C F Vinci, C Pontesilli, D Fo
Art forms (music, painting, sculpture, literature and theatre) are essential components in all social and human contexts. The role of art, in this case of theatre, is to express a visual event that aims to help the spectator identify himself/herself in the characters. The play presented here is "A...come non so" and shows the characteristic aspects of Alzheimer's disease from the first stage of the disease to the last stage: amnesia, aphasia, agnosia and apraxia. It tells the story of Carlo Pontercoli, a gerontologist and specialist in cardiovascular disease, who, while writing his paper on "The elderly and sexuality", manifests the first signs of the disease that killed his mother not so long before...
July 2005: Neurological Sciences
Michael N Lopez, Michael D Lazar, Sherwin M Imperio
The present study investigated the types of inaccurate responses, i.e., Don't Know, Semantic, Visual (nonlinguistic), Phonological, Circumlocutory, and Perseverative, made on the Hooper Visual Organization Test by a heterogeneous sample of 68 brain-damaged and 63 substance abuse patients. The mean age of the brain-damaged and substance abuse groups were 46.0 (SD=13.5) and 43.7 (SD=12.9) yr., respectively. Analysis showed that the brain-damaged group made significantly more visual and perseverative responses than the substance abuse group...
June 2005: Perceptual and Motor Skills
Thomas Nyffeler, Tobias Pflugshaupt, Helene Hofer, Uli Baas, Klemens Gutbrod, Roman von Wartburg, Christian W Hess, René M Müri
The aim of the present single case study was to investigate oculomotor recovery in a patient with simultanagnosia due to biparietal hypoxic lesions. Applying visual exploration as well as basic oculomotor tasks in three consecutive test sessions--i.e. 8 weeks, 14 weeks, and 37 weeks after brain damage had occurred--differential recovery was observed. While visual exploration remarkably improved, an impaired disengagement of attention persisted. The improvement of exploration behaviour is interpreted within an oculomotor network theory and implications for a deficit-specific recovery from simultanagnosia are discussed...
2005: Neuropsychologia
M Delazer, E Karner, L Zamarian, E Donnemiller, Th Benke
Posterior cortical atrophy (PCA) is an uncommon syndrome of dementia with early onset, characterised by disorders of higher visual function, variable symptoms of Balint's syndrome, visual agnosia, alexia, agraphia, finger agnosia, right-left disorientation and dyscalculia [Benson D. F., Davis R. J., & Snyder B. D. (1988). Posterior cortical atrophy. Archives of Neurology, 45, 789-793]. In a single case study specific numerical deficits were observed which may be predicted by parietal neurodegeneration (more pronounced on the right side; verified by SPECT)...
2006: Neuropsychologia
David A Wolk, H Branch Coslett, Guila Glosser
The role of sensory-motor representations in object recognition was investigated in experiments involving AD, a patient with mild visual agnosia who was impaired in the recognition of visually presented living as compared to non-living entities. AD named visually presented items for which sensory-motor information was available significantly more reliably than items for which such information was not available; this was true when all items were non-living. Naming of objects from their associated sound was normal...
August 2005: Brain and Language
Daniel Saumier, Howard Chertkow, Martin Arguin, Christine Whatmough
Individuals with Alzheimer's disease (AD) often have problems in recognizing common objects. This visual agnosia may stem from difficulties in establishing appropriate visual boundaries between visually similar objects. In support of this hypothesis, showed that AD subjects have difficulties in establishing visual category boundaries between continuously graded shapes. In an attempt to investigate the neural basis of these impairments, the current study required a group of neurologically healthy elderly participants to categorically classify a series of ellipses varying in width while regional blood flow changes were measured using positron emission tomography (PET)...
December 2005: Brain and Cognition
Pamela D Butler, Vance Zemon, Isaac Schechter, Alice M Saperstein, Matthew J Hoptman, Kelvin O Lim, Nadine Revheim, Gail Silipo, Daniel C Javitt
BACKGROUND: Patients with schizophrenia show deficits in early-stage visual processing, potentially reflecting dysfunction of the magnocellular visual pathway. The magnocellular system operates normally in a nonlinear amplification mode mediated by glutamatergic (N-methyl-D-aspartate) receptors. Investigating magnocellular dysfunction in schizophrenia therefore permits evaluation of underlying etiologic hypotheses. OBJECTIVES: To evaluate magnocellular dysfunction in schizophrenia, relative to known neurochemical and neuroanatomical substrates, and to examine relationships between electrophysiological and behavioral measures of visual pathway dysfunction and relationships with higher cognitive deficits...
May 2005: Archives of General Psychiatry
Marlene Behrmann, Jonathan Marotta, Isabel Gauthier, Michael J Tarr, Thomas J McKeeff
Agnosia, the impairment in object and face recognition despite intact vision and intelligence, is one of the most intriguing and debilitating neuropsychological deficits. The goal of this study was to determine whether S.M., an individual with longstanding visual agnosia and concomitant prosopagnosia, can be retrained to perform visual object recognition and, if so, what neural substrates mediate this reacquisition. Additionally, of interest is the extent to which training on one type of visual stimulus generalizes to other visual stimuli, as this informs our understanding of the organization of ventral visual cortex...
April 2005: Journal of Cognitive Neuroscience
Naomi Fujinaga, Taro Muramatsu, Misao Ogano, Motoichiro Kato
Dissociation between the ability to recognize misoriented objects and to determine their orientation has been reported in a small number of patients, but the long-term course of this deficit has not been reported so far. Here, we describe the case of a 32-year-old female who had bilateral occipito-temporal damage caused by a cerebrovascular accident. Neuropsychological assessment performed at 6 months after the occurrence of the cerebrovascular accident revealed that she was almost generally agnostic for object orientation...
2005: Neuropsychologia
R Shayna Rosenbaum, Fuqiang Gao, Brian Richards, Sandra E Black, Morris Moscovitch
Recent research suggests that the hippocampus is not needed for the maintenance and recovery of extensively used environments learned long ago. Instead, a network of neocortical regions differentially supports memory for locationnavigation knowledge and visual appearance of well-known places. In this study, we present a patient, S. B., who was diagnosed with probable Alzheimer's disease long after retiring from his 40 years as a taxi driver in downtown Toronto, a place that he has visited rarely, if ever, in the last decade...
March 2005: Journal of Cognitive Neuroscience
Brad Duchaine, Ken Nakayama
Neuropsychological studies with patients suffering from prosopagnosia have provided the main evidence for the hypothesis that the recognition of faces and objects rely on distinct mechanisms. Yet doubts remain, and it has been argued that no case demonstrating an unequivocal dissociation between face and object recognition exists due in part to the lack of appropriate response time measurements (Gauthier et al., 1999). We tested seven developmental prosopagnosics to measure their accuracy and reaction times with multiple tests of face recognition and compared this with a larger battery of object recognition tests...
February 2005: Journal of Cognitive Neuroscience
Antonio Incisa della Rocchetta, Lisa Cipolotti
We describe two patients with selectively preserved knowledge of the category of countries. Following a series of cerebral infarcts, patient DB presented with severe perceptual impairment, including dense apperceptive agnosia,prosopagnosia, and topographical agnosia. Despite these deficits, he could effortlessly name countries from their outline maps. Patient WH, who suffered from semantic dementia, had severe naming and comprehension difficulties, with extremely sparse residual semantic knowledge. Remarkably, the category of countries was preserved...
June 2004: Neurocase
Helmut Hildebrandt, Cathleen Schütze, Markus Ebke, Karoline Spang
The term "visual form agnosia" describes a disorder characterized by problems recognizing objects, poor copying,and distinguishing between simple geometric shapes despite normal intellectual abilities. Visual agnosia has been interpreted as a disorder of the magnocellular visual system, caused by an inability to separate figure from ground by sampling information from extended regions of space and to integrate it with fine-grain local information. However,this interpretation has hardly been tested with neuropsychological or functional brain imaging methods, mainly because the magnocellular and parvocellular structures are highly interconnected in the visual system...
June 2004: Neurocase
H Alonso-Navarro, F J Jiménez-Jiménez, I Puertas-Muñoz, J Rábano, J G de Yébenes, J L Sarasa-Corral
AIMS: The purpose of this paper is to report the case of a patient with Kluver-Bucy syndrome caused by adult-type ceroid lipofuscinosis (Kufs' disease) and to review the literature dealing with the causes of this syndrome. CASE REPORT: A 38-year-old male examined because of behavioural changes and cognitive impairment. Brain biopsy findings were characteristic of adult-type ceroid lipofuscinosis. This patient fulfilled the criteria of Kufs' disease, since he had mixed clinical features belonging to both type A (neuropsychiatric disorders) and B (aphasia-apraxia-agnosia syndrome) of the disease...
January 16, 2005: Revista de Neurologia
Cécile Ballaz, Luc Boutsen, Carole Peyrin, Glyn W Humphreys, Christian Marendaz
The authors studied the influence of canonical orientation on visual search for object orientation. Displays consisted of pictures of animals whose axis of elongation was either vertical or tilted in their canonical orientation. Target orientation could be either congruent or incongruent with the object's canonical orientation. In Experiment 1, vertical canonical targets were detected faster when they were tilted (incongruent) than when they were vertical (congruent). This search asymmetry was reversed for tilted canonical targets...
February 2005: Journal of Experimental Psychology. Human Perception and Performance
Klaus Schmidtke, Michael Hüll, Jochen Talazko
Nine patients with posterior cortical atrophy (PCA), a rare degenerative brain disease of unclear etiology and nosology, were followed over a mean time of 7.4 years. The mean age at onset was low (56.2 years). At onset, eight patients had visuo-spatial and eight had memory impairment. A minority showed early signs of occipital lobe involvement with visual agnosia or hemianopia. Eight patients developed dementia after a mean course of five years. 18F-FDG-PET data of six patients were analysed with statistical parametric mapping...
January 2005: Journal of Neurology
Kyoko Suzuki
There are two cortical visual processing streams, the ventral and dorsal stream. The ventral visual stream plays the major role in constructing our perceptual representation of the visual world and the objects within it. Disturbance of visual processing at any stage of the ventral stream could result in impairment of visual recognition. Thus we need systematic investigations to diagnose visual agnosia and its type. Two types of category-selective visual agnosia, prosopagnosia and landmark agnosia, are different from others in that patients could recognize a face as a face and buildings as buildings, but could not identify an individual person or building...
November 2004: Rinshō Shinkeigaku, Clinical Neurology
Kousuke Kanemoto
For decades, psychiatrists have considered that concepts of impaired consciousness in the study of psychiatry were inconsistent with those applied in the field of neurology, in which the usefulness of the concept of consciousness has long been seriously doubted. Gloor concluded that the concept of consciousness does not further the understanding of seizure mechanisms or brain function, which is the current representative opinion of most epileptologists. Loss of consciousness tends to be reduced to aggregates of individual impairments of higher cognitive functions, and the concept of consciousness is preferably avoided by neurologists by assigning various behavioral disturbances during disturbed consciousness to particular neuropsychological centers...
2004: Seishin Shinkeigaku Zasshi, Psychiatria et Neurologia Japonica
Max Coltheart
Many models of the processing of printed or spoken words or objects or faces propose that systems of local representations of the forms of such stimuli--lexicons--exist. This is denied by partisans of the distributed-representation connectionist approach to cognitive modelling. An experimental paradigm of key theoretical importance here is lexical decision and its analogue in the domain of objects, object decision. How does each theoretical camp account for our ability to perform these two tasks? The localists say that the tasks are done by matching or failing to match a stimulus to a local representation in a lexicon...
October 2004: Quarterly Journal of Experimental Psychology. A, Human Experimental Psychology
Oliver H Turnbull, Jon Driver, Rosaleen A McCarthy
Patients with visual agnosia exhibit acquired impairments in visual object recognition, that may or may not involve deficits in low-level perceptual abilities. Here we report a case (patient DM) who after head injury presented with object-recognition deficits. He still appears able to extract 2D information from the visual world in a relatively intact manner; but his ability to extract pictorial information about 3D object-structure is greatly compromised. His copying of line drawings is relatively good, and he is accurate and shows apparently normal mental rotation when matching or judging objects tilted in the picture-plane...
September 2004: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
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