Littérature scientifique sur le sujet « Neglect dyslexia »

Evidence from various subtypes of Specific Language Impairment and developmental peripheral dyslexias is presented to support the idea that even developmental disorders can be modular. However, in developmental letter position dyslexia and neglect dyslexia we show that additional errors can occur because of insufficient orthographic-lexical knowledge.

In our daily life, attention plays a fundamental role in governing our visual experience. Indeed, every visual experience consists in an overwhelming amount of visual information reaching our visual system. Selective attention allows us to select the relevant information, which is important for our goals, while ignoring the irrelevant information in our environment. However, selective attention is not a unitary notion, but a multi-faceted concept constituted by different components. Several models on how the attentional resources can be allocated in the space identify two distinct components: an orientation component, which moves the attentional resources to relevant locations for further processing, and a focal component, which allows us to converge our resource on a limited amount of space. The present dissertation inquires the classical view of these two components of selective attention, providing a characterization of both and their mutual relationship. Using a combination of behavioural and neuropsychological evidence, I investigated how these two components operate in different viewing conditions, with different temporal trends and different task demands. Finally, I examined how a deficit in the ability to adjust the attentional focus can condition the reading process in brain-damaged patients. By measuring the cue-size effect in healthy participants, the first set of studies characterizes how the focal component is deployed in the centre of the visual field. These studies show that, even if detectable in both exogenous and endogenous conditions, the facilitatory effect of the focal component is best revealed and more effective in exogenous conditions. Moreover, I elucidated the role played by the task demands and the stimuli used in evoking this facilitatory effect. The second set of studies, always on healthy participants, further extends these findings by showing that the focal and the orientation component are two independent components, which displayed their effects in different viewing conditions and with different temporal trends. The dissociation of these two components is evident not only in simple tasks, as single letter detection or discrimination, but also in a more reading-related task, consisting in discriminating a letter among others. At complement with evidence in healthy participants, the third set of studies investigates how a deficit in the control of the focal component could be responsible for the substitution errors that brain-damage patients affected by Neglect Dyslexia (ND) make in reading texts and single words. The substitution errors would depend on the difficulty to perceptually segregate the letters between each other, and a deficit in the control of the focal component would play a main role in increasing this phenomenon, by preventing the adjustment of the integration field necessary to identify and read the letter correctly. Overall, this set of experiments illustrates a dissociation between the focal and the orientation component of selective attention and suggests the existence of a causal link between the former one and the substitution errors in reading.

Αντικείμενο μελέτης της παρούσας εργασίας αποτελεί ο βαθμός επιρροής της κεφαλής κατά την ανάγνωση παρατακτικών συνθέτων από ασθενείς με neglect dyslexia (ND). Ενώ η πλειοψηφία των συνθέτων της ελληνικής, τα επονομαζόμενα ‘υποτακτικά’ (subordinative compounds), υπακούουν στον νόμο της δεξιόστροφης κεφαλής (Williams, 1981) (π.χ. ελαφο-κυνηγός), τα παρατακτικά σύνθετα (coordinative compounds) δεν εμφανίζουν αυτή την κανονικότητα στη θέση της κεφαλής τους (π.χ αλατο-πίπερο). Κάποιοι θεωρητικοί μορφολόγοι θεωρούν ότι κανένα από τα δύο συστατικά δεν αποτελεί τη βάση του συνθέτου, ούτε μορφολογικά ούτε σημασιολογικά (Ralli, 2005: 174), άλλοι υποστηρίζουν ότι τα παρατακτικά εμφανίζουν δύο κεφαλές, τόσο στο α’ όσο και στο β’ συνθετικό (Kageyama, 2009), ενώ δεν λείπουν και αυτοί που επιχειρηματολογούν για την υπεροχή του δεύτερου συστατικού, λόγω του ότι αυτό καθορίζει το γένος, τον αριθμό και την πτώση των συνθέτων (Guevara & Scalise, 2008). Στο πλαίσιο αυτό, θα προσπαθήσουμε να απαντήσουμε στο ερώτημα της θεωρητικής μορφολογίας σχετικά με τη θέση της κεφαλής στα παρατακτικά [ΟΟ] και [ΕΕ] σύνθετα της Νέας Ελληνικής, καθώς και στο ερώτημα της κλινικής γλωσσολογίας σχετικά με το ρόλο της κεφαλής στην ανάκληση και επεξεργασία των συνθέτων από ασθενείς με neglect dyslexia. Ένα ιδιαίτερα σημαντικό χαρακτηριστικό των ασθενών με ND είναι η ικανότητά τους να αναγνωρίζουν και να σέβονται τα όρια των δύο συστατικών κατά την ανάγνωση των συνθέτων (Behrmann et al., 1990). Επιπλέον, οι Semenza et al. (2011) αναφέρουν για τα Ιταλικά ότι τα λάθη στο α’ συνθετικό είναι πολύ πιο συχνά στα σύνθετα των οποίων η κεφαλή συμπίπτει με το β’ συνθετικό, παρά όταν συμπίπτει με το πρώτο. Ο εξισορροπητικός ρόλος της κεφαλής ως προς την εμφάνιση λαθών πάνω στο συστατικό της, αναμένουμε να έχει αντίκτυπο και στη δική μας περίπτωση: τα υποτακτικά σύνθετα με την κεφαλή στα δεξιά θα πρέπει να εμφανίζουν περισσότερα λάθη στο α’ συνθετικό από τα παρατακτικά, εφόσον τα τελευταία έχουν δύο κεφαλές. Στο πείραμα ανάγνωσης που σχεδιάσαμε, συμπεριλάβαμε 31 παρατακτικά σύνθετα, ονοματικά και επιθετικά (π.χ. ψωμοτύρι ‘bread-cheese’ και κοντόχοντρος αντιστοίχως) και 32 υποτακτικά σύνθετα, επίσης ονοματικά και επιθετικά (π.χ. ερημονήσι και χοντροαλεσμένος αντιστοίχως), τα οποία είχαμε ελένξει ως προς όλες τις σημαντικές ψυχογλωσσολογικές και μορφολογικές παραμέτρους ανά γραμματική κατηγορία. Το πείραμα αυτό το διεξάγαμε σε μία ασθενή 79 ετών, η οποία έχει υποστεί ΔΕ αγγειακό εγκεφαλικό επεισόδιο (ΑΕΕ) και με βάση την επίδοσή της στο BELLS test έχει διαγνωσθεί με left-sided neglect dyslexia. Ενώ στα παρατακτικά σύνθετα της ονοματικής κατηγορίας, η ασθενής τείνει να παραλείπει ή να υποκαθιστά το α΄συστατικό των συνθέτων αυτών εξίσου συχνά με αυτό των υποτακτικών, δεν ισχύει το ίδιο και για τα επιθετικά παρατακτικά, κατά την ανάγνωση των οποίων ο ασθενής κάνει στατιστικά σημαντικά λιγότερα λάθη στο α’ συστατικό απ’ ότι στην ανάγνωση των αντίστοιχων υποτακτικών ( x²= 3.970, p < 0.05). Η συμβολή της παρούσας μελέτης μπορεί να συνοψιστεί στα ακόλουθα σημεία: Πρώτον, αποδεικνύεται ότι οι λεξικοί παράγοντες μπορούν να επηρεάσουν την επιλεκτική προσοχή σε μεγάλο βαθμό. Δεύτερον, παρέχονται τεκμήρια ότι η θεωρητική έννοια της κεφαλής έχει επίδραση στην επεξεργασία των συνθέτων, καθώς η εστίαση της προσοχής επηρεάζεται από και επικεντρώνεται στο συστατικό που λειτουργεί ως κεφαλή, έπειτα από την σιωπηρή ανάγνωση ολόκληρης της λέξης. Τρίτον, ως προς την επίδραση της κεφαλής στα παρατακτικά σύνθετα της ΚΝΕ, από την έρευνά μας προκύπτει ότι ένας διαχωρισμός ανάμεσα στα ονοματικά και τα επιθετικά παρατακτικά σύνθετα, με τα πρώτα να συμπεριφέρονται όπως τα υποτακτικά, ενώ τα δεύτερα να εμφανίζουν μια διευκόλυνση στην ανάγνωση ως απόρροια της ύπαρξης δύο κεφαλών. Στην τελευταία αυτή περίπτωση, ίσως η ανάγνωση επηρεάζεται από την δυνατότητα εναλλαγής της σειράς των όρων ορισμένων επιθετικών παρατακτικών συνθέτων (π.χ. μακρόστενος ~ στενόμακρος), αλλά αυτό είναι κάτι που απαιτεί περαιτέρω μελέτη.
Reading coordinative compound words is investigated in neglect dyslexia in order to assess the influence of ‘headedness’. While the majority of Modern Greek compounds, the so called ‘subordinative compounds’, comply with Williams’ (1981) ‘Righthand Head Rule’ (e.g. elafo-kinigos ‘deer-hunter’), coordinative compounds do not demonstrate clear headedness (e.g. alato-pipero ‘salt-pepper’). Some theoretical morphologists argue that none of the two constituents serves as the basis of the formation, neither morphologically nor semantically (Ralli, 2005: 174), others attest that the formations’ head coincides with their second constituent, because of the second’s constituent inflectional suffix which determine the gender, number and case of the compound (Guevara & Scalise, 2008), while others argue that coordinative compounds are double-headed (Kageyama, 2009). In this context, the theoretical morphology’s question regarding the position of the head in coordinative [NN] and [AA] Greek compounds will be addressed, as well as the question about the function of headedness in compounds’ retrieval and processing by patients suffering from neglect dyslexia. When reading compounds in neglect dyslexia, a common finding is that patients seem to respect the boundaries between the first and the second component (Behrmann et al., 1990). Moreover, Semenza et al. (2011) ascertained that left-headed Italian compounds are read better than right-headed compounds, indicating that the appearance of head on the first constituent, counterbalance the deficit at the processing of this first constituent. According to these findings, it seems reasonable to hypothesize that, if coordinative compounds are indeed headless or double-headed, patients with neglect dyslexia will make fewer mistakes in reading their left constituents compared to subordinative compounds, which have a clear head. A female 79-year old patient, who suffered RH damage and was affected by left-sided neglect dyslexia as diagnosed based on BELLS test, had to read 32 subordinative [NN] and [AA] compounds (e.g. domatosalata ‘tomato-salad’ and piknokatikimenos ‘densely populated’ respectively) and 32 coordinative [NN] and [AA] compounds (e.g. psomotiri ‘bread-cheese’ and glikopikros ‘sweet-bitter’ respectively). Compounds and their constituents were matched for frequency, familiarity, imageability, age of acquisition and orthographic neighbors. Patient performed significantly fewer substitution and omission errors on the left constituent of coordinative compounds when reading compound adjectives (x²= 3.970, p < 0.05), but the same amount of errors in subordinative and coordinative compounds when reading compound nouns. The contribution of the study can be summarized in the following points: First, it showed that lexical factors can influence selective attention to a great extent. Second, it showed that the theoretical concept of headedness does have a processing effect, with the head capturing more attention after implicit reading of the whole word. Third, as for headedness in Greek coordinative compounds, the study revealed a dissociation depending on grammatical class (adjectival vs. nominal compounds) with adjectival coordinative compounds behaving as double-headed while nominal coordinative compounds patterning with subordinative ones. A key factor here might be the interchangeable word order that characterizes adjectival coordinative compounds (e.g makrostenos ‘long-narrow’ ~ stenomakros ‘narrow-long’), but this is something that requires further research.

Left unilateral spatial neglect is the most frequent and disabling neuropsychological syndrome caused by lesions to the right hemisphere. Over 50% of right-brain-damaged patients show neglect, while right neglect after left-hemispheric damage is less frequent. Neglect patients are unable to orient towards the side contralateral to the lesion, to detect and report sensory events in that portion of space, as well as to explore it by motor action. Neglect is a multicomponent disorder, which may involve the contralesional side of the body or of extra-personal physical or imagined space, different sensory modalities, specific domains (e.g. ‘neglect dyslexia’), and worsen sensorimotor deficits. Neglect is due to higher-order unilateral deficits of spatial attention and representation, so that patients are not aware of contralesional events, which, however, undergo a substantial amount of unconscious processing up to the semantic level. Cross-modal sensory integration is also largely preserved. Neglect is primarily a spatially specific disorder of perceptual consciousness. The responsible lesions involve a network including the fronto-temporo-parietal cortex (particularly the posterior-inferior parietal lobe, at the temporo-parietal junction), their white matter connections, and some subcortical grey nuclei (thalamus, basal ganglia). Damage to primary sensory and motor regions is not associated to neglect. A variety of physiological lateralized and asymmetrical sensory stimulations (vestibular, optokinetic, prism adaptation, motor activation), and transcranial electrical and magnetic stimulations, may temporarily improve or worsen neglect. Different procedures have been successfully developed to rehabilitate neglect, using both ‘top down’ (training the voluntary orientation of attention) and ‘bottom up’ (the above-mentioned stimulations) approaches.

The themes included in this book, involving active collaborators, confirm the need to fill the gap for health and education professionals. By presenting information from reliable sources and step-by-step activities to implement interventions with visual and phonological, dysgraphic, dyscalculic and ADHD dyslexics, it aims to provide effective procedures for screening, evaluation, intervention selection and monitoring. Issues examined such as visual dyslexia analyze developmental dyslexia as a condition that has been associated with motor difficulties, but little is known about what is shared or differentiated between its subtypes. The assessment of dyscalculia, which is often neglected, is clearly presented providing a tool for assessment and addressing family or support networks of students with Learning Disorders deepens our understanding Understanding the development of the school allows us to recognize specific situations that are often ignored. All activities have multisensory instruction, that is, students use more than one sense at a time, and multisensory instruction offers students more than one way to make connections and learn concepts The contributors to this book are active researchers in the teachinglearning process and the objective was to expand information on Learning Disorders with content chosen in a selective manner, giving relevance to the multidisciplinary team.

This chapter discusses localized cognitive functions. The functions ascribed to the dominant, usually left, cerebral hemisphere show much more clear-cut laterality than those associated with the so-called minor hemisphere. This applies particularly to spoken language. This chapter discusses aspects of normal and abnormal language function in the framework of contemporary cognitive neuroscience with descriptions of the classic post-stroke variants of aphasia (Broca’s, Wernicke’s, conduction, etc.) although these are rarely seen in the context of neurodegenerative diseases. There is also a description of disorders of written language (the dyslexias and dysgraphias), of calculation (acalculia), and of higher-order motor control (apraxia). This is followed by descriptions of the syndromes associated with disturbed right hemisphere functions: neglect phenomena, dressing and constructional apraxia, and complex visuoperceptual disorders (agnosias). Each cognitive syndrome is placed in the context of its neural basis, disorders which affect the ability and methods of assessment at the bedside and using neuropsychological tasks.

This chapter analyses David Assaf's The Regal Way: The Life and Times of R. Israel of Ruzhin. Here, Assaf draws upon an astonishing array of sources, several of which were hitherto unknown or neglected, and provides the first critical historical account of the life of the hasidic leader Israel of Ruzhin (1796–1850) and his court. R. Israel, dyslexic and uneducated, assumed hasidic leadership at the age of 16 on the strength of his personality and distinguished yikhus. R. Israel's accession on the strength of yikhus — prestige derived through the scholarly, mystical, or economic achievements of one's forebears and living family members — at so young an age and with so few scholarly qualifications marked, according to Assaf, the triumph of the principle of hereditary succession in Ukrainian hasidism. Throughout his description, Assaf attempts to navigate between the cynical denunciations of R. Israel's ostentatious lifestyle by contemporary maskilim (enlightened reformers) and the rationalizations of R. Israel and his followers.