88 research outputs found
How strong is the relationship between general phonological processes and pseudo-word reading? (51st Academy of Aphasia Proceedings)
Phonological dyslexia (PD) is an acquired reading disorder characterised by an abnormally strong lexicality effect, i.e., with impaired pseudo-word reading contrasting with relatively preserved real word reading (Beauvois & Derouesne, 1979). Parallel distributed models of reading aloud (Harm & Seidenberg, 2001) have made the strong
claim that PD is due to a general, non-reading specific deficit to central phonological representations which
manifests during pseudo-word reading due to the inherently high demands they place on the phonological system.
Under this account, patients with impaired phonology should show impaired pseudo-word reading and vice-versa.
Consistent with this view, phonological deficits frequently co-occur with PD (Friedman, 1996). In contrast, dual route
models posit that PD may result from a deficit to grapheme-phoneme conversion processes (sublexical reading
process) that does not have to implicate a general phonological deficit. We present two cases that directly challenge the phonological deficit view
Lexical neighborhood effects in pseudoword spelling
The general aim of this study is to contribute to a better understanding of the cognitive processes that underpin skilled adult spelling. More specifically, it investigates the influence of lexical neighbors on pseudo-word spelling with the goal of providing a more detailed account of the interaction between lexical and sublexical sources of knowledge in spelling. In prior research examining this topic, adult participants typically heard lists composed of both words and pseudo-words and had to make a lexical decision to each stimulus before writing the pseudo-words. However, these priming paradigms are susceptible to strategic influence and may therefore not give a clear picture of the processes normally engaged in spelling unfamiliar words. In our two Experiments involving 71 French-speaking literate adults, only pseudo-words we represented which participants were simply requested to write to dictation using the first spelling that came to mind. Unbeknownst to participants, pseudo-words varied according to whether they did or did not have a phonological word neighbor. Results revealed that low-probability yphoneme/grapheme mapping(e.g.,/o/-> aud in French)were used significantly more often in spelling pseudo-words with a close phonological lexical neighbour with that spelling(e.g.,/krepo/derived from “crapaud,”/krapo/)than in spelling pseudo-words with no close neighbors(e.g.,/frøpo/).In addition, the strength of this lexical influence increased with the lexical frequency of the word neighbors as well as with their degree of phonetic overlap with the pseudoword targets. These results indicate that information from lexical and sublexical processes is integrated in the course of spelling, and a specific theoretical account as to how such integration may occur is introduced
Processing deficits for familiar and novel faces in patients with left posterior fusiform lesions
Pure alexia (PA) arises fromdamage to the left posterior fusiformgyrus (pFG) and the striking
reading disorder that defines this condition has meant that such patients are often cited as
evidence for the specialisation of this regiontoprocessing of writtenwords.There is,however,
an alternative view that suggests this region is devoted to processing of high acuity foveal
input, which is particularly salient for complex visual stimuli like letter strings. Previous reports
have highlighted disrupted processing of non-linguistic visual stimuli after damage to
the left pFG, both for familiar and unfamiliar objects and also for novel faces. This study
explored the nature of face processing deficits in patients with left pFG damage. Identification
of famous faces was found to be compromised in both expressive and receptive tasks.
Discrimination of novel faces was also impaired, particularly for those that varied in terms of
second-order spacing information, and this deficit was most apparent for the patients with
the more severe reading deficits. Interestingly, discrimination of faces that varied in terms of
feature identity was considerably better in these patients and it was performance in this
condition that was related to the size of the length effects shown in reading. This finding
complements functional imaging studies showing left pFG activation for faces varying only in
spacing and frontal activation for faces varying only on features. These results suggest that
the sequential part-based processing strategy that promotes the length effect inthe reading of
these patients also allows themto discriminate between faces on the basis of feature identity,
but processing of second-order configural information is most compromised due to their left
pFG lesion. This study supports a view in which the left pFG is specialised for processing of
high acuity foveal visual information that supports processing of both words and faces.variou
Treating clinical mastitis in dairy cows with essential oils
Clinical mastitis is the main concern in dairy farming today, but there are very few drugs that are compatible with organic specifications. Our study was conducted in order to evaluate the therapeutic efficiency of the intramammary infusion of three essential oils, Thymus vulgaris, Rosmarinus verbenone and Laurus nobilis. Fifty-five cases of mastitis were treated with 10 ml of a mixture of the three oils (1.5% each in sunflower oil). Forty-five others were treated with 10 ml of a mixture of Thymus vulgaris and Rosmarinus verbenone (6% of each in sunflower oil or in water). The recovery rate was only 40%, which is deemed unsatisfactory
Impaired integration of object knowledge and visual input in a case of ventral simultanagnosia with bilateral damage to area V4
In this study we report some of the first evidence showing how brain-damage can
affect the underlying processes that support the integration of sensory input and prior
knowledge during the visual perception of shape. We report the case of patient MT
with an acquired ventral simultanagnosia following posterior occipito-temporal
lesions encompassing V4 bilaterally. Despite showing normal object recognition for
single items, and intact low-level vision, MT was impaired in object identification
with overlapping figures displays.Task performance was modulated by familiarity:
unlike controls, MT was faster with overlapping displays of abstract shapes than
common objects. His performance with overlapping common object displays was also
influenced by both the semantic relatedness and visual similarity of the display items.
These findings challenge claims that visual perception is driven solely by feedforward
mechanisms, and show how brain-damage can selectively impair high-level
perceptual processes supporting the integration of stored knowledge and visual
sensory input
Developmental surface dysgraphia without surface dyslexia
The case is reported of an individual (NK) with a developmental spelling impairment (dysgraphia) who has no apparent problems in reading. His performance is therefore similar to a case of dysgraphia without dyslexia (PJT) reported by Hepner, McCloskey & Rapp (2017), and provides further evidence of a classical dissociation between impaired spelling and preserved reading in individuals with developmental literacy problems. The dissociation is observed when NK is asked to read and spell in either his first (Greek) or his second language (English). An investigation of his spelling performance revealed that his impairment was more selective than that of PJT. Although his spelling of regular words and nonwords was normal, NK had a problem in spelling words with atypical sound-letter associations despite having no problems in reading aloud or understanding the meaning of words of this kind. It is argued that NK’s pattern of performance can be best explained in terms of normal development of an orthographic system that allows access to the meaning and pronunciation of written words during reading. In terms of a dual route model of spelling, his poor spelling appears to be the result of a developmental impairment that impedes access to the orthographic system from phonology and semantics. In terms of the triangle model, his poor spelling appears to be the result of a developmental impairment that affects activation of orthography from semantics
Costs and benefits of orthographic inconsistency in reading:evidence from a cross-linguistic comparison
We compared reading acquisition in English and Italian children up to late primary school analyzing RTs and errors as a function of various psycholinguistic variables and changes due to experience. Our results show that reading becomes progressively more reliant on larger processing units with age, but that this is modulated by consistency of the language. In English, an inconsistent orthography, reliance on larger units occurs earlier on and it is demonstrated by faster RTs, a stronger effect of lexical variables and lack of length effect (by fifth grade). However, not all English children are able to master this mode of processing yielding larger inter-individual variability. In Italian, a consistent orthography, reliance on larger units occurs later and it is less pronounced. This is demonstrated by larger length effects which remain significant even in older children and by larger effects of a global factor (related to speed of orthographic decoding) explaining changes of performance across ages. Our results show the importance of considering not only overall performance, but inter-individual variability and variability between conditions when interpreting cross-linguistic differences
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