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Revue Medicale de Liege Oct 1973
Topics: Agnosia; Aphasia; Audiometry; Auditory Perception; Brain Diseases; Hearing Disorders; Humans; Perceptual Disorders
PubMed: 4757064
DOI: No ID Found -
Neuropsychologia Feb 1997Instances in which objects are copied accurately, but are dramatically rotated relative to the original, have been interpreted as evidence for viewpoint-independent... (Clinical Trial)
Clinical Trial
Instances in which objects are copied accurately, but are dramatically rotated relative to the original, have been interpreted as evidence for viewpoint-independent accounts of the object recognition process. In two case reports, we demonstrate that patients who show rotation in copying also show difficulties in informing the examiner of the canonical orientation of known objects. In copying rotated versions of familiar objects, one subject showed a tendency to copy them in their canonical upright orientation, and both subjects copied non-representational line drawings with their principal axis vertically aligned, and with the irregular end pointing 'upwards'.
Topics: Aged; Agnosia; Cerebrovascular Disorders; Cognition; Discrimination, Psychological; Form Perception; Humans; Male; Middle Aged; Neuropsychological Tests; Orientation; Tomography, X-Ray Computed
PubMed: 9025119
DOI: 10.1016/s0028-3932(96)00063-2 -
Acta Neurologica Belgica Oct 2023A precise understanding of the neural substrates underlying tactually-related cognitive impairments such as bilateral tactile agnosia, bilateral agraphesthesia,...
INTRODUCTION
A precise understanding of the neural substrates underlying tactually-related cognitive impairments such as bilateral tactile agnosia, bilateral agraphesthesia, kinesthetic alexia and kinesthetic reading difficulty is currently incomplete. In particular, recent data have implicated a role for the lateral occipital tactile visual region, or LOtv, in tactile object naming (Amedi et al. Cerebral Cortex 2002). Thus, this study set out to examine the degree to which the LOtv may be involved in tactually-related cognitive impairments by examining two unique cases.
METHODS
To assess whether LOtv or the visual word form area (VWFA) is involved in tactually-related cognitive impairments, the average activation point of LOtv and that of VWFA were placed on the single-photon emission computed tomography (SPECT) cerebral blood flow images of two patients: one with bilateral associative tactile agnosia, bilateral agraphesthesia, and ineffective kinesthetic reading, and the other with kinesthetic reading difficulty.
RESULTS
The average LOtv coordinate was involved in the area of hypoperfusion in both patients, whereas that of VWFA was not included in any of the hypoperfused areas.
CONCLUSIONS
The results support the view that interruption of LOtv or disconnection to LOtv and to VWFA may cause these tactually-related cognitive impairments. Further, bilateral associative tactile agnosia and bilateral agraphesthesia are attributable toward the damage of the occipital lobe, whereas unilateral or predominantly one-sided associative tactile agnosia and agraphesthesia are attributable toward the damage of the parietal lobe.
Topics: Humans; Reading; Agnosia; Touch; Cerebral Cortex; Cognitive Dysfunction
PubMed: 36336779
DOI: 10.1007/s13760-022-02130-9 -
Annals of Neurology Apr 2000
Topics: Agnosia; Brain Diseases; Humans; Terminology as Topic; Visual Fields
PubMed: 10762176
DOI: No ID Found -
Cognitive Neuropsychology 2018
Topics: Agnosia; Humans; Prosopagnosia; Visual Perception
PubMed: 29658418
DOI: 10.1080/02643294.2018.1431875 -
Seminars in Neurology 2000Agnosias are disorders of recognition, specific to one sensory channel, that affect either the perceptual analysis of the stimulus or the recognition of its meaning. In... (Review)
Review
Agnosias are disorders of recognition, specific to one sensory channel, that affect either the perceptual analysis of the stimulus or the recognition of its meaning. In the visual modality, objects, faces, and colors can be separately disrupted. Apperceptive object agnosia refers to failure to achieve a structured description of the shape of the object. Associative agnosia refers to inability to attribute a meaning to a correctly perceived stimulus. It must be differentiated from optic aphasia, in which the object is recognized but cannot be named in the visual modality. Associative agnosia and optic aphasia are associated with left occipitotemporal damage, and they differ more quantitatively than qualitatively. The inability to recognize familiar faces (prosopagnosia) can appear in isolation and be, in some cases, associated with a lesion confined to the occipitotemporal region of the right hemisphere. These findings are supportive of the idea that faces have a separate representation in the brain. Disorders of color cognition can affect color categorization, color-name association, and color-object association. They are linked to left hemisphere damage. The ability to recognize objects presented in the visual modality is a hierarchical process in which several cortical areas, corresponding to about 30% of the cortical mantle, participate. Their selective lesion results in a gamut of disorders whose identification provides the experienced neurologist with clues to the locus of damage and contributes to the understanding of the cognitive architecture underpinning recognition. They can result either in the inability to detect any change occurring in the visual field or in the impairment of further stages of the recognition process, from the analysis of the perceptual properties of the stimulus (form, color, motion, depth, etc.) to the achievement of its structural description and, eventually, the attribution of a meaning. In this paper, I focus on the diagnostic and clinical features characterizing the disruption of the last stage of visual information processing; that is, the failure to identify what a stimulus represents despite evidence that its three-dimensional structure has been properly reconstructed. In the literature, this impairment is traditionally referred to as associative agnosia, a psychological construct that attributes the deficit to the inability to associate a well-discriminated percept with its semantic attributes, which are stored in separate cortical areas. In the visual modality, three discrete forms of associative agnosia have been described, affecting objects, faces, and colors. These are treated separately.
Topics: Agnosia; Cerebral Cortex; Color Perception; Functional Laterality; Humans; Pattern Recognition, Visual; Prosopagnosia; Visual Pathways
PubMed: 11149704
DOI: 10.1055/s-2000-13181 -
Shinkei Kenkyu No Shimpo. Advances in... 1971
Topics: Agnosia; Female; Humans; Middle Aged; Visual Perception
PubMed: 5106771
DOI: No ID Found -
Neurocase Jun 2011Patients with neurological disorders are often partially or completely unaware of the deficits caused by their disease. This impairment is referred to as anosognosia,... (Review)
Review
Patients with neurological disorders are often partially or completely unaware of the deficits caused by their disease. This impairment is referred to as anosognosia, and it is very common in neurodegenerative disease, particularly in frontotemporal dementia. Anosognosia has significant impacts on function and quality of life for patients with neurodegenerative disease and their caregivers, but the phenomenon has received little formal study, especially in non-Alzheimer's (non-AD) dementias. Furthermore, few studies have attempted to systematically verify the potential role of specific cognitive impairments in producing anosognosia. As a result, the mechanisms underlying this phenomenon are poorly understood. Episodic memory likely plays an important role. In addition, the frontal lobe systems are important for intact self-awareness, but the most relevant frontal functions have not been identified. Motivation required to engage in self-monitoring and emotional activation marking errors as significant are often-overlooked aspects of performance monitoring that may underlie anosognosia in some patients. The present review offers a working model that incorporates these functions and stipulates specific processes that may be important for awareness of changes in one's abilities. Specification of the specific processes whose potential failure results in anosognosia can establish a roadmap for future studies.
Topics: Agnosia; Caregivers; Dementia; Frontal Lobe; Humans; Neurodegenerative Diseases; Neuropsychological Tests; Self Concept
PubMed: 21667396
DOI: 10.1080/13554794.2010.522588 -
Brain : a Journal of Neurology Dec 1987A single case study of a patient with visual agnosia is presented. The patient had a marked impairment in visual object recognition along with good tactile object...
A single case study of a patient with visual agnosia is presented. The patient had a marked impairment in visual object recognition along with good tactile object identification and a preserved ability to copy. Detailed investigations demonstrated impaired perceptual processes, with the patient's identification strongly affected by duration of stimulus exposure and by using overlapping figures. However, his stored knowledge of objects was shown to be intact. The results demonstrate that agnosia may be determined by a specific deficit in integrating form information; and that the input description for visual object recognition, disrupted in this patient, is functionally separate from stored object descriptions, which are intact. The implications of the results for understanding visual agnosia and for theories of normal visual object recognition are discussed.
Topics: Agnosia; Cerebrovascular Disorders; Color; Form Perception; Humans; Male; Memory; Middle Aged; Neuropsychological Tests; Pattern Recognition, Visual; Tomography, X-Ray Computed; Verbal Behavior; Visual Perception
PubMed: 3427396
DOI: 10.1093/brain/110.6.1431 -
Neurocase Oct 2020Delusional misidentification syndrome (DMS) is an umbrella term encompassing a variety of disorders. One rare form of DMS is the delusional misidentification of one's...
Delusional misidentification syndrome (DMS) is an umbrella term encompassing a variety of disorders. One rare form of DMS is the delusional misidentification of one's own reflection, known as "mirrored self-misidentification syndrome". In "mirror image agnosia", the ability to identify the image of self and/or others in the mirror is lost, while the ability to identify the mirror itself is preserved. To our knowledge, mirror image agnosia has never been described in a patient with schizophrenia. Herein we present a case of a patient with schizophrenia with severe delusions of both mirrored self-misidentification and mirror image agnosia without any structural abnormalities or dementia.
Topics: Agnosia; Delusions; Facial Recognition; Female; Humans; Middle Aged; Schizophrenia; Self Concept
PubMed: 32726169
DOI: 10.1080/13554794.2020.1799019