1/29. On some neurobiological and cultural-anthropological aspects of the contralateral-neglect syndrome.Contralateral neglect is a frequent clinical syndrome which can be provoked by lesions in several brain areas (primarily inferior parietal and frontal) and includes symptoms of motor and perceptual negligence of both real and imaginative contralateral hemi-space. Attentional and representative theories attempting to explain neglect are presently the most popular. This paper analyzes two cases of neglect patients. Paying attention especially to their reading defects, a possible role of the persons with contralateral neglect is proposed in the development of script. Other neurobiological and cultural-anthropological questions arising from the analysis of these cases are also discussed.- - - - - - - - - - ranking = 1keywords = reading (Clic here for more details about this article) |
2/29. Unconscious letter discrimination is enhanced by association with conscious color perception in visual form agnosia.Adaptive behavior guided by unconscious visual cues occurs in patients with various kinds of brain damage as well as in normal observers, all of whom can process visual information of which they are fully unaware [1] [2] [3] [4] [5] [6] [7] [8]. Little is known on the possibility that unconscious vision is influenced by visual cues that have access to consciousness [9]. Here we report a 'blind' letter discrimination induced through a semantic interaction with conscious color processing in a patient who is agnosic for visual shapes, but has normal color vision and visual imagery. In seeing the initial letters of color names printed in different colors, it is normally easier to name the print color when it is congruent with the initial letter of the color name than when it is not [10]. The patient could discriminate the initial letters of the words 'red' and 'green' printed in the corresponding colors significantly above chance but without any conscious accompaniment, whereas he performed at chance with the reverse color-letter mapping as well as in standard tests of letter reading. We suggest that the consciously perceived colors activated a representation of the corresponding word names and their component letters, which in turn brought out a partially successful, unconscious processing of visual inputs corresponding to the activated letter representations.- - - - - - - - - - ranking = 1keywords = reading (Clic here for more details about this article) |
3/29. Long-term follow-up of auditory agnosia as a sequel of herpes encephalitis in a child.We report a pediatric patient with auditory agnosia as a sequel of herpes encephalitis. His early development was completely normal. He uttered three words at 12 months old. disease onset was 1 year and 2 months of age. He was discharged from the hospital seemingly with no sequel; however, he could not recover his intelligible words even at age 2 years. He was diagnosed as having auditory agnosia caused by bilateral temporal lobe injury. We began to train him at once, individually and intensively. adult patients with pure auditory agnosia followed by two episodes of temporal lobe infarction have impairment in central hearing but not inner language. Therefore, they can communicate by reading and writing. Moreover, impairment in hearing is not always severe and is often transient. However, despite long-term (more than 15 years) energetic education and almost normal intellectual ability (Performance IQ of Wechsler intelligence Scale for Children-Revised was 91), our patient's language ability was extremely poor. Cerebral plasticity could not work fully on our patient, whose bilateral temporal lobe was severely injured in early childhood. The establishment of a systematic training method in such patients is an urgent objective in this field.- - - - - - - - - - ranking = 1keywords = reading (Clic here for more details about this article) |
4/29. Generalized auditory agnosia with spared music recognition in a left-hander. Analysis of a case with a right temporal stroke.After a right temporoparietal stroke, a left-handed man lost the ability to understand speech and environmental sounds but developed greater appreciation for music. The patient had preserved reading and writing but poor verbal comprehension. Slower speech, single syllable words, and minimal written cues greatly facilitated his verbal comprehension. On identifying environmental sounds, he made predominant acoustic errors. Although he failed to name melodies, he could match, describe, and sing them. The patient had normal hearing except for presbyacusis, right-ear dominance for phonemes, and normal discrimination of basic psychoacoustic features and rhythm. Further testing disclosed difficulty distinguishing tone sequences and discriminating two clicks and short-versus-long tones, particularly in the left ear. Together, these findings suggest impairment in a direct route for temporal analysis and auditory word forms in his right hemisphere to Wernicke's area in his left hemisphere. The findings further suggest a separate and possibly rhythm-based mechanism for music recognition.- - - - - - - - - - ranking = 1keywords = reading (Clic here for more details about this article) |
5/29. Visuospatial deficits with preserved reading ability in a patient with posterior cortical atrophy.Visuospatial deficits are characteristic of posterior cortical atrophy (PCA). A 58 year old woman had progressive dressing apraxia and environmental disorientation but continued to read voraciously. Positron emission tomography revealed hypometabolism of the occipitoparietal regions bilaterally, consistent with PCA. The symptoms suggested predominant dysfunction of the dorsal ("where") stream with abnormalities in visual localization and visuospatial integration; however, the patient also had a less pronounced apperceptive object agnosia. Further analysis of her preserved reading ability was performed. Familiar irregular words were read rapidly, but nonsense words were read slowly in a letter-by-letter fashion. She had a word superiority effect for embedded words and words with obscured letters but had difficulty reading stylized script or printing in unusual fonts. These findings suggested a dissociation between reading routes. Although the patient had a phonological dyslexia, her visuospatial processing was sufficient for access to preserved visual word forms for efficient lexical reading.- - - - - - - - - - ranking = 8keywords = reading (Clic here for more details about this article) |
6/29. Visual agnosia and prosopagnosia in childhood: a prospective case study.Selective impairments in visual processing are well documented in adults but rarely reported in children. The few childhood cases reported are mostly retrospective accounts with little attention paid to developmental, assessment or management issues. We report a prospective case study of a boy with prosopagnosia and visual processing deficits of presumed developmental origin. At the age of 4 years, AL presented with a range of cognitive and visual recognition deficits. Subsequent assessments revealed an evolving pattern in visual recognition and dissociations between developing skills. At the age of 7 AL has impairments in early perceptual analysis, visual organisation and in complex visual processing. Although he can identify facial features and match faces he is unable to recognise familiar faces. His reading and spelling are developing normally. The nature of his deficits and his progress are discussed within a cognitive neuropsychological framework.- - - - - - - - - - ranking = 1keywords = reading (Clic here for more details about this article) |
7/29. Balint's syndrome in a 10-year-old male.A 10-year-old male was referred with difficulties at school. He had particular difficulty with reading long words, following the sequence of text down a page, writing words in the correct order, writing words in line, and copying from the blackboard. He had a history of infective endocarditis complicated by intracerebral haemorrhage at the age of three years. Detailed history taking revealed symptoms typical of 'dorsal stream' pathology, namely a deficit of 'vision for action'. This included a spatial disorder of attention (simultanagnosia), defective hand and foot movements under visual control (optic ataxia), and acquired oculomotor apraxia which are consistent with Balint's syndrome. Strategies were suggested for coping with the symptoms and one year later a distinct improvement in adapting to the disability was found.- - - - - - - - - - ranking = 1keywords = reading (Clic here for more details about this article) |
8/29. writing, calculating, and finger recognition in the region of the angular gyrus: a cortical stimulation study of gerstmann syndrome.OBJECT: In an attempt to gain a better understanding of the cerebral functions represented in the angular gyrus and to spare them during surgery, the authors studied patients with brain tumors located close to the angular gyrus and mapped cortical sites by using electrostimulation. methods: Before undergoing tumor removal, six right-handed patients (five with left and one with right hemisphere tumors) were studied using cortical mapping with the aid of calculating, writing, finger-recognition, and color-naming tasks in addition to standard reading and object-naming tasks (for a total of 36 brain mapping studies). Strict conditions of functional site validation were applied to include only those cortical sites that produced repetitive interferences in the function tested. Preoperatively, four of the patients exhibited discrete symptoms related to gerstmann syndrome while performing very specific tasks, whereas the other two patients presented with no symptoms of the syndrome. No patient had significant language or apraxic deficits. Distinct or shared cortical sites producing interferences in calculating, finger recognition, and writing were repeatedly found in the angular gyrus. Object- or color-naming sites and reading-interference sites were also found in or close to the angular gyrus; although frequently demonstrated, these latter results were variable and unpredictable in the group of patients studied. Finger agnosia and acalculia sites were also found elsewhere, such as in the supramarginal gyrus or close to the intraparietal sulcus. Mechanisms involved in acalculia, agraphia, or finger agnosia (either complete interferences or hesitations) during stimulation were various, from an aphasia-like form (for instance, the patient did not understand the numbers or words given for calculating or writing tasks) to an apparently pure interference in the function tested (patients understood the numbers, but were unable to perform a simple addition). CONCLUSIONS: Symptoms of gerstmann syndrome can be found during direct brain mapping in the angular gyrus region. In this series of patients, sites producing interferences in writing, calculating, and finger recognition were demonstrated in the angular gyrus, which may or may not have been associated with object-naming, color-naming, or reading sites.- - - - - - - - - - ranking = 3keywords = reading (Clic here for more details about this article) |
9/29. reading aloud in jargonaphasia: an unusual dissociation in speech output.A patient is described who showed several dissociations between oral and written language processing after bilateral retrorolandic vascular lesion. Dissociation was firstly between abolished auditory comprehension and preserved written comprehension and then involved confrontation naming, clearly superior in the written modality. The third striking dissociation involved oral output; spontaneous speech, although fluent and well articulated, consisted of neologistic jargon, while reading aloud was clearly superior though not perfect. Data are discussed with reference to a cognitive model of word processing. The pattern of dissociation in word production may be due to a failure in retrieving the phonological word form from the semantic system.- - - - - - - - - - ranking = 1keywords = reading (Clic here for more details about this article) |
10/29. Are specific reading and writing difficulties causally connected with developmental spatial inability? Evidence from two cases of developmental agnosia and apraxia.Two cases studies of subjects suffering from severe developmental constructional apraxia are presented. These two subjects demonstrated normal to high ability in reading, writing and arithmetical tests. The analysis of cognitive tests performed by them indicates that extreme developmental, perceptual, spatial and motor deficits may be dissociated from the acquisition of efficient reading ability.- - - - - - - - - - ranking = 6keywords = reading (Clic here for more details about this article) |
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