Word Reading and Spelling Processing and Acquired Dyslexia post Unilateral Stroke

This study investigates the performance of adults with cerebrovascular lesion in the right hemisphere (RHL) or left hemisphere (LHL) in word reading (TLPP) and spelling (TEPP) tasks based on the dual-route models. A total of 85 adults were assessed, divided into three groups: 10 with RHL, 15 with LHL, and 60 neurologically healthy ones. The performance of the three groups was compared in terms of the characteristics of the words (regularity, frequency, and length) and pseudowords (length), error types, and psycholinguistic effects. A cluster analysis was performed to investigate the profiles of the reading. The LHL group showed lower scores in reading and spelling tasks of words and pseudowords, as well as a higher frequency of errors. Four LHL cases were found to have an acquired dyslexia profile. This study highlights that the tasks developed in Brazil are in accordance with theoretical models of written language, and the results point to the heterogeneous performance of the cases with acquired dyslexia.

Serial order and consonant-vowel structure in a graphemic output buffer model

We review features of the spelling errors of dysgraphic patients with "Graphemic Buffer Disorder" (GBD). We argue that the errors made by such patients suggest the breakdown of a system used to generate serial order in the output stages of spelling production, and we develop a model for this system based on an existing theory of sequential behaviour--"Competitive Queuing." We show that constraints on response categories may be straightforwardly applied during sequence production in such a model, and this enables us to account for the preservation of consonant-vowel status in the spelling errors of GBD patients. When the sequence generation process is disrupted by the addition of random noise the model shows the major features of GBD. The results are compared in detail against data from a number of patients.

Neuropsychological outcome in long-term survivors of a childhood extracranial solid tumor who have undergone autologous bone marrow transplantation

The purpose of this study was to evaluate neuropsychological and adaptive functioning of children who have undergone bone marrow transplantation (BMT) without previous cranial irradiation. In total, 76 children treated for an extracranial tumor with BMT without total body irradiation (TBI) were evaluated at least 5 years after the end of the treatment.Overall, their performance and skills were in the normal range and their professional and academic outcomes were satisfactory. Nevertheless, we observed a deleterious effect of deafness on verbal IQ associated with the previous administration of cisplatin during conventional chemotherapy. In addition, reading difficulties had arisen. This could be related to absence from kindergarten or primary school during hospitalization. Finally, in the younger subgroup, visual-perceptual skills were found to be more fragile.

[Cerebral activation during Stroop's test in a case of early focal brain injury]

INTRODUCTION

Functional magnetic resonance imaging (fMRI) offers an important advantage over other functional neuroimaging techniques used with children because of its harmlessness. Previous studies conducted with adults with alexia suggested two ways the brain can reorganise reading after a brain injury affecting the left hemisphere, one contralateral and the other ipsilateral.

CASE REPORT

We describe a study carried out using fMRI of a 10 year old girl with an injury to the left hemisphere caused by a fishing harpoon when she was 6 years old. As a result of the accident the girl presented a right hemiparesia. The girl s parents and teachers also reported difficulties in the acquisition of reading writing and arithmetic, as well as a certain degree of attentional deficit. An fMRI exploration was performed while the girl was doing the Stroop test. The structural MR images showed left hemisphere cortical lesions in the orbital and angular gyrus regions, in addition to the caudate and putamen nuclei, and in the inferior longitudinal bundle. The fRMI revealed a strong overactivation of the right dorsolateral frontal cortex, in the evaluation of interference, and activations of the right angular and bilateral supramarginal gyri, in the evaluation of word reading.

CONCLUSION

The functional study suggests the existence of a reorganisation of reading that is both intra and inter hemispheric.

[Language and aphasias]

INTRODUCTION AND OBJECTIVE

Approximately 400,000 years ago men started to use language. Initially it was probably poor with few phonemes. With social evolution it became more complex, with the appearance of new phonemes and a more complete grammatical structure. The current concept of the processing of language dates, with little change, from the nineteenth century.

DEVELOPMENT

With the birth of phrenology language began to be studied. This lead to the hypothesis of Wernicke, with two main areas joined by the fasciculo arcuato, which is still held to be valid with modifications by Gerchwind and Damasio, amongst others. Important advances in the study of language are due to Chomsky and his transformational grammar. This supports the universal structure of language, since one learns it following genetically determined laws. Language has three main aspects: creativity which makes both the transmitter and the receiver active participants in communication, the form from which words are constructed and the content of the message. Aphasia is an alteration in the comprehension and understanding of language, which may be the clinical expression of many different aetiologies. They help us to localize the lesion topographically. They are divided depending on the clinical signs, into motor or Broca's aphasia, in which understanding is conserved but the patient uses a language with poor grammatical structure, although the semantic content is acceptable: sensitive or Wernicke's aphasia, with inability to understand and language which is fluid but unintelligible; conduction aphasia due to limitation in the transmission of impulses from Wernicke's area to that of Broca, with acceptable understanding and fluid language and the trans-cortical aphasias where the main characteristic is indemnity of the capacity of repetition.

CONCLUSIONS

The aphasias, as the expression of an alteration of language are an important support in the topographical localization of lesions, even before these can be shown on computerized tomography.

[Aphasia without alexia after surgical treatment of aneurysm of the right middle cerebral artery--incomplete lateralization of verbal functions?]

The authors present a case of aphatic disorders after surgical treatment of the right middle cerebral artery aneurysm. A prominent dissociation of verbal function was noticed.

Modelling acquired dyslexia: a software tool for developing grapheme-phoneme correspondences

In extending a computer model of acquired dyslexia, it has become necessary to develop a way to group printed characters in a word so that the character groups essentially have a one-to-one correspondence with the word's phonemes (speech sounds). This requires deriving a set of correspondences (legal character groupings, legal associations of character groups with phonemes, etc.) that yield a single grouping or "segmentation" of characters when applied to any English word. To facilitate and partially automate this task, a segmentation program has been developed that uses an interchangeable set of correspondences. The program segments words according to these correspondences and tabulates their success over large sets of words. The program has been used successfully to segment a 20,000 word corpus, demonstrating that this approach can be used effectively and efficiently.

Aphasia, dyslexia and the phonological coding of written words

A possible account of the reading difficulty of certain aphasic-dyslexic patients includes the notion that they are impaired in translating the written word into a phonological code via grapheme-phoneme conversion rules. This notion was tested in two experiments, both utilizing orthographically regular non-words (like dake) as stimuli. The first experiment provides an analysis of two patients' (largely successful) attempts to repeat non-words, and their (almost totally unsuccessful) attempts to read them. Second, in a lexical decision task (is this written letter-string a word or not?), the finding that normals are slowed by non-words homophonic with real words (like flore) was replicated using a modified technique. This effect, attributable to phonological coding, was not shown by the patients. At the same time, their ability to discriminate between words and non-words was essentially intact. Consideration was given to mechanisms which might underlie such patients' correct and erroneous readings of words and non-words.

Performance of disabled and normal readers on the Bender-Gestalt, Auditory Discrimination Test, and visual-motor matching

Research comparing normal and disabled readers on perceptual tasks is equivocal. Benton (1962) cites inadequate matching of groups on the factor of general intelligence as a reason for the disparate findings. Groups of disabled and normal readers ( N = 20 each) were compared on the Bender-Gestalt, Auditory Discrimination Test, and a visual-motor matching task. No significant differences between the groups were found on the Bender-Gestalt and the visual-motor matching task. The normal readers were superior to disabled readers on the Auditory Discrimination Test ( p < .01). Implications for early identification and remediation were discussed.