated with long-term memory, contributed to learning in a time-dependent manner, with maximal activation at the beginning of the process. The neural system specifically activated when learning new vocabulary was strongly lateralized to the left hemisphere. This evidence refines current models of memory function and supports theories which emphasise the importance of phonological competence in hemispheric dominance for language.

Traces of vocabulary acquisition in the brain: Evidence from covert object naming.

One of the strongest predictors of the speed with which adults can name a pictured object is the age at which the object and its name are first learned. Age of acquisition also predicts the retention or loss of individual words following brain damage in conditions like aphasia and Alzheimer's disease. Functional Magnetic Resonance Imaging (fMRI) was used to reveal brain areas differentially involved in naming objects with early or late acquired names. A baseline task involved passive viewing of non-objects. The comparison between the silent object naming conditions (early and late) with baseline showed significant activation in frontal, parietal and mediotemporal regions bilaterally and in the lingual and fusiform gyri on the left. Direct comparison of early and late items identified clusters with significantly greater activation for early acquired items at the occipital poles (in the posterior parts of the middle occipital gyri) and at the left temporal pole. In contrast, the left middle occipital and fusiform gyri showed significantly greater activation for late than early acquired items. We propose that greater activation to early than late objects at the occipital poles and at the left temporal pole reflects the more detailed visual and semantic representations of early than late acquired items. We propose that greater activation to late than early objects in the left middle occipital and fusiform gyri occurs because those areas are involved in mapping visual onto semantic representations, which is more difficult, and demands more resource, for late than for early items.

Word reading and picture naming in Italian.

Results from two separate norming studies of lexical access in Italian were merged, permitting a comparison of word-reading and picture-naming latencies and the factors that predict each one for an overlapping subsample of 128 common nouns. Factor analysis of shared lexical predictors yielded four latent variables: a frequency factor, a semantic factor, a length factor, and a final factor dominated by frication on the initial phoneme. Age of acquisition (AoA) loaded highly on the first two factors, suggesting that it can be split into separate sources of variance. Regression analyses using factor scores as predictors showed that word reading and picture naming are both influenced by the frequency/AoA factor. The semantics/AoA factor influenced only picture naming, whereas the length and frication factors influenced only word reading. Generalizability of these results to other languages is discussed, including potential effects of cross-language differences in orthographic transparency.

Morpholexical access and naming: the semantic interpretability of new root-suffix combinations.

In two experiments, pseudowords made up of Italian roots and derivational suffixes were investigated. In visual lexical decision, the licensing of a new root-suffix combination was affected by its semantic interpretability, but not by its grammatical appropriateness. By contrast, the degree of interpretability of new root-suffix combinations did not affect naming. However, and irrespective of differences in interpretability, pseudowords made up of two morphemes were named more efficiently than pseudowords with no morphological constituency. These results, while showing the involvement of the semantic component in the licensing process, also show its dissociability in lexical naming, thus suggesting morpholexical nonsemantic naming.

Automatic semantic facilitation in Alzheimer's disease.

To explore the nature of semantic deficit in Alzheimer's disease patients (AD patients) we compared two tasks that are known to be very different with respect to the type of attentional demand and conscious effort they require: lexical decision (automatic) in a semantic priming paradigm and semantic relatedness judgements (intentional). In order to minimise post-lexical facilitation we devised a semantic priming experiment that met an automatic condition as much as possible, and we selected patients without severe word recognition deficits. AD patients showed reduced accuracy in the semantic relatedness judgements as compared to controls. Some effect of priming was found, but this was weaker than in normals. AD patients also differed from controls on targets preceded by a nonlinguistic prime (neutral condition) where their reaction times were slower as compared to neutral condition.