keyword
MENU ▼
Read by QxMD icon Read
search

agnosia

keyword
https://www.readbyqxmd.com/read/28545844/rise-and-fall-of-the-two-visual-systems-theory
#1
Yves Rossetti, Laure Pisella, Robert D McIntosh
Among the many dissociations describing the visual system, the dual theory of two visual systems, respectively dedicated to perception and action, has yielded a lot of support. There are psychophysical, anatomical and neuropsychological arguments in favor of this theory. Several behavioral studies that used sensory and motor psychophysical parameters observed differences between perceptive and motor responses. The anatomical network of the visual system in the non-human primate was very readily organized according to two major pathways, dorsal and ventral...
May 22, 2017: Annals of Physical and Rehabilitation Medicine
https://www.readbyqxmd.com/read/28532578/impaired-peripheral-reaching-and-on-line-corrections-in-patient-df-optic-ataxia-with-visual-form-agnosia
#2
Stéphanie Rossit, Monika Harvey, Stephen H Butler, Larissa Szymanek, Stéphanie Morand, Simona Monaco, Robert D McIntosh
An influential model of vision suggests the presence of two visual streams within the brain: a dorsal occipito-parietal stream which mediates action and a ventral occipito-temporal stream which mediates perception. One of the cornerstones of this model is DF, a patient with visual form agnosia following bilateral ventral stream lesions. Despite her inability to identify and distinguish visual stimuli, DF can still use visual information to control her hand actions towards these stimuli. These observations have been widely interpreted as demonstrating a double dissociation from optic ataxia, a condition observed after bilateral dorsal stream damage in which patients are unable to act towards objects that they can recognize...
April 22, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
https://www.readbyqxmd.com/read/28484905/historical-perspectives-on-ancient-greek-derived-a-prefixed-nomenclature-for-acquired-neurocognitive-impairment
#3
REVIEW
Philip Gerard Gasquoine
Distinct forms of acquired neurocognitive impairment are often described by "a" prefixed terms that derive from ancient Greek (and in one case Latin). Two modern English language neurological and neuropsychological reference books were searched to identify 17 such terms in contemporary usage: amnesia, akinesia, ataxia, aphasia, agraphia, anosmia, apraxia, athetosis, ageusia, achromatopsia, agnosia, alexia, amusia, anomia, anarthria, anosognosia, and acalculia. These were traced to their initial association with acquired neurocognitive impairment in German, English, and French language medical publications from the late 18th, 19th, and early 20th centuries (1770 through 1920)...
May 8, 2017: Neuropsychology Review
https://www.readbyqxmd.com/read/28437623/selective-scene-perception-deficits-in-a-case-of-topographical-disorientation
#4
Jessica Robin, Matthew X Lowe, Sara Pishdadian, Josée Rivest, Jonathan S Cant, Morris Moscovitch
Topographical disorientation (TD) is a neuropsychological condition characterized by an inability to find one's way, even in familiar environments. One common contributing cause of TD is landmark agnosia, a visual recognition impairment specific to scenes and landmarks. Although many cases of TD with landmark agnosia have been documented, little is known about the perceptual mechanisms which lead to selective deficits in recognizing scenes. In the present study, we test LH, a man who exhibits TD and landmark agnosia, on measures of scene perception that require selectively attending to either the configural or surface properties of a scene...
April 2, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
https://www.readbyqxmd.com/read/28424400/-brodmann-areas-39-and-40-human-parietal-association-area-and-higher-cortical-function
#5
Yasuhisa Sakurai
The anatomy and function of the angular gyrus (Brodmann Area 39) and supramarginal gyrus (Brodmann Area 40) are described here. Both gyri constitute the inferior part of the parietal lobe. Association fibers from the angular gyrus project to the dorsolateral prefrontal cortex via the superior longitudinal fasciculus (SLF) II/arcuate fasciculus (AF), whereas those from the supramarginal gyrus project to the ventrolateral prefrontal cortex via SLF III/AF. Damage to the left angular gyrus causes kanji agraphia (lexical agraphia) and mild anomia, whereas damage to the left supramarginal gyrus causes kana alexia (phonological dyslexia) and kana agraphia (phonological agraphia)...
April 2017: Brain and Nerve, Shinkei Kenkyū No Shinpo
https://www.readbyqxmd.com/read/28424394/-brodmann-areas-17-18-and-19-in-the-human-brain-an-overview
#6
Juro Kawachi
Brodmann areas 17, 18, and 19 in the human brain are visual cortices of the occipital lobe. Each area has its own retinotopic representations, particulary area 19, which has many small retinotopic areas representing half or all of the contralateral visual field, several functional areas, and nine cytoarchitectonic areas. Several fasciculi are known as occipital fiber connections, but their precise endpoints are not clear. Lesions in the visual cortices cause several visual disorders including visual field defect, visual hallucinations, metamorphopsia, and different kinds of visual agnosia...
April 2017: Brain and Nerve, Shinkei Kenkyū No Shinpo
https://www.readbyqxmd.com/read/28397005/sneaking-a-peek-pigeons-use-peripheral-vision-not-mirrors-to-find-hidden-food
#7
Emre Ünver, Alexis Garland, Sepideh Tabrik, Onur Güntürkün
A small number of species are capable of recognizing themselves in the mirror when tested with the mark-and-mirror test. This ability is often seen as evidence of self-recognition and possibly even self-awareness. Strangely, a number of species, for example monkeys, pigs and dogs, are unable to pass the mark test but can locate rewarding objects by using the reflective properties of a mirror. Thus, these species seem to understand how a visual reflection functions but cannot apply it to their own image. We tested this discrepancy in pigeons-a species that does not spontaneously pass the mark test...
April 10, 2017: Animal Cognition
https://www.readbyqxmd.com/read/28393489/grouped-factors-of-the-ssade-signs-and-symptoms-accompanying-dementia-while-eating-and-nutritional-status-an-analysis-of-older-people-receiving-nutritional-care-in-long-term-care-facilities-in-japan
#8
Kento Takada, Kazumi Tanaka, Mihoko Hasegawa, Michiko Sugiyama, Nobuo Yoshiike
BACKGROUND: Behavioural and psychological symptoms of dementia (BPSD) are very common among older people, and previous studies showed that BPSD affects eating behaviour negatively, possibly resulting in undernutrition. In a previous study, we constructed a set of 11 items based on direct observations of older people with dementia during mealtime and named them 'SSADE: signs and symptoms accompanying dementia while eating'. AIMS: This study aimed to conduct a factor analysis to clarify the structure of the set of 11 SSADE items and to analyse the relationship of the SSADE with nutritional status...
April 9, 2017: International Journal of Older People Nursing
https://www.readbyqxmd.com/read/28367609/topographical-disorientation-in-a-patient-with-right-parahippocampal-infarction
#9
Kazuhiro Ishii, Reiko Koide, Naomi Mamada, Akira Tamaoka
We here describe a patient showing topographical disorientation (TD) after infarction of the right medial occipital lobe; the lesion included the parahippocampal gyrus. Clinical and neuropsychological observations demonstrated a specific pattern of impairment in terms of visual and visuospatial (topographical) learning, and memory. He had no landmark agnosia. His defective route finding resulted from impaired allocentric and egocentric spatial representations. Drawing illustrations of both familial and unfamiliar place and orientation tasks in an egocentric coordination context is a useful means of recognizing the influence of egocentric and/or allocentric spatial disturbance...
April 3, 2017: Neurological Sciences
https://www.readbyqxmd.com/read/28284488/agnosic-vision-is-like-peripheral-vision-which-is-limited-by-crowding
#10
Francesca Strappini, Denis G Pelli, Enrico Di Pace, Marialuisa Martelli
Visual agnosia is a neuropsychological impairment of visual object recognition despite near-normal acuity and visual fields. A century of research has provided only a rudimentary account of the functional damage underlying this deficit. We find that the object-recognition ability of agnosic patients viewing an object directly is like that of normally-sighted observers viewing it indirectly, with peripheral vision. Thus, agnosic vision is like peripheral vision. We obtained 14 visual-object-recognition tests that are commonly used for diagnosis of visual agnosia...
February 1, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
https://www.readbyqxmd.com/read/28258660/pure-optic-ataxia-and-visual-hemiagnosia-extending-the-dual-visual-hypothesis
#11
Jurka R Meichtry, Dario Cazzoli, Silvia Chaves, Sebastian von Arx, Tobias Pflugshaupt, Roger Kalla, Claudio L Bassetti, Klemens Gutbrod, René M Müri
Goodale and Milner's two visual system hypothesis is an influential model for the understanding of the primate visual system. Lesions of either the ventral (occipito-temporal) or the dorsal (occipito-parietal) stream produce distinct and dissociated syndromes in humans: visual agnosia is typical for ventral damage, whereas optic ataxia (OA) for dorsal damage. We studied the case of a 59-year-old left-handed woman with a circumscribed lesion around the left posterior occipital sulcus, extending to the underlying white matter...
March 4, 2017: Journal of Neuropsychology
https://www.readbyqxmd.com/read/28255843/how-do-the-two-visual-streams-interact-with-each-other
#12
REVIEW
A D Milner
The current consensus divides primate cortical visual processing into two broad networks or "streams" composed of highly interconnected areas (Milner and Goodale 2006, 2008; Goodale 2014). The ventral stream, passing from primary visual cortex (V1) through to inferior parts of the temporal lobe, is considered to mediate the transformation of the contents of the visual signal into the mental furniture that guides memory, recognition and conscious perception. In contrast the dorsal stream, passing from V1 through to various areas in the posterior parietal lobe, is generally considered to mediate the visual guidance of action, primarily in real time...
May 2017: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
https://www.readbyqxmd.com/read/28254833/yellow-fever-vaccine-associated-neurological-disease-a-suspicious-case
#13
Pedro Beirão, Patrícia Pereira, Andreia Nunes, Pedro Antunes
A 70-year-old man with known cardiovascular risk factors, presented with acute onset expression aphasia, agraphia, dyscalculia, right-left disorientation and finger agnosia, without fever or meningeal signs. Stroke was thought to be the cause, but cerebrovascular disease investigation was negative. Interviewing the family revealed he had undergone yellow fever vaccination 18 days before. Lumbar puncture revealed mild protein elevation. Cultural examinations, Coxiella burnetti, and neurotropic virus serologies were negative...
March 2, 2017: BMJ Case Reports
https://www.readbyqxmd.com/read/28223685/finger-posture-modulates-structural-body-representations
#14
Luigi Tamè, Elanah Dransfield, Thomas Quettier, Matthew R Longo
Patients with lesions of the left posterior parietal cortex commonly fail in identifying their fingers, a condition known as finger agnosia, yet are relatively unimpaired in sensation and skilled action. Such dissociations have traditionally been interpreted as evidence that structural body representations (BSR), such as the body structural description, are distinct from sensorimotor representations, such as the body schema. We investigated whether performance on tasks commonly used to assess finger agnosia is modulated by changes in hand posture...
February 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28180083/lateralized-occipital-degeneration-in-posterior-cortical-atrophy-predicts-visual-field-deficits
#15
Rebecca S Millington, Merle James-Galton, Mari N Maia Da Silva, Gordon T Plant, Holly Bridge
BACKGROUND: Posterior cortical atrophy (PCA), the visual variant of Alzheimer's disease, leads to high-level visual deficits such as alexia or agnosia. Visual field deficits have also been identified, but often inconsistently reported. Little is known about the pattern of visual field deficits or the underlying cortical changes leading to this visual loss. METHODS: Multi-modal magnetic resonance imaging was used to investigate differences in gray matter volume, cortical thickness, white matter microstructure and functional activity in patients with PCA compared to age-matched controls...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28164221/landmark-agnosia-evaluating-the-definition-of-landmark-based-navigation-impairment
#16
Ineke J M van der Ham, Marieke A G Martens, Michiel H G Claessen, Esther van den Berg
Objective: Landmark agnosia is a rare type of navigation impairment, for which various definitions have been presented. From a clinical as well as theoretical perspective, consensus on the characteristics of landmark agnosia would be valuable. In the current study we review the literature concerning landmark agnosia and present a new case study. Existing literature highlights the importance of examining familiar as well as novel landmark processing and substantial variation in performance patterns of individual patients...
June 1, 2017: Archives of Clinical Neuropsychology: the Official Journal of the National Academy of Neuropsychologists
https://www.readbyqxmd.com/read/27956263/functional-modulation-of-contralateral-bias-in-early-and-object-selective-areas-after-stroke-of-the-occipital-ventral-cortices
#17
Maren Praß, Cathleen Grimsen, Manfred Fahle
Object agnosia is a rare symptom, occurring mainly after bilateral damage of the ventral visual cortex. Most patients suffering from unilateral ventral lesions are clinically non-agnosic. Here, we studied the effect of unilateral occipito-temporal lesions on object categorization and its underlying neural correlates in visual areas. Thirteen non-agnosic stroke patients and twelve control subjects performed an event-related rapid object categorization task in the fMRI scanner where images were presented either to the left or to the right of a fixed point...
January 27, 2017: Neuropsychologia
https://www.readbyqxmd.com/read/27903133/emotional-quotient-in-frontotemporal-dementia-vs-alzheimer-s-disease-the-role-of-socioemotional-agnosia
#18
Andrew R Carr, Mersal S Samimi, Pongsatorn Paholpak, Elvira E Jimenez, Mario F Mendez
INTRODUCTION: Socioemotional dysfunction distinguishes behavioural variant frontotemporal dementia (bvFTD) from other dementias. Patients with bvFTD not only have early social impairment and emotional blunting, but they also have agnosia of their socioemotional dysfunction. METHODS: To investigate the relationship between agnosia and dysfunction, we assessed self-knowledge of socioemotional dysfunction with an emotional quotient (EQ) scale administered to 12 patients with bvFTD and a comparison group of 12 age-matched patients with Alzheimer's disease (AD), and compared these self-ratings to caregiver ratings of social dysfunction and emotional blunting...
November 30, 2016: Cognitive Neuropsychiatry
https://www.readbyqxmd.com/read/27863703/reprint-of-object-based-attentional-facilitation-and-inhibition-are-neuropsychologically-dissociated
#19
Daniel T Smith, Keira Ball, Robert Swalwell, Thomas Schenk
Salient peripheral cues produce a transient shift of attention which is superseded by a sustained inhibitory effect. Cueing part of an object produces an inhibitory cueing effect (ICE) that spreads throughout the object. In dynamic scenes the ICE stays with objects as they move. We examined object-centred attentional facilitation and inhibition in a patient with visual form agnosia. There was no evidence of object-centred attentional facilitation. In contrast, object-centred ICE was observed in 3 out of 4 tasks...
November 2016: Neuropsychologia
https://www.readbyqxmd.com/read/27821572/pearls-oy-sters-visual-agnosia-an-overlooked-cortical-sign
#20
Bruno Bergmans, Olivier Deryck, Rose Bruffaerts
No abstract text is available yet for this article.
November 8, 2016: Neurology
keyword
keyword
50721
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"