1,720,985 research outputs found
Predicting the reading profiles of different neurodegenerative impairments: The case of Alzheimer's disease, Progressive Primary Aphasia and Posterior Cortical Atrophy
No full textDeficit di lettura nelle patologie neurodegenerative: malattia di Alzheimer, afasia primaria progressiva ed atrofia corticale posteriore a confronto
No full textForme diverse di malattie neurodegenerative possono manifestarsi con profili cognitivi diversi, verosimilmente in relazione alle aree cerebrali interessate dalla patologia.
Come esempi di patologia a diversa espressione cognitiva, abbiamo studiato le abilità di lettura in pazienti affetti da malattia di Alzheimer (AD, n=19), da afasia primaria progressiva (PPA, n=6: 4 con variante logopenica, 1 con variante semantica e 1 con prevalente anomia) e da atrofia corticale posteriore (PCA, n=4). Come gruppo di controllo sono stati esaminati 34 soggetti esenti da patologia neurologica e di pari età e scolarità.
Le prove sperimentali utilizzate consistevano in compiti di lettura (Toraldo et al., 2006) e ripetizione di parole e non-parole, lettura di parole con accento piano o sdrucciolo test di decisione lessicale orale e scritta.
Nei compiti di decisione lessicale orale i soggetti con AD hanno ottenuto prestazioni significativamente inferiori rispetto ai soggetti con PCA, mentre il profilo opposto è emerso per la prova di decisione lessicale scritta. La lettura di non-parole è risultata significativamente peggiore rispetto a quella di parole sia nei soggetti con AD che in quelli con PPA.
L’analisi per casi singoli ha permesso di individuare la presenza di dislessia fonologica nel 50% (n=2) dei casi con PCA, in una percentuale molto minore nei casi con AD (15.8%) e con PPA (16.7%). In un unico caso affetto da AD il disturbo di lettura è stato classificato come dislessia superficiale.
Profili diversi delle abilità di lettura sono stati osservati in tutti i gruppi, senza quindi poter identificare alcun profilo fortemente diagnostico. In generale i pazienti con PCA risultano maggiormente compromessi rispetto agli altri due gruppi. Inoltre, peggiori prestazioni in modalità visiva sembrano indirizzare verso una diagnosi di PCA, mentre peggiori prestazioni in modalità orale potrebbero orientare verso una diagnosi di AD. Pur con i limiti dovuti alla scarsa numerosità del campione, è ipotizzabile il ruolo di una critica localizzazione posteriore della patologia neurodegenerativa, più focalizzata ed evidente nei casi di PCA, a cui, negli stessi casi, si associa uno specifico deficit visuospaziale.
Bibliografia
Toraldo A. et al. Reading disorders in a language with shallow orthography: A multiple single-case study in Italian. Aphasiology, 20: 823-850, 200
Reading in neurodegenerative diseases: different impairments?
No full textIt is well known that neurodegenerative diseases may affect different areas of the brain, thereby giving rise to different patterns of cognitive deficits. We investigated reading performance in patients suffering from Alzheimer’s Disease (AD, n=19), Primary Progressive Aphasia (PPA, n=6: 4 logopenic, 1 semantic and 1 purely anomic aphasia) and Posterior Cortical Atrophy (PCA, n=4), plus a control group of healthy subjects (n=20). Participants were examined by means of tasks of auditory and visual lexical decision, word and non-word reading, reading trisyllabic words with unpredictable stress position (Toraldo et al, 2006) and word and non-word repetition. The lexical decision tasks proved relevant to differentiate AD and PCA patients, the former being disproportionately impaired in the auditory task while the opposite pattern emerged in the latter. Non-word reading was more impaired with respect to word reading in both AD and PPA patients. A multiple single case analysis of reading tasks identified phonological dyslexia in two out of four PCA participants (50%), much less so in AD (15.8%) and PPA (16.7%). Surface dyslexia occurred in one AD case only. We suggest that these results may be related to the different distribution of pathological changes in the three groups
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Reading impairment in neurodegenerative diseases:A multiple single-case study
No full textBackground: Reading impairment is frequently associated with neurodegenerative diseases, such as Alzheimer Disease (AD), Primary Progressive Aphasia (PPA) and Posterior Cortical Atrophy (PCA). Notwithstanding the clinical relevance of reading processes in these impairments, only a relative paucity of studies has been already published on this topic.
Aims: We investigated the reading impairment in patients suffering from different types of neurodegenerative diseases. In the light of a marked variability in pathological changes affecting brain areas potentially relevant to reading, it could be hypothesized that these neurodegenerative conditions may lead to different patterns of reading impairment.
Methods and procedures: Three groups of patients (AD, PPA, and PCA) and a control sample of neurologically healthy participants were examined with five tasks to test the ability to read and to repeat words and nonwords, as well as with an auditory and visual lexical decision task.
Outcomes & Results: No specific pattern emerged as strongly diagnostic of a specific degenerative disease. Overall, AD and PPA patients were significantly more impaired in reading nonwords than words. A lexical decision impairment in the visual modality appears to be related to PCA, while a similar deficit in the auditory modality is more suggestive of AD. A multiple single-case analysis on the reading performance was run to identify the distribution of different kinds of dyslexia: phonological dyslexia occurred in 50% of patients affected by PCA: it occurred less often in patients affected by AD (15.8%) and PPA (16.7%). Surface dyslexia occurred only in one case of AD. Age of acquisition was predictive of the reading performance for AD patients, but not for PCA and PPA patients.
Conclusions: Phonological dyslexia predominates in PCA; Surface dyslexia only occurred in one AD patient. Impairment in reading nonwords was predominantly associated with AD and PPA cases. Impairment in visual lexical decision was associated with PCA, whereas a lexical decision deficit in the auditory modality emerged in AD. Data indicate the importance of extensive testing reading and input lexical abilities in neurodegenerative impairment
- …
