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Aging, even when healthy, involves changes in cognitive functioning that can gradually affect the everyday activities and well-being of older people. Reading, which requires the integrity of several functions and their integration, is important to maintaining high cognitive and emotional stimulation over time. Our study aimed to investigate whether reading ability declines with aging. To explore also why reading would decline, we explored the changes in the performance of visual and attention tasks. A group of 58 neurologically healthy older people aged from 65 to 75 underwent neuropsychological assessment to investigate their global cognitive functioning, reading skills, crowding, and attention components. We found a decline in reading abilities as a function of aging (ß = 0.34, p < 0.05). We did not find an increase in crowding or difficulties in visual acuity. Furthermore, we found no decline with age in tasks of simple reaction times, visuospatial attention, and other single components of attention. Interestingly, we instead found a worsening with age in the Symbol Digit Modalities Test (ß = -0.26, p < 0.05), involving attention, working memory, and processing speed, which explains part of the reading decline. Our results suggest that task complexity is a fundamental aspect to account for aging changes.
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Studies in the literature have shown how the preference towards local or global processing can vary according to different characteristics of the stimuli involved, such as stimulus type and stimulus time duration. In the present study, we investigated whether letters and faces undergo similar or different global/local processing and the attentional mechanisms that might be linked to eventual differences. We used hierarchical, congruent, and incongruent letters and faces in different time conditions (180 and 500 ms) and we conducted three different experiments. The results of Experiment 1 showed that with stimuli shown for 180 ms, letters are processed more efficiently at the local level, with an inversion of the global interference effect. Conversely, faces are still processed more efficiently at the global level, with evidence of global advantage and global interference. The results of Experiment 2 showed that when the same stimuli are presented for longer (500 ms), they are still processed differently. Indeed, we observed faster local processing for letters but still a tendency, even if not significant, toward a global processing advantage for faces. Moreover, the cue-size effect, i.e., the ability to modulate visual focal attention based on the characteristics of the cue, was measured. In Experiment 3, the cue-size effect showed a statistically significant correlation with the local processing advantage for letters but not for faces. We conclude that during the almost automatic processing of letters it is possible to modulate focal attention on the basis of the task, narrowing the field of visual attention during the local task and neglecting the global stimulus. Conversely, during face processing, the holistic mechanism tends to prevail over focal attention modulation skills, even when it is explicitly required to focus on the local stimulus.
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In the present investigation we adopted the Rapid Parallel Visual Presentation Paradigm with the aim of studying the timing of parafoveal semantic processing. The paradigm consisted in the simultaneous presentation of couple of words, one in fovea (W1) and one in parafovea (W2). In three experiments, we manipulated word frequency, semantic relatedness between the two words and the effect of stimulus duration (150, 100, 50 ms). Accuracy on W2 was higher when W1 and W2 were both of high-frequency and when they were semantically related. W1 reading times were faster when both words were highly-frequent but only when the two words were semantically related (150 ms); when W2 was highly frequent and semantically related to the foveal word (100 ms). When the stimuli were presented for 50 ms, the reading times were reduced when W1 was highly frequent and, crucially, in case of a semantic relation between the two words. Our results suggest that it is possible to extract semantic information from the parafovea very fast (within 100 ms) and in parallel to the processing of the foveal word, especially when the cognitive load required for the latter is reduced, as is the case for high-frequency words. We discuss the resulting data in terms of word recognition and eye movements' models.
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Objective: Right brain-damaged patients may show omissions and/or additional marks in target cancellation. The latter is classified as perseverative behavior and has been attributed to defective response inhibition or attentional disengagement deficit. This study aimed at (a) verifying that consecutive (immediate) and return (temporally distant) motor perseverations could be due to different mechanisms; (b) investigating the relationships among different types of perseveration (e.g., consecutive, return, scribble), spatial neglect and the impairment in specific components of executive functioning. Method: Seventeen right brain-damaged patients underwent letter, star, bell, and apple cancellation tasks. A global index for each type of perseveration found and Mean Position of Hits, as a neglect index, were calculated. The following components of executive functioning were evaluated: motor programming (Frontal Assessment Battery [FAB] subtest), inhibitory control FAB, interference sensitivity (FAB and Stroop color-word interference test), set-shifting (Weigl sorting test, Phonemic/semantic alternate fluencies), and working memory (Backward Digit span). Results: Ten patients out of 17 showed some degree of perseveration. Regularized linear regression analyses demonstrated that interference sensitivity and Stroop test performances were related to return perseverations and backward digit to scribble ones. No significant relationships were found for consecutive perseverations and between neglect and any type of perseverations. Conclusions: The present study showed that return perseverations might have a distinct etiology from consecutive ones, being related to an inability to update and shift between action programs according to the visual stimuli. A finer classification of perseverations could help in unveiling the neuropsychological mechanisms underlying each type of behavior. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
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Lesiones Encefálicas/fisiopatología , Lateralidad Funcional , Trastornos de la Percepción/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Lesiones Encefálicas/psicología , Isquemia Encefálica/fisiopatología , Isquemia Encefálica/psicología , Neoplasias Encefálicas/fisiopatología , Neoplasias Encefálicas/psicología , Corteza Cerebral , Función Ejecutiva , Femenino , Humanos , Hemorragias Intracraneales/fisiopatología , Hemorragias Intracraneales/psicología , Masculino , Memoria a Corto Plazo , Persona de Mediana Edad , Pruebas Neuropsicológicas , Trastornos de la Percepción/psicología , Estudios Prospectivos , Desempeño Psicomotor/fisiología , Test de StroopRESUMEN
Acquired Neglect Dyslexia is often associated with right-hemisphere brain damage and is mainly characterized by omissions and substitutions in reading single words. Martelli et al. proposed in 2011 that these two types of error are due to different mechanisms. Omissions should depend on neglect plus an oculomotor deficit, whilst substitutions on the difficulty with which the letters are perceptually segregated from each other (i.e., crowding phenomenon). In this study, we hypothesized that a deficit of focal attention could determine a pathological crowding effect, leading to imprecise letter identification and consequently substitution errors. In Experiment 1, three brain-damaged patients, suffering from peripheral dyslexia, mainly characterized by substitutions, underwent an assessment of error distribution in reading pseudowords and a T detection task as a function of cue size and timing, in order to measure focal attention. Each patient, when compared to a control group, showed a deficit in adjusting the attentional focus. In Experiment 2, a group of 17 right-brain-damaged patients were asked to perform the focal attention task and to read single words and pseudowords as a function of inter-letter spacing. The results allowed us to confirm a more general association between substitution-type reading errors and the performance in the focal attention task.
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Introduction: Personal neglect (PN) refers to a form of hemi-inattention toward the contralesional body space and it usually occurs following a right brain lesion. Recent studies suggest that PN indicates a disorder of body representation. Specifically, patients with PN show difficulties in identifying differences between left and right hands and have an altered visuospatial body map, which is associated with disrupted mental body representations. However, the metric representation of the body, and in particular the hands, has not been systematically addressed in patients showing this form of neglect. Method: In the present study, we have investigated this representation by testing the perceived hands' width of 11 hemiplegic patients with right hemisphere cerebral lesions (5 with PN) and 12 healthy controls on a judgment of passability task. Patients and controls were asked to imagine inserting their hand (left and right) through a series of vertical apertures of different sizes and to judge whether their hand could fit through. Due to the heterogeneity of the data, both parametric and non-parametric approaches were used. Furthermore, additional single-case analyses were conducted. Results: Study findings showed that patients with PN showed a significant underestimation of the left hand compared with their right hand. In contrast, whilst the right hand was equally distorted in both patients' groups, the hemiplegic patients with no evidence of PN tended to perceive the affected hand as larger than their ipsilesional one. Conclusions: In line with the literature, our findings confirm an underlying distorted body representation following right brain damage. However, for the first time, we report both a quantitative and qualitative difference in impact of hemiplegia and PN on body representation of the contralesional body space.
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Corteza Cerebral/patología , Corteza Cerebral/fisiopatología , Lateralidad Funcional/fisiología , Mano , Hemiplejía/fisiopatología , Trastornos de la Percepción/fisiopatología , Percepción del Tamaño/fisiología , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
This study explores whether semantic processing in parafoveal reading in the Italian language is modulated by the perceptual and lexical features of stimuli by analyzing the results of the rapid parallel visual presentation (RPVP) paradigm experiment, which simultaneously presented two words, with one in the fovea and one in the parafovea. The words were randomly sampled from a set of semantically related and semantically unrelated pairs. The accuracy and reaction times in reading the words were measured as a function of the stimulus length and written word frequency. Fewer errors were observed in reading parafoveal words when they were semantically related to the foveal ones, and a larger semantic facilitatory effect was observed when the foveal word was highly frequent and the parafoveal word was short. Analysis of the reaction times suggests that the semantic relation between the two words sped up the naming of the foveal word when both words were short and highly frequent. Altogether, these results add further evidence in favor of the semantic processing of words in the parafovea during reading, modulated by the orthographic and lexical features of the stimuli. The results are discussed within the context of the most prominent models of word processing and eye movement controls in reading.
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The human brain has a remarkable capacity to focus processing resources based on the features and the relevance of the task at hand. The two cerebral hemispheres contribute differentially to this capacity, with the left hemisphere linguistic and right hemisphere visuo-spatial abilities each offering unique contributions. For example, previous research has established that healthy participants set the subjective mid-point of written sentences more leftwards of center, compared to unpronounceable letter strings or simple lines. Remarkably, patients with right hemisphere damage exhibiting unilateral spatial neglect also show this pattern, even though, as well known in the literature, they tend toward a rightward- bias for non-linguistic stimuli. This evidence suggests that the leftward bias for sentential material is due to linguistic, mainly left-hemisphere mediated processes, which are largely unimpaired in right brain-damaged patients, and intact in heathy participants. To test this hypothesis, we compared sentence bisection performance to that of letter strings and simple lines in left brain-damaged patients (with and without aphasia). If the larger leftward bias in the bisection of sentential material is based on linguistic processes, then the left brain-damaged patients should show a reduction or absence of a leftward bias in sentence bisection. We tested twenty-four left brain-damaged patients (12 with aphasia and 12 without aphasia), and 24 age-matched elderly participants (patients and controls were all right-handed). Participants were asked to bisect 240 stimuli, comprising: (i) affirmative and interrogative clauses, (ii) sentences with lexical and syntactic violations, (iii) letter strings and (iv) simple lines. As predicted, neurologically intact participants showed larger leftward biases in bisecting written readable sentences compared to strings of letters. In contrast, the left hemispheredamaged patients (both with and without aphasia) showed no differences in bisecting sentences and letter strings or lines. These findings indicate that the larger leftward bias exhibited by healthy participants in the bisection of sentences is likely due to ortho-phonological coding taking place implicitly during the bisection task. This ortho-phonological coding is impaired with left brain damage - also in absence of apparent aphasia - leading to the left hemispheredamaged patients showing a reduced leftward bias in sentence bisection. These findings support the hypothesis that the leftward bias in the bisection of written sentences is the result of ortho-phonological influences rather than visual-spatial biases.
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Afasia/fisiopatología , Lateralidad Funcional/fisiología , Reconocimiento Visual de Modelos/fisiología , Trastornos de la Percepción/fisiopatología , Psicolingüística , Lectura , Percepción Espacial/fisiología , Accidente Cerebrovascular/fisiopatología , Anciano , Anciano de 80 o más Años , Afasia/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastornos de la Percepción/etiología , Accidente Cerebrovascular/complicacionesRESUMEN
Our motor behavior and interactions with the external world are mediated by many spatial systems. This study investigated the absence of visual control of performance in the manual line bisection task, with the goal of teasing apart the role of the motor component of the visuomotor spatial system. Results show a rightward bias when right-handed individuals bisect lines using their right hand. This effect is traced back to a motor-spatial representation of space centered on the dominant hand. This finding was replicated and further explored in 4 experiments, with the same "open loop" bisection procedure. The mechanism underlying the rightward bias does not interact with the visuo-perceptual processing involved in visual illusions of extension. Besides, this bias no longer appears when perceptual judgments of prebisected lines are required, and is substantially reduced when the influence of visual feedback is minimized by a ballistic movement. The emergence of a leftward shift in left-handed individuals, when using their left hand, confirms the hypothesis of a dominant-hand-centered motor-spatial bias. Finally, when the lines to be bisected are placed to the left or to the right of the midsagittal plane of the participants' trunk, the error shifts overall toward the side of displacement of the stimulus, both in left- and right-handers, independent of the bisection bias, which does not appear related to the egocentric position of the stimulus. We reexamined the spatial biases occurring both in healthy (i.e., pseudoneglect) and neurological (i.e., neglect) populations, by emphasizing the integration mechanism of different spatial coordinate systems. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
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Lateralidad Funcional/fisiología , Ilusiones/fisiología , Desempeño Psicomotor/fisiología , Percepción Espacial/fisiología , Adulto , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
Expert readers have been repeatedly reported to misperceive the centre of visual stimuli, shifting systematically to the left the bisection of any lines (pseudoneglect) while showing a cross-over effect while bisecting different types of orthographic strings (Arduino et al., 2010, Neuropsychologia, 48, 2140). This difference has been attributed to asymmetrical allocation of attention that visuo-verbal material receives when lexical access occurs (e.g., Fischer, 2004, Cognitive Brain Research, 4, 163). The aim of this study was to further examine which visual features guide recognition of potentially orthographic materials. To disentangle the role of orthography, heterogeneity, and visuo-perceptual discreteness, we presented Italian unimpaired adults with four experiments exploiting the bisection paradigm. The results showed that a cross-over effect emerges in most discrete strings, especially when their internal structure, that is being composed of heterogeneous elements, is suggestive of orthographically relevant material. Interestingly, the cross-over effect systematically characterized the processing of letter strings (Experiment 2) and words (Experiments 3 and 4), whether visually discrete or not. Overall, this pattern of results suggests that neither discreteness nor heterogeneity per se are responsible for activating visual scanning mechanisms implied in text exploration, although both contribute to increasing the chance of a visual stimulus undergoing a perceptual analysis dedicated to pre-lexical processing.
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Atención/fisiología , Lenguaje , Lectura , Adulto , Femenino , Humanos , Masculino , Reconocimiento Visual de Modelos , Adulto JovenRESUMEN
Increasing evidence supports the contribution of both biological and cultural factors to visuospatial processing. The present study adds to the literature by exploring the interplay of perceptual and linguistic mechanisms in determining visuospatial asymmetries in adults (Experiment 1) and children (Experiment 2). In particular, pre-schoolers (3 and 5 year-olds), school-aged children (8 year-old), and adult participants were required to bisect different types of stimuli, that is, lines, words, and figure strings. In accordance with the literature, results yielded a leftward bias for lines and words and a rightward bias for figure strings, in adult participants. More critically, different biases were found for lines, words, and figure strings in children as a function of age, reflecting the impact of both cultural and biological factors on the processing of different visuospatial materials. Specifically, an adult-like pattern of results emerged only in the older group of children (8 year-old), but not in pre-schoolers. Results are discussed in terms of literacy, reading habits exposure, and biological maturation.
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Desarrollo Infantil , Cultura , Percepción Espacial , Percepción Visual , Adulto , Niño , Desarrollo Infantil/fisiología , Preescolar , Femenino , Lateralidad Funcional , Humanos , Masculino , Psicolingüística , Pruebas Psicológicas , Psicología Infantil , Lectura , Adulto JovenRESUMEN
The bisection of lines positioned radially (with the two ends of the line close and far, with respect to the participant's body) has been less investigated than that of lines placed horizontally (with their two ends left and right, with respect to the body's midsagittal plane). In horizontal bisection, patients with left neglect typically show a rightward bias for both lines and words, greater with longer stimuli. As for radial bisection, available data indicate that neurologically unimpaired participants make a distal error, while results from right-brain-damaged patients with left spatial neglect are contradictory. We investigated the bisection of radially oriented words, with the prediction that, during bisection, linguistic material would be recoded to its canonical left-to-right format in reading, with the performance of neglect patients being similar to that for horizontal words. Thirteen right-brain-damaged patients (seven with left spatial neglect) and fourteen healthy controls were asked to manually bisect 40 radial and 40 horizontal words (5-10 letters), and 80 lines, 40 radial and 40 horizontal, of comparable length. Right-brain-damaged patients with spatial neglect exhibited a proximal bias in the bisection of short radial words, with the proximal part corresponding to the final right part of horizontally oriented words. This proximal error was not found in patients without neglect and healthy controls. For bisection, short radial words may be recoded to the canonical orthographic horizontal format, unveiling the impact of left neglect on radially oriented stimuli.
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Lesiones Encefálicas/complicaciones , Lesiones Encefálicas/psicología , Lateralidad Funcional , Trastornos de la Percepción/complicaciones , Trastornos de la Percepción/psicología , Lectura , Percepción Espacial , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Estimulación LuminosaRESUMEN
Crowding is a phenomenon that characterizes normal periphery limiting letter identification when other letters surround the signal. We investigated the nature of the reading limitation of crowding by analyzing eye-movement patterns. The stimuli consisted of two items varying across trials for letter spacing (spaced, unspaced and increased size), lexicality (words or pseudowords), number of letters (4, 6, 8), and reading modality (oral and silent). In Experiments 1 and 2 (oral and silent reading, respectively) the results show that an increase in letter spacing induced an increase in the number of fixations and in gaze duration, but a reduction in the first fixation duration. More importantly, increasing letter size (Experiment 3) produced the same first fixation duration advantage as empty spacing, indicating that, as predicted by crowding, only center-to-center letter distance, and not spacing per se, matters. Moreover, when the letter size was enlarged the number of fixations did not increase as much as in the previous experiments, suggesting that this measure depends on visual acuity rather than on crowding. Finally, gaze duration, a measure of word recognition, did not change with the letter size enlargement. No qualitative differences were found between oral and silent reading experiments (1 and 2), indicating that the articulatory process did not influence the outcome. Finally, a facilitatory effect of lexicality was found in all conditions, indicating an interaction between perceptual and lexical processing. Overall, our results indicate that crowding influences normal word reading by means of an increase in first fixation duration, a measure of word encoding, which we interpret as a modulatory effect of attention on critical spacing.
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Atención/fisiología , Movimientos Oculares/fisiología , Reconocimiento Visual de Modelos/fisiología , Lectura , Adulto , Femenino , Fijación Ocular/fisiología , Humanos , Masculino , Adulto JovenRESUMEN
Unilateral spatial neglect (USN) is a common neuropsychological disorder following a right-sided brain lesion. Although USN is mostly characterized by symptoms involving the left hemispace, other symptoms are not left lateralized. Recently, it was shown that patients with neglect dyslexia, a reading disturbance that affects about 40% of USN patients, manifest a non-lateralized impairment of eye movement behaviour in association with their reading deficit when they read aloud and perform non-verbal saccadic tasks (Primativo et al., 2013). In the present paper, we aimed to demonstrate that the eye movement impairment shown by some USN patients reflects a more general oculo-motor disorder that is not confined to orthographic material, the horizontal axis or constrained saccadic tasks. We conjectured that inaccurate oculo-motor behaviour in USN patients indicates the presence of a reading deficit. With this aim we evaluated 20 patients, i.e., 10 right-sided brain-damaged patients without neglect and 10 patients affected by USN. On the basis of the patients' eye movement patterns during a scene exploration task, we found that 4 out of the 10 USN patients presented an abnormal oculo-motor pattern. These same four patients (but not the others) also failed in performing 5 different saccadic tasks and produced neglect dyslexia reading errors in both single words and texts. First, we show that a large proportion of USN patients have inaccurate eye movement behaviour in non-reading tasks. Second, we demonstrate that this exploratory deficit is predictive of the reading impairment. Thus, we conclude that the eye movement deficit prevents reading and impairs the performance on many other perceptual tests, including scene exploration. The large percentage of patients with impaired eye-movement pattern suggests that particular attention should be paid to eye movement behaviour during the diagnostic phase in order to program the best rehabilitation strategy for each patient.
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Dislexia/etiología , Lateralidad Funcional/fisiología , Trastornos de la Motilidad Ocular/etiología , Trastornos de la Percepción/complicaciones , Percepción Espacial/fisiología , Anciano , Anciano de 80 o más Años , Atención , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Trastornos de la Motilidad Ocular/diagnóstico , Trastornos de la Percepción/patología , Tiempo de Reacción , Estadísticas no Paramétricas , Conducta VerbalRESUMEN
In line bisection right-brain-damaged patients with left spatial neglect show a rightward deviation, with respect to the line's physical center. In word bisection ortho-phonological features of the stimulus' final (right-sided) part modulate performance of both patients and healthy participants (Veronelli, Vallar, Marinelli, Primativo, & Arduino, 2014). We investigated the role of linguistic factors in sentence bisection, in patients with and without neglect, and control participants. The effects of information in the right-sided part of the sentence (Experiment #1), and of lexical and syntactic violations (Experiment #2) were assessed. Neglect patients showed an overall rightward bias, larger than those of patients without neglect and controls. The neglect patients' bias was modulated by stimulus type, decreasing from lines, to letter strings and to all types of sentences. In sum, in visuo-manual sentence bisection a basic linguistic mechanism, such as sentence readability, brings about a more leftward appreciation of the stimulus, reducing the neglect patients' rightward bias.
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Infarto Cerebral/fisiopatología , Dislexia/fisiopatología , Lateralidad Funcional , Lingüística , Trastornos de la Percepción/fisiopatología , Procesamiento Espacial , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Infarto Cerebral/complicaciones , Infarto Cerebral/diagnóstico , Dislexia/etiología , Femenino , Humanos , Masculino , Examen Neurológico , Trastornos de la Percepción/etiología , LecturaRESUMEN
Right-brain-damaged patients with left unilateral spatial neglect typically set the mid-point of horizontal lines to the right of the objective center. By contrast, healthy participants exhibit a reversed bias (pseudoneglect). The same effect has been described also when bisecting orthographic strings. In particular, for this latter kind of stimulus, some recent studies have shown that visuo-perceptual characteristics, like stimulus length, may contribute to both the magnitude and the direction bias of the bisection performance (Arduino et al. in Neuropsychologia 48:2140-2146, 2010). Furthermore, word stress was shown to modulate reading performances in both healthy participants, and patients with left spatial neglect and neglect dyslexia (Cubelli and Beschin in Brain Lang 95:319-326, 2005; Rusconi et al. in Neuropsychology 18:135-140, 2004). In Experiment I, 22 right-brain-damaged patients (11 with left visuo-spatial neglect) and 11 matched neurologically unimpaired control participants were asked to set the subjective mid-point of word letter strings, and of lines of comparable length. Most patients exhibited an overall disproportionate rightward bias, sensitive to stimulus length, and similar for words and lines. Importantly, in individual patients, biases differed according to stimulus type (words vs. lines), indicating that at least partly different mechanisms may be involved. In Experiment II, the putative effects on the bisection bias of ortho-phonological information (i.e., word stress endings), arising from the non-neglected right hand side of the stimulus were investigated. The orthographic cue induced a rightward shift of the perceived mid-point in both patients and controls, with short words stressed on the antepenultimate final sequence inducing a smaller rightward deviation with respect to short words stressed on the penultimate final sequence. In conclusion, partly different mechanisms, including both visuo-spatial and lexical factors, may support line and word bisection performance of right-brain-damaged patients with left spatial neglect, and healthy participants.
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Lesiones Encefálicas/fisiopatología , Encéfalo/fisiopatología , Lateralidad Funcional/fisiología , Trastornos de la Percepción/psicología , Lectura , Adolescente , Anciano , Lesiones Encefálicas/psicología , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Trastornos de la Percepción/fisiopatología , Desempeño Psicomotor/fisiología , Percepción Espacial/fisiologíaRESUMEN
In the present study we investigated how the vocabulary size of English-Italian bilinguals affects reading aloud in Italian (L2) modulating the reader's sensitivity to lexical aspects of the language. We divided adult bilinguals in two groups according to their vocabulary size (Larger - LV, and smaller - SV), and compared their naming performance to that of native Italian (NI) readers. In Experiment 1 we investigated the lexicality and word frequency effects in reading aloud. Similarly to NI, both groups of bilinguals showed these effects. In Experiment 2 we investigated stress assignment - which is not predictable by rule - to Italian words. The SV group made more stress errors in reading words with a non-dominant stress pattern compared to the LV group. The results suggest that the size of the reader's L2 lexicon affects the probability of correct reading aloud. Overall, the results indicate that proficient adult bilinguals show a similar sensibility to the statistical and distributional properties of the language as compared to Italian monolinguals.
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Multilingüismo , Lectura , Vocabulario , Adulto , Anciano , Femenino , Humanos , Italia , Masculino , Persona de Mediana EdadRESUMEN
Although omission and substitution errors in neglect dyslexia (ND) patients have always been considered as different manifestations of the same acquired reading disorder, recently, we proposed a new dual mechanism model. While omissions are related to the exploratory disorder which characterizes unilateral spatial neglect (USN), substitutions are due to a perceptual integration mechanism. A consequence of this hypothesis is that specific training for omission-type ND patients would aim at restoring the oculo-motor scanning and should not improve reading in substitution-type ND. With this aim we administered an optokinetic stimulation (OKS) to two brain-damaged patients with both USN and ND, MA and EP, who showed ND mainly characterized by omissions and substitutions, respectively. MA also showed an impairment in oculo-motor behavior with a non-reading task, while EP did not. The two patients presented a dissociation with respect to their sensitivity to OKS, so that, as expected, MA was positively affected, while EP was not. Our results confirm a dissociation between the two mechanisms underlying omission and substitution reading errors in ND patients. Moreover, they suggest that such a dissociation could possibly be extended to the effectiveness of rehabilitative procedures, and that patients who mainly omit contralesional-sided letters would benefit from OKS.
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Brain-damaged patients with right-sided unilateral spatial neglect (USN) often make left-sided errors in reading single words or pseudowords (neglect dyslexia, ND). We propose that both left neglect and low fixation accuracy account for reading errors in neglect dyslexia. Eye movements were recorded in USN patients with (ND+) and without (ND-) neglect dyslexia and in a matched control group of right brain-damaged patients without neglect (USN-). Unlike ND- and controls, ND+ patients showed left lateralized omission errors and a distorted eye movement pattern in both a reading aloud task and a non-verbal saccadic task. During reading, the total number of fixations was larger in these patients independent of visual hemispace, and most fixations were inaccurate. Similarly, in the saccadic task only ND+ patients were unable to reach the moving dot. A third experiment addressed the nature of the left lateralization in reading error distribution by simulating neglect dyslexia in ND- patients. ND- and USN- patients had to perform a speeded reading-at-threshold task that did not allow for eye movements. When stimulus exploration was prevented, ND- patients, but not controls, produced a pattern of errors similar to that of ND+ with unlimited exposure time (e.g., left-sided errors). We conclude that neglect dyslexia reading errors may arise in USN patients as a consequence of an additional and independent deficit unrelated to the orthographic material. In particular, the presence of an altered oculo-motor pattern, preventing the automatic execution of the fine saccadic eye movements involved in reading, uncovers, in USN patients, the attentional bias also in reading single centrally presented words.
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Dislexia/fisiopatología , Movimientos Oculares/fisiología , Trastornos de la Percepción/fisiopatología , Lectura , Anciano , Anciano de 80 o más Años , Atención/fisiología , Femenino , Lateralidad Funcional/fisiología , Humanos , Masculino , Persona de Mediana Edad , Percepción Espacial/fisiología , Campos Visuales/fisiologíaRESUMEN
In 4 naming experiments we investigated how Italian readers assign stress to pseudowords. We assessed whether participants assign stress following distributional information such as stress neighborhood (the proportion and number of existent words sharing orthographic ending and stress pattern) and whether such distributional information affects naming speed. Experiments 1 and 2 tested how readers assign stress to pseudowords. The results showed that participants assign stress on the basis of the pseudowords' stress neighborhood, but only when this orthographic/phonological information is widely represented in the lexicon. Experiments 3 and 4 tested the naming speed of pseudowords with different stress patterns. Participants were faster in reading pseudowords with antepenultimate than with penultimate stress. The effect was not driven by distributional information, but it was related to the stage of articulation planning. Overall, the experiments showed that, under certain conditions, readers assign stress using orthographic/phonological distributional information. However, the distributional information does not speed up pseudoword naming, which is affected by stress computation at the level of the articulation planning of the stimulus. It is claimed that models of reading aloud and speech production should be merged at the level of phonological encoding, when segmental and metrical information are assembled and articulation is planned.