Pure Amorphagnosia without Tactile Object Agnosia.

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Kubota, Shinichirou; Yamada, Mai; Satoh, Hideyo; Satoh, Akira; Tsujihata, Mitsuhiro

2017-01-01

A 54-year-old female showed amorphagnosia without ahylognosia and tactile agnosia 40 days after the onset of right cerebral infarction. Her basic somatosensory functions were normal. The appreciation of substance qualities (hylognosia) was preserved, but the patient's inability to recognize the size and shape (morphagnosia) was confined to 2- and 3-dimensional shapes (amorphagnosia) in the left hand. However, the patient's ability to recognize real daily objects was well preserved. Brain MRI after admission showed ischemic lesions confined to the right pre- and postcentral gyri and the medial frontal cortex on DWI and FLAIR images. An analysis of SPECT images revealed that the most decreased areas were localized to the pre- and postcentral gyri, superior and inferior parietal lobules, supramarginal gyrus, and angular gyrus. Considering the previous reported cases, the responsible lesion for the impaired perception of hylognosia and morphagnosia may not necessarily be confined to the right hemisphere. To date, 5 reports (6 cases) of tactile agnosia have been published; 4 cases presented with both ahylognosia and amorphagnosia, while 1 presented with only amorphagnosia, and another showed amorphagnosia and mild ahylognosia. Our case is the first to present with only amorphagnosia without tactile agnosia. The mechanism for the well-preserved recognition of real objects may depend on the preserved hylognosia. Of note, there have been no reports showing only ahylognosia without amorphagnosia. Further studies are necessary to clarify whether or not patients with preserved hylognosia or morphagnosia retain the ability to perceive real objects.

When apperceptive agnosia is explained by a deficit of primary visual processing.

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Serino, Andrea; Cecere, Roberto; Dundon, Neil; Bertini, Caterina; Sanchez-Castaneda, Cristina; Làdavas, Elisabetta

2014-03-01

Visual agnosia is a deficit in shape perception, affecting figure, object, face and letter recognition. Agnosia is usually attributed to lesions to high-order modules of the visual system, which combine visual cues to represent the shape of objects. However, most of previously reported agnosia cases presented visual field (VF) defects and poor primary visual processing. The present case-study aims to verify whether form agnosia could be explained by a deficit in basic visual functions, rather that by a deficit in high-order shape recognition. Patient SDV suffered a bilateral lesion of the occipital cortex due to anoxia. When tested, he could navigate, interact with others, and was autonomous in daily life activities. However, he could not recognize objects from drawings and figures, read or recognize familiar faces. He was able to recognize objects by touch and people from their voice. Assessments of visual functions showed blindness at the centre of the VF, up to almost 5°, bilaterally, with better stimulus detection in the periphery. Colour and motion perception was preserved. Psychophysical experiments showed that SDV's visual recognition deficits were not explained by poor spatial acuity or by the crowding effect. Rather a severe deficit in line orientation processing might be a key mechanism explaining SDV's agnosia. Line orientation processing is a basic function of primary visual cortex neurons, necessary for detecting "edges" of visual stimuli to build up a "primal sketch" for object recognition. We propose, therefore, that some forms of visual agnosia may be explained by deficits in basic visual functions due to widespread lesions of the primary visual areas, affecting primary levels of visual processing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mirror agnosia and the mirrored-self misidentification delusion: a hypnotic analogue.

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Connors, Michael H; Cox, Rochelle E; Barnier, Amanda J; Langdon, Robyn; Coltheart, Max

2012-05-01

Mirrored-self misidentification is the delusional belief that one's reflection in the mirror is a stranger. Current theories suggest that one pathway to the delusion is mirror agnosia (a deficit in which patients are unable to use mirror knowledge when interacting with mirrors). This study examined whether a hypnotic suggestion for mirror agnosia can recreate features of the delusion. Ten high hypnotisable participants were given either a suggestion to not understand mirrors or to see the mirror as a window. Participants were asked to look into a mirror and describe what they saw. Participants were tested on their understanding of mirrors and received a series of challenges. Participants then received a detailed postexperimental inquiry. Three of five participants given the suggestion to not understand mirrors reported seeing a stranger and maintained this belief when challenged. These participants also showed signs of mirror agnosia. No participants given the suggestion to see a window reported seeing a stranger. Results indicate that a hypnotic suggestion for mirror agnosia can be used to recreate the mirrored-self misidentification delusion. Factors influencing the effectiveness of hypnotic analogues of psychopathology, such as participants' expectations and interpretations, are discussed.

Neurodegeneration and Mirror Image Agnosia

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Chandra, Sadanandavalli Retnaswami; Issac, Thomas Gregor

2014-01-01

Background: Normal Percept with abnormal meaning (Agnosias) has been described from nineteenth century onwards. Later literature became abundant with information on the spectrum of Prosopagnosias. However, selective difficulty in identifying reflected self images with relatively better cognitive functions leads to problems in differentiating it from non-organic psychosis. Aim: In the present study, we investigated patients with dementia who showed difficulty in identifying reflected self images while they were being tested for problems in gnosis with reference to identification of reflected objects, animals, relatives, and themselves and correlate with neuropsychological and radiological parameters. Patients and Methods: Five such patients were identified and tested with a 45 cm × 45 cm mirror kept at 30-cm distance straight ahead of them. Results: Mirror image agnosia is seen in patients with moderate stage posterior dementias who showed neuropsychological and radiological evidence of right parietal dysfunction. Conclusion: Interpretation of reflected self images perception in real time probably involves distinct data-linking circuits in the right parietal lobe, which may get disrupted early in the course of the disease. PMID:25317393

Pure Amorphagnosia without Tactile Object Agnosia

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Shinichirou Kubota

2017-04-01

Full Text Available A 54-year-old female showed amorphagnosia without ahylognosia and tactile agnosia 40 days after the onset of right cerebral infarction. Her basic somatosensory functions were normal. The appreciation of substance qualities (hylognosia was preserved, but the patient’s inability to recognize the size and shape (morphagnosia was confined to 2- and 3-dimensional shapes (amorphagnosia in the left hand. However, the patient’s ability to recognize real daily objects was well preserved. Brain MRI after admission showed ischemic lesions confined to the right pre- and postcentral gyri and the medial frontal cortex on DWI and FLAIR images. An analysis of SPECT images revealed that the most decreased areas were localized to the pre- and postcentral gyri, superior and inferior parietal lobules, supramarginal gyrus, and angular gyrus. Considering the previous reported cases, the responsible lesion for the impaired perception of hylognosia and morphagnosia may not necessarily be confined to the right hemisphere. To date, 5 reports (6 cases of tactile agnosia have been published; 4 cases presented with both ahylognosia and amorphagnosia, while 1 presented with only amorphagnosia, and another showed amorphagnosia and mild ahylognosia. Our case is the first to present with only amorphagnosia without tactile agnosia. The mechanism for the well-preserved recognition of real objects may depend on the preserved hylognosia. Of note, there have been no reports showing only ahylognosia without amorphagnosia. Further studies are necessary to clarify whether or not patients with preserved hylognosia or morphagnosia retain the ability to perceive real objects.

Agnosia for mirror stimuli: a new case report with a small parietal lesion.

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Martinaud, Olivier; Mirlink, Nicolas; Bioux, Sandrine; Bliaux, Evangéline; Lebas, Axel; Gerardin, Emmanuel; Hannequin, Didier

2014-11-01

Only seven cases of agnosia for mirror stimuli have been reported, always with an extensive lesion. We report a new case of an agnosia for mirror stimuli due to a circumscribed lesion. An extensive battery of neuropsychological tests and a new experimental procedure to assess visual object mirror and orientation discrimination were assessed 10 days after the onset of clinical symptoms, and 5 years later. The performances of our patient were compared with those of four healthy control subjects matched for age. This test revealed an agnosia for mirror stimuli. Brain imaging showed a small right occipitoparietal hematoma, encompassing the extrastriate cortex adjoining the inferior parietal lobe. This new case suggests that: (i) agnosia for mirror stimuli can persist for 5 years after onset and (ii) the posterior part of the right intraparietal sulcus could be critical in the cognitive process of mirror stimuli discrimination. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Agnosia for accents in primary progressive aphasia☆

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Fletcher, Phillip D.; Downey, Laura E.; Agustus, Jennifer L.; Hailstone, Julia C.; Tyndall, Marina H.; Cifelli, Alberto; Schott, Jonathan M.; Warrington, Elizabeth K.; Warren, Jason D.

2013-01-01

As an example of complex auditory signal processing, the analysis of accented speech is potentially vulnerable in the progressive aphasias. However, the brain basis of accent processing and the effects of neurodegenerative disease on this processing are not well understood. Here we undertook a detailed neuropsychological study of a patient, AA with progressive nonfluent aphasia, in whom agnosia for accents was a prominent clinical feature. We designed a battery to assess AA's ability to process accents in relation to other complex auditory signals. AA's performance was compared with a cohort of 12 healthy age and gender matched control participants and with a second patient, PA, who had semantic dementia with phonagnosia and prosopagnosia but no reported difficulties with accent processing. Relative to healthy controls, the patients showed distinct profiles of accent agnosia. AA showed markedly impaired ability to distinguish change in an individual's accent despite being able to discriminate phonemes and voices (apperceptive accent agnosia); and in addition, a severe deficit of accent identification. In contrast, PA was able to perceive changes in accents, phonemes and voices normally, but showed a relatively mild deficit of accent identification (associative accent agnosia). Both patients showed deficits of voice and environmental sound identification, however PA showed an additional deficit of face identification whereas AA was able to identify (though not name) faces normally. These profiles suggest that AA has conjoint (or interacting) deficits involving both apperceptive and semantic processing of accents, while PA has a primary semantic (associative) deficit affecting accents along with other kinds of auditory objects and extending beyond the auditory modality. Brain MRI revealed left peri-Sylvian atrophy in case AA and relatively focal asymmetric (predominantly right sided) temporal lobe atrophy in case PA. These cases provide further evidence for the

Agnosia for accents in primary progressive aphasia.

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Fletcher, Phillip D; Downey, Laura E; Agustus, Jennifer L; Hailstone, Julia C; Tyndall, Marina H; Cifelli, Alberto; Schott, Jonathan M; Warrington, Elizabeth K; Warren, Jason D

2013-08-01

As an example of complex auditory signal processing, the analysis of accented speech is potentially vulnerable in the progressive aphasias. However, the brain basis of accent processing and the effects of neurodegenerative disease on this processing are not well understood. Here we undertook a detailed neuropsychological study of a patient, AA with progressive nonfluent aphasia, in whom agnosia for accents was a prominent clinical feature. We designed a battery to assess AA's ability to process accents in relation to other complex auditory signals. AA's performance was compared with a cohort of 12 healthy age and gender matched control participants and with a second patient, PA, who had semantic dementia with phonagnosia and prosopagnosia but no reported difficulties with accent processing. Relative to healthy controls, the patients showed distinct profiles of accent agnosia. AA showed markedly impaired ability to distinguish change in an individual's accent despite being able to discriminate phonemes and voices (apperceptive accent agnosia); and in addition, a severe deficit of accent identification. In contrast, PA was able to perceive changes in accents, phonemes and voices normally, but showed a relatively mild deficit of accent identification (associative accent agnosia). Both patients showed deficits of voice and environmental sound identification, however PA showed an additional deficit of face identification whereas AA was able to identify (though not name) faces normally. These profiles suggest that AA has conjoint (or interacting) deficits involving both apperceptive and semantic processing of accents, while PA has a primary semantic (associative) deficit affecting accents along with other kinds of auditory objects and extending beyond the auditory modality. Brain MRI revealed left peri-Sylvian atrophy in case AA and relatively focal asymmetric (predominantly right sided) temporal lobe atrophy in case PA. These cases provide further evidence for the

The neuropsychological rehabilitation of visual agnosia and Balint's syndrome.

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Heutink, Joost; Indorf, Dana L; Cordes, Christina

2018-01-24

Visual agnosia and Balint's syndrome are complex neurological disorders of the higher visual system that can have a remarkable impact on individuals' lives. Rehabilitation of these individuals is important to enable participation in everyday activities despite the impairment. However, the literature about the rehabilitation of these disorders is virtually silent. Therefore, the aim of this systematic review is to give an overview of available literature describing treatment approaches and their effectiveness with regard to these disorders. The search engines Psychinfo, Amed, and Medline were used, resulting in 22 articles meeting the criteria for inclusion. Only articles describing acquired disorders were considered. These articles revealed that there is some information available on the major subtypes of visual agnosia as well as on Balint's syndrome which practising clinicians can consult for guidance. With regard to the type of rehabilitation, compensatory strategies have proven to be beneficial in most of the cases. Restorative training on the other hand has produced mixed results. Concluding, although still scarce, a scientific foundation about the rehabilitation of visual agnosia and Balint's syndrome is evolving. The available approaches give valuable information that can be built upon in the future.

Agnosia integrativa causada por una epilepsia focal occipital izquierda: estudio de caso

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Óscar Mauricio Aguilar Mejía

2011-01-01

Full Text Available La agnosia integrativa es un tipo de agnosia visual asociada a lesiones occipitales bilaterales que se caracteriza por la incapacidad para identificar estímulos en fondos complejos, especialmente, cuando se trata de formas superpuestas o entrelazadas. Existen dificultades para codificar y agrupar el todo a partir de las partes del estímulo. Se presenta un caso de una paciente de 14 años, con una agnosia integrativa como consecuencia de una epilepsia focal sintomática refractaria, con un foco epileptogénico occipital izquierdo. Se plantean las características clínicas de la paciente y se hace un análisis de sus procesos de reconocimiento visual discutidos a partir de los diferentes modelos teóricos que tratan de explicar la percepción visual.

Detecting gradual visual changes in colour and brightness agnosia: a double dissociation.

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Nijboer, Tanja C W; te Pas, Susan F; van der Smagt, Maarten J

2011-03-09

Two patients, one with colour agnosia and one with brightness agnosia, performed a task that required the detection of gradual temporal changes in colour and brightness. The results for these patients, who showed anaverage or an above-average performance on several tasks designed to test low-level colour and luminance (contrast) perception in the spatial domain, yielded a double dissociation; the brightness agnosic patient was within the normal range for the coloured stimuli, but much slower to detect brightness differences, whereas the colour agnosic patient was within the normal range for the achromatic stimuli, but much slower for the coloured stimuli. These results suggest that a modality-specific impairment in the detection of gradual temporal changes might be related to, if not underlie, the phenomenon of visual agnosia.

Associative (prosop)agnosia without (apparent) perceptual deficits: a case-study.

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Anaki, David; Kaufman, Yakir; Freedman, Morris; Moscovitch, Morris

2007-04-09

In associative agnosia early perceptual processing of faces or objects are considered to be intact, while the ability to access stored semantic information about the individual face or object is impaired. Recent claims, however, have asserted that associative agnosia is also characterized by deficits at the perceptual level, which are too subtle to be detected by current neuropsychological tests. Thus, the impaired identification of famous faces or common objects in associative agnosia stems from difficulties in extracting the minute perceptual details required to identify a face or an object. In the present study, we report the case of a patient DBO with a left occipital infarct, who shows impaired object and famous face recognition. Despite his disability, he exhibits a face inversion effect, and is able to select a famous face from among non-famous distractors. In addition, his performance is normal in an immediate and delayed recognition memory for faces, whose external features were deleted. His deficits in face recognition are apparent only when he is required to name a famous face, or select two faces from among a triad of famous figures based on their semantic relationships (a task which does not require access to names). The nature of his deficits in object perception and recognition are similar to his impairments in the face domain. This pattern of behavior supports the notion that apperceptive and associative agnosia reflect distinct and dissociated deficits, which result from damage to different stages of the face and object recognition process.

Auditory agnosia associated with bilateral putaminal hemorrhage: A case report of clinical course of recovery.

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Tokida, Haruki; Kanaya, Yuhei; Shimoe, Yutaka; Imagawa, Madoka; Fukunaga, Shinya; Kuriyama, Masaru

2017-08-31

A 45-year-old right-handed man with a past history (10 years) of putaminal hemorrage presented with auditory agnosia associated with left putaminal hemorrhage. It was suspected that the auditory agnosia was due to bilateral damage in the acoustic radiations. Generalized auditory agnosia, verbal and non-verbal (music and environmental), was diagnosed by neuropsychological examinations. It improved 4 months after the onset. However, the clinical assessment of attention remained poor. The cognition for speech sounds improved slowly, but once it started to improve, the progress of improvement was rapid. Subsequently, the cognition for music sounds also improved, while the recovery of the cognition for environmental sounds remained delayed. There was a dissociation in recovery between these cognitions. He was able to return to work a year after the onset. We also reviewed the literature for cases with auditory agnosia and discuss their course of recovery in this report.

[Agnosia for streets and defective root finding].

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Takahashi, Nobuyoshi

2011-08-01

Topographical disorientation is identified as a condition in which patients are unable to find their way in familiar surroundings, such as their home neighborhood or the admitting hospital after the onset of illness. I proposed to classify topographical disorientation into two categories: agnosia for streets (landmark agnosia) and defective root finding (heading disorientation). Patients with agnosia for streets are unable to identify familiar buildings and landscapes. They can, however, morphologically perceive them and remember their way around familiar areas. The lesions are located in the right posterior part of the parahippocampus gyrus, anterior half of the lingual gyrus and adjacent fusiform gyrus. Clinical findings and functional imaging studies suggest that these regions play a crucial role in the interaction between the visual information of streets and memories of them, which are thought to be retained in the right anterior part of the temporal lobe. In particular, the posterior part of the parahippocampus gyrus is critical for the acquisition of novel information. On the other hand, patients with defective root finding can identify familiar streets, but cannot remember their own location or positional relation between two points within a comparatively wide range not surveyable at one time. The lesions are located in the right retrosplenial cortex (Areas 29, 30), posterior cingulate cortex (Areas 23, 31) and precuneus. Clinical findings and functional imaging studies suggest that these regions are involved in the orientation function for navigating in wide spaces. In particular, the retrosplenial cortex is critical for encoding novel information.

Agnosia for streets and defective root finding

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Takahashi, Nobuyoshi

2011-01-01

Topographical disorientation is identified as a condition in which patients are unable to find their way in familiar surroundings, such as their home neighborhood or the admitting hospital after the onset of illness. I proposed to classify topographical disorientation into two categories: agnosia for streets (landmark agnosia) and defective root finding (heading disorientation). Patients with agnosia for streets are unable to identify familiar buildings and landscapes. They can, however, morphologically perceive them and remember their way around familiar areas. The lesions are located in the right posterior part of the parahippocampus gyrus, anterior half of the lingual gyrus and adjacent fusiform gyrus. Clinical findings and functional imaging studies suggest that these regions play a crucial role in the interaction between the visual information of streets and memories of them, which are thought to be retained in the right anterior part of the temporal lobe. In particular, the posterior part of the parahippocampus gyrus is critical for the acquisition of novel information. On the other hand, patients with defective root finding can identify familiar streets, but cannot remember their own location or positional relation between two points within a comparatively wide range not surveyable at one time. The lesions are located in the right retrosplenial cortex (Areas 29, 30), posterior cingulate cortex (Areas 23, 31) and precuneus. Clinical findings and functional imaging studies suggest that these regions are involved in the orientation function for navigating in wide spaces. In particular, the retrosplenial cortex is critical for encoding novel information. (author)

Fixation and saliency during search of natural scenes: the case of visual agnosia.

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Foulsham, Tom; Barton, Jason J S; Kingstone, Alan; Dewhurst, Richard; Underwood, Geoffrey

2009-07-01

Models of eye movement control in natural scenes often distinguish between stimulus-driven processes (which guide the eyes to visually salient regions) and those based on task and object knowledge (which depend on expectations or identification of objects and scene gist). In the present investigation, the eye movements of a patient with visual agnosia were recorded while she searched for objects within photographs of natural scenes and compared to those made by students and age-matched controls. Agnosia is assumed to disrupt the top-down knowledge available in this task, and so may increase the reliance on bottom-up cues. The patient's deficit in object recognition was seen in poor search performance and inefficient scanning. The low-level saliency of target objects had an effect on responses in visual agnosia, and the most salient region in the scene was more likely to be fixated by the patient than by controls. An analysis of model-predicted saliency at fixation locations indicated a closer match between fixations and low-level saliency in agnosia than in controls. These findings are discussed in relation to saliency-map models and the balance between high and low-level factors in eye guidance.

[A case of carbon monoxide poisoning by explosion of coal mine presenting as visual agnosia: re-evaluation after 40 years].

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Takaiwa, Akiko; Yamashita, Kenichiro; Nomura, Takuo; Shida, Kenshiro; Taniwaki, Takayuki

2005-11-01

We re-evaluated a case of carbon monoxide poisoning presenting as visual agnosia who had been injured by explosion of Miike-Mikawa coal mine 40 years ago. In an early stage, his main neuropsychological symptoms were visual agnosia, severe anterograde amnesia, alexia, agraphia, constructional apraxia, left hemispatial neglect and psychic paralysis of gaze, in addition to pyramidal and extra pyramidal signs. At the time of re-evaluation after 40 years, he still showed visual agnosia associated with agraphia and constructional apraxia. Concerning visual agnosia, recognition of the real object was preserved, while recognition of object photographs and picture was impaired. Thus, this case was considered to have picture agnosia as he could not recognize the object by pictorial cues on the second dimensional space. MRI examination revealed low signal intensity lesions and cortical atrophy in the bilateral parieto-occipital lobes on T1-weighted images. Therefore, the bilateral parieto-occipital lesions are likely to be responsible for his picture agnosia.

A case of carbon monoxide poisoning by explosion of coal mine presenting as visual agnosia: re-evaluation after 40 years

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Takaiwa, A.; Yamashita, K.; Nomura, T.; Shida, K.; Taniwaki, T. [Kyushu University, Fukuoka (Japan). Department of Neurology, Graduate School of Medical Science

2005-11-15

We re-evaluated a case of carbon monoxide poisoning presenting as visual agnosia who had been injured by explosion of Miike-Mikawa coal mine 40 years ago. In an early stage, his main neuropsychological symptoms were visual agnosia, severe anterograde amnesia, alexia, agraphia, constructional apraxia, left hemispatial neglect and psychic paralysis of gaze, in addition to pyramidal and extra pyramidal signs. At the time of re-evaluation after 40 years, he still showed visual agnosia associated with agraphia and constructional apraxia. Concerning visual agnosia, recognition of the real object was preserved, while recognition of object photographs and picture was impaired. Thus, this case was considered to have picture agnosia as he could not recognize the object by pictorial cues on the second dimensional space. MRI examination revealed low signal intensity lesions and cortical atrophy in the bilateral parieto-occipital lobes on T1-weighted images. Therefore, the bilateral parieto-occipital lesions are likely to be responsible for his picture agnosia.

Acquired Auditory Verbal Agnosia and Seizures in Childhood

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Cooper, Judith A.; Ferry, Peggy C.

1978-01-01

The paper presents a review of cases of children with acquired aphasia with convulsive disorder and discusses clinical features of three additional children in whom the specific syndrome of auditory verbal agnosia was identified. (Author/CL)

Toe agnosia in Gerstmann syndrome

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Tucha, O.; Steup, A.; Smely, C.; Lange, K.

1997-01-01

The following case report presents a patient exhibiting Gerstmann syndrome accompanied by toe agnosia. A 72 year old right handed woman had a focal lesion in the angular gyrus of the left hemisphere which was caused by a glioblastoma multiforme. The first symptom she had complained of was severe headache. Standardised neuropsychological tests of intelligence, memory, attention, fluency, apraxia, and language functions as well as tests for the assessment of agraphia, acalculia, right-...

Associative visual agnosia: a case study.

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Charnallet, A; Carbonnel, S; David, D; Moreaud, O

2008-01-01

We report a case of massive associative visual agnosia. In the light of current theories of identification and semantic knowledge organization, a deficit involving both levels of structural description system and visual semantics must be assumed to explain the case. We suggest, in line with a previous case study, an alternative account in the framework of (non abstractive) episodic models of memory.

Relationship between somatosensory event-related potential N140 aberrations and hemispatial agnosia in patients with stroke: a preliminary study.

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Ueno, Tomoyuki; Hada, Yasushi; Shimizu, Yukiyo; Yamada, Thoru

2018-06-01

The somatosensory event-related potential N140 is thought to be related to selective attention. This study aimed to compare the somatosensory event-related potential N140 in healthy subjects to that in patients with stroke to determine whether N140 and attentiveness are associated in patients with stroke with or without hemispatial agnosia. Normal somatosensory event-related potential N140 values were determined using data from ten healthy subjects. Fifteen patients with stroke were divided into two groups based on the presence of hemispatial neglect. Somatosensory event-related potential N140 components were compared between the two groups. Stimulation of the affected limb in the hemispatial agnosia group resulted in significantly longer N140 latency at the contralateral vs. the ipsilateral electrode. This was the inverse of the relationship observed in normal subjects, with stimulation of the intact side in patients with hemispatial agnosia, and with stimulation of both the intact and affected sides in patients without agnosia. In the hemispatial agnosia group, the peak latency of N140 following stimulation of the affected side was significantly longer than it was following stimulation of the intact side and when compared to that in patients without agnosia. In addition, abnormal N140 peak latencies were observed at the Cz and ipsilateral electrodes in patients with hemispatial agnosia following stimulation of the intact side. These findings suggest that somatosensory event-related potential N140 is independently generated in each hemisphere and may reflect cognitive attention.

Associative Visual Agnosia: A Case Study

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A. Charnallet

2008-01-01

Full Text Available We report a case of massive associative visual agnosia. In the light of current theories of identification and semantic knowledge organization, a deficit involving both levels of structural description system and visual semantics must be assumed to explain the case. We suggest, in line with a previous case study [1], an alternative account in the framework of (non abstractive episodic models of memory [4].

Associative Visual Agnosia: A Case Study

OpenAIRE

Charnallet, A.; Carbonnel, S.; David, D.; Moreaud, O.

2008-01-01

We report a case of massive associative visual agnosia. In the light of current theories of identification and semantic knowledge organization, a deficit involving both levels of structural description system and visual semantics must be assumed to explain the case. We suggest, in line with a previous case study [1], an alternative account in the framework of (non abstractive) episodic models of memory [4].

Perception of biological motion in visual agnosia

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Elisabeth eHuberle

2012-08-01

Full Text Available Over the past twenty-five years, visual processing has been discussed in the context of the dual stream hypothesis consisting of a ventral (‘what' and a dorsal ('where' visual information processing pathway. Patients with brain damage of the ventral pathway typically present with signs of visual agnosia, the inability to identify and discriminate objects by visual exploration, but show normal perception of motion perception. A dissociation between the perception of biological motion and non-biological motion has been suggested: Perception of biological motion might be impaired when 'non-biological' motion perception is intact and vice versa. The impact of object recognition on the perception of biological motion remains unclear. We thus investigated this question in a patient with severe visual agnosia, who showed normal perception of non-biological motion. The data suggested that the patient's perception of biological motion remained largely intact. However, when tested with objects constructed of coherently moving dots (‘Shape-from-Motion’, recognition was severely impaired. The results are discussed in the context of possible mechanisms of biological motion perception.

Dyspraxia and Agnosia in Schizophrenia

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P. F. Liddle

1993-01-01

Full Text Available A battery of tests for dyspraxia and agnosia was administered to 51 chronic schizophrenic patients to test the hypothesis that these cortical neurological signs are associated with psychomotor poverty syndrome (poverty of speech, flat affect, decreased spontaneous movement, disorganization syndrome (various disorders of the form of thought, inappropriate affect, abnormal involuntary movements, cognitive impairment, and duration of illness. The findings supported all elements of the hypothesis, and in particular, demonstrated a strong correlation of cortical signs with psychomotor poverty and with cognitive impairment.

Episodic epileptic verbal auditory agnosia in Landau Kleffner syndrome treated with combination diazepam and corticosteroids.

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Devinsky, Orrin; Goldberg, Rina; Miles, Daniel; Bojko, Aviva; Riviello, James

2014-10-01

We report 2 pediatric patients who presented initially with seizures followed by subacute language regression characterized by a verbal auditory agnosia. These previously normal children had no evidence of expressive aphasia during their symptomatic periods. Further, in both cases, auditory agnosia was associated with sleep-activated electroencephalographic (EEG) epileptiform activity, consistent with Landau-Kleffner syndrome. However, both cases are unique since the episodic auditory agnosia and sleep-activated EEG epileptiform activity rapidly responded to combination therapy with pulse benzodiazepine and corticosteroids. Further, in each case, recurrences were characterized by similar symptoms, EEG findings, and beneficial responses to the pulse benzodiazepine and corticosteroid therapy. These observations suggest that pulse combination high-dose corticosteroid and benzodiazepine therapy may be especially effective in Landau-Kleffner syndrome. © The Author(s) 2014.

Verbal auditory agnosia in a patient with traumatic brain injury: A case report.

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Kim, Jong Min; Woo, Seung Beom; Lee, Zeeihn; Heo, Sung Jae; Park, Donghwi

2018-03-01

Verbal auditory agnosia is the selective inability to recognize verbal sounds. Patients with this disorder lose the ability to understand language, write from dictation, and repeat words with reserved ability to identify nonverbal sounds. However, to the best of our knowledge, there was no report about verbal auditory agnosia in adult patient with traumatic brain injury. He was able to clearly distinguish between language and nonverbal sounds, and he did not have any difficulty in identifying the environmental sounds. However, he did not follow oral commands and could not repeat and dictate words. On the other hand, he had fluent and comprehensible speech, and was able to read and understand written words and sentences. Verbal auditory agnosia INTERVENTION:: He received speech therapy and cognitive rehabilitation during his hospitalization, and he practiced understanding of verbal language by providing written sentences together. Two months after hospitalization, he regained his ability to understand some verbal words. Six months after hospitalization, his ability to understand verbal language was improved to an understandable level when speaking slowly in front of his eyes, but his comprehension of verbal sound language was still word level, not sentence level. This case gives us the lesson that the evaluation of auditory functions as well as cognition and language functions important for accurate diagnosis and appropriate treatment, because the verbal auditory agnosia tends to be easily misdiagnosed as hearing impairment, cognitive dysfunction and sensory aphasia.

Affective agnosia: Expansion of the alexithymia construct and a new opportunity to integrate and extend Freud's legacy.

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Lane, Richard D; Weihs, Karen L; Herring, Anne; Hishaw, Alex; Smith, Ryan

2015-08-01

We describe a new type of agnosia consisting of an impairment in the ability to mentally represent or know what one is feeling. Freud the neurologist coined the term "agnosia" in 1891 before creating psychoanalysis in 1895 but the term has not been previously applied to the domain of affective processing. We propose that the concept of "affective agnosia" advances the theory, measurement and treatment of what is now called "alexithymia," meaning "lack of words for emotion." We trace the origin of the alexithymia construct and discuss the strengths and limitations of extant research. We review evidence that the ability to represent and put emotions into words is a developmental achievement that strongly influences one's ability to experience, recognize, understand and use one's own emotional responses. We describe the neural substrates of emotional awareness and affective agnosia and compare and contrast these with related conditions. We then describe how this expansion of the conceptualization and measurement of affective processing deficits has important implications for basic emotion research and clinical practice. Copyright © 2015 Elsevier Ltd. All rights reserved.

''I Could See, and Yet, Mon, I Could Na' See'': William Macewen, the Agnosias, and Brain Surgery

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Macmillan, Malcolm

2004-01-01

Two little noticed cases in which William Macewen used symptoms of visual agnosia to plan brain surgery on the angular gyrus are reviewed and evaluated. Following a head injury, Macewen's first patient had an immediate and severe visual object agnosia that lasted for about 2 weeks. After that he gradually became homicidal and depressed and it was…

A tale of two agnosias: distinctions between form and integrative agnosia.

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Riddoch, M Jane; Humphreys, Glyn W; Akhtar, Nabeela; Allen, Harriet; Bracewell, R Martyn; Schofield, Andrew J

2008-02-01

The performance of two patients with visual agnosia was compared across a number of tests examining visual processing. The patients were distinguished by having dorsal and medial ventral extrastriate lesions. While inanimate objects were disadvantaged for the patient with a dorsal extrastriate lesion, animate items are disadvantaged for the patient with the medial ventral extrastriate lesion. The patients also showed contrasting patterns of performance on the Navon Test: The patient with a dorsal extrastriate lesion demonstrated a local bias while the patient with a medial ventral extrastriate lesion had a global bias. We propose that the dorsal and medial ventral visual pathways may be characterized at an extrastriate level by differences in local relative to more global visual processing and that this can link to visually based category-specific deficits in processing.

Picture agnosia as a characteristic of posterior cortical atrophy.

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Sugimoto, Azusa; Midorikawa, Akira; Koyama, Shinichi; Futamura, Akinori; Hieda, Sotaro; Kawamura, Mitsuru

2012-01-01

Posterior cortical atrophy (PCA) is a degenerative disease characterized by progressive visual agnosia with posterior cerebral atrophy. We examine the role of the picture naming test and make a number of suggestions with regard to diagnosing PCA as atypical dementia. We investigated 3 cases of early-stage PCA with 7 control cases of Alzheimer disease (AD). The patients and controls underwent a naming test with real objects and colored photographs of familiar objects. We then compared rates of correct answers. Patients with early-stage PCA showed significant inability to recognize photographs compared to real objects (F = 196.284, p = 0.0000) as measured by analysis of variants. This difficulty was also significant to AD controls (F = 58.717, p = 0.0000). Picture agnosia is a characteristic symptom of early-stage PCA, and the picture naming test is useful for the diagnosis of PCA as atypical dementia at an early stage. Copyright © 2012 S. Karger AG, Basel.

Integration of tactile input across fingers in a patient with finger agnosia.

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Anema, Helen A; Overvliet, Krista E; Smeets, Jeroen B J; Brenner, Eli; Dijkerman, H Chris

2011-01-01

Finger agnosia has been described as an inability to explicitly individuate between the fingers, which is possibly due to fused neural representations of these fingers. Hence, are patients with finger agnosia unable to keep tactile information perceived over several fingers separate? Here, we tested a finger agnosic patient (GO) on two tasks that measured the ability to keep tactile information simultaneously perceived by individual fingers separate. In experiment 1 GO performed a haptic search task, in which a target (the absence of a protruded line) needed to be identified among distracters (protruded lines). The lines were presented simultaneously to the fingertips of both hands. Similarly to the controls, her reaction time decreased when her fingers were aligned as compared to when her fingers were stretched and in an unaligned position. This suggests that she can keep tactile input from different fingers separate. In experiment two, GO was required to judge the position of a target tactile stimulus to the index finger, relatively to a reference tactile stimulus to the middle finger, both in fingers uncrossed and crossed position. GO was able to indicate the relative position of the target stimulus as well as healthy controls, which indicates that she was able to keep tactile information perceived by two neighbouring fingers separate. Interestingly, GO performed better as compared to the healthy controls in the finger crossed condition. Together, these results suggest the GO is able to implicitly distinguish between tactile information perceived by multiple fingers. We therefore conclude that finger agnosia is not caused by minor disruptions of low-level somatosensory processing. These findings further underpin the idea of a selective impaired higher order body representation restricted to the fingers as underlying cause of finger agnosia. Copyright © 2010 Elsevier Ltd. All rights reserved.

On Building Bridges: Cultural Agnosia, HipHopEd, and Urban Education

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Emdin, Christopher

2017-01-01

In this article, the author describes a lens for engaging in research and practice in urban education rooted in deep cultural understandings of the concept of building bridges and the impact of cultural agnosia.

Patterns of music agnosia associated with middle cerebral artery infarcts.

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Ayotte, J; Peretz, I; Rousseau, I; Bard, C; Bojanowski, M

2000-09-01

The objective of the study is to evaluate if the rupture of an aneurysm located on the middle cerebral artery (MCA) results in disorders of music recognition. To this aim, 20 patients having undergone brain surgery for the clipping of a unilateral left (LBS), right (RBS) or bilateral (BBS) aneurysm(s) of the MCA and 20 neurologically intact control subjects (NC) were evaluated with a series of tests assessing most of the abilities involved in music recognition. In general, the study shows that a ruptured aneurysm on the MCA that is repaired by brain surgery is very likely to produce deficits in the auditory processing of music. The incidence of such a deficit was not only very high but also selective. The results show that the LBS group was more impaired than the NC group in all three tasks involving musical long-term memory. The study also uncovered two new cases of apperceptive agnosia for music. These two patients (N.R. and R.C.) were diagnosed as such because both exhibit a clear deficit in each of the three music memory tasks and both are impaired in all discrimination tests involving musical perception. Interestingly, the lesions overlap in the right superior temporal lobe and in the right insula, making the two new cases very similar to an earlier case report. Altogether, the results are also consistent with the view that apperceptive agnosia results from damage to right hemispheric structures while associative agnosia results from damage to the left hemisphere.

Agnosia, apraxia, callosal disconnection and other specific cognitive disorders.

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Acciarresi, Monica

2012-01-01

Cortical function deficits have long been studied by anatomoclinic correlations. Recent functional imaging studies have allowed scientists to better understand which cerebral areas and which networks are involved in cognitive function deficit. This chapter will review the current knowledge on agnosia, apraxia and callosal disconnection syndromes. Copyright © 2012 S. Karger AG, Basel.

Visual object agnosia is associated with a breakdown of object-selective responses in the lateral occipital cortex.

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Ptak, Radek; Lazeyras, François; Di Pietro, Marie; Schnider, Armin; Simon, Stéphane R

2014-07-01

Patients with visual object agnosia fail to recognize the identity of visually presented objects despite preserved semantic knowledge. Object agnosia may result from damage to visual cortex lying close to or overlapping with the lateral occipital complex (LOC), a brain region that exhibits selectivity to the shape of visually presented objects. Despite this anatomical overlap the relationship between shape processing in the LOC and shape representations in object agnosia is unknown. We studied a patient with object agnosia following isolated damage to the left occipito-temporal cortex overlapping with the LOC. The patient showed intact processing of object structure, yet often made identification errors that were mainly based on the global visual similarity between objects. Using functional Magnetic Resonance Imaging (fMRI) we found that the damaged as well as the contralateral, structurally intact right LOC failed to show any object-selective fMRI activity, though the latter retained selectivity for faces. Thus, unilateral damage to the left LOC led to a bilateral breakdown of neural responses to a specific stimulus class (objects and artefacts) while preserving the response to a different stimulus class (faces). These findings indicate that representations of structure necessary for the identification of objects crucially rely on bilateral, distributed coding of shape features. Copyright © 2014 Elsevier Ltd. All rights reserved.

Superior voice recognition in a patient with acquired prosopagnosia and object agnosia.

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Hoover, Adria E N; Démonet, Jean-François; Steeves, Jennifer K E

2010-11-01

Anecdotally, it has been reported that individuals with acquired prosopagnosia compensate for their inability to recognize faces by using other person identity cues such as hair, gait or the voice. Are they therefore superior at the use of non-face cues, specifically voices, to person identity? Here, we empirically measure person and object identity recognition in a patient with acquired prosopagnosia and object agnosia. We quantify person identity (face and voice) and object identity (car and horn) recognition for visual, auditory, and bimodal (visual and auditory) stimuli. The patient is unable to recognize faces or cars, consistent with his prosopagnosia and object agnosia, respectively. He is perfectly able to recognize people's voices and car horns and bimodal stimuli. These data show a reverse shift in the typical weighting of visual over auditory information for audiovisual stimuli in a compromised visual recognition system. Moreover, the patient shows selectively superior voice recognition compared to the controls revealing that two different stimulus domains, persons and objects, may not be equally affected by sensory adaptation effects. This also implies that person and object identity recognition are processed in separate pathways. These data demonstrate that an individual with acquired prosopagnosia and object agnosia can compensate for the visual impairment and become quite skilled at using spared aspects of sensory processing. In the case of acquired prosopagnosia it is advantageous to develop a superior use of voices for person identity recognition in everyday life. Copyright © 2010 Elsevier Ltd. All rights reserved.

[Simultanagnosia and scene agnosia induced by right posterior cerebral artery infarction: a case report].

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Kobayashi, Yasutaka; Muramatsu, Tomoko; Sato, Mamiko; Hayashi, Hiromi; Miura, Toyoaki

2015-01-01

A 68-year-old man was admitted to our hospital for rehabilitation of topographical disorientation. Brain magnetic resonance imaging revealed infarction in the right medial side of the occipital lobe. On neuropsychological testing, he scored low for the visual information-processing task; however, his overall cognitive function was retained. He could identify parts of the picture while describing the context picture of the Visual Perception Test for Agnosia but could not explain the contents of the entire picture, representing so-called simultanagnosia. Further, he could morphologically perceive both familiar and new scenes, but could not identify them, representing so-called scene agnosia. We report this case because simultanagnosia associated with a right occipital lobe lesion is rare.

Visual agnosia for line drawings and silhouettes without apparent impairment of real-object recognition: a case report.

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Hiraoka, Kotaro; Suzuki, Kyoko; Hirayama, Kazumi; Mori, Etsuro

2009-01-01

We report on a patient with visual agnosia for line drawings and silhouette pictures following cerebral infarction in the region of the right posterior cerebral artery. The patient retained the ability to recognize real objects and their photographs, and could precisely copy line drawings of objects that she could not name. This case report highlights the importance of clinicians and researchers paying special attention to avoid overlooking agnosia in such cases. The factors that lead to problems in the identification of stimuli other than real objects in agnosic cases are discussed.

Visual Agnosia for Line Drawings and Silhouettes without Apparent Impairment of Real-Object Recognition: A Case Report

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Kotaro Hiraoka

2009-01-01

Full Text Available We report on a patient with visual agnosia for line drawings and silhouette pictures following cerebral infarction in the region of the right posterior cerebral artery. The patient retained the ability to recognize real objects and their photographs, and could precisely copy line drawings of objects that she could not name. This case report highlights the importance of clinicians and researchers paying special attention to avoid overlooking agnosia in such cases. The factors that lead to problems in the identification of stimuli other than real objects in agnosic cases are discussed.

Implicit integration in a case of integrative visual agnosia.

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Aviezer, Hillel; Landau, Ayelet N; Robertson, Lynn C; Peterson, Mary A; Soroker, Nachum; Sacher, Yaron; Bonneh, Yoram; Bentin, Shlomo

2007-05-15

We present a case (SE) with integrative visual agnosia following ischemic stroke affecting the right dorsal and the left ventral pathways of the visual system. Despite his inability to identify global hierarchical letters [Navon, D. (1977). Forest before trees: The precedence of global features in visual perception. Cognitive Psychology, 9, 353-383], and his dense object agnosia, SE showed normal global-to-local interference when responding to local letters in Navon hierarchical stimuli and significant picture-word identity priming in a semantic decision task for words. Since priming was absent if these features were scrambled, it stands to reason that these effects were not due to priming by distinctive features. The contrast between priming effects induced by coherent and scrambled stimuli is consistent with implicit but not explicit integration of features into a unified whole. We went on to show that possible/impossible object decisions were facilitated by words in a word-picture priming task, suggesting that prompts could activate perceptually integrated images in a backward fashion. We conclude that the absence of SE's ability to identify visual objects except through tedious serial construction reflects a deficit in accessing an integrated visual representation through bottom-up visual processing alone. However, top-down generated images can help activate these visual representations through semantic links.

Impaired Integration of Emotional Faces and Affective Body Context in a Rare Case of Developmental Visual Agnosia

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Aviezer, Hillel; Hassin, Ran. R.; Bentin, Shlomo

2011-01-01

In the current study we examined the recognition of facial expressions embedded in emotionally expressive bodies in case LG, an individual with a rare form of developmental visual agnosia who suffers from severe prosopagnosia. Neuropsychological testing demonstrated that LG‘s agnosia is characterized by profoundly impaired visual integration. Unlike individuals with typical developmental prosopagnosia who display specific difficulties with face identity (but typically not expression) recognition, LG was also impaired at recognizing isolated facial expressions. By contrast, he successfully recognized the expressions portrayed by faceless emotional bodies handling affective paraphernalia. When presented with contextualized faces in emotional bodies his ability to detect the emotion expressed by a face did not improve even if it was embedded in an emotionally-congruent body context. Furthermore, in contrast to controls, LG displayed an abnormal pattern of contextual influence from emotionally-incongruent bodies. The results are interpreted in the context of a general integration deficit in developmental visual agnosia, suggesting that impaired integration may extend from the level of the face to the level of the full person. PMID:21482423

La «agnosia» del creyente

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Gómez Caffarena, José

2002-04-01

Full Text Available Not available

Agnosia, un término griego para ignorancia, fue usado por un cristiano del siglo V que tuvo gran influjo para caracterizar el modestísimo conocimiento (gnosis de Dios a que pueden aspirar los humanos. El creyente reflexivo actual recoge con sumo interés esa modestia y encuentra en ella la clave de una real cercanía con aquellos agnósticos actuales que siguen valorando la teología. Coinciden ambos en lo que saben (sobre el mundo y el hombre y en el interés por las cuestiones-límite; ante las que tienen convicciones (y actitudes diferentes.

Psychic blindness or visual agnosia: early descriptions of a nervous disorder.

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Baumann, Christian

2011-01-01

This article briefly reports on three early contributions to the understanding of visual agnosia as a syndrome sui generis. The authors of the respective papers worked in different fields such as physiology, ophthalmology, and neurology, and, although they were not in direct contact with each other, their results converged upon a consistent view of a nervous disorder that they called psychic blindness.

What's in the name 'alexithymia'? A commentary on "Affective agnosia: Expansion of the alexithymia construct and a new opportunity to integrate and extend Freud's legacy.".

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Taylor, Graeme J; Bagby, R Michael; Parker, James D A

2016-09-01

The recent proposal of a new type of agnosia termed 'affective agnosia' extends Freud's legacy and captures the concept of not knowing one's own emotions. This concept links well with the theory of levels of emotional awareness and maps onto a hierarchical model of neural substrates of emotional experience, but does not encompass the pensée opératoire component of the alexithymia construct. Moreover, identifying agnosia and anomia subtypes, which connotes a categorical conceptualization of alexithymia, is inconsistent with the dimensional nature of the construct. We describe a more widely accepted definition of alexithymia, and argue that although aptly descriptive, the concept of affective agnosia does not advance the theory, measurement, and treatment of alexithymia. A review of alexithymia literature indicates that impairment in the mental representation of emotions has been a central aspect of alexithymia theory since the concept was introduced, and guided the development of the Toronto Alexithymia Scale and other measures of the construct. Moreover, techniques to enhance mentalization of emotions have been used by psychotherapists for several decades. Copyright © 2016 Elsevier Ltd. All rights reserved.

Independent Representation of Parts and the Relations between Them: Evidence from Integrative Agnosia

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Behrmann, Marlene; Peterson, Mary A.; Moscovitch, Morris; Suzuki, Satoru

2006-01-01

Whether objects are represented as a collection of parts whose relations are coded independently remains a topic of ongoing discussion among theorists in the domain of shape perception. S. M., an individual with integrative agnosia, and neurologically intact ("normal") individuals learned initially to identify 4 target objects constructed of 2…

A case of tactile agnosia with a lesion restricted to the post-central gyrus.

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Estañol, Bruno; Baizabal-Carvallo, José Fidel; Sentíes-Madrid, Horacio

2008-01-01

Tactile agnosia has been described after lesions of the primary sensory cortex but the exact location and extension of those lesions is not clear. We report the clinical features and imaging findings in a patient with an acute ischemic stroke restricted to the primary sensory area (S1). A 73-year-old man had a sudden onset of a left alien hand, without left hemiparesis. Neurological examination showed intact primary sensory functions, but impaired recognition of shape, size (macrogeometrical) and texture (microgeometrical) of objects; damage confined to the post-central gyrus, sparing the posterior parietal cortex was demonstrated on MRI. An embolic occlusion of the anterior parietal artery was suspected as mechanism of stroke. Tactile agnosia with impaired microgeometrical and macrogeometrical features' recognition can result from a single lesion in the primary sensory cortex (S1) in the right parietal hemisphere, sparing other regions of the cerebral cortex which presumably participate in tactile object recognition.

[A case of transient auditory agnosia and schizophrenia].

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Kanzaki, Jin; Harada, Tatsuhiko; Kanzaki, Sho

2011-03-01

We report a case of transient functional auditory agnosia and schizophrenia and discuss their relationship. A 30-year-old woman with schizophrenia reporting bilateral hearing loss was found in history taking to be able to hear but could neither understand speech nor discriminate among environmental sounds. Audiometry clarified normal but low speech discrimination. Otoacoustic emission and auditory brainstem response were normal. Magnetic resonance imaging (MRI) elsewhere evidenced no abnormal findings. We assumed that taking care of her grandparents who had been discharged from the hospital had unduly stressed her, and her condition improved shortly after she stopped caring for them, returned home and started taking a minor tranquilizer.

Structural and functional changes across the visual cortex of a patient with visual form agnosia.

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Bridge, Holly; Thomas, Owen M; Minini, Loredana; Cavina-Pratesi, Cristiana; Milner, A David; Parker, Andrew J

2013-07-31

Loss of shape recognition in visual-form agnosia occurs without equivalent losses in the use of vision to guide actions, providing support for the hypothesis of two visual systems (for "perception" and "action"). The human individual DF received a toxic exposure to carbon monoxide some years ago, which resulted in a persisting visual-form agnosia that has been extensively characterized at the behavioral level. We conducted a detailed high-resolution MRI study of DF's cortex, combining structural and functional measurements. We present the first accurate quantification of the changes in thickness across DF's occipital cortex, finding the most substantial loss in the lateral occipital cortex (LOC). There are reduced white matter connections between LOC and other areas. Functional measures show pockets of activity that survive within structurally damaged areas. The topographic mapping of visual areas showed that ordered retinotopic maps were evident for DF in the ventral portions of visual cortical areas V1, V2, V3, and hV4. Although V1 shows evidence of topographic order in its dorsal portion, such maps could not be found in the dorsal parts of V2 and V3. We conclude that it is not possible to understand fully the deficits in object perception in visual-form agnosia without the exploitation of both structural and functional measurements. Our results also highlight for DF the cortical routes through which visual information is able to pass to support her well-documented abilities to use visual information to guide actions.

Mutism and auditory agnosia due to bilateral insular damage--role of the insula in human communication.

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Habib, M; Daquin, G; Milandre, L; Royere, M L; Rey, M; Lanteri, A; Salamon, G; Khalil, R

1995-03-01

We report a case of transient mutism and persistent auditory agnosia due to two successive ischemic infarcts mainly involving the insular cortex on both hemispheres. During the 'mutic' period, which lasted about 1 month, the patient did not respond to any auditory stimuli and made no effort to communicate. On follow-up examinations, language competences had re-appeared almost intact, but a massive auditory agnosia for non-verbal sounds was observed. From close inspection of lesion site, as determined with brain resonance imaging, and from a study of auditory evoked potentials, it is concluded that bilateral insular damage was crucial to both expressive and receptive components of the syndrome. The role of the insula in verbal and non-verbal communication is discussed in the light of anatomical descriptions of the pattern of connectivity of the insular cortex.

Category Specificity in Normal Episodic Learning: Applications to Object Recognition and Category-Specific Agnosia

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Bukach, Cindy M.; Bub, Daniel N.; Masson, Michael E. J.; Lindsay, D. Stephen

2004-01-01

Studies of patients with category-specific agnosia (CSA) have given rise to multiple theories of object recognition, most of which assume the existence of a stable, abstract semantic memory system. We applied an episodic view of memory to questions raised by CSA in a series of studies examining normal observers' recall of newly learned attributes…

A case of complex regional pain syndrome with agnosia for object orientation.

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Robinson, Gail; Cohen, Helen; Goebel, Andreas

2011-07-01

This systematic investigation of the neurocognitive correlates of complex regional pain syndrome (CRPS) in a single case also reports agnosia for object orientation in the context of persistent CRPS. We report a patient (JW) with severe long-standing CRPS who had no difficulty identifying and naming line drawings of objects presented in 1 of 4 cardinal orientations. In contrast, he was extremely poor at reorienting these objects into the correct upright orientation and in judging whether an object was upright or not. Moreover, JW made orientation errors when copying drawings of objects, and he also showed features of mirror reversal in writing single words and reading single letters. The findings are discussed in relation to accounts of visual processing. Agnosia for object orientation is the term for impaired knowledge of an object's orientation despite good recognition and naming of the same misoriented object. This defect has previously only been reported in patients with major structural brain lesions. The neuroanatomical correlates are discussed. The patient had no structural brain lesion, raising the possibility that nonstructural reorganisation of cortical networks may be responsible for his deficits. Other patients with CRPS may have related neurocognitive defects. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Characteristics of Auditory Agnosia in a Child with Severe Traumatic Brain Injury: A Case Report

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Hattiangadi, Nina; Pillion, Joseph P.; Slomine, Beth; Christensen, James; Trovato, Melissa K.; Speedie, Lynn J.

2005-01-01

We present a case that is unusual in many respects from other documented incidences of auditory agnosia, including the mechanism of injury, age of the individual, and location of neurological insult. The clinical presentation is one of disturbance in the perception of spoken language, music, pitch, emotional prosody, and temporal auditory…

The Role of Sensory-Motor Information in Object Recognition: Evidence from Category-Specific Visual Agnosia

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Wolk, D.A.; Coslett, H.B.; Glosser, G.

2005-01-01

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…

Auditory agnosia as a clinical symptom of childhood adrenoleukodystrophy.

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Furushima, Wakana; Kaga, Makiko; Nakamura, Masako; Gunji, Atsuko; Inagaki, Masumi

2015-08-01

To investigate detailed auditory features in patients with auditory impairment as the first clinical symptoms of childhood adrenoleukodystrophy (CSALD). Three patients who had hearing difficulty as the first clinical signs and/or symptoms of ALD. Precise examination of the clinical characteristics of hearing and auditory function was performed, including assessments of pure tone audiometry, verbal sound discrimination, otoacoustic emission (OAE), and auditory brainstem response (ABR), as well as an environmental sound discrimination test, a sound lateralization test, and a dichotic listening test (DLT). The auditory pathway was evaluated by MRI in each patient. Poor response to calling was detected in all patients. Two patients were not aware of their hearing difficulty, and had been diagnosed with normal hearing by otolaryngologists at first. Pure-tone audiometry disclosed normal hearing in all patients. All patients showed a normal wave V ABR threshold. Three patients showed obvious difficulty in discriminating verbal sounds, environmental sounds, and sound lateralization and strong left-ear suppression in a dichotic listening test. However, once they discriminated verbal sounds, they correctly understood the meaning. Two patients showed elongation of the I-V and III-V interwave intervals in ABR, but one showed no abnormality. MRIs of these three patients revealed signal changes in auditory radiation including in other subcortical areas. The hearing features of these subjects were diagnosed as auditory agnosia and not aphasia. It should be emphasized that when patients are suspected to have hearing impairment but have no abnormalities in pure tone audiometry and/or ABR, this should not be diagnosed immediately as psychogenic response or pathomimesis, but auditory agnosia must also be considered. Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

No double-dissociation between optic ataxia and visual agnosia: Multiple sub-streams for multiple visuo-manual integrations

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Pisella, L.; Binkofski, F.; Lasek, K.; Toni, I.; Rossetti, Y.

2006-01-01

The current dominant view of the visual system is marked by the functional and anatomical dissociation between a ventral stream specialised for perception and a dorsal stream specialised for action. The "double-dissociation" between visual agnosia (VA), a deficit of visual recognition, and optic

Middle components of the auditory evoked response in bilateral temporal lobe lesions. Report on a patient with auditory agnosia

DEFF Research Database (Denmark)

Parving, A; Salomon, G; Elberling, Claus

1980-01-01

An investigation of the middle components of the auditory evoked response (10--50 msec post-stimulus) in a patient with auditory agnosia is reported. Bilateral temporal lobe infarctions were proved by means of brain scintigraphy, CAT scanning, and regional cerebral blood flow measurements...

"Mirror agnosia" in a patient with right occipitotemporal infarct

Directory of Open Access Journals (Sweden)

Menon Bijoy

2006-01-01

Full Text Available We report the clinical profile and investigation of K, a patient suffering from agnosia for the concept of "mirrors". Normal people rarely confuse a mirror image for the real image. Our patient ′K′ has intact attention, memory and language with a left visual neglect with left hemianopia. When shown an object on his left with a mirror kept sagitally on his right, K grabs for the reflection and even gropes behind the mirror for it. Yet, when shown the mirror alone, he is able to tell that it is a mirror. Thus the concept of a ′mirror′ is lost in the experimental paradigm. An explanation for mirror ′agnosia′ is provided and recent controversies in the analysis of visuospatial functions in humans is highlighted.

Auditory agnosia due to long-term severe hydrocephalus caused by spina bifida - specific auditory pathway versus nonspecific auditory pathway.

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Zhang, Qing; Kaga, Kimitaka; Hayashi, Akimasa

2011-07-01

A 27-year-old female showed auditory agnosia after long-term severe hydrocephalus due to congenital spina bifida. After years of hydrocephalus, she gradually suffered from hearing loss in her right ear at 19 years of age, followed by her left ear. During the time when she retained some ability to hear, she experienced severe difficulty in distinguishing verbal, environmental, and musical instrumental sounds. However, her auditory brainstem response and distortion product otoacoustic emissions were largely intact in the left ear. Her bilateral auditory cortices were preserved, as shown by neuroimaging, whereas her auditory radiations were severely damaged owing to progressive hydrocephalus. Although she had a complete bilateral hearing loss, she felt great pleasure when exposed to music. After years of self-training to read lips, she regained fluent ability to communicate. Clinical manifestations of this patient indicate that auditory agnosia can occur after long-term hydrocephalus due to spina bifida; the secondary auditory pathway may play a role in both auditory perception and hearing rehabilitation.

Training-Induced Recovery of Low-Level Vision Followed by Mid-Level Perceptual Improvements in Developmental Object and Face Agnosia

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Lev, Maria; Gilaie-Dotan, Sharon; Gotthilf-Nezri, Dana; Yehezkel, Oren; Brooks, Joseph L.; Perry, Anat; Bentin, Shlomo; Bonneh, Yoram; Polat, Uri

2015-01-01

Long-term deprivation of normal visual inputs can cause perceptual impairments at various levels of visual function, from basic visual acuity deficits, through mid-level deficits such as contour integration and motion coherence, to high-level face and object agnosia. Yet it is unclear whether training during adulthood, at a post-developmental…

Selective preservation of the beat in apperceptive music agnosia: a case study.

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Baird, Amee D; Walker, David G; Biggs, Vivien; Robinson, Gail A

2014-04-01

Music perception involves processing of melodic, temporal and emotional dimensions that have been found to dissociate in healthy individuals and after brain injury. Two components of the temporal dimension have been distinguished, namely rhythm and metre. We describe an 18 year old male musician 'JM' who showed apperceptive music agnosia with selectively preserved metre perception, and impaired recognition of sad and peaceful music relative to age and music experience matched controls after resection of a right temporoparietal tumour. Two months post-surgery JM underwent a comprehensive neuropsychological evaluation including assessment of his music perception abilities using the Montreal Battery for Evaluation of Amusia (MBEA, Peretz, Champod, & Hyde, 2003). He also completed several experimental tasks to explore his ability to recognise famous songs and melodies, emotions portrayed by music and a broader range of environmental sounds. Five age-, gender-, education- and musical experienced-matched controls were administered the same experimental tasks. JM showed selective preservation of metre perception, with impaired performances compared to controls and scoring below the 5% cut-off on all MBEA subtests, except for the metric condition. He could identify his favourite songs and environmental sounds. He showed impaired recognition of sad and peaceful emotions portrayed in music relative to controls but intact ability to identify happy and scary music. This case study contributes to the scarce literature documenting a dissociation between rhythmic and metric processing, and the rare observation of selectively preserved metric interpretation in the context of apperceptive music agnosia. It supports the notion that the anterior portion of the superior temporal gyrus (STG) plays a role in metric processing and provides the novel observation that selectively preserved metre is sufficient to identify happy and scary, but not sad or peaceful emotions portrayed in music

Eye movements during object recognition in visual agnosia.

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Charles Leek, E; Patterson, Candy; Paul, Matthew A; Rafal, Robert; Cristino, Filipe

2012-07-01

This paper reports the first ever detailed study about eye movement patterns during single object recognition in visual agnosia. Eye movements were recorded in a patient with an integrative agnosic deficit during two recognition tasks: common object naming and novel object recognition memory. The patient showed normal directional biases in saccades and fixation dwell times in both tasks and was as likely as controls to fixate within object bounding contour regardless of recognition accuracy. In contrast, following initial saccades of similar amplitude to controls, the patient showed a bias for short saccades. In object naming, but not in recognition memory, the similarity of the spatial distributions of patient and control fixations was modulated by recognition accuracy. The study provides new evidence about how eye movements can be used to elucidate the functional impairments underlying object recognition deficits. We argue that the results reflect a breakdown in normal functional processes involved in the integration of shape information across object structure during the visual perception of shape. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nonverbal auditory agnosia with lesion to Wernicke's area.

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Saygin, Ayse Pinar; Leech, Robert; Dick, Frederic

2010-01-01

We report the case of patient M, who suffered unilateral left posterior temporal and parietal damage, brain regions typically associated with language processing. Language function largely recovered since the infarct, with no measurable speech comprehension impairments. However, the patient exhibited a severe impairment in nonverbal auditory comprehension. We carried out extensive audiological and behavioral testing in order to characterize M's unusual neuropsychological profile. We also examined the patient's and controls' neural responses to verbal and nonverbal auditory stimuli using functional magnetic resonance imaging (fMRI). We verified that the patient exhibited persistent and severe auditory agnosia for nonverbal sounds in the absence of verbal comprehension deficits or peripheral hearing problems. Acoustical analyses suggested that his residual processing of a minority of environmental sounds might rely on his speech processing abilities. In the patient's brain, contralateral (right) temporal cortex as well as perilesional (left) anterior temporal cortex were strongly responsive to verbal, but not to nonverbal sounds, a pattern that stands in marked contrast to the controls' data. This substantial reorganization of auditory processing likely supported the recovery of M's speech processing.

The neural basis of body form and body action agnosia.

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Moro, Valentina; Urgesi, Cosimo; Pernigo, Simone; Lanteri, Paola; Pazzaglia, Mariella; Aglioti, Salvatore Maria

2008-10-23

Visual analysis of faces and nonfacial body stimuli brings about neural activity in different cortical areas. Moreover, processing body form and body action relies on distinct neural substrates. Although brain lesion studies show specific face processing deficits, neuropsychological evidence for defective recognition of nonfacial body parts is lacking. By combining psychophysics studies with lesion-mapping techniques, we found that lesions of ventromedial, occipitotemporal areas induce face and body recognition deficits while lesions involving extrastriate body area seem causatively associated with impaired recognition of body but not of face and object stimuli. We also found that body form and body action recognition deficits can be double dissociated and are causatively associated with lesions to extrastriate body area and ventral premotor cortex, respectively. Our study reports two category-specific visual deficits, called body form and body action agnosia, and highlights their neural underpinnings.

Agnosia Interferes With Daily Hygiene in Patients With Dementia

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Hamdy, R. C.; Kinser, A.; Culp, J.E.; Kendall-Wilson, T.; Depelteau, A.; Copeland, R.; Whalen, K.

2018-01-01

Patients with dementia, particularly Alzheimer’s disease, may not recognize that their clothes are dirty. They may see the food stains and discoloration of the clothes and yet because of their agnosia are unable to integrate these observations and deduce that their clothes are dirty and need to be changed. They will, therefore, resist attempts to get them to change clothes, especially if these clothes happen to be their favorite ones. This often causes caregivers to become frustrated, especially, if it represents a change in the patient’s previous habits of only wearing clean clothes. In this case study, we present a 72-year-old woman with moderate Alzheimer’s disease who lives with her daughter, who adamantly refuses to change the clothes she has been wearing for a few days and which are now clearly dirty. We report the interaction, highlight what went wrong in the patient–daughter interaction, and discuss how the catastrophic ending could have been avoided or averted. PMID:29900188

Psychosis, agnosia, and confabulation: an alternative two-factor account.

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Turner, Mark A

2014-01-01

Theories of delusions which rely on a combination of abnormal experience and defective belief evaluation and/ or cognitive bias are the subject of an emerging consensus. This paper challenges the validity of these theories and constructs a two factor alternative. The paper starts by identifying the difficulty the current theories have explaining the complex delusions of schizophrenia and then, by considering, first, the aetiology of somatopsychotic symptoms, and second, the literature on the relationship between confabulation and allopsychotic symptoms, demonstrates that the natural solution is to retain the experiential factor whilst replacing the second factor with confabulation. The paper is then able to demonstrate that the resultant two-factory theory can clarify recent work on the aetiological role of autonoetic agnosia and on the relationships between confabulation, delusion, and thought disorder. The theory supersedes currently available theories in terms of its simplicity, fruitfulness, scope and conservatism and represents an advance in the search for unified theory of psychosis.

Selective Impairment of Living Things and Musical Instruments on a Verbal "Semantic Knowledge Questionnaire" in a Case of Apperceptive Visual Agnosia

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Masullo, Carlo; Piccininni, Chiara; Quaranta, Davide; Vita, Maria Gabriella; Gaudino, Simona; Gainotti, Guido

2012-01-01

Semantic memory was investigated in a patient (MR) affected by a severe apperceptive visual agnosia, due to an ischemic cerebral lesion, bilaterally affecting the infero-mesial parts of the temporo-occipital cortices. The study was made by means of a Semantic Knowledge Questionnaire (Laiacona, Barbarotto, Trivelli, & Capitani, 1993), which takes…

Impairments in part-whole representations of objects in two cases of integrative visual agnosia.

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Behrmann, Marlene; Williams, Pepper

2007-10-01

How complex multipart visual objects are represented perceptually remains a subject of ongoing investigation. One source of evidence that has been used to shed light on this issue comes from the study of individuals who fail to integrate disparate parts of visual objects. This study reports a series of experiments that examine the ability of two such patients with this form of agnosia (integrative agnosia; IA), S.M. and C.R., to discriminate and categorize exemplars of a rich set of novel objects, "Fribbles", whose visual similarity (number of shared parts) and category membership (shared overall shape) can be manipulated. Both patients performed increasingly poorly as the number of parts required for differentiating one Fribble from another increased. Both patients were also impaired at determining when two Fribbles belonged in the same category, a process that relies on abstracting spatial relations between parts. C.R., the less impaired of the two, but not S.M., eventually learned to categorize the Fribbles but required substantially more training than normal perceivers. S.M.'s failure is not attributable to a problem in learning to use a label for identification nor is it obviously attributable to a visual memory deficit. Rather, the findings indicate that, although the patients may be able to represent a small number of parts independently, in order to represent multipart images, the parts need to be integrated or chunked into a coherent whole. It is this integrative process that is impaired in IA and appears to play a critical role in the normal object recognition of complex images.

An adult case of the developmental apraxia, agnosia, Gerstmann's syndrome with bilateral parieto-temporo-occipital lesions in brain CT

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Suzuki, Toshihito; Shiraishi, Hiroyasu; Koizumi, Junzo; Ichikawa, Tadahiko; Hayakawa, Tatsuo.

1986-01-01

A 36-year-old woman with a history of cerebral meningitis had various neuropsychological disorders, such as Gerstmann's syndrome, developmental apraxia and agnosia and difficulty in reading, in addition to moderate mental retardation and epileptoid. Cranial CT showed bilateral low-density areas with temporo-parieto-occipital extension. It seems that these lesions result from meningitis and are responsible for the occurrence of neuropsychological disorders. (Namekawa, K.)

Differences in finger localisation performance of patients with finger agnosia.

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Anema, Helen A; Kessels, Roy P C; de Haan, Edward H F; Kappelle, L Jaap; Leijten, Frans S; van Zandvoort, Martine J E; Dijkerman, H Chris

2008-09-17

Several neuropsychological studies have suggested parallel processing of somatosensory input when localising a tactile stimulus on one's own by pointing towards it (body schema) and when localising this touched location by pointing to it on a map of a hand (body image). Usually these reports describe patients with impaired detection, but intact sensorimotor localisation. This study examined three patients with a lesion of the angular gyrus with intact somatosensory processing, but with selectively disturbed finger identification (finger agnosia). These patients performed normally when pointing towards the touched finger on their own hand but failed to indicate this finger on a drawing of a hand or to name it. Similar defects in the perception of other body parts were not observed. The findings provide converging evidence for the dissociation between body image and body schema and, more importantly, reveal for the first time that this distinction is also present in higher-order cognitive processes selectively for the fingers.

Impaired Velocity Processing Reveals an Agnosia for Motion in Depth.

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Barendregt, Martijn; Dumoulin, Serge O; Rokers, Bas

2016-11-01

Many individuals with normal visual acuity are unable to discriminate the direction of 3-D motion in a portion of their visual field, a deficit previously referred to as a stereomotion scotoma. The origin of this visual deficit has remained unclear. We hypothesized that the impairment is due to a failure in the processing of one of the two binocular cues to motion in depth: changes in binocular disparity over time or interocular velocity differences. We isolated the contributions of these two cues and found that sensitivity to interocular velocity differences, but not changes in binocular disparity, varied systematically with observers' ability to judge motion direction. We therefore conclude that the inability to interpret motion in depth is due to a failure in the neural mechanisms that combine velocity signals from the two eyes. Given these results, we argue that the deficit should be considered a prevalent but previously unrecognized agnosia specific to the perception of visual motion. © The Author(s) 2016.

Emergence delirium with transient associative agnosia and expressive aphasia reversed by flumazenil in a pediatric patient.

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Drobish, Julie K; Kelz, Max B; DiPuppo, Patricia M; Cook-Sather, Scott D

2015-06-01

Multiple factors may contribute to the development of emergence delirium in a child. We present the case of a healthy 12-year-old girl who received preoperative midazolam with the desired anxiolytic effect, underwent a brief general anesthetic, and then exhibited postoperative delirium, consisting of a transient associative agnosia and expressive aphasia. Administration of flumazenil led to immediate and lasting resolution of her symptoms. We hypothesize that γ-aminobutyric acid type A receptor-mediated effects, most likely related to an atypical offset of midazolam, are an important subset of emergence delirium that is amenable to pharmacologic therapy with flumazenil.

Modeling eye movements in visual agnosia with a saliency map approach: bottom-up guidance or top-down strategy?

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Foulsham, Tom; Barton, Jason J S; Kingstone, Alan; Dewhurst, Richard; Underwood, Geoffrey

2011-08-01

Two recent papers (Foulsham, Barton, Kingstone, Dewhurst, & Underwood, 2009; Mannan, Kennard, & Husain, 2009) report that neuropsychological patients with a profound object recognition problem (visual agnosic subjects) show differences from healthy observers in the way their eye movements are controlled when looking at images. The interpretation of these papers is that eye movements can be modeled as the selection of points on a saliency map, and that agnosic subjects show an increased reliance on visual saliency, i.e., brightness and contrast in low-level stimulus features. Here we review this approach and present new data from our own experiments with an agnosic patient that quantifies the relationship between saliency and fixation location. In addition, we consider whether the perceptual difficulties of individual patients might be modeled by selectively weighting the different features involved in a saliency map. Our data indicate that saliency is not always a good predictor of fixation in agnosia: even for our agnosic subject, as for normal observers, the saliency-fixation relationship varied as a function of the task. This means that top-down processes still have a significant effect on the earliest stages of scanning in the setting of visual agnosia, indicating severe limitations for the saliency map model. Top-down, active strategies-which are the hallmark of our human visual system-play a vital role in eye movement control, whether we know what we are looking at or not. Copyright © 2011 Elsevier Ltd. All rights reserved.

Acquired auditory agnosia in childhood and normal sleep electroencephalography subsequently diagnosed as Landau-Kleffner syndrome: a report of three cases.

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van Bogaert, Patrick; King, Mary D; Paquier, Philippe; Wetzburger, Catherine; Labasse, Catherine; Dubru, Jean-Marie; Deonna, Thierry

2013-06-01

  We report three cases of Landau-Kleffner syndrome (LKS) in children (two females, one male) in whom diagnosis was delayed because the sleep electroencephalography (EEG) was initially normal.   Case histories including EEG, positron emission tomography findings, and long-term outcome were reviewed.   Auditory agnosia occurred between the age of 2 years and 3 years 6 months, after a period of normal language development. Initial awake and sleep EEG, recorded weeks to months after the onset of language regression, during a nap period in two cases and during a full night of sleep in the third case, was normal. Repeat EEG between 2 months and 2 years later showed epileptiform discharges during wakefulness and strongly activated by sleep, with a pattern of continuous spike-waves during slow-wave sleep in two patients. Patients were diagnosed with LKS and treated with various antiepileptic regimens, including corticosteroids. One patient in whom EEG became normal on hydrocortisone is making significant recovery. The other two patients did not exhibit a sustained response to treatment and remained severely impaired.   Sleep EEG may be normal in the early phase of acquired auditory agnosia. EEG should be repeated frequently in individuals in whom a firm clinical diagnosis is made to facilitate early treatment. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.

A selective deficit in the appreciation and recognition of brightness: brightness agnosia?

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Nijboer, Tanja C W; Nys, Gudrun M S; van der Smagt, Maarten J; de Haan, Edward H F

2009-01-01

We report a patient with extensive brain damage in the right hemisphere who demonstrated a severe impairment in the appreciation of brightness. Acuity, contrast sensitivity as well as luminance discrimination were normal, suggesting her brightness impairment is not a mere consequence of low-level sensory impairments. The patient was not able to indicate the darker or the lighter of two grey squares, even though she was able to see that they differed. In addition, she could not indicate whether the lights in a room were switched on or off, nor was she able to differentiate between normal greyscale images and inverted greyscale images. As the patient recognised objects, colours, and shapes correctly, the impairment is specific for brightness. As low-level, sensory processing is normal, this specific deficit in the recognition and appreciation of brightness appears to be of a higher, cognitive level, the level of semantic knowledge. This appears to be the first report of 'brightness agnosia'.

Pleasurable emotional response to music: a case of neurodegenerative generalized auditory agnosia.

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Matthews, Brandy R; Chang, Chiung-Chih; De May, Mary; Engstrom, John; Miller, Bruce L

2009-06-01

Recent functional neuroimaging studies implicate the network of mesolimbic structures known to be active in reward processing as the neural substrate of pleasure associated with listening to music. Psychoacoustic and lesion studies suggest that there is a widely distributed cortical network involved in processing discreet musical variables. Here we present the case of a young man with auditory agnosia as the consequence of cortical neurodegeneration who continues to experience pleasure when exposed to music. In a series of musical tasks, the subject was unable to accurately identify any of the perceptual components of music beyond simple pitch discrimination, including musical variables known to impact the perception of affect. The subject subsequently misidentified the musical character of personally familiar tunes presented experimentally, but continued to report that the activity of 'listening' to specific musical genres was an emotionally rewarding experience. The implications of this case for the evolving understanding of music perception, music misperception, music memory, and music-associated emotion are discussed.

Memory-guided saccade processing in visual form agnosia (patient DF).

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Rossit, Stéphanie; Szymanek, Larissa; Butler, Stephen H; Harvey, Monika

2010-01-01

According to Milner and Goodale's model (The visual brain in action, Oxford University Press, Oxford, 2006) areas in the ventral visual stream mediate visual perception and oV-line actions, whilst regions in the dorsal visual stream mediate the on-line visual control of action. Strong evidence for this model comes from a patient (DF), who suffers from visual form agnosia after bilateral damage to the ventro-lateral occipital region, sparing V1. It has been reported that she is normal in immediate reaching and grasping, yet severely impaired when asked to perform delayed actions. Here we investigated whether this dissociation would extend to saccade execution. Neurophysiological studies and TMS work in humans have shown that the posterior parietal cortex (PPC), on the right in particular (supposedly spared in DF), is involved in the control of memory-guided saccades. Surprisingly though, we found that, just as reported for reaching and grasping, DF's saccadic accuracy was much reduced in the memory compared to the stimulus-guided condition. These data support the idea of a tight coupling of eye and hand movements and further suggest that dorsal stream structures may not be sufficient to drive memory-guided saccadic performance.

Hurt but still alive: Residual activity in the parahippocampal cortex conditions the recognition of familiar places in a patient with topographic agnosia.

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van Assche, Mitsouko; Kebets, Valeria; Lopez, Ursula; Saj, Arnaud; Goldstein, Rachel; Bernasconi, Françoise; Vuilleumier, Patrik; Assal, Frédéric

2016-01-01

The parahippocampal cortex (PHC) participates in both perception and memory. However, the way perceptual and memory processes cooperate when we navigate in our everyday life environment remains poorly understood. We studied a stroke patient presenting a brain lesion in the right PHC, which resulted in a mild and quantifiable topographic agnosia, and allowed us to investigate the role of this structure in overt place recognition. Photographs of personally familiar and unfamiliar places were displayed during functional magnetic resonance imaging (fMRI). Familiar places were either recognized or unrecognized by the patient and 6 age- and education-matched controls in a visual post-scan recognition test. In fMRI, recognized places were associated with a network comprising the fusiform gyrus in the intact side, but also the right anterior PHC, which included the lesion site. Moreover, this right PHC showed increased connectivity with the left homologous PHC in the intact hemisphere. By contrasting recognized with unrecognized familiar places, we replicate the finding of the joint involvement of the retrosplenial cortex, occipito-temporal areas, and posterior parietal cortex in place recognition. This study shows that the ability for left and right anterior PHC to communicate despite the neurological damage conditioned place recognition success in this patient. It further highlights a hemispheric asymmetry in this process, by showing the fundamental role of the right PHC in topographic agnosia.

Radical “Visual Capture” Observed in a Patient with Severe Visual Agnosia

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Takaiwa, Akiko; Yoshimura, Hirokazu; Abe, Hirofumi; Terai, Satoshi

2003-01-01

We report the case of a 79-year-old female with visual agnosia due to brain infarction in the left posterior cerebral artery. She could recognize objects used in daily life rather well by touch (the number of objects correctly identified was 16 out of 20 presented objects), but she could not recognize them as well by vision (6 out of 20). In this case, it was expected that she would recognize them well when permitted to use touch and vision simultaneously. Our patient, however, performed poorly, producing 5 correct answers out of 20 in the Vision-and-Touch condition. It would be natural to think that visual capture functions when vision and touch provide contradictory information on concrete positions and shapes. However, in the present case, it functioned in spite of the visual deficit in recognizing objects. This should be called radical visual capture. By presenting detailed descriptions of her symptoms and neuropsychological and neuroradiological data, we clarify the characteristics of this type of capture. PMID:12719638

Radical “Visual Capture” Observed in a Patient with Severe Visual Agnosia

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Akiko Takaiwa

2003-01-01

Full Text Available We report the case of a 79-year-old female with visual agnosia due to brain infarction in the left posterior cerebral artery. She could recognize objects used in daily life rather well by touch (the number of objects correctly identified was 16 out of 20 presented objects, but she could not recognize them as well by vision (6 out of 20. In this case, it was expected that she would recognize them well when permitted to use touch and vision simultaneously. Our patient, however, performed poorly, producing 5 correct answers out of 20 in the Vision-and-Touch condition. It would be natural to think that visual capture functions when vision and touch provide contradictory information on concrete positions and shapes. However, in the present case, it functioned in spite of the visual deficit in recognizing objects. This should be called radical visual capture. By presenting detailed descriptions of her symptoms and neuropsychological and neuroradiological data, we clarify the characteristics of this type of capture.

Configural Gestalts Remain Nothing More Than the Sum of Their Parts in Visual Agnosia

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Lee H. de-Wit

2013-12-01

Full Text Available We report converging evidence that higher stages of the visual system are critically required for the whole to become more than the sum of its parts by studying patient DF with visual agnosia using a configural superiority paradigm. We demonstrate a clear dissociation between this patient and normal controls such that she could more easily report information about parts, demonstrating a striking reversal of the normal configural superiority effect. Furthermore, by comparing DF's performance to earlier neuroimaging and novel modeling work, we found a compelling consistency between her performance and representations in the early visual areas, which are spared in this patient. The reversed pattern of performance in this patient highlights that in some cases visual Gestalts do not emerge early on without processing in higher visual areas. More broadly, this study demonstrates how neuropsychological patients can be used to unmask representations maintained at early stages of processing.

Development of a vocabulary of object shapes in a child with a very-early-acquired visual agnosia: a unique case.

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Funnell, Elaine; Wilding, John

2011-02-01

We report a longitudinal study of an exceptional child (S.R.) whose early-acquired visual agnosia, following encephalitis at 8 weeks of age, did not prevent her from learning to construct an increasing vocabulary of visual object forms (drawn from different categories), albeit slowly. S.R. had problems perceiving subtle differences in shape; she was unable to segment local letters within global displays; and she would bring complex scenes close to her eyes: a symptom suggestive of an attempt to reduce visual crowding. Investigations revealed a robust ability to use the gestalt grouping factors of proximity and collinearity to detect fragmented forms in noisy backgrounds, compared with a very weak ability to segment fragmented forms on the basis of contrasts of shape. When contrasts in spatial grouping and shape were pitted against each other, shape made little contribution, consistent with problems in perceiving complex scenes, but when shape contrast was varied, and spatial grouping was held constant, S.R. showed the same hierarchy of difficulty as the controls, although her responses were slowed. This is the first report of a child's visual-perceptual development following very early neurological impairments to the visual cortex. Her ability to learn to perceive visual shape following damage at a rudimentary stage of perceptual development contrasts starkly with the loss of such ability in childhood cases of acquired visual agnosia that follow damage to the established perceptual system. Clearly, there is a critical period during which neurological damage to the highly active, early developing visual-perceptual system does not prevent but only impairs further learning.

Functional Mapping of the Human Auditory Cortex: fMRI Investigation of a Patient with Auditory Agnosia from Trauma to the Inferior Colliculus.

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Poliva, Oren; Bestelmeyer, Patricia E G; Hall, Michelle; Bultitude, Janet H; Koller, Kristin; Rafal, Robert D

2015-09-01

To use functional magnetic resonance imaging to map the auditory cortical fields that are activated, or nonreactive, to sounds in patient M.L., who has auditory agnosia caused by trauma to the inferior colliculi. The patient cannot recognize speech or environmental sounds. Her discrimination is greatly facilitated by context and visibility of the speaker's facial movements, and under forced-choice testing. Her auditory temporal resolution is severely compromised. Her discrimination is more impaired for words differing in voice onset time than place of articulation. Words presented to her right ear are extinguished with dichotic presentation; auditory stimuli in the right hemifield are mislocalized to the left. We used functional magnetic resonance imaging to examine cortical activations to different categories of meaningful sounds embedded in a block design. Sounds activated the caudal sub-area of M.L.'s primary auditory cortex (hA1) bilaterally and her right posterior superior temporal gyrus (auditory dorsal stream), but not the rostral sub-area (hR) of her primary auditory cortex or the anterior superior temporal gyrus in either hemisphere (auditory ventral stream). Auditory agnosia reflects dysfunction of the auditory ventral stream. The ventral and dorsal auditory streams are already segregated as early as the primary auditory cortex, with the ventral stream projecting from hR and the dorsal stream from hA1. M.L.'s leftward localization bias, preserved audiovisual integration, and phoneme perception are explained by preserved processing in her right auditory dorsal stream.

Colour agnosia impairs the recognition of natural but not of non-natural scenes.

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Nijboer, Tanja C W; Van Der Smagt, Maarten J; Van Zandvoort, Martine J E; De Haan, Edward H F

2007-03-01

Scene recognition can be enhanced by appropriate colour information, yet the level of visual processing at which colour exerts its effects is still unclear. It has been suggested that colour supports low-level sensory processing, while others have claimed that colour information aids semantic categorization and recognition of objects and scenes. We investigated the effect of colour on scene recognition in a case of colour agnosia, M.A.H. In a scene identification task, participants had to name images of natural or non-natural scenes in six different formats. Irrespective of scene format, M.A.H. was much slower on the natural than on the non-natural scenes. As expected, neither M.A.H. nor control participants showed any difference in performance for the non-natural scenes. However, for the natural scenes, appropriate colour facilitated scene recognition in control participants (i.e., shorter reaction times), whereas M.A.H.'s performance did not differ across formats. Our data thus support the hypothesis that the effect of colour occurs at the level of learned associations.

Tactile Toe Agnosia and Percept of a "Missing Toe" in Healthy Humans.

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Cicmil, Nela; Meyer, Achim P; Stein, John F

2016-03-01

A disturbance of body representation is central to many neurological and psychiatric conditions, but the mechanisms by which body representations are constructed by the brain are not fully understood. We demonstrate a directional disturbance in tactile identification of the toes in healthy humans. Nineteen young adult participants underwent tactile stimulation of the digits with the eyes closed and verbally reported the identity of the stimulated digit. In the majority of individuals, responses to the second and third toes were significantly biased toward the laterally neighboring digit. The directional bias was greater for the nondominant foot and was affected by the identity of the immediately preceding stimulated toe. Unexpectedly, 9/19 participants reported the subjective experience of a "missing toe" or "missing space" during the protocol. These findings challenge current models of somatosensory localization, as they cannot be explained simply by a lack of distinct representations for toes compared with fingers, or by overt toe-finger correspondences. We present a novel theory of equal spatial representations of digit width combined with a "preceding neighbor" effect to explain the observed phenomena. The diagnostic implications for neurological disorders that involve "digit agnosia" are discussed. © The Author(s) 2015.

Making Memories: The Development of Long-Term Visual Knowledge in Children with Visual Agnosia

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Tiziana Metitieri

2013-01-01

Full Text Available There are few reports about the effects of perinatal acquired brain lesions on the development of visual perception. These studies demonstrate nonseverely impaired visual-spatial abilities and preserved visual memory. Longitudinal data analyzing the effects of compromised perceptions on long-term visual knowledge in agnosics are limited to lesions having occurred in adulthood. The study of children with focal lesions of the visual pathways provides a unique opportunity to assess the development of visual memory when perceptual input is degraded. We assessed visual recognition and visual memory in three children with lesions to the visual cortex having occurred in early infancy. We then explored the time course of visual memory impairment in two of them at 2 years and 3.7 years from the initial assessment. All children exhibited apperceptive visual agnosia and visual memory impairment. We observed a longitudinal improvement of visual memory modulated by the structural properties of objects. Our findings indicate that processing of degraded perceptions from birth results in impoverished memories. The dynamic interaction between perception and memory during development might modulate the long-term construction of visual representations, resulting in less severe impairment.

Making memories: the development of long-term visual knowledge in children with visual agnosia.

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Metitieri, Tiziana; Barba, Carmen; Pellacani, Simona; Viggiano, Maria Pia; Guerrini, Renzo

2013-01-01

There are few reports about the effects of perinatal acquired brain lesions on the development of visual perception. These studies demonstrate nonseverely impaired visual-spatial abilities and preserved visual memory. Longitudinal data analyzing the effects of compromised perceptions on long-term visual knowledge in agnosics are limited to lesions having occurred in adulthood. The study of children with focal lesions of the visual pathways provides a unique opportunity to assess the development of visual memory when perceptual input is degraded. We assessed visual recognition and visual memory in three children with lesions to the visual cortex having occurred in early infancy. We then explored the time course of visual memory impairment in two of them at 2  years and 3.7  years from the initial assessment. All children exhibited apperceptive visual agnosia and visual memory impairment. We observed a longitudinal improvement of visual memory modulated by the structural properties of objects. Our findings indicate that processing of degraded perceptions from birth results in impoverished memories. The dynamic interaction between perception and memory during development might modulate the long-term construction of visual representations, resulting in less severe impairment.

Positron emission tomographic localization of left-sided unilateral spatial agnosia

International Nuclear Information System (INIS)

Tagawa, Koichi; Nagata, Ken; Shishido, Fumio; Uemura, Kazuo

1986-01-01

Positron emission tomography (PET) was used to clarify the localization and the underlying mechanisms of left-sided unilateral spatial agnosia (LUSA). Eleven right-handed patients with cerebral infarction in the territory of the right middle cerebral artery who had LUSA were included in this study. Cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO 2 ) were measured with PET using 15 O steady state method. Sixteen right-handed patients with cerebral infarction who did not exhibit LUSA served as a control group. The mean local values of CBF and CMRO 2 in the control group were 37.4 ml/100 ml tissue/min and 2.66 ml/100 ml tissue/min, respectively. By contrast, those values of CBF and CMRO 2 in the patients with LUSA were 21.7 ml/100 ml tissue/min and 1.43 ml/100 ml tissue/min, respectively. Both CBF and CMRO 2 in the right posterior parietal region were significantly lower in the patients with LUSA as compared with the control group (p 2 between 1.8 and 2.2 ml/100 ml tissue/min. These ranges of CBF and CMRO 2 in the right parietal region were considered to include the threshold level producing LUSA. The CMRO 2 values were more stabilized in the course of cerebral infarction as compared with the CBF values which may be variable on account of luxury perfusion syndrome. The right posterior parietal CMRO 2 values less than 2.0 ml/100 ml tissue/min was considered to be critical in causing LUSA. The above results may suggest that severe damages of CBF and metabolism in the posterior part of the right parietal lobe play an important role in the occurrence of LUSA. (J.P.N.)

Separate processing of texture and form in the ventral stream: evidence from FMRI and visual agnosia.

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Cavina-Pratesi, C; Kentridge, R W; Heywood, C A; Milner, A D

2010-02-01

Real-life visual object recognition requires the processing of more than just geometric (shape, size, and orientation) properties. Surface properties such as color and texture are equally important, particularly for providing information about the material properties of objects. Recent neuroimaging research suggests that geometric and surface properties are dealt with separately within the lateral occipital cortex (LOC) and the collateral sulcus (CoS), respectively. Here we compared objects that differed either in aspect ratio or in surface texture only, keeping all other visual properties constant. Results on brain-intact participants confirmed that surface texture activates an area in the posterior CoS, quite distinct from the area activated by shape within LOC. We also tested 2 patients with visual object agnosia, one of whom (DF) performed well on the texture task but at chance on the shape task, whereas the other (MS) showed the converse pattern. This behavioral double dissociation was matched by a parallel neuroimaging dissociation, with activation in CoS but not LOC in patient DF and activation in LOC but not CoS in patient MS. These data provide presumptive evidence that the areas respectively activated by shape and texture play a causally necessary role in the perceptual discrimination of these features.

Functional dissociation between action and perception of object shape in developmental visual object agnosia.

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Freud, Erez; Ganel, Tzvi; Avidan, Galia; Gilaie-Dotan, Sharon

2016-03-01

According to the two visual systems model, the cortical visual system is segregated into a ventral pathway mediating object recognition, and a dorsal pathway mediating visuomotor control. In the present study we examined whether the visual control of action could develop normally even when visual perceptual abilities are compromised from early childhood onward. Using his fingers, LG, an individual with a rare developmental visual object agnosia, manually estimated (perceptual condition) the width of blocks that varied in width and length (but not in overall size), or simply picked them up across their width (grasping condition). LG's perceptual sensitivity to target width was profoundly impaired in the manual estimation task compared to matched controls. In contrast, the sensitivity to object shape during grasping, as measured by maximum grip aperture (MGA), the time to reach the MGA, the reaction time and the total movement time were all normal in LG. Further analysis, however, revealed that LG's sensitivity to object shape during grasping emerged at a later time stage during the movement compared to controls. Taken together, these results demonstrate a dissociation between action and perception of object shape, and also point to a distinction between different stages of the grasping movement, namely planning versus online control. Moreover, the present study implies that visuomotor abilities can develop normally even when perceptual abilities developed in a profoundly impaired fashion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Patient DF's visual brain in action: Visual feedforward control in visual form agnosia.

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Whitwell, Robert L; Milner, A David; Cavina-Pratesi, Cristiana; Barat, Masihullah; Goodale, Melvyn A

2015-05-01

Patient DF, who developed visual form agnosia following ventral-stream damage, is unable to discriminate the width of objects, performing at chance, for example, when asked to open her thumb and forefinger a matching amount. Remarkably, however, DF adjusts her hand aperture to accommodate the width of objects when reaching out to pick them up (grip scaling). While this spared ability to grasp objects is presumed to be mediated by visuomotor modules in her relatively intact dorsal stream, it is possible that it may rely abnormally on online visual or haptic feedback. We report here that DF's grip scaling remained intact when her vision was completely suppressed during grasp movements, and it still dissociated sharply from her poor perceptual estimates of target size. We then tested whether providing trial-by-trial haptic feedback after making such perceptual estimates might improve DF's performance, but found that they remained significantly impaired. In a final experiment, we re-examined whether DF's grip scaling depends on receiving veridical haptic feedback during grasping. In one condition, the haptic feedback was identical to the visual targets. In a second condition, the haptic feedback was of a constant intermediate width while the visual target varied trial by trial. Despite this incongruent feedback, DF still scaled her grip aperture to the visual widths of the target blocks, showing only normal adaptation to the false haptically-experienced width. Taken together, these results strengthen the view that DF's spared grasping relies on a normal mode of dorsal-stream functioning, based chiefly on visual feedforward processing. Copyright © 2014 Elsevier B.V. All rights reserved.

Analysis of lesions in patients with unilateral tactile agnosia using cytoarchitectonic probabilistic maps.

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Hömke, Lars; Amunts, Katrin; Bönig, Lutz; Fretz, Christian; Binkofski, Ferdinand; Zilles, Karl; Weder, Bruno

2009-05-01

We propose a novel methodical approach to lesion analyses involving high-resolution MR images in combination with probabilistic cytoarchitectonic maps. 3D-MR images of the whole brain and the manually segmented lesion mask are spatially normalized to the reference brain of a stereotaxic probabilistic cytoarchitectonic atlas using a multiscale registration algorithm based on an elastic model. The procedure is demonstrated in three patients suffering from aperceptive tactile agnosia of the right hand due to chronic infarction of the left parietal cortex. Patient 1 presents a lesion in areas of the postcentral sulcus, Patient 3 in areas of the superior parietal lobule and adjacent intraparietal sulcus, and Patient 2 lesions in both regions. On the basis of neurobehavioral data, we conjectured degradation of sequential elementary sensory information processing within the postcentral gyrus, impeding texture recognition in Patients 1 and 2, and disturbed kinaesthetic information processing in the posterior parietal lobe, causing degraded shape recognition in the patients 2 and 3. The involvement of Brodmann areas 4a, 4p, 3a, 3b, 1, 2, and areas IP1 and IP2 of the intraparietal sulcus was assessed in terms of the voxel overlap between the spatially transformed lesion masks and the 50%-isocontours of the cytoarchitectonic maps. The disruption of the critical cytoarchitectonic areas and the impaired subfunctions, texture and shape recognition, relate as conjectured above. We conclude that the proposed method represents a promising approach to hypothesis-driven lesion analyses, yielding lesion-function correlates based on a cytoarchitectonic model. Finally, the lesion-function correlates are validated by functional imaging reference data. (c) 2008 Wiley-Liss, Inc.

[Associative visual agnosia. The less visible consequences of a cerebral infarction].

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Diesfeldt, H F A

2011-02-01

preserved abilities is considered to be a specific difficulty to access a full semantic representation from an intact structural representation of visually presented objects, i.e., a form of visual object agnosia.

Hurt but still alive: Residual activity in the parahippocampal cortex conditions the recognition of familiar places in a patient with topographic agnosia

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Mitsouko van Assche

2016-01-01

Photographs of personally familiar and unfamiliar places were displayed during functional magnetic resonance imaging (fMRI. Familiar places were either recognized or unrecognized by the patient and 6 age- and education-matched controls in a visual post-scan recognition test. In fMRI, recognized places were associated with a network comprising the fusiform gyrus in the intact side, but also the right anterior PHC, which included the lesion site. Moreover, this right PHC showed increased connectivity with the left homologous PHC in the intact hemisphere. By contrasting recognized with unrecognized familiar places, we replicate the finding of the joint involvement of the retrosplenial cortex, occipito-temporal areas, and posterior parietal cortex in place recognition. This study shows that the ability for left and right anterior PHC to communicate despite the neurological damage conditioned place recognition success in this patient. It further highlights a hemispheric asymmetry in this process, by showing the fundamental role of the right PHC in topographic agnosia.

Complicações neurológicas no decurso de tratamento pelo ACTH: A propósito de um caso de agnosia visual

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O. Freitas Julião

1953-12-01

Full Text Available Os autores relatam a observação de um menino de 8 anos de idade, portador de síndrome nefrótica tratada pelo ACTH e que apresentou uma série de graves distúrbios neurológicos conseqüentes a uma crise hipertensiva (a pressão arterial elevou-se a 220-130 mm Hg, ocorrida por ocasião desse tratamento. Manifestando-se inicialmente por cefaléia intensa, depois por crise convulsiva generalizada, à qual se seguiu estado comatoso e posteriormente síndrome confusional, a encefalopatía hipertensiva condicionou, como seqüelas neurológicas mais importantes, distúrbios visuais. Êstes, que se apresentaram, a princípio, sob a forma de amaurose total, assumiram depois o aspecto de distúrbios da percepção, tipo agnóstico, persistentes ainda hoje. A agnosia visual refere-se aos objetos, pessoas, figuras simbólicas e côres.

Functional Specialization in the Lower and Upper Visual Fields in Humans: Its Ecological Origins and Neurophysiological Implications

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1990-01-01

loss), color agnosia , visual object agnosia , Baldwin 1958), reminiscent of the transient LVF atten- prosopagnosia (impaired facial recognition), and...et al. 1989). Finally, it has been reported that pattern- scanning mechanisms may underlie object agnosia sensitive epilepsy - presumably associated...improved. He held so that the bill is oriented well below the horizon with an also had a visual agnosia and, as briefly mentioned, vertical eye-center

The anatomy of object recognition--visual form agnosia caused by medial occipitotemporal stroke.

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Karnath, Hans-Otto; Rüter, Johannes; Mandler, André; Himmelbach, Marc

2009-05-06

The influential model on visual information processing by Milner and Goodale (1995) has suggested a dissociation between action- and perception-related processing in a dorsal versus ventral stream projection. It was inspired substantially by the observation of a double dissociation of disturbed visual action versus perception in patients with optic ataxia on the one hand and patients with visual form agnosia (VFA) on the other. Unfortunately, almost all cases with VFA reported so far suffered from inhalational intoxication, the majority with carbon monoxide (CO). Since CO induces a diffuse and widespread pattern of neuronal and white matter damage throughout the whole brain, precise conclusions from these patients with VFA on the selective role of ventral stream structures for shape and orientation perception were difficult. Here, we report patient J.S., who demonstrated VFA after a well circumscribed brain lesion due to stroke etiology. Like the famous patient D.F. with VFA after CO intoxication studied by Milner, Goodale, and coworkers (Goodale et al., 1991, 1994; Milner et al., 1991; Servos et al., 1995; Mon-Williams et al., 2001a,b; Wann et al., 2001; Westwood et al., 2002; McIntosh et al., 2004; Schenk and Milner, 2006), J.S. showed an obvious dissociation between disturbed visual perception of shape and orientation information on the one side and preserved visuomotor abilities based on the same information on the other. In both hemispheres, damage primarily affected the fusiform and the lingual gyri as well as the adjacent posterior cingulate gyrus. We conclude that these medial structures of the ventral occipitotemporal cortex are integral for the normal flow of shape and of contour information into the ventral stream system allowing to recognize objects.

Visual processing of words in a patient with visual form agnosia: a behavioural and fMRI study.

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Cavina-Pratesi, Cristiana; Large, Mary-Ellen; Milner, A David

2015-03-01

Patient D.F. has a profound and enduring visual form agnosia due to a carbon monoxide poisoning episode suffered in 1988. Her inability to distinguish simple geometric shapes or single alphanumeric characters can be attributed to a bilateral loss of cortical area LO, a loss that has been well established through structural and functional fMRI. Yet despite this severe perceptual deficit, D.F. is able to "guess" remarkably well the identity of whole words. This paradoxical finding, which we were able to replicate more than 20 years following her initial testing, raises the question as to whether D.F. has retained specialized brain circuitry for word recognition that is able to function to some degree without the benefit of inputs from area LO. We used fMRI to investigate this, and found regions in the left fusiform gyrus, left inferior frontal gyrus, and left middle temporal cortex that responded selectively to words. A group of healthy control subjects showed similar activations. The left fusiform activations appear to coincide with the area commonly named the visual word form area (VWFA) in studies of healthy individuals, and appear to be quite separate from the fusiform face area (FFA). We hypothesize that there is a route to this area that lies outside area LO, and which remains relatively unscathed in D.F. Copyright © 2014 Elsevier Ltd. All rights reserved.

Alteraciones en el reconocimiento de gestos por daño a nivel del praxicon de entrada de acciones. (Agnosia de las pantomimas

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Daniel G. Politis

2002-01-01

Full Text Available Clásicamente el estudio de la apraxia estuvo limitado a los problemas en la ejecución gestual (Geschwind, 1965; Liepmann, 1908 [c.f. De Renzi, 1990]; Luria, 1977. Si bien se presentaron varias hipótesis sobre la capacidad de reconocer gestos y su alteración por lesiones cerebrales, González Rothi, Ochipa y Heilman (1991,1997 en su modelo cognitivo de las apraxias de los miembros incluyen la capacidad de reconocer gestos y proponen que la misma es mediada por un sub-componente específico, el praxicón de entrada de acciones. La alteración de este produce un cuadro caracterizado por un déficit en el reconocimiento de gestos que denominaron Agnosia de las Pantomimas. En este trabajo se presenta el estudio de un paciente con dificultades en el reconocimiento de gestos y sin dificultades en la producción gesrual lo que constituye una disociación, que reafirma la hipótesis planteada por González Rothi y colaboradores (1991, 1997 y se discute el valor de estos hallazgos en relación con el modelo antes mencionado.

The Neuropsychology of Imagery Processing

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1991-01-25

B. (1985). Agnosia . In K. M. Heilman and E. Valenstein (Eds.), Clinical Neuropsychology. New York: Oxford University Press. Biederman, I. (1987...Campion, J. (1987). Apperceptive agnosia : the specification and description of constructs. In Humphreys, G. W., and Riddoch, M. J. (1987a) (Eds...R. (1986). Disorders of complex visual processing: agnosias , achromatopsia, Balint’s syndrome and related difficulties of orientation and

Pure associative tactile agnosia for the left hand: clinical and anatomo-functional correlations.

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Veronelli, Laura; Ginex, Valeria; Dinacci, Daria; Cappa, Stefano F; Corbo, Massimo

2014-09-01

Associative tactile agnosia (TA) is defined as the inability to associate information about object sensory properties derived through tactile modality with previously acquired knowledge about object identity. The impairment is often described after a lesion involving the parietal cortex (Caselli, 1997; Platz, 1996). We report the case of SA, a right-handed 61-year-old man affected by first ever right hemispheric hemorrhagic stroke. The neurological examination was normal, excluding major somaesthetic and motor impairment; a brain magnetic resonance imaging (MRI) confirmed the presence of a right subacute hemorrhagic lesion limited to the post-central and supra-marginal gyri. A comprehensive neuropsychological evaluation detected a selective inability to name objects when handled with the left hand in the absence of other cognitive deficits. A series of experiments were conducted in order to assess each stage of tactile recognition processing using the same stimulus sets: materials, 3D geometrical shapes, real objects and letters. SA and seven matched controls underwent the same experimental tasks during four sessions in consecutive days. Tactile discrimination, recognition, pantomime, drawing after haptic exploration out of vision and tactile-visual matching abilities were assessed. In addition, we looked for the presence of a supra-modal impairment of spatial perception and of specific difficulties in programming exploratory movements during recognition. Tactile discrimination was intact for all the stimuli tested. In contrast, SA was able neither to recognize nor to pantomime real objects manipulated with the left hand out of vision, while he identified them with the right hand without hesitations. Tactile-visual matching was intact. Furthermore, SA was able to grossly reproduce the global shape in drawings but failed to extract details of objects after left-hand manipulation, and he could not identify objects after looking at his own drawings. This case

The Right Place at the Right Time: Priming Facial Expressions with Emotional Face Components in Developmental Visual Agnosia

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Aviezer, Hillel; Hassin, Ran. R.; Perry, Anat; Dudarev, Veronica; Bentin, Shlomo

2012-01-01

The current study examined the nature of deficits in emotion recognition from facial expressions in case LG, an individual with a rare form of developmental visual agnosia (DVA). LG presents with profoundly impaired recognition of facial expressions, yet the underlying nature of his deficit remains unknown. During typical face processing, normal sighted individuals extract information about expressed emotions from face regions with activity diagnostic for specific emotion categories. Given LG’s impairment, we sought to shed light on his emotion perception by examining if priming facial expressions with diagnostic emotional face components would facilitate his recognition of the emotion expressed by the face. LG and control participants matched isolated face components with components appearing in a subsequently presented full-face and then categorized the face’s emotion. Critically, the matched components were from regions which were diagnostic or non-diagnostic of the emotion portrayed by the full face. In experiment 1, when the full faces were briefly presented (150 ms), LG’s performance was strongly influenced by the diagnosticity of the components: His emotion recognition was boosted within normal limits when diagnostic components were used and was obliterated when non-diagnostic components were used. By contrast, in experiment 2, when the face-exposure duration was extended (2000 ms), the beneficial effect of the diagnostic matching was diminished as was the detrimental effect of the non-diagnostic matching. These data highlight the impact of diagnostic facial features in normal expression recognition and suggest that impaired emotion recognition in DVA results from deficient visual integration across diagnostic face components. PMID:22349446

The right place at the right time: priming facial expressions with emotional face components in developmental visual agnosia.

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Aviezer, Hillel; Hassin, Ran R; Perry, Anat; Dudarev, Veronica; Bentin, Shlomo

2012-04-01

The current study examined the nature of deficits in emotion recognition from facial expressions in case LG, an individual with a rare form of developmental visual agnosia (DVA). LG presents with profoundly impaired recognition of facial expressions, yet the underlying nature of his deficit remains unknown. During typical face processing, normal sighted individuals extract information about expressed emotions from face regions with activity diagnostic for specific emotion categories. Given LG's impairment, we sought to shed light on his emotion perception by examining if priming facial expressions with diagnostic emotional face components would facilitate his recognition of the emotion expressed by the face. LG and control participants matched isolated face components with components appearing in a subsequently presented full-face and then categorized the face's emotion. Critically, the matched components were from regions which were diagnostic or non-diagnostic of the emotion portrayed by the full face. In experiment 1, when the full faces were briefly presented (150 ms), LG's performance was strongly influenced by the diagnosticity of the components: his emotion recognition was boosted within normal limits when diagnostic components were used and was obliterated when non-diagnostic components were used. By contrast, in experiment 2, when the face-exposure duration was extended (2000 ms), the beneficial effect of the diagnostic matching was diminished as was the detrimental effect of the non-diagnostic matching. These data highlight the impact of diagnostic facial features in normal expression recognition and suggest that impaired emotion recognition in DVA results from deficient visual integration across diagnostic face components. Copyright © 2012 Elsevier Ltd. All rights reserved.

Is Visual Imagery Really Visual? Overlooked Evidence from Neuropsychology.

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1987-08-07

the study of imagery. British Journal of Psychology, 47 101-114 Bauer,R. M.. & Rubens. A B (1985). Agnosia In K. M. Heilman & E. Valenstein (Ed Clinical...Neuropsychology. New York: Oxford University Press. 2nd edition. Beauvois. M.F . & Saillant. B (1985) Optic aphasia for colours and colour agnosia A...integrative visual agnosia . Brain, Roland. P.E. (1982). Cortical regulation of selective attention in man. Journal of Neuroohysiology, 48. 1059-1078

Neuropsychological Component of Imagery Processing

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1991-01-25

and von Bonin, G. (1951). The Isocortex of Man. Urbana, IL: University of Illinois Press. Bauer, R. M., and Rubens, A. B. (1985). Agnosia . In K. M...Apperceptive agnosia : the specification and description of constructs. In Humphreys, G. W., and Riddoch, M. J. (1987a) (Eds.). Visual Object Processing: A...visual processing: agnosias , achromatopsia, Balint’s syndrome and related difficulties of orientation and construction. In M.-M. Mesulam (Ed

Neuropsychological Components of Object Identification

Science.gov (United States)

1992-01-10

Man. Urbana, IL: University of Illinois Press. Bauer, R. M., and Rubens, A. B. (1985). Agnosia . In K. M. Heilman and E. Valenstein (Eds.), Clinical...J. (1987). Apperceptive agnosia : the specification and description of constructs. In Humphreys, G. W., and Riddoch, M. J. (1987a) (Eds.). Visual... agnosias , achromatopsia, Balint’s syndrome and related difficulties of orientation and construction. In M.-M. Mesulam (Ed.), Principles of Behavioral

Vision and Action

Science.gov (United States)

1994-06-01

Recent results from Cognitive Neurophysiology-the discipline which is concerned, among other topics, with the study of visual agnosia (a condition...and A. Newell. GPS: A Case Study in Generality and Problem Solving. Academic Press, New York, 1969. [13] M. Farah. Visual Agnosia : Diesorders of Object...A Case Study of Visual Agnosia . Lawrence Erlbaum, Hillsdale, New Jersey, 1992. [31] D. Jacobs. Space efficient 3d model indexing. In Proc. IEEE

The Role of Attention in Binocular Rivalry as Revealed through Optokinetic Nystagmus.

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1995-11-01

break down selectively when parts of the stri- ate and prestriate cortex is damaged. Speci cally, a group of patients su ering fromApperceptive Agnosia ...1981). Visual performance in cases of visual agnosia . In M. van- Ho , & G. Hohn (Eds.), Functional recovery from brain damage (pp. 275{286...macaques. Nature, 373, 609{611. Breese, B. (1899). On inhibition. Psychol.Rev., 3, 1{65. Campion, J., & Latto, R. (1985). Apperceptive agnosia due to

Toward a Computational Neuropsychology of High-Level Vision.

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1984-08-20

known as visual agnosia ’ (also called "mindblindness’)l this patient failed to *recognize her nurses, got lost frequently when travelling familiar routes...visual agnosia are not blind: these patients can compare two shapes reliably when Computational neuropsychology 16 both are visible, but they cannot...visually recognize what an object is (although many can recognize objects by touch). This sort of agnosia has been well-documented in the literature (see

Klüver-Bucy Syndrome

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... inappropriate sexual behavior. Other symptoms may include visual agnosia (inability to visually recognize objects), loss of normal ... inappropriate sexual behavior. Other symptoms may include visual agnosia (inability to visually recognize objects), loss of normal ...

Gerstmann's Syndrome

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... left, and an inability to identify fingers (finger agnosia). The disorder should not be confused with Gerstmann- ... left, and an inability to identify fingers (finger agnosia). The disorder should not be confused with Gerstmann- ...

Selective scene perception deficits in a case of topographical disorientation.

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Robin, Jessica; Lowe, Matthew X; Pishdadian, Sara; Rivest, Josée; Cant, Jonathan S; Moscovitch, Morris

2017-07-01

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. Compared to healthy controls, LH demonstrates perceptual impairments when attending to the configuration of a scene, but not when attending to its surface properties, such as the pattern of the walls or whether the ground is sand or grass. In contrast, when focusing on objects instead of scenes, LH demonstrates intact perception of both geometric and surface properties. This study demonstrates that in a case of TD and landmark agnosia, the perceptual impairments are selective to the layout of scenes, providing insight into the mechanism of landmark agnosia and scene-selective perceptual processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Training-induced recovery of low-level vision followed by mid-level perceptual improvements in developmental object and face agnosia.

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Lev, Maria; Gilaie-Dotan, Sharon; Gotthilf-Nezri, Dana; Yehezkel, Oren; Brooks, Joseph L; Perry, Anat; Bentin, Shlomo; Bonneh, Yoram; Polat, Uri

2015-01-01

Long-term deprivation of normal visual inputs can cause perceptual impairments at various levels of visual function, from basic visual acuity deficits, through mid-level deficits such as contour integration and motion coherence, to high-level face and object agnosia. Yet it is unclear whether training during adulthood, at a post-developmental stage of the adult visual system, can overcome such developmental impairments. Here, we visually trained LG, a developmental object and face agnosic individual. Prior to training, at the age of 20, LG's basic and mid-level visual functions such as visual acuity, crowding effects, and contour integration were underdeveloped relative to normal adult vision, corresponding to or poorer than those of 5-6 year olds (Gilaie-Dotan, Perry, Bonneh, Malach & Bentin, 2009). Intensive visual training, based on lateral interactions, was applied for a period of 9 months. LG's directly trained but also untrained visual functions such as visual acuity, crowding, binocular stereopsis and also mid-level contour integration improved significantly and reached near-age-level performance, with long-term (over 4 years) persistence. Moreover, mid-level functions that were tested post-training were found to be normal in LG. Some possible subtle improvement was observed in LG's higher-order visual functions such as object recognition and part integration, while LG's face perception skills have not improved thus far. These results suggest that corrective training at a post-developmental stage, even in the adult visual system, can prove effective, and its enduring effects are the basis for a revival of a developmental cascade that can lead to reduced perceptual impairments. © 2014 The Authors. Developmental Science Published by John Wiley & Sons Ltd.

A Behavioral Treatment for Traumatic Brain Injury-Associated Visual Dysfunction Based on Adult Cortical Plasticity

Science.gov (United States)

2014-12-01

Zomet, Lev, Yehezkel, Sterkin & Levi, 2012b) and developmental object and face agnosia (Lev, Gilaie-Dotan, Gotthilf-Nezri, Yehezkel, Brooks, Perry...followed by mid-level perceptual improvements in developmental object and face agnosia . Dev Sci, Lev, M., Ludwig, K., Gilaie-Dotan, S., Voss, S

The Functional Architecture of Visual Object Recognition

Science.gov (United States)

1991-07-01

different forms of agnosia can provide clues to the representations underlying normal object recognition (Farah, 1990). For example, the pair-wise...patterns of deficit and sparing occur. In a review of 99 published cases of agnosia , the observed patterns of co- occurrence implicated two underlying

An Epidemiologic Investigation of Health Effects in Air Force Personnel Following Exposure to Herbicides. Volume 2. First Followup Examination Results.

Science.gov (United States)

1987-10-01

ABNORMAL___________________________________ -ESSENTIAL NORM. SKILLED ACTS - - ESSENTIAL AB -g-NTENTION NORM SPEECH ARTICULATION. APHASIA. AGNOSIA ) miN~rNTCGN AB...DYSARTHRIA *OTHER NORMAL GROSSLY APHASIA -~ miABNORMAL AGNOSIA NCS Trons.Optic EPOI-21159 321 A8900 W* -ABNORMAL - NORMAL LE F7 RIGHT BOTH- STRAIGH-T

’What’ and ’Where’ in Visual Attention: Evidence from the Neglect Syndrome

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1992-01-01

representations of the visual world, visual attention, and object representations. 24 Bauer, R. M., & Rubens, A. B. (1985). Agnosia . In K. M. Heilman, & E...visual information. Journal of Experimental Psychology: General, 1-1, 501-517. Farah, M. J. (1990). Visual Agnosia : Disorders of Object Recognition and

On the use of cognitive neuropsychological methods in developmental disorders

DEFF Research Database (Denmark)

Starrfelt, Randi; Robotham, Ro Julia

2018-01-01

This is a commentary on Geskin & Behrmann (2018) Congenital prosopagnosia without object agnosia? A literature review appearing in the same issue of this journal.......This is a commentary on Geskin & Behrmann (2018) Congenital prosopagnosia without object agnosia? A literature review appearing in the same issue of this journal....

Epidemiologic Investigation of Health Effects in Air Force Personnel Following Exposure to Herbicides: Study Protocol

Science.gov (United States)

1982-12-01

articulation, Ipoasia, agnosia ) Gr~ssly LF1orhal [1Abnormal -Specif’y Dysarthria 0Z Aphasia 02 .- 99 A Reflexes (0-absent; 1-sluggish; 2-active; 3-very...If indicated, ONormal E7Abnormal (b) Speech (articulation, aphasia, agnosia ) Grossly O7Normal Ofbnormal -Specify Dysarthria LZ Aphasia 0 142

Categorical Perception of Lexical Tones in Mandarin-speaking Congenital Amusics

Directory of Open Access Journals (Sweden)

Wan Ting Huang

2015-06-01

Full Text Available Previous research suggests that within Mandarin-speaking congenital amusics, only a subgroup has behavioral lexical tone perception impairments (tone agnosia, whereas the rest of amusics do not. The purpose of the current study was to investigate the categorical nature of lexical tone perception in Mandarin-speaking amusics with and without behavioral lexical tone deficits. Three groups of listeners (controls, pure amusics and amusics with tone agnosia participated in tone identification and discrimination tasks. Indexes of the categorical perception of a physical continuum of fundamental frequencies ranging from a rising to level tone were measured. Specifically, the stimulus durations were manipulated at 100 and 200 ms. For both stimulus durations, all groups exhibited similar categorical boundaries. The pure amusics showed sharp identification slopes and significantly peaked discrimination functions similar to those of normal controls. However, such essential characteristics for the categorical perception of lexical tones were not observed in amusics with tone agnosia. An enlarged step-size from 20 Hz to 35 Hz was not able to produce any discrimination peaks in tone agnosics either. The current study revealed that only amusics with tone agnosia showed a lack of categorical tone perception, while the pure amusics demonstrated typical categorical perception of lexical tones, indicating that the deficit of pitch processing in music does not necessarily result in the deficit in the categorical perception of lexical tones. The different performance between congenital amusics with and without tone agnosia provides a new perspective on the proposition of the relationship between music and speech perception.

Mirrored and rotated stimuli are not the same: A neuropsychological and lesion mapping study.

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Martinaud, Olivier; Mirlink, Nicolas; Bioux, Sandrine; Bliaux, Evangéline; Champmartin, Cécile; Pouliquen, Dorothée; Cruypeninck, Yohann; Hannequin, Didier; Gérardin, Emmanuel

2016-05-01

Agnosia for mirrored stimuli is a rare clinical deficit. Only eight patients have been reported in the literature so far and little is known about the neural substrates of this agnosia. Using a previously developed experimental test designed to assess this agnosia, namely the Mirror and Orientation Agnosia Test (MOAT), as well as voxel-lesion symptom mapping (VLSM), we tested the hypothesis that focal brain-injured patients with right parietal damage would be impaired in the discrimination between the canonical view of a visual object and its mirrored and rotated images. Thirty-four consecutively recruited patients with a stroke involving the right or left parietal lobe have been included: twenty patients (59%) had a deficit on at least one of the six conditions of the MOAT, fourteen patients (41%) had a deficit on the mirror condition, twelve patients (35%) had a deficit on at least one the four rotated conditions and one had a truly selective agnosia for mirrored stimuli. A lesion analysis showed that discrimination of mirrored stimuli was correlated to the mesial part of the posterior superior temporal gyrus and the lateral part of the inferior parietal lobule, while discrimination of rotated stimuli was correlated to the lateral part of the posterior superior temporal gyrus and the mesial part of the inferior parietal lobule, with only a small overlap between the two. These data suggest that the right visual 'dorsal' pathway is essential for accurate perception of mirrored and rotated stimuli, with a selective cognitive process and anatomical network underlying our ability to discriminate between mirrored images, different from the process of discriminating between rotated images. Copyright © 2016 Elsevier Ltd. All rights reserved.

Selective impairment of living things and musical instruments on a verbal 'Semantic Knowledge Questionnaire' in a case of apperceptive visual agnosia.

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Masullo, Carlo; Piccininni, Chiara; Quaranta, Davide; Vita, Maria Gabriella; Gaudino, Simona; Gainotti, Guido

2012-10-01

Semantic memory was investigated in a patient (MR) affected by a severe apperceptive visual agnosia, due to an ischemic cerebral lesion, bilaterally affecting the infero-mesial parts of the temporo-occipital cortices. The study was made by means of a Semantic Knowledge Questionnaire (Laiacona, Barbarotto, Trivelli, & Capitani, 1993), which takes separately into account four categories of living beings (animals, fruits, vegetables and body parts) and of artefacts (furniture, tools, vehicles and musical instruments), does not require a visual analysis and allows to distinguish errors concerning super-ordinate categorization, perceptual features and functional/encyclopedic knowledge. When the total number of errors obtained on all the categories of living and non-living beings was considered, a non-significant trend toward a higher number of errors in living stimuli was observed. This difference, however, became significant when body parts and musical instruments were excluded from the analysis. Furthermore, the number of errors obtained on the musical instruments was similar to that obtained on the living categories of animals, fruits and vegetables and significantly higher of that obtained in the other artefact categories. This difference was still significant when familiarity, frequency of use and prototypicality of each stimulus entered into a logistic regression analysis. On the other hand, a separate analysis of errors obtained on questions exploring super-ordinate categorization, perceptual features and functional/encyclopedic attributes showed that the differences between living and non-living stimuli and between musical instruments and other artefact categories were mainly due to errors obtained on questions exploring perceptual features. All these data are at variance with the 'domains of knowledge' hypothesis', which assumes that the breakdown of different categories of living and non-living things respects the distinction between biological entities and

Cortical Auditory Disorders: A Case of Non-Verbal Disturbances Assessed with Event-Related Brain Potentials

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Sönke Johannes

1998-01-01

Full Text Available In the auditory modality, there has been a considerable debate about some aspects of cortical disorders, especially about auditory forms of agnosia. Agnosia refers to an impaired comprehension of sensory information in the absence of deficits in primary sensory processes. In the non-verbal domain, sound agnosia and amusia have been reported but are frequently accompanied by language deficits whereas pure deficits are rare. Absolute pitch and musicians’ musical abilities have been associated with left hemispheric functions. We report the case of a right handed sound engineer with the absolute pitch who developed sound agnosia and amusia in the absence of verbal deficits after a right perisylvian stroke. His disabilities were assessed with the Seashore Test of Musical Functions, the tests of Wertheim and Botez (Wertheim and Botez, Brain 84, 1961, 19–30 and by event-related potentials (ERP recorded in a modified 'oddball paradigm’. Auditory ERP revealed a dissociation between the amplitudes of the P3a and P3b subcomponents with the P3b being reduced in amplitude while the P3a was undisturbed. This is interpreted as reflecting disturbances in target detection processes as indexed by the P3b. The findings that contradict some aspects of current knowledge about left/right hemispheric specialization in musical processing are discussed and related to the literature concerning cortical auditory disorders.

Cortical auditory disorders: a case of non-verbal disturbances assessed with event-related brain potentials.

Science.gov (United States)

Johannes, Sönke; Jöbges, Michael E.; Dengler, Reinhard; Münte, Thomas F.

1998-01-01

In the auditory modality, there has been a considerable debate about some aspects of cortical disorders, especially about auditory forms of agnosia. Agnosia refers to an impaired comprehension of sensory information in the absence of deficits in primary sensory processes. In the non-verbal domain, sound agnosia and amusia have been reported but are frequently accompanied by language deficits whereas pure deficits are rare. Absolute pitch and musicians' musical abilities have been associated with left hemispheric functions. We report the case of a right handed sound engineer with the absolute pitch who developed sound agnosia and amusia in the absence of verbal deficits after a right perisylvian stroke. His disabilities were assessed with the Seashore Test of Musical Functions, the tests of Wertheim and Botez (Wertheim and Botez, Brain 84, 1961, 19-30) and by event-related potentials (ERP) recorded in a modified 'oddball paradigm'. Auditory ERP revealed a dissociation between the amplitudes of the P3a and P3b subcomponents with the P3b being reduced in amplitude while the P3a was undisturbed. This is interpreted as reflecting disturbances in target detection processes as indexed by the P3b. The findings that contradict some aspects of current knowledge about left/right hemispheric specialization in musical processing are discussed and related to the literature concerning cortical auditory disorders.

On the Origins of Calculation Abilities

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A. Ardila

1993-01-01

Full Text Available A historical review of calculation abilities is presented. Counting, starting with finger sequencing, has been observed in different ancient and contemporary cultures, whereas number representation and arithmetic abilities are found only during the last 5000–6000 years. The rationale for selecting a base of ten in most numerical systems and the clinical association between acalculia and finger agnosia are analyzed. Finger agnosia (as a restricted form of autotopagnosia, right–left discrimination disturbances, semantic aphasia, and acalculia are proposed to comprise a single neuropsychological syndrome associated with left angular gyrus damage. A classification of calculation disturbances resulting from brain damage is presented. It is emphasized that using historical/anthropological analysis, it becomes evident that acalculia, finger agnosia, and disorders in right–left discrimination (as in general, in the use of spatial concepts must constitute a single clinical syndrome, resulting from the disruption of some common brain activity and the impairment of common cognitive mechanisms.

Agnosic vision is like peripheral vision, which is limited by crowding.

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Strappini, Francesca; Pelli, Denis G; Di Pace, Enrico; Martelli, Marialuisa

2017-04-01

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. Our "standard" normal observer took these tests at various eccentricities in his periphery. Analyzing the published data of 32 apperceptive agnosia patients and a group of 14 posterior cortical atrophy (PCA) patients on these tests, we find that each patient's pattern of object recognition deficits is well characterized by one number, the equivalent eccentricity at which our standard observer's peripheral vision is like the central vision of the agnosic patient. In other words, each agnosic patient's equivalent eccentricity is conserved across tests. Across patients, equivalent eccentricity ranges from 4 to 40 deg, which rates severity of the visual deficit. In normal peripheral vision, the required size to perceive a simple image (e.g., an isolated letter) is limited by acuity, and that for a complex image (e.g., a face or a word) is limited by crowding. In crowding, adjacent simple objects appear unrecognizably jumbled unless their spacing exceeds the crowding distance, which grows linearly with eccentricity. Besides conservation of equivalent eccentricity across object-recognition tests, we also find conservation, from eccentricity to agnosia, of the relative susceptibility of recognition of ten visual tests. These findings show that agnosic vision is like eccentric vision. Whence crowding? Peripheral vision, strabismic amblyopia, and possibly apperceptive agnosia are all limited by crowding, making it

Real-time vision, tactile cues, and visual form agnosia in pantomimed grasping: removing haptic feedback induces a switch from natural to pantomime-like grasps

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Robert Leslie Whitwell

2015-05-01

Full Text Available Investigators study the kinematics of grasping movements (prehension under a variety of conditions to probe visuomotor function in normal and brain-damaged individuals. When patient DF, who suffers from visual form agnosia, performs natural grasps, her in-flight hand aperture is scaled to the widths of targets ('grip scaling' that she cannot discriminate amongst. In contrast, when DF's pantomime grasps are based on a memory of a previewed object, her grip scaling is very poor. Her failure on this task has been interpreted as additional support for the dissociation between the use of object vision for action and object vision for perception. Curiously, however, when DF directs her pantomimed grasps towards a displaced imagined copy of a visible object where her fingers make contact with the surface of the table, her grip scaling does not appear to be particularly poor. In the first of two experiments, we revisit this previous work and show that her grip scaling in this real-time pantomime grasping task does not differ from controls, suggesting that terminal tactile feedback from a proxy of the target can maintain DF's grip scaling. In a second experiment with healthy participants, we tested a recent variant of a grasping task in which no tactile feedback is available (i.e. no haptic feedback by comparing the kinematics of target-directed grasps with and without haptic feedback to those of real-time pantomime grasps without haptic feedback. Compared to natural grasps, removing haptic feedback increased RT, slowed the velocity of the reach, reduced grip aperture, sharpened the slopes relating grip aperture to target width, and reduced the final grip aperture. All of these effects were also observed in the pantomime grasping task. Taken together, these results provide compelling support for the view that removing haptic feedback induces a switch from real-time visual control to one that depends more on visual perception and cognitive supervision.

The assessment of auditory function in CSWS: lessons from long-term outcome.

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Metz-Lutz, Marie-Noëlle

2009-08-01

In Landau-Kleffner syndrome (LKS), the prominent and often first symptom is auditory verbal agnosia, which may affect nonverbal sounds. It was early suggested that the subsequent decline of speech expression might result from defective auditory analysis of the patient's own speech. Indeed, despite normal hearing levels, the children behave as if they were deaf, and very rapidly speech expression deteriorates and leads to the receptive aphasia typical of LKS. The association of auditory agnosia more or less restricted to speech with severe language decay prompted numerous studies aimed at specifying the defect in auditory processing and its pathophysiology. Long-term follow-up studies have addressed the issue of the outcome of verbal auditory processing and the development of verbal working memory capacities following the deprivation of phonologic input during the critical period of language development. Based on a review of neurophysiologic and neuropsychological studies of auditory and phonologic disorders published these last 20 years, we discuss the association of verbal agnosia and speech production decay, and try to explain the phonologic working memory deficit in the late outcome of LKS within the Hickok and Poeppel dual-stream model of speech processing.

Developmental Disorders of Communication With Special Reference to Deaf Children With Additional Handicaps

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Denmark, John C.

1971-01-01

Reviews 9 examples of "non-communicating children" whose probelms stem from: 1) intellectual impairment; 2) mental illness; 3) congenital verbal agnosia; 4) physical disease; or, 5) early profound deafness. (MB)

The Management of Developmental Apraxia.

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Gubbay, S. S.

1978-01-01

Of 39 children (5-12 years old) with developmental apraxia and agnosia, who were assessed neurologically, 19 were also given simple standarized tests of motor ability. Journal availability: see EC 112 661. (Author/SBH)

Cortical activity in the left and right hemispheres during language-related brain functions

DEFF Research Database (Denmark)

Lassen, N A; Larsen, B

1980-01-01

of cortical activity seen during various language functions, emphasizing the practically symmetrical involvement in both hemispheres. A case of auditive agnosia (with complete cortical word deafness but preserved pure tone thresholds) is presented. The patient's normal speech constitutes evidence...

Kluver – Bucy Syndrome in a Nigeria Male | Aina | Nigerian ...

African Journals Online (AJOL)

Kluver-Bucy Syndrome, first described in monkeys as a result of bilateral ablation of their temporal lobes consists of hypermetamorphosis, visual agnosia, hyperarality and hyper-sexuality. In man, similar but not exact syndrome had been described and the symptom manifestations included placidity, apathy, bulimia, ...

Is word recognition crowded in pure alexia?

DEFF Research Database (Denmark)

Sand, Katrine; Habekost, Thomas; Petersen, Anders

2017-01-01

Pure alexia is a selective deficit in reading, which arises following damage to the left ventral occipito-temporal cortex. Crowding, the inability to recognise objects in a clutter, has recently been hypothesised to be the underlying deficit of apperceptive visual agnosia1. Crowding normally occurs...

Blissymbols and Manual Signs: A Multimodal Approach to Intervention in a Case of Multiple Disability.

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Hooper, Janice; And Others

1987-01-01

A multimodal intervention program designed for a nine-year-old with severe communication problems (secondary to cerebral palsy, receptive dysphasia, and auditory agnosia) combined manual signs and graphic symbols to help her communicate. The intensive, highly structured program had significant positive results. (Author/CB)

A Patient with Difficulty of Object Recognition: Semantic Amnesia for Manipulable Objects

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A. Yamadori

1992-01-01

Full Text Available We studied a patient who had recognition difficulty for manipulable objects. MRI showed a lesion in the left occipito-parietotemporal area. Differential diagnosis of agnosia, aphasia and apraxia is discussed. We believe this “object meaning amnesia” constitutes a distinct subtype of semantic amnesia.

Establishing Visual Category Boundaries between Objects: A PET Study

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Saumier, Daniel; Chertkow, Howard; Arguin, Martin; Whatmough, Cristine

2005-01-01

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, Saumier, Arguin, Chertkow, and Renfrew (2001) showed that AD subjects have difficulties in…

78 FR 11939 - Social Security Ruling, SSR 13-2p.; Titles II and XVI: Evaluating Cases Involving Drug Addiction...

Science.gov (United States)

2013-02-20

... memory impairment and at least one of the following cognitive disturbances: aphasia, apraxia, agnosia, or... of multiple memory deficits that significantly impair social or occupational functioning and... that a claimant is disabled. A finding that DAA is not material also implies that there is no treatment...

[Agraphia and preservation of music writing in a bilingual piano teacher].

Science.gov (United States)

Assal, G; Buttet, J

1983-01-01

A bilingual virtuoso piano teacher developed aphasia and amusia, probably due to cerebral embolism. The perfectly demarcated and unique lesion was located in the left posterior temporoparietal region. Language examinations in French and Italian demonstrated entirely comparable difficulties in both languages. The linguistic course was favorable after a period of auditory agnosia and global aphasia. Language became fluent again 3 months after the onset, with a marked vocabulary loss and phonemic paraphasias with attempts at self-correction. Repetition was altered markedly with a deficit in auditory comprehension but no remaining elements of auditory agnosia. Reading was possible, but with some difficulty and total agraphia and acalculia persisted. Musical ability was better conserved, particularly with respect to repetition and above all to writing, the sparing of the latter constituting a fairly uncommon dissociation in relation to agraphia. Findings are discussed in relation to data in the literature concerning hemispheric participation in various musical tasks.

Historical Perspectives on Ancient Greek Derived "a" Prefixed Nomenclature for Acquired Neurocognitive Impairment.

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Gasquoine, Philip Gerard

2017-06-01

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). Some of these terms (e.g., agnosia) were used in ancient Greek, although not associated with neurocognitive impairment. The remainder constitute novel semantically plausible (e.g., anosmia) and unclear (e.g., alexia) formulations. In the localizationist thinking of the time, neurocognition was conceived as being organized within specialized "centers" in specific locations connected by pathways within the brain.

The Impact of Colour, Spatial Resolution, and Presentation Speed on Category Naming

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Laws, Keith R.; Hunter, Maria Z.

2006-01-01

Studies of neurological patients with category-specific agnosia have provided important contributions to our understanding of object recognition, although the meaning of such disorders is still hotly debated. One crucial line of research for our understanding of category effects, is through the examination of category biases in healthy normal…

Vision after 53 years of blindness

Czech Academy of Sciences Publication Activity Database

Šikl, Radovan; Šimeček, Michal; Porubanová-Norquist, M.; Bezdíček, O.; Kremláček, J.; Stodůlka, P.; Fine, I.; Ostrovsky, Y.

2013-01-01

Roč. 4, č. 8 (2013), s. 498-507 ISSN 2041-6695 R&D Projects: GA ČR(CZ) GAP407/12/2528 Institutional support: RVO:68081740 Keywords : sight recovery * blindness * visual deprivation * object agnosia * prosopagnosia Subject RIV: AN - Psychology http://i-perception.perceptionweb.com/fulltext/i04/i0611.pdf

Visual Barriers to Prevent Ambulatory ALzheimer's Patients from Exiting through an Emergency Door.

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Namazi, Kevan H.; And Others

1989-01-01

Conducted study on Alzheimer's unit to test seven different visual barrier conditions for reducing patient exits. Findings indicated that exiting was eliminated under two conditions. Results suggest visual agnosia, the inability to interpret what the eye sees, may be used as tool in managing wandering behavior of Alzheimer's patients. (Author/NB)

A Study to Determine the Existence and Characteristics of Distinctively Different Subpopulations Subsumed within the Reading Disabled Population.

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Steinberg, Laurie S.

Forty-five third-grade and fourth-grade boys identified by their schools as being both normal in intelligence and severely disabled in reading were given a battery of tests of language, visual perception, silent reading comprehension, and finger agnosia. Three consistent groups of subjects emerged from cluster analyses of the results. One group…

Congenital prosopagnosia: A case report

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Rodrigo Rizek Schultz

Full Text Available Abstract Prosopagnosia is a visual agnosia characterized by an inability to recognize previously known human faces and to learn new faces. The aim of this study was to present a forty-six year-old woman with congenital prosopagnosia, and to discuss the neural bases of perception and recognition of faces. The patients had a lifetime impairment in recognizing faces of family members, close friends, and even her own face in photos. She also had impairment in recognizing animals such as discriminating between cats and dogs. The patient's basic visual skills showed impairment in identifying and recognizing the animal form perception on the coding subtest of the WAIS-R, recognizing overlapping pictures (Luria, and in identifying silhouettes depicting animals and objects (VOSP. Unconventional tests using pictures evidenced impairment in her capacity to identify famous faces, facial emotions and animals. Her face perception abilities were preserved, but recognition could not take place. Therefore, it appears that the agnosia in this case best fits the group of categories termed "associative".

[Amusia and its topic specification].

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Buklina, S B; Skvortsova, V B

2007-01-01

A historical development of views on amusia and its clinical phenomenology is reviewed. The authors present a case of atypical amusia in a patient aged 32 years with glioma of the right temporal lobe including the upper temporal gyrus. Amusia was combined with euphoria and disturbances of evaluation of speech intonation. It has been assumed that different mechanisms implicated with different regions of both brain hemispheres may underlie amusia. Sometimes these mechanisms appear to be universal, e.g. disorders of symbolic gnosis in posterior hemisphere lesions, being comorbid with amusia as disturbances in reading music and letter agnosia. In our case, the right temporal lobe lesion, especially with involvement of the upper temporal gyrus, caused specific music agnosia with disturbances of perception of some notes and duration of their phonation or a musical contour of the whole melody. Motor amusia is developed due to additional disturbances of motor and premotor brain functions, with significant contribution of the Broca's speech area. Music may be a model for investigation into processes of multimodal integration and hemisphere interaction.

Regional cerebral blood flow in primary degenerative dementia

International Nuclear Information System (INIS)

Kawakatsu, Shinobu; Totsuka, Shiro; Shinohara, Masao; Koyama, Hideki; Sagawa, Katsuo; Morinobu, Shigeru; Oiji, Arata; Komatani, Akio

1991-01-01

Regional cerebral blood flow (rCBF) was examined, using SPECT by Xe-133 inhalation, in patients with primary degenerative dementia who were subgrouped according to predominant symptoms with respect to amnesia, apraxia, agnosia, aphasia, and personality changes. Also the effect of sex and age at dementia onset on the rCBF patterns was assessed. (author). 26 refs.; 1 fig.; 7 tabs

Gerstmann's syndrome and unilateral optic ataxia in the emergency department

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Barbosa, Breno José Alencar Pires; de Brito, Marcelo Houat; Rodrigues, Júlia Chartouni; Kubota, Gabriel Taricani; Parmera, Jacy Bezerra

2017-01-01

ABSTRACT. A 75-year-old right-handed woman presented to the emergency department with simultanagnosia and right unilateral optic ataxia. Moreover, the patient had agraphia, acalculia, digital agnosia and right-left disorientation, consistent with complete Gerstmann's syndrome. This case highlights the concurrence of Gerstmann's syndrome and unilateral optic ataxia in the acute phase of a left middle cerebral artery stroke. PMID:29354229

Gerstmann's syndrome and unilateral optic ataxia in the emergency department

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Breno José Alencar Pires Barbosa

Full Text Available ABSTRACT. A 75-year-old right-handed woman presented to the emergency department with simultanagnosia and right unilateral optic ataxia. Moreover, the patient had agraphia, acalculia, digital agnosia and right-left disorientation, consistent with complete Gerstmann's syndrome. This case highlights the concurrence of Gerstmann's syndrome and unilateral optic ataxia in the acute phase of a left middle cerebral artery stroke.

SU34. A Systematic Review of Behavioral Research and Lesion Evidence for the 2-Factor Theory of Monothematic Delusions

Science.gov (United States)

Neustadter, Eli; Pinder, Juno; Corlett, Philip

2017-01-01

Abstract Background: Two-factor theory (TFT) posits monothematic delusion formation requires damage producing delusion content (factor 1) and a deficit in belief evaluation (factor 2, posited to be localized in right frontal cortex). The purpose of the current study was 2-fold: (1) to review the behavioral data supporting TFT and (2) to assess whether locations of delusion-inducing lesions were consistent with TFT predictions: ie, common factor 1 damage within a particular monothematic delusion and common factor 2 damage across delusions. Furthermore, factor 2 damage ought to distinguish Capgras syndrome (the delusion that a previously familiar person is an imposter) from nondelusional-affective agnosia (unfamiliarity without delusion). Methods: We reviewed all papers concerned with TFT and all studies of galvanic skin response (GSR) in monothematic delusions (frequently cited as behavioral evidence for TFT). Next, we reviewed case reports of lesion-induced monothematic delusions including Capgras, Fregoli, Cotard, and somatoparaphrenia, as well as affective agnosia. We report lesion location frequencies in 12 regions of interest. Results: We found 27 articles on TFT. Only 3 contained empirical evidence (11%, all hypnosis studies): one had no direct hypothesis regarding TFT, one was inconclusive, and another failed to support TFT. We found 7 additional GSR studies of Capgras, 6 of which reported statistically significant abnormal GSR, but no effects were specific to the familiar person accused of being an imposter. One neuroimaging case study of Capgras did find fMRI correlates of perceiving the imposter in the left hemisphere. One study of somatoparaphrenia reported a GSR deficit to noxious stimuli approaching the denied limb. There were no published studies testing TFT predictions about Cotard or Fregoli. We analyzed 46 reports of lesion-induced delusions and 20 cases of affective agnosia. Right hemisphere damage was most common in monothematic delusion cases (�

Occipital lobe infarction and positron emission tomography

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Tagawa, Koichi; Nagata, Ken; Shishido, Fumio (Research Inst. of Brain and Blood Vessels, Akita (Japan))

1990-08-01

Even though the PET study revealed a total infarct in the territory of the left PCA in our 3 cases of pure alesia, it is still obscure which part of the left occipital lobe is most closely associated with the occurrence of the pure alexia. In order to elucidate the intralobar localization of the pure alexia, it is needed to have an ideal case who shows an pure alexia due to the localized lesion within the left occipital lobe. Furthermore, high-resolution PET scanner will circumvent the problem in detecting the metabolism and blood flow in the corpus callosum which plays an important role in the pathogenesis. We have shown that the occlusion of the right PCA also produced a left unilateral agnosia which is one of the common neurological signs in the right MCA infarction. To tell whether the responsible lesion for the unilateral spatial agnosia differs between the PCA occlusion and the MCA occlusion, the correlation study should be carried out in a greater number of the subjects. Two distinctive neuropsychological manifestations, cerebral color blidness and prosopagnosia, have been considered to be produced by the bilateral occipital lesion. The PET studies disclosed reduction of blood flow and oxygen metabolism in both occipital lobes in our particular patient who exibited cerebral color blindness and posopagnosia. (author).

Occipital lobe infarction and positron emission tomography

International Nuclear Information System (INIS)

Tagawa, Koichi; Nagata, Ken; Shishido, Fumio

1990-01-01

Even though the PET study revealed a total infarct in the territory of the left PCA in our 3 cases of pure alesia, it is still obscure which part of the left occipital lobe is most closely associated with the occurrence of the pure alexia. In order to elucidate the intralobar localization of the pure alexia, it is needed to have an ideal case who shows an pure alexia due to the localized lesion within the left occipital lobe. Furthermore, high-resolution PET scanner will circumvent the problem in detecting the metabolism and blood flow in the corpus callosum which plays an important role in the pathogenesis. We have shown that the occlusion of the right PCA also produced a left unilateral agnosia which is one of the common neurological signs in the right MCA infarction. To tell whether the responsible lesion for the unilateral spatial agnosia differs between the PCA occlusion and the MCA occlusion, the correlation study should be carried out in a greater number of the subjects. Two distinctive neuropsychological manifestations, cerebral color blidness and prosopagnosia, have been considered to be produced by the bilateral occipital lesion. The PET studies disclosed reduction of blood flow and oxygen metabolism in both occipital lobes in our particular patient who exibited cerebral color blindness and posopagnosia. (author)

Kluver–Bucy syndrome in one case with systemic lupus erythematosus

Directory of Open Access Journals (Sweden)

Hsiu-Fen Lin

2011-04-01

Full Text Available Kluver–Bucy syndrome (KBS is a collection of neuropsychiatric symptoms, including visual agnosia (prosopagnosia, hypermetamorphosis, placidity, hypersexuality, and hyperorality. Although neuropsychiatric manifestation is prevalent in cases with systemic lupus erythematosus (SLE, only one literature reported a case with SLE that had KBS previously. In this article, a 37-year-old woman with SLE who developed KBS and other neuropsychiatric symptoms is presented. Brain imaging proved the relevant structural lesion. The possible explanation of pathogenesis of KBS in SLE is discussed.

About the neurolinguistics of the implicatures: abstract of a study

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Juliano Luís Fontanari

1989-06-01

Full Text Available Taking into account recent data on linguistics of production and comprehension in aphasia, a protocol was executed including the several types of implicatures. The protocol was applied to 90 subjects classified according to the localization of cerebral lesions, as shown by CT. Results are discussed in report to clinical manifestations of brain lesions, as aphasia, apraxia, agnosia, and intelligence and pragmatics disturbances. Discussion supports the impression that there is a mechanism that correlates extra-linguistics contexts with the 'said' at the right hemisphere.

Correlations between neurological signs and brain MR images of patients in consecutive stages of subacute sclerosing panencephalitis

International Nuclear Information System (INIS)

Kulczycki, J.; Kryst-Widzgowska, T.; Sobczyk, W.; Bochynska, A.; Pilkowska, E.; Milewska, D.

1994-01-01

Correlations between neurological symptoms and brain MRI changes during the course of SSPE in 10 patients were studied. Visual agnosia and mental regression - very frequent symptoms at the early stages of the disease were caused by nearly symmetrical, focal involvement of the occipital and frontal white matter in all cases. Pyramidal and extrapyramidal disturbances reflected rather diffuse lesions of both cerebral hemispheres in late second stage of the illness. In cases with clinical improvement the brain changes disclosed an entire stability, but not diminishing intensity. (author)

[Brodmann Areas 17, 18, and 19 in the Human Brain: An Overview].

Science.gov (United States)

Kawachi, Juro

2017-04-01

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.

Síndrome de gerstmann de desenvolvimento associada a neoplasia cerebelar: relato de um caso e revisão da literatura Developmental Gerstmann syndrome associated with cerebellar neoplasm: a case report with review of litterature

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Lineu César Werneck

1975-03-01

Full Text Available É relatado um caso de síndrome de Gerstmann de Desenvolvimento, que apresentava acalculia, agrafía, confusão direita-esquerda, agnosia de dedos e apraxia construcional, em um menino de 7 anos. O tratamento inicial com metilfenidato determinou bons resultados no que concerne à hiperatividade, à atenção e à apraxia construcional. Durante o curso clínico, o paciente apresentou sintomatologia cerebelar, hipertensão intracraniana, tendo sido feita intervenção cirúrgica na fossa posterior, sendo excisado um meduloblastoma de cerebelo. O autor acredita que é esta a primeira descrição na literatura da concomitância da síndrome de Gerstmann de Desenvolvimento e neoplasia de fossa posterior. São feitos comentários focalizando cada um dos aspectos clínicos, fatores etiológicos e topográficos.A Developmental Gerstmann syndrome in a 7 years-old-boy with hyperactivity, short attention span, acalculia, agraphia, right-left confusion, finger agnosia and constructional apraxia is reported. An initial trial with methylphenidate was done with good improvement regarding hyperactivity, attention span and constructional apraxia. In the clinical course developed a cerebellar syndrome and intracranial hypertension. Surgical exploration of the cerebellum discovered a medulloblastoma. The author believes that this is the first described association of Developmental Gerstmann syndrome and cerebellar neoplasia. The clinical findings, the etiology and the topography of the Gerstmann syndrome are discussed.

Neuropsicología clínica y cognoscitiva

OpenAIRE

Montañés, Patricia; Brigard, Felipe de

2005-01-01

En este libro se realiza la descripción semiológica y sistemática de los procesos que permiten al hombre «ser» (lo que se llama los procesos cognoscitivos), cosa que se perfila como uno de los desafíos más importantes del ser humano: el saber cómo percibimos, hablamos, escribimos, sumamos, aprendemos, recordamos, reconocemos y actuamos, a luz del estudio de las difunciones en cada uno de los procesos, v.gr. afasia, alexia, acalculia, agnosia, apraxia. / Contenido. Preliminares; Capítulo 1 - A...

Correlations between neurological signs and brain MR images of patients in consecutive stages of subacute sclerosing panencephalitis

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Kulczycki, J.; Kryst-Widzgowska, T.; Sobczyk, W.; Bochynska, A.; Pilkowska, E.; Milewska, D. [Pracownia Rezonansu Magnetycznego, Inst. Psychiatrii i Neurologii, Warsaw (Poland)

1994-12-31

Correlations between neurological symptoms and brain MRI changes during the course of SSPE in 10 patients were studied. Visual agnosia and mental regression - very frequent symptoms at the early stages of the disease were caused by nearly symmetrical, focal involvement of the occipital and frontal white matter in all cases. Pyramidal and extrapyramidal disturbances reflected rather diffuse lesions of both cerebral hemispheres in late second stage of the illness. In cases with clinical improvement the brain changes disclosed an entire stability, but not diminishing intensity. (author) 9 refs, 8 figs, 3 tabs

The functional neuroanatomy of object agnosia: a case study.

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Konen, Christina S; Behrmann, Marlene; Nishimura, Mayu; Kastner, Sabine

2011-07-14

Cortical reorganization of visual and object representations following neural injury was examined using fMRI and behavioral investigations. We probed the visual responsivity of the ventral visual cortex of an agnosic patient who was impaired at object recognition following a lesion to the right lateral fusiform gyrus. In both hemispheres, retinotopic mapping revealed typical topographic organization and visual activation of early visual cortex. However, visual responses, object-related, and -selective responses were reduced in regions immediately surrounding the lesion in the right hemisphere, and also, surprisingly, in corresponding locations in the structurally intact left hemisphere. In contrast, hV4 of the right hemisphere showed expanded response properties. These findings indicate that the right lateral fusiform gyrus is critically involved in object recognition and that an impairment to this region has widespread consequences for remote parts of cortex. Finally, functional neural plasticity is possible even when a cortical lesion is sustained in adulthood. Copyright © 2011 Elsevier Inc. All rights reserved.

Stroke of the inferiomedial temporal lobe causing word agnosia.

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Hassan, Hardi; Ehsanula, Huq; Pattanshetti, Mahendra

2017-07-26

A 69-year-old man presented with sudden loss of ability to recognise written words and remember the meaning of words and names. He could not name the town he lived in nor name his children. It was difficult for him to remember the meaning of concrete and abstract nouns. His speech fluency and understanding of casual talks were normal. He remembered that he had a conversation with his family that morning, but not the exact content. He was referred to the transient ischaemic attack clinic by his general practitioner as he scored low on the abbreviated mental test score. He underwent a brain MRI scan (T2 weighted, diffusion weighted and fluid-attenuated inversion recovery) which showed an acute infarction in the left medial temporal region affecting the fusiform and parahippocampal gyri. He also noticed that it was easier to retrieve numbers, for example, his mobile number. He recovered on waking up the next day. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

A novel device for the study of somatosensory information processing

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Holden, Jameson K.; Nguyen, Richard H.; Francisco, Eric M.; Zhang, Zheng; Dennis, Robert G.; Tommerdahl, Mark

2012-01-01

Current methods for applying multi-site vibratory stimuli to the skin typically involve the use of multiple, individual vibrotactile stimulators. Limitations of such an arrangement include difficulty with both positioning the stimuli as well as ensuring that stimuli are delivered in a synchronized and deliberate manner. Previously, we reported a two-site tactile stimulator that was developed in order to solve these problems (Tannan et al., 2007a). Due to both the success of that novel stimulator and the limitations that were inherent in that device, we designed and fabricated a four-site stimulator that provides a number of advantages over the previous version. First, the device can stimulate four independent skin sites and is primarily designed for stimulating the digit tips. Second, the positioning of the probe tips has been re-designed to provide better ergonomic hand placement. Third, the device is much more portable than the previously-reported stimulator. Fourth, the stimulator head has a much smaller footprint on the table or surface where it resides. To demonstrate the capacity of the device for delivering tactile stimulation at four independent sites, a finger agnosia protocol, in the presence and absence of conditioning stimuli, was conducted on seventeen healthy control subjects. The study demonstrated that with increasing amplitudes of vibrotactile conditioning stimuli concurrent with the agnosia test, inaccuracies of digit identification increased, particularly at digits D3 and D4. The results are consistent with prior studies that implicated synchronization of adjacent and near-adjacent cortical ensembles with conditioning stimuli in impacting TOJ performance (Tommerdahl et al., 2007). PMID:22155443

Neurological, neuropsychological and neuroradiological studies of the posterior cerebral artery occlusion

International Nuclear Information System (INIS)

Tagawa, Koichi

1978-01-01

Neurological, neuropsychological and neuroradiological studies were performed on 31 cases of the posterior cerebral artery (PCA) occlusion diagnosed by cerebral angiography and/or computed tomography (CT). Neurological examinations revealed visual field defect in 28 cases, contralateral sensory disturbance and hemiparesis in 23 cases and mental syndrome of memory disturbance, disorientation or confusion in 8 cases. CT was done on 17 cases out of 23 cases with contralateral sensory disturbance and hemiparesis. Ten cases of them revealed to have thalamic lesions by CT. In 7 cases which had no evidence of thalamic lesion by CT, 3 cases were highly suspected to have thalamic involvement clinically. The neurological and neuroradiological findings revealed high incidence and its pathomechanism of thalamic lesion in the cases of PCA occlusion. Neuropsychological examinations disclosed pure alexia in 6 cases, cortical blindness in 2 cases and hemispatial agnosia in 2 cases. Four cases with pure alexia were followed their alexic symptoms. Alexic symptoms lasted long in 3 cases. In these cases, collateral flow to the territory of the occlude PCA was hardly visible. One case with a relatively good collateral filling of the occluded PCA, alexic symptoms showed gradual improvement. Two cases with cortical blindness were proven to have bilateral PCA occlusion. In these 2 cases, collateral filling was hardly visible and their symptoms were permanent. The neurological and neuroradiological findings mentioned above suggest that the prognosis of pure alexia and cortical blindness depends largely on the degree of development of collateral circulation to the occluded PCA. Hemispatial agnosia was seen in 2 cases. (author)

Posterior cortical atrophy - a prototypical case of dementia beginning with visual symptoms: case report

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Leonardo Ferreira Caixeta

2013-10-01

Full Text Available Dementia presenting with prominent higher order visual symptoms may be observed in a range of neurodegenerative conditions and is often challenging to diagnose. We describe a case of progressive dementia presenting with prominent visual cortical symptoms. A 55-year-old, right-handed, woman with early onset of visual impairment not associated with anterior visual pathology, presenting with dyslexia, visual agnosia, Balint's syndrome, and spatial disorientation. Ophthalmologists should consider this condition especially in presenile patients with slowly progressive higher-order visual symptoms. Although described in association with different conditions, it may also occur in Alzheimer disease.

Surgical techniques in radiation induced temporal lobe necrosis in nasopharyngeal carcinoma patients.

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Alfotih, Gobran Taha Ahmed; Zheng, Mei Guang; Cai, Wang Qing; Xu, Xin Ke; Hu, Zhen; Li, Fang Cheng

2016-01-01

Radiation induced brain injury ranges from acute reversible edema to late, irreversible radiation necrosis. Radiation induced temporal lobe necrosis is associated with permanent neurological deficits and occasionally progresses to death. We present our experience with surgery on radiation induced temporal lobe necrosis (RTLN) in nasopharyngeal carcinoma (NPC) patients with special consideration of clinical presentation, surgical technique, and outcomes. This retrospective study includes 12 patients with RTLN treated by the senior author between January 2010 and December 2014. Patients initially sought medical treatment due to headache; other symptoms were hearing loss, visual deterioration, seizure, hemiparesis, vertigo, memory loss and agnosia. A temporal approach through a linear incision was performed for all cases. RTLN was found in one side in 7 patients, and bilaterally in 5. 4 patients underwent resection of necrotic tissue bilaterally and 8 patients on one side. No death occurred in this series of cases. There were no post-operative complications, except 1 patient who developed aseptic meningitis. All 12 patients were free from headache. No seizure occurred in patients with preoperative epilepsy. Other symptoms such as hemiparesis and vertigo improved in all patients. Memory loss, agnosia and hearing loss did not change post-operatively in all cases. The follow-up MR images demonstrated no recurrence of necrotic lesions in all 12 patients. Neurosurgical intervention through a temporal approach with linear incision is warranted in patients with radiation induced temporal lobe necrosis with significant symptoms and signs of increased intracranial pressure, minimum space occupying effect on imaging, or neurological deterioration despite conservative management. Copyright © 2016 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Impaired Velocity Processing Reveals an Agnosia for Motion in Depth

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Barendregt, Martijn; Dumoulin, Serge O.; Rokers, Bas

2016-01-01

Many individuals with normal visual acuity are unable to discriminate the direction of 3-D motion in a portion of their visual field, a deficit previously referred to as a stereomotion scotoma. The origin of this visual deficit has remained unclear. We hypothesized that the impairment is due to a

Differences in finger localisation performance of patients with finger agnosia

NARCIS (Netherlands)

Anema, H.A.; Kessels, R.P.C.; de Haan, E.H.F.; Kappelle, L.J.; Leijten, F.S.; van Zandvoort, M.J.E.; Dijkerman, H.C.

2008-01-01

Several neuropsychological studies have suggested parallel processing of somatosensory input when localising a tactile stimulus on one's own by pointing towards it (body schema) and when localising this touched location by pointing to it on a map of a hand (body image). Usually these reports

Differences in finger localisation performance of patients with finger agnosia

NARCIS (Netherlands)

Anema, H.A.; Kessels, R.P.C.; Haan, E.H.F. de; Kappelle, L.J.; Leijten, F.S.S.; Zandvoort, M.J.E. van; Dijkerman, H.C.

2008-01-01

Several neuropsychological studies have suggested parallel processing of somatosensory input when localising a tactile stimulus on ones own by pointing towards it (body schema) and when localising this touched location by pointing to it on a map of a hand (body image). Usually these reports describe

Differences in finger localisation performance of patients with finger agnosia.

NARCIS (Netherlands)

Anema, H.A.; Kessels, R.P.C.; Haan, E.H.F. de; Kappelle, L.J.; Leijten, F.S.S.; Zandvoort, M.J. Van; Dijkerman, H.C.

2008-01-01

Several neuropsychological studies have suggested parallel processing of somatosensory input when localising a tactile stimulus on one's own by pointing towards it (body schema) and when localising this touched location by pointing to it on a map of a hand (body image). Usually these reports

A new selective developmental deficit: Impaired object recognition with normal face recognition.

Science.gov (United States)

Germine, Laura; Cashdollar, Nathan; Düzel, Emrah; Duchaine, Bradley

2011-05-01

Studies of developmental deficits in face recognition, or developmental prosopagnosia, have shown that individuals who have not suffered brain damage can show face recognition impairments coupled with normal object recognition (Duchaine and Nakayama, 2005; Duchaine et al., 2006; Nunn et al., 2001). However, no developmental cases with the opposite dissociation - normal face recognition with impaired object recognition - have been reported. The existence of a case of non-face developmental visual agnosia would indicate that the development of normal face recognition mechanisms does not rely on the development of normal object recognition mechanisms. To see whether a developmental variant of non-face visual object agnosia exists, we conducted a series of web-based object and face recognition tests to screen for individuals showing object recognition memory impairments but not face recognition impairments. Through this screening process, we identified AW, an otherwise normal 19-year-old female, who was then tested in the lab on face and object recognition tests. AW's performance was impaired in within-class visual recognition memory across six different visual categories (guns, horses, scenes, tools, doors, and cars). In contrast, she scored normally on seven tests of face recognition, tests of memory for two other object categories (houses and glasses), and tests of recall memory for visual shapes. Testing confirmed that her impairment was not related to a general deficit in lower-level perception, object perception, basic-level recognition, or memory. AW's results provide the first neuropsychological evidence that recognition memory for non-face visual object categories can be selectively impaired in individuals without brain damage or other memory impairment. These results indicate that the development of recognition memory for faces does not depend on intact object recognition memory and provide further evidence for category-specific dissociations in visual

[The role of evidence-based medicine in the neurorehabilitation: the innovative technologies (a review)].

Science.gov (United States)

Sidiakina, I V; Dobrushina, O R; Liadov, K V; Shapovalenko, T V; Romashin, O V

2015-01-01

The present review is focused on the randomized controlled trials and meta-analyses in the field of technological means for neurorehabilitation. The available literature data and the results of original observations provide a basis for distinguishing between the following levels of evidence: instrumental verticalization--2a, robot-assisted mechanotherapy--1a, biological feedback--1a, virtual reality--1a, transcranial magnetic stimulation--1a for central hemiparesis and 1b for speech disturbance and unilateral spatial agnosia, transcranial electrical stimulation--2b, electromyostimulation--1a, telerehabilitation--3. It is concluded that the use of the innovative technologies for the purpose of neurorehabiltation is objectively substantiated. Further investigations are needed to allow their application on an individual basis.

Visual agnosia and posterior cerebral artery infarcts: an anatomical-clinical study.

Science.gov (United States)

Martinaud, Olivier; Pouliquen, Dorothée; Gérardin, Emmanuel; Loubeyre, Maud; Hirsbein, David; Hannequin, Didier; Cohen, Laurent

2012-01-01

To evaluate systematically the cognitive deficits following posterior cerebral artery (PCA) strokes, especially agnosic visual disorders, and to study anatomical-clinical correlations. We investigated 31 patients at the chronic stage (mean duration of 29.1 months post infarct) with standardized cognitive tests. New experimental tests were used to assess visual impairments for words, faces, houses, and objects. Forty-one healthy subjects participated as controls. Brain lesions were normalized, combined, and related to occipitotemporal areas responsive to specific visual categories, including words (VWFA), faces (FFA and OFA), houses (PPA) and common objects (LOC). Lesions were located in the left hemisphere in 15 patients, in the right in 13, and bilaterally in 3. Visual field defects were found in 23 patients. Twenty patients had a visual disorder in at least one of the experimental tests (9 with faces, 10 with houses, 7 with phones, 3 with words). Six patients had a deficit just for a single category of stimulus. The regions of maximum overlap of brain lesions associated with a deficit for a given category of stimuli were contiguous to the peaks of the corresponding functional areas as identified in normal subjects. However, the strength of anatomical-clinical correlations was greater for words than for faces or houses, probably due to the stronger lateralization of the VWFA, as compared to the FFA or the PPA. Agnosic visual disorders following PCA infarcts are more frequent than previously reported. Dedicated batteries of tests, such as those developed here, are required to identify such deficits, which may escape clinical notice. The spatial relationships of lesions and of regions activated in normal subjects predict the nature of the deficits, although individual variability and bilaterally represented systems may blur those correlations.

Visual agnosia and posterior cerebral artery infarcts: an anatomical-clinical study.

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Olivier Martinaud

Full Text Available BACKGROUND: To evaluate systematically the cognitive deficits following posterior cerebral artery (PCA strokes, especially agnosic visual disorders, and to study anatomical-clinical correlations. METHODS AND FINDINGS: We investigated 31 patients at the chronic stage (mean duration of 29.1 months post infarct with standardized cognitive tests. New experimental tests were used to assess visual impairments for words, faces, houses, and objects. Forty-one healthy subjects participated as controls. Brain lesions were normalized, combined, and related to occipitotemporal areas responsive to specific visual categories, including words (VWFA, faces (FFA and OFA, houses (PPA and common objects (LOC. Lesions were located in the left hemisphere in 15 patients, in the right in 13, and bilaterally in 3. Visual field defects were found in 23 patients. Twenty patients had a visual disorder in at least one of the experimental tests (9 with faces, 10 with houses, 7 with phones, 3 with words. Six patients had a deficit just for a single category of stimulus. The regions of maximum overlap of brain lesions associated with a deficit for a given category of stimuli were contiguous to the peaks of the corresponding functional areas as identified in normal subjects. However, the strength of anatomical-clinical correlations was greater for words than for faces or houses, probably due to the stronger lateralization of the VWFA, as compared to the FFA or the PPA. CONCLUSIONS: Agnosic visual disorders following PCA infarcts are more frequent than previously reported. Dedicated batteries of tests, such as those developed here, are required to identify such deficits, which may escape clinical notice. The spatial relationships of lesions and of regions activated in normal subjects predict the nature of the deficits, although individual variability and bilaterally represented systems may blur those correlations.

Dyscalculia, Dysgraphia, and Left-Right Confusion from a Left Posterior Peri-Insular Infarct

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S. Bhattacharyya

2014-01-01

Full Text Available The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation.

Transient Gerstmann syndrome as manifestation of stroke: Case report and brief literature review

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Rafael Batista João

Full Text Available ABSTRACT Gerstmann Syndrome (GS is a rare neurological condition described as a group of cognitive changes corresponding to a tetrad of symptoms comprising agraphia, acalculia, right-left disorientation and finger agnosia. It is known that some specific brain lesions may lead to such findings, particularly when there is impairment of the angular gyrus and adjacent structures. In addition, the possibility of disconnection syndrome should be considered in some cases. The purpose of this article is to report a case of a young, cardiac patient, non-adherent to treatment, who presented with a stroke in which transient clinical symptoms were compatible with the tetrad of GS. The case report is followed by a discussion and brief review of the relevant literature.

[Acquired amusia and musical anhedonia].

Science.gov (United States)

Hirel, C; Lévêque, Y; Deiana, G; Richard, N; Cho, T-H; Mechtouff, L; Derex, L; Tillmann, B; Caclin, A; Nighoghossian, N

2014-01-01

Amusia is defined as an auditory agnosia, specifically related to music, resulting from a cerebral lesion or being of congenital origin. Amusia is rarely associated to musical anhedonia. We report the case of a 43-year-old patient who suffered in January 2012 from a right ischemic lesion affecting the superior temporal cortex, in particular lateral Heschl Gyrus and the posterior part of the Superior Temporal Gyrus (Brodmann areas 21 and 22). Neuropsychological tests revealed an amusia combined to musical anhedonia. The specificity of this case is based on the combination of both syndromes highlighting the relation between neural networks involved in the processing of musical information in both its perceptual and emotional components. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Dyscalculia, dysgraphia, and left-right confusion from a left posterior peri-insular infarct.

Science.gov (United States)

Bhattacharyya, S; Cai, X; Klein, J P

2014-01-01

The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI) showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation.

Progressive posterior cortical dysfunction

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Fábio Henrique de Gobbi Porto

Full Text Available Abstract Progressive posterior cortical dysfunction (PPCD is an insidious syndrome characterized by prominent disorders of higher visual processing. It affects both dorsal (occipito-parietal and ventral (occipito-temporal pathways, disturbing visuospatial processing and visual recognition, respectively. We report a case of a 67-year-old woman presenting with progressive impairment of visual functions. Neurologic examination showed agraphia, alexia, hemispatial neglect (left side visual extinction, complete Balint's syndrome and visual agnosia. Magnetic resonance imaging showed circumscribed atrophy involving the bilateral parieto-occipital regions, slightly more predominant to the right . Our aim was to describe a case of this syndrome, to present a video showing the main abnormalities, and to discuss this unusual presentation of dementia. We believe this article can contribute by improving the recognition of PPCD.

Progressive posterior cortical dysfunction

Science.gov (United States)

Porto, Fábio Henrique de Gobbi; Machado, Gislaine Cristina Lopes; Morillo, Lilian Schafirovits; Brucki, Sonia Maria Dozzi

2010-01-01

Progressive posterior cortical dysfunction (PPCD) is an insidious syndrome characterized by prominent disorders of higher visual processing. It affects both dorsal (occipito-parietal) and ventral (occipito-temporal) pathways, disturbing visuospatial processing and visual recognition, respectively. We report a case of a 67-year-old woman presenting with progressive impairment of visual functions. Neurologic examination showed agraphia, alexia, hemispatial neglect (left side visual extinction), complete Balint’s syndrome and visual agnosia. Magnetic resonance imaging showed circumscribed atrophy involving the bilateral parieto-occipital regions, slightly more predominant to the right. Our aim was to describe a case of this syndrome, to present a video showing the main abnormalities, and to discuss this unusual presentation of dementia. We believe this article can contribute by improving the recognition of PPCD. PMID:29213665

Visual Attention in Posterior Stroke and Relations to Alexia

DEFF Research Database (Denmark)

Petersen, Anders; Vangkilde, Signe; Fabricius, Charlotte

2016-01-01

that reduced visual speed and span may explain pure alexia. Eight patients with unilateral PCA strokes (four left hemisphere, four right hemisphere) were selected on the basis of lesion location, rather than the presence of any visual symptoms. Visual attention was characterized by a whole report paradigm......Impaired visual attention is common following strokes in the territory of the middle cerebral artery, particularly in the right hemisphere, while attentional effects of more posterior lesions are less clear. Commonly, such deficits are investigated in relation to specific syndromes like visual...... agnosia or pure alexia. The aim of this study was to characterize visual processing speed and apprehension span following posterior cerebral artery (PCA) stroke. In addition, the relationship between these attentional parameters and single word reading is investigated, as previous studies have suggested...

A selective deficit in the appreciation and recognition of brightness: brightness agnosia?

NARCIS (Netherlands)

Nijboer, T.C.W.; Nys, G.M.S.; van der Smagt, M.J.; de Haan, E.H.F.

2009-01-01

We report a patient with extensive brain damage in the right hemisphere who demonstrated a severe impairment in the appreciation of brightness. Acuity, contrast sensitivity as well as luminance discrimination were normal, suggesting her brightness impairment is not a mere consequence of low-level

Congenital Amusia in Speakers of a Tone Language: Association with Lexical Tone Agnosia

Science.gov (United States)

Nan, Yun; Sun, Yanan; Peretz, Isabelle

2010-01-01

Congenital amusia is a neurogenetic disorder that affects the processing of musical pitch in speakers of non-tonal languages like English and French. We assessed whether this musical disorder exists among speakers of Mandarin Chinese who use pitch to alter the meaning of words. Using the Montreal Battery of Evaluation of Amusia, we tested 117…

Knowledge and attitudes of allied health professional students regarding the stroke rehabilitation team and the role of the Speech and Language Therapist.

Science.gov (United States)

Byrne, Aine; Pettigrew, Catharine M

2010-01-01

One of the major barriers to effective team working among healthcare professionals is a lack of knowledge of each other's roles. The importance of understanding Irish healthcare students' attitudes towards team working and each other's roles led to the development of this study. The aims were to investigate allied health professional students' perceptions and experiences of the stroke rehabilitation team and the role of the Speech and Language Therapist (SLT). A survey first developed by Felsher and Ross (1994) and further developed by Insalaco et al. (2007) was adapted to the Irish healthcare setting. The survey was administered to final-year Occupational Therapy (n = 23), Speech and Language Therapy (21) students and Physiotherapy (20) students (64 in total) (a 98.5% response rate). Results indicate that students had a good understanding of teamwork in the healthcare setting and the possible benefits and challenges it presents. Students had a strong appreciation for interprofessional collaboration, with the majority (79%) choosing shared leadership as their preferred option for the stroke rehabilitation team. Further to this, the team approaches that students felt were most appropriate for the stroke rehabilitation setting were the more collaborative approaches of interdisciplinary (43.5%) and transdisciplinary (37.1%). The students had clear perceptions of the SLT's role in aphasia, dysphagia, dysarthria, apraxia and auditory agnosia, but were less knowledgeable of the SLT's role in the acquired disorders of alexia and agraphia (p < 0.05). More than half of all students perceived that the SLT is involved in the treatment of hemispatial neglect (55.5%), depression (71.5%) and visual agnosia (59.4%). The results provide valuable information for further developments in interprofessional education at an undergraduate level. Further opportunities should be provided to students to collaborate with each other, particularly in their final year of training as, by then

Visual Dysfunction in Posterior Cortical Atrophy

Science.gov (United States)

Maia da Silva, Mari N.; Millington, Rebecca S.; Bridge, Holly; James-Galton, Merle; Plant, Gordon T.

2017-01-01

Posterior cortical atrophy (PCA) is a syndromic diagnosis. It is characterized by progressive impairment of higher (cortical) visual function with imaging evidence of degeneration affecting the occipital, parietal, and posterior temporal lobes bilaterally. Most cases will prove to have Alzheimer pathology. The aim of this review is to summarize the development of the concept of this disorder since it was first introduced. A critical discussion of the evolving diagnostic criteria is presented and the differential diagnosis with regard to the underlying pathology is reviewed. Emphasis is given to the visual dysfunction that defines the disorder, and the classical deficits, such as simultanagnosia and visual agnosia, as well as the more recently recognized visual field defects, are reviewed, along with the evidence on their neural correlates. The latest developments on the imaging of PCA are summarized, with special attention to its role on the differential diagnosis with related conditions. PMID:28861031

Síndrome de gerstmann de desenvolvimento associada a neoplasia cerebelar: relato de um caso e revisão da literatura

Directory of Open Access Journals (Sweden)

Lineu César Werneck

1975-03-01

Full Text Available É relatado um caso de síndrome de Gerstmann de Desenvolvimento, que apresentava acalculia, agrafía, confusão direita-esquerda, agnosia de dedos e apraxia construcional, em um menino de 7 anos. O tratamento inicial com metilfenidato determinou bons resultados no que concerne à hiperatividade, à atenção e à apraxia construcional. Durante o curso clínico, o paciente apresentou sintomatologia cerebelar, hipertensão intracraniana, tendo sido feita intervenção cirúrgica na fossa posterior, sendo excisado um meduloblastoma de cerebelo. O autor acredita que é esta a primeira descrição na literatura da concomitância da síndrome de Gerstmann de Desenvolvimento e neoplasia de fossa posterior. São feitos comentários focalizando cada um dos aspectos clínicos, fatores etiológicos e topográficos.

Visual Dysfunction in Posterior Cortical Atrophy

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Mari N. Maia da Silva

2017-08-01

Full Text Available Posterior cortical atrophy (PCA is a syndromic diagnosis. It is characterized by progressive impairment of higher (cortical visual function with imaging evidence of degeneration affecting the occipital, parietal, and posterior temporal lobes bilaterally. Most cases will prove to have Alzheimer pathology. The aim of this review is to summarize the development of the concept of this disorder since it was first introduced. A critical discussion of the evolving diagnostic criteria is presented and the differential diagnosis with regard to the underlying pathology is reviewed. Emphasis is given to the visual dysfunction that defines the disorder, and the classical deficits, such as simultanagnosia and visual agnosia, as well as the more recently recognized visual field defects, are reviewed, along with the evidence on their neural correlates. The latest developments on the imaging of PCA are summarized, with special attention to its role on the differential diagnosis with related conditions.

Yellow fever vaccine-associated neurological disease, a suspicious case.

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Beirão, Pedro; Pereira, Patrícia; Nunes, Andreia; Antunes, Pedro

2017-03-02

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. Regarding the yellow fever virus, IgG was identified in serum and cerebrospinal fluid (CSF), with negative IgM and virus PCR in CSF. EEG showed an encephalopathic pattern. The patient improved gradually and a week after discharge was his usual self. Only criteria for suspect neurotropic disease were met, but it's possible the time spent between symptom onset and lumbar puncture prevented a definite diagnosis of yellow fever vaccine-associated neurological disease. This gap would have been smaller if the vaccination history had been collected earlier. 2017 BMJ Publishing Group Ltd.

[A patient with prosopagnosia which developed after an infarction in the left occipital lobe in addition to an old infarction in the right occipital lobe].

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Iwanaga, Keisuke; Satoh, Akira; Satoh, Hideyo; Seto, Makiko; Ochi, Makoto; Tsujihata, Mitsuhiro

2011-05-01

A 66-year-old, right-handed male, was admitted to our hospital with difficulty in recognizing faces and colors. He had suffered a stroke in the right occipital region three years earlier that had induced left homonymous hemianopsia, but not prosopagnosia. A neurological examination revealed prosopagnosia, color agnosia, constructional apraxia, and topographical disorientation, but not either hemineglect or dressing apraxia. The patient was unable to distinguish faces of familiar persons such as his family and friends, as well as those of unfamiliar persons such as doctors and nurses. Brain MRI demonstrated an old infarction in the right medial occipital lobe and a new hemorrhagic infarction in the left medial occipital lobe, including the fusiform and lingual gyrus. It is unclear whether a purely right medial occipital lesion can be responsible for prosopagnosia, or whether bilateral medial occipital lesions are necessary for this occurrence. The current case indicated that bilateral medial occipital lesions play an important role in inducing porsopagnosia.

Patients With Dementia Are Easy Victims to Predators

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R. C. Hamdy MD

2017-10-01

Full Text Available Patients with dementia, especially Alzheimer’s disease and particularly those in early stages, are susceptible to become victims of predators: Their agnosia (see Case 1 prevents them from detecting and accurately interpreting subtle signals that otherwise would have alerted them that they are about to fall for a scam. Furthermore, their judgment is impaired very early in the disease process, often before other symptoms manifest themselves and usually before a diagnosis is made. Patients with early stages of dementia are therefore prime targets for unscrupulous predators, and it behooves caregivers and health care professionals to ensure the integrity of these patients. In this case study, we discuss how a man with mild Alzheimer’s disease was about to fall for a scam were it not for his vigilant wife. We discuss what went wrong in the patient/caregiver interaction and how the catastrophic ending could have been avoided or averted.

Mindblindness: metaphor and neuroaesthetics in the works of Silas Weir Mitchell and Simon Baron-Cohen.

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Swenson, Kristine

2013-01-01

Silas Weir Mitchell's novel, When All the Woods are Green (1894), acknowledges the medical use of mindblindness (agnosia) but also casts it as a developmental disorder, bringing it provocatively close to how current neuropsychologist, Simon Baron-Cohen and his followers use the term in relation to autism. This chapter traces the mindblindess metaphor in the works of Mitchell and Baron-Cohen to show how mindblindness informs the larger paradigms by which they theorize the brain. This analysis suggests that Baron-Cohen, and thus much current thinking about autism spectrum conditions, is influenced by Victorian-era cultural assumptions and neurosexism, a connection that calls for scrutiny of Baron-Cohen's current models of the brain and theories of autism. This chapter also demonstrates the extent to which Mitchell used fiction and advocated writing as neuroaesthetic tools and thus bridged in his work cognitive science and aesthetics--a connection that current scholars of neuroaesthetics are now theorizing. © 2013 Elsevier B.V. All rights reserved.

[Brodmann Areas 39 and 40: Human Parietal Association Area and Higher Cortical Function].

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Sakurai, Yasuhisa

2017-04-01

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). Damage to either gyrus causes Gerstmann's syndrome (finger agnosia, left-right disorientation, agraphia and acalculia) and verbal short-term memory impairment. "Angular alexia with agraphia" results from damage to the middle occipital gyrus posterior to the angular gyrus. Alexia and agraphia, with lesions in the angular or supramarginal gyrus, are characterized by kana transposition errors in reading words, which suggests the impairment of sequential phonological processing.

The contribution of single case studies to the neuroscience of vision.

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Zihl, Josef; Heywood, Charles A

2016-03-01

Visual neuroscience is concerned with the neurobiological foundations of visual perception, that is, the morphological, physiological, and functional organization of the visual brain and its co-operative partners. One important approach for understanding the functional organization of the visual brain is the study of visual perception from the pathological perspective. The study of patients with focal injury to the visual brain allows conclusions about the representation of visual perceptual functions in the framework of association and dissociation of functions. Selective disorders have been reported for more "elementary" visual capabilities, for example, color and movement vision, but also for visuo-cognitive capacities, such as visual agnosia or the visual field of attention. Because these visual disorders occur rather seldom as selective and specific dysfunctions, single cases have always played, and still play, a significant role in gaining insights into the functional organization of the visual brain. © 2016 The Institute of Psychology, Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

[Dissociations between music and language functions after cerebral resection: A new case of amusia without aphasia].

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Peretz, I; Belleville, S; Fontaine, S

1997-12-01

We present the neuropsychological study of a patient, I.R., who sustained bilateral damage to the temporal lobes and to the right frontal lobe as a result of successive brain surgeries that occurred ten years earlier. The patient is 40 years old and right-handed; she had no special training in music or in language, representing, therefore, the large majority of listeners. Her performance is compared to that of four neurologically intact subjects who are closely matched in terms of education, sex and age. In the present study, we report I.R.'s performance on various tests aiming at assessing her general cognitive functioning with a particular focus on auditory aspects. The results show that, despite extensive damage to her auditory cortex, I.R.'s speech abilities are essentially intact (see Tables 1 and 2). The only impairments that are detected in the language domain are related to a short-term memory deficit, to some abnormal sensitivity to retroactive interference in long-term memory (see Table 3) and to articulation. These difficulties do not, however, affect linguistic communication, which is obviously undisturbed I.R. is not aphasic). Similarly, I.R. does not experience any difficulty in the recognition and memorization of familiar sounds such as animal cries, traffic noises and the like (see Tables 5 and 7). In contrast, I.R. is severely impaired in most musical abilities: She can no longer discriminate nor identify melodies that were once highly familiar to her; she can no longer discriminate nor memorize novel melodies (see Table 4). Her pattern of musical losses is compatible with a basic and severe perceptual deficit that compromises access to and registration in memory systems. The observation that the auditory impairment affects music and spares language and environmental sounds refers to a neuropsychological condition that is known as music agnosia. I.R. represents, to our knowledge, the fourth case of music agnosia available in the literature (Peretz

Pure word deafness with auditory object agnosia after bilateral lesion of the superior temporal sulcus.

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Gutschalk, Alexander; Uppenkamp, Stefan; Riedel, Bernhard; Bartsch, Andreas; Brandt, Tobias; Vogt-Schaden, Marlies

2015-12-01

Based on results from functional imaging, cortex along the superior temporal sulcus (STS) has been suggested to subserve phoneme and pre-lexical speech perception. For vowel classification, both superior temporal plane (STP) and STS areas have been suggested relevant. Lesion of bilateral STS may conversely be expected to cause pure word deafness and possibly also impaired vowel classification. Here we studied a patient with bilateral STS lesions caused by ischemic strokes and relatively intact medial STPs to characterize the behavioral consequences of STS loss. The patient showed severe deficits in auditory speech perception, whereas his speech production was fluent and communication by written speech was grossly intact. Auditory-evoked fields in the STP were within normal limits on both sides, suggesting that major parts of the auditory cortex were functionally intact. Further studies showed that the patient had normal hearing thresholds and only mild disability in tests for telencephalic hearing disorder. Prominent deficits were discovered in an auditory-object classification task, where the patient performed four standard deviations below the control group. In marked contrast, performance in a vowel-classification task was intact. Auditory evoked fields showed enhanced responses for vowels compared to matched non-vowels within normal limits. Our results are consistent with the notion that cortex along STS is important for auditory speech perception, although it does not appear to be entirely speech specific. Formant analysis and single vowel classification, however, appear to be already implemented in auditory cortex on the STP. Copyright © 2015 Elsevier Ltd. All rights reserved.

Neurological soft signs in Chinese adolescents with antisocial personality traits.

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Wang, Xin; Cai, Lin; Li, Lingyan; Yang, Yanjie; Yao, Shuqiao; Zhu, Xiongzhao

2016-09-30

The current study was designed to explore the specific relationship between neurologic soft signs (NSSs) and characteristics of antisocial personality traits in adolescents, and to investigate particular NSSs linked to certain brain regions in adolescents with antisocial personality traits. The research was conducted on 96 adolescents diagnosed with ASP traits (ASP trait group) using the ASPD subscale of the Personality Diagnostic Questionnaire for the DSM-IV (PDQ-4+) and 96 adolescents without traits of any personality disorder (control group). NSSs were assessed using the soft sign subscales of the Cambridge Neurological Inventory. Adolescents with ASP traits showed more motor coordination, sensory integration, disinhibition, and total NSSs than the control group. Seven NSSs, including stereognosia in right hand, finger agnosia and graphesthesia in both hands, left-right orientation, and go/no go stimulus, were significantly more frequent in teenagers with ASP traits. Sensory integration was positively associated with ASP traits. Adolescents with antisocial personality traits might have abnormalities in the central nervous system, and sensory integration might be the particular indicator of antisocial personality disorder. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Stereoscopic vision in the absence of the lateral occipital cortex.

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Jenny C A Read

2010-09-01

Full Text Available Both dorsal and ventral cortical visual streams contain neurons sensitive to binocular disparities, but the two streams may underlie different aspects of stereoscopic vision. Here we investigate stereopsis in the neurological patient D.F., whose ventral stream, specifically lateral occipital cortex, has been damaged bilaterally, causing profound visual form agnosia. Despite her severe damage to cortical visual areas, we report that DF's stereo vision is strikingly unimpaired. She is better than many control observers at using binocular disparity to judge whether an isolated object appears near or far, and to resolve ambiguous structure-from-motion. DF is, however, poor at using relative disparity between features at different locations across the visual field. This may stem from a difficulty in identifying the surface boundaries where relative disparity is available. We suggest that the ventral processing stream may play a critical role in enabling healthy observers to extract fine depth information from relative disparities within one surface or between surfaces located in different parts of the visual field.

Critical appraisal of the long-term impact of memantine in treatment of moderate to severe Alzheimer’s disease

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Umamon Puangthong

2009-10-01

Full Text Available Umamon Puangthong, Ging-Yuek Robin HsiungDivision of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, CanadaAbstract: Alzheimer’s disease is the most common cause of dementia in older adults. The clinical features include progressive memory decline as well as cognitive deficits with executive dysfunction, language, visual perceptual difficulties, apraxia and agnosia. During the moderate to severe stage of the disease, there is a major decline in memory and function, while neuropsychiatric disturbances often emerge and patients become difficult to manage. These distressing symptoms increase caregiver burden and add to the direct costs of care of the patients. Any improvements in patient function and behavioral symptoms can reduce caregiver burden. Memantine has been available for a number of years in Europe and in North America. In this article, we examine the pharmacological rationale for its use, and the current clinical evidence for its efficacy and long-term effectiveness in the management of cognitive and behavioral symptoms in moderate to severe stages of Alzheimer’s disease.Keywords: memantine, Alzheimer’s disease, dementia

Preserved local but disrupted contextual figure-ground influences in an individual with abnormal function of intermediate visual areas

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Brooks, Joseph L.; Gilaie-Dotan, Sharon; Rees, Geraint; Bentin, Shlomo; Driver, Jon

2012-01-01

Visual perception depends not only on local stimulus features but also on their relationship to the surrounding stimulus context, as evident in both local and contextual influences on figure-ground segmentation. Intermediate visual areas may play a role in such contextual influences, as we tested here by examining LG, a rare case of developmental visual agnosia. LG has no evident abnormality of brain structure and functional neuroimaging showed relatively normal V1 function, but his intermediate visual areas (V2/V3) function abnormally. We found that contextual influences on figure-ground organization were selectively disrupted in LG, while local sources of figure-ground influences were preserved. Effects of object knowledge and familiarity on figure-ground organization were also significantly diminished. Our results suggest that the mechanisms mediating contextual and familiarity influences on figure-ground organization are dissociable from those mediating local influences on figure-ground assignment. The disruption of contextual processing in intermediate visual areas may play a role in the substantial object recognition difficulties experienced by LG. PMID:22947116

Amusia and musical functioning.

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Alossa, Nicoletta; Castelli, Lorys

2009-01-01

Music, as language, is a universal and specific trait to humans; it is a complex ability with characteristics that are unique compared to other cognitive abilities. Nevertheless, several issues are still open to debate, such as, for example, whether music is a faculty that is independent from the rest of the cognitive system, and whether musical skills are mediated by a single mechanism or by a combination of processes that are independent from one another. Moreover, the anatomical correlations of music have yet to be clarified. The goal of this review is to illustrate the current condition of the neuropsychology of music and to describe different approaches to the study of the musical functions. Hereby, we will describe the neuropsychological findings, suggesting that music is a special function carried out by different and dedicated processes that are probably subserved by different anatomical regions of the brain. Moreover, we will review the evidence obtained by working with brain-damaged patients suffering from music agnosia, a selective impairment in music recognition. Copyright 2009 S. Karger AG, Basel.

Separate channels for processing form, texture, and color: evidence from FMRI adaptation and visual object agnosia.

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Cavina-Pratesi, C; Kentridge, R W; Heywood, C A; Milner, A D

2010-10-01

Previous neuroimaging research suggests that although object shape is analyzed in the lateral occipital cortex, surface properties of objects, such as color and texture, are dealt with in more medial areas, close to the collateral sulcus (CoS). The present study sought to determine whether there is a single medial region concerned with surface properties in general or whether instead there are multiple foci independently extracting different surface properties. We used stimuli varying in their shape, texture, or color, and tested healthy participants and 2 object-agnosic patients, in both a discrimination task and a functional MR adaptation paradigm. We found a double dissociation between medial and lateral occipitotemporal cortices in processing surface (texture or color) versus geometric (shape) properties, respectively. In Experiment 2, we found that the medial occipitotemporal cortex houses separate foci for color (within anterior CoS and lingual gyrus) and texture (caudally within posterior CoS). In addition, we found that areas selective for shape, texture, and color individually were quite distinct from those that respond to all of these features together (shape and texture and color). These latter areas appear to correspond to those associated with the perception of complex stimuli such as faces and places.

Prosopagnosia: current perspectives

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Corrow SL

2016-09-01

Full Text Available Sherryse L Corrow,1,2 Kirsten A Dalrymple,3 Jason JS Barton,1,2 1Human Vision and Eye Movement Laboratory, Neurology Division, Department of Medicine, 2Department of Ophthalmology and Visual Science, University of British Columbia, Vancouver, Canada; 3Institute of Child Development, University of Minnesota, Minneapolis, MN, USA Abstract: Prosopagnosia is a selective visual agnosia characterized by the inability to recognize the identity of faces. There are both acquired forms secondary to brain damage and developmental forms without obvious structural lesions. In this review, we first discuss the diagnosis of acquired and developmental prosopagnosia, and the challenges present in the latter case. Second, we discuss the evidence regarding the selectivity of the prosopagnosic defect, particularly in relation to the recognition of other objects, written words (another visual object category requiring high expertise, and voices. Third, we summarize recent findings about the structural and functional basis of prosopagnosia from studies using magnetic resonance imaging, functional magnetic resonance imaging, and event-related potentials. Finally, we discuss recent attempts at rehabilitation of face recognition in prosopagnosia. Keywords: face recognition, perception, fusiform gyrus, anterior temporal, review

Developmental prosopagnosia and adaptative compensatory strategies: Case study

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Anair Rodrigues

Full Text Available Abstract Prosopagnosia is a type of visual agnosia with inability to identify faces, usually secondary to brain lesion in associative cortex areas, but there is also a congenital form known as developmental prosopagnosia. Objectives: To describe a case of developmental prosopagnosia that illustrates the specificity of the pathways for perception of faces in the visual system. Also, we will describe possible mechanisms of recognition used by this patient. Methods: R.S., a 50 year-old woman, was referred for neuropsychological assessment due to difficulties in perception of familiar faces since childhood, unexplained by any loss of visual acuity. Results: The exam showed good performance for comprehension, reasoning, concept formation, constructional abilities, criticism, judgment, mental control, memory and visual perception for other kinds of stimuli. No difficulties were seen regarding identification of ethnicity, age and types of animals. The patient was able to match celebrities' faces in different positions, but could not identify the matching pictures for unknown people. Conclusions: These findings indicate the patient had developed strategies, throughout life, to recognize familiar faces (relatives, celebrities from memorized fragments, but still had difficulties in identifying non-familiar faces holistically.

A PDP model of the simultaneous perception of multiple objects

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Henderson, Cynthia M.; McClelland, James L.

2011-06-01

Illusory conjunctions in normal and simultanagnosic subjects are two instances where the visual features of multiple objects are incorrectly 'bound' together. A connectionist model explores how multiple objects could be perceived correctly in normal subjects given sufficient time, but could give rise to illusory conjunctions with damage or time pressure. In this model, perception of two objects benefits from lateral connections between hidden layers modelling aspects of the ventral and dorsal visual pathways. As with simultanagnosia, simulations of dorsal lesions impair multi-object recognition. In contrast, a large ventral lesion has minimal effect on dorsal functioning, akin to dissociations between simple object manipulation (retained in visual form agnosia and semantic dementia) and object discrimination (impaired in these disorders) [Hodges, J.R., Bozeat, S., Lambon Ralph, M.A., Patterson, K., and Spatt, J. (2000), 'The Role of Conceptual Knowledge: Evidence from Semantic Dementia', Brain, 123, 1913-1925; Milner, A.D., and Goodale, M.A. (2006), The Visual Brain in Action (2nd ed.), New York: Oxford]. It is hoped that the functioning of this model might suggest potential processes underlying dorsal and ventral contributions to the correct perception of multiple objects.

Hippocampal sclerosis dementia: An amnesic variant of frontotemporal degeneration

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Chiadi U. Onyike

Full Text Available ABSTRACT Objective: To describe characteristics of hippocampal sclerosis dementia. Methods: Convenience sample of Hippocampal sclerosis dementia (HSD recruited from the Johns Hopkins University Brain Resource Center. Twenty-four cases with post-mortem pathological diagnosis of hippocampal sclerosis dementia were reviewed for clinical characterization. Results: The cases showed atrophy and neuronal loss localized to the hippocampus, amygdala and entorrhinal cortex. The majority (79.2% had amnesia at illness onset, and many (54.2% showed abnormal conduct and psychiatric disorder. Nearly 42% presented with an amnesic state, and 37.5% presented with amnesia plus abnormal conduct and psychiatric disorder. All eventually developed a behavioral or psychiatric disorder. Disorientation, executive dysfunction, aphasia, agnosia and apraxia were uncommon at onset. Alzheimer disease (AD was the initial clinical diagnosis in 89% and the final clinical diagnosis in 75%. Diagnosis of frontotemporal dementia (FTD was uncommon (seen in 8%. Conclusion: HSD shows pathological characteristics of FTD and clinical features that mimic AD and overlap with FTD. The findings, placed in the context of earlier work, support the proposition that HSD belongs to the FTD family, where it may be identified as an amnesic variant.

Tc-99m HMPAO brain uptake patterns in patients with dementia of Alzheimer type

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Costa, D.C.; Burns, A.; Philpot, M.; Levy, R.; Ell, P.J.

1988-01-01

Conventional gamma camera SPECT with Tc-99m HMPAO (10 MBq/kg patient weight) was carried out in 21 patients with dementia of Alzheimer type (DAT), fulfilling the criteria established by the National Institute of Neurological and Communicative Disorders and Stroke and the ADRDA criteria (nine with amnesia as the main symptom [group 1], 12 with amnesia, aphasia, and/or apraxia and agnosia [group 2], and eight age-matched control subjects. Perfusion was quantitatively studied by means of cerebrum-cerebellum activity ratios. In group 1, perfusion deficits in the mesial cortex of the temporal lobes (right, 0.70; left, 0.68) were found, and ratios were significantly lower than in the control group (right, 0.77; left, 0.76 [P < .05]). Group 2 showed low ratios throughout both temporal lobes (mesial and lateral cortex), bilaterally in the posterior parietal cortex (right, 0.69; left, 0.66 [control: right, 0.80; left, 0.81] [P < .001]), and left frontal cortex (0.75 [control, 0.79] [P < .05]). In conclusion, SPECT with Tc-99m HMPAO identifies perfusion deficits in patients with DAT, and these correlate well with the clinical findings and are significantly different from those in the control group

Hippocampal sclerosis dementia: an amnesic variant of frontotemporal degeneration

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Onyike, Chiadi U.; Pletnikova, Olga; Sloane, Kelly L.; Sullivan, Campbell; Troncoso, Juan C.; Rabins, Peter V.

2013-01-01

OBJECTIVE To describe characteristics of hippocampal sclerosis dementia. METHODS Convenience sample of Hippocampal sclerosis dementia (HSD) recruited from the Johns Hopkins University Brain Resource Center. Twenty-four cases with post-mortem pathological diagnosis of hippocampal sclerosis dementia were reviewed for clinical characterization. RESULTS The cases showed atrophy and neuronal loss localized to the hippocampus, amygdala and entorrhinal cortex. The majority (79.2%) had amnesia at illness onset, and many (54.2%) showed abnormal conduct and psychiatric disorder. Nearly 42% presented with an amnesic state, and 37.5% presented with amnesia plus abnormal conduct and psychiatric disorder. All eventually developed a behavioral or psychiatric disorder. Disorientation, executive dysfunction, aphasia, agnosia and apraxia were uncommon at onset. Alzheimer disease (AD) was the initial clinical diagnosis in 89% and the final clinical diagnosis in 75%. Diagnosis of frontotemporal dementia (FTD) was uncommon (seen in 8%). CONCLUSION HSD shows pathological characteristics of FTD and clinical features that mimic AD and overlap with FTD. The findings, placed in the context of earlier work, support the proposition that HSD belongs to the FTD family, where it may be identified as an amnesic variant. PMID:24363834

Auditory Dysfunction in Patients with Cerebrovascular Disease

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Sadaharu Tabuchi

2014-01-01

Full Text Available Auditory dysfunction is a common clinical symptom that can induce profound effects on the quality of life of those affected. Cerebrovascular disease (CVD is the most prevalent neurological disorder today, but it has generally been considered a rare cause of auditory dysfunction. However, a substantial proportion of patients with stroke might have auditory dysfunction that has been underestimated due to difficulties with evaluation. The present study reviews relationships between auditory dysfunction and types of CVD including cerebral infarction, intracerebral hemorrhage, subarachnoid hemorrhage, cerebrovascular malformation, moyamoya disease, and superficial siderosis. Recent advances in the etiology, anatomy, and strategies to diagnose and treat these conditions are described. The numbers of patients with CVD accompanied by auditory dysfunction will increase as the population ages. Cerebrovascular diseases often include the auditory system, resulting in various types of auditory dysfunctions, such as unilateral or bilateral deafness, cortical deafness, pure word deafness, auditory agnosia, and auditory hallucinations, some of which are subtle and can only be detected by precise psychoacoustic and electrophysiological testing. The contribution of CVD to auditory dysfunction needs to be understood because CVD can be fatal if overlooked.

Changes in higher mental functions in persons with late sequels of exposure to small ionizing radiation doses

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Turuspekova, S.

2002-01-01

This is a report on the results of studies on the state of higher mental function in individuals with a previous history of exposure to small doses ionizing radiations. The disorders observed are assigned under several groups as follows: dyspraxia, gnostic, visual-spatial agnosia, mnestic, mental processes impairment, neurodynamic. Mnestic and acoustic-gnostical disturbances, and those of the mental processes are rather markedly expressed. Mnestic derangements play a major role in the general pattern of cognitive disorders, being characterized by both modal-specific, and modal-nonspecific features. The topical principle of the classification proposed enables to distinguish the syndrome of middle nonspecific brain structures involvement and the cortical syndromes among the higher mental function disorders, invariably encountered in combination and not isolated. The aforementioned points to the diffuse nature of the neuropsychological disorders, with involvement in the process of both nonspecific and specific structures, characterized by predomination of the frontal and temporal brain cortex sections. Impairment of the higher mental functions in young persons of active age with a past history of exposure to small doses ionizing radiations, necessitate to work out effective measures precluding occurrence and intensification of the cognitive defect. (author)

The perceptions of students in the allied health professions towards stroke rehabilitation teams and the SLP's role.

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Insalaco, Deborah; Ozkurt, Elcin; Santiago, Digna

2007-01-01

The purpose of this study was to determine the perceptions and knowledge of final-year speech-language pathology (SLP), physical and occupational therapy (PT, OT) students toward stroke rehabilitation teams and the SLPs' roles on them. The investigators adapted a survey developed by (Felsher & Ross, 1994) and administered it to 35 PT, 35 OT, and 35 SLP final year students (n=105). We found that the students preferred the transdisciplinary team approach and agreed that the advantages of teamwork were the exchange of ideas, opportunities for participatory learning, and holistic treatment. Communication problems, time-consuming meetings, and role confusion were chosen as disadvantages. The students had clear perceptions of the SLP's role in aphasia, apraxia of speech, dysarthria, dysphagia, and auditory agnosia, but fewer recognized the SLP's role in alexia and memory. Some thought SLPs had a role in dressing apraxia and proprioceptive disorders. Suggestions to maximize the advantages and minimize possible disadvantages of teamwork are provided. Learners will: (1) identify the perceived advantages and disadvantages of stroke rehabilitation teamwork; (2) discover some allied health students' perceptions of the SLP's roles in stroke rehabilitation; (3) infer methods to create positive perceptions of stroke rehabilitation team members.

Dromosagnosia, or why some people lose their sense of direction while driving.

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Tseng, Wei-Shih; Tzeng, Nian-Sheng

2013-11-01

We coined a new word, "dromosagnosia", from the Greek words, dromos ("way, road")+agnosia, to describe the loss of direction while driving, an orientation disorder similar to but different from pure topographic disorientation. Historically, human beings have moved more quickly, from using domesticated animals to high speed vehicles, and this may be beyond the brain's ability to react. Without the benefit of an automatic navigation system, automobiles are associated with more problems of dromosagnosia than are fast-moving aircraft or ships. Previous studies have noted that some areas of the brain are associated with spatial orientation, spatial memory, and even emotion, and abnormalities there could exacerbate the loss of sense of direction. We hypothesize that some people are especially disadvantaged from these brain differences and emotional disturbances when driving their cars. Functional magnetic resonance imaging (fMRI) and event-related potentials (ERP) studies combined with a virtual reality driving simulation might be used to find the areas of the brain related to dromosagnosia. Future applications: some people with dromosagnosia might benefit from special remedial training and a driving safety support system to avoid potential problems. Copyright © 2013 Elsevier Ltd. All rights reserved.

Which visual functions depend on intermediate visual regions? Insights from a case of developmental visual form agnosia.

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Gilaie-Dotan, Sharon

2016-03-01

A key question in visual neuroscience is the causal link between specific brain areas and perceptual functions; which regions are necessary for which visual functions? While the contribution of primary visual cortex and high-level visual regions to visual perception has been extensively investigated, the contribution of intermediate visual areas (e.g. V2/V3) to visual processes remains unclear. Here I review more than 20 visual functions (early, mid, and high-level) of LG, a developmental visual agnosic and prosopagnosic young adult, whose intermediate visual regions function in a significantly abnormal fashion as revealed through extensive fMRI and ERP investigations. While expectedly, some of LG's visual functions are significantly impaired, some of his visual functions are surprisingly normal (e.g. stereopsis, color, reading, biological motion). During the period of eight-year testing described here, LG trained on a perceptual learning paradigm that was successful in improving some but not all of his visual functions. Following LG's visual performance and taking into account additional findings in the field, I propose a framework for how different visual areas contribute to different visual functions, with an emphasis on intermediate visual regions. Thus, although rewiring and plasticity in the brain can occur during development to overcome and compensate for hindering developmental factors, LG's case seems to indicate that some visual functions are much less dependent on strict hierarchical flow than others, and can develop normally in spite of abnormal mid-level visual areas, thereby probably less dependent on intermediate visual regions. Copyright © 2015 Elsevier Ltd. All rights reserved.

The mitochondrial DNA 10197 G > A mutation causes MELAS/Leigh overlap syndrome presenting with acute auditory agnosia.

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Leng, Yinglin; Liu, Yuhe; Fang, Xiaojing; Li, Yao; Yu, Lei; Yuan, Yun; Wang, Zhaoxia

2015-04-01

Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes/Leigh (MELAS/LS) overlap syndrome is a mitochondrial disorder subtype with clinical and magnetic resonance imaging (MRI) features that are characteristic of both MELAS and Leigh syndrome (LS). Here, we report an MELAS/LS case presenting with cortical deafness and seizures. Cranial MRI revealed multiple lesions involving bilateral temporal lobes, the basal ganglia and the brainstem, which conformed to neuroimaging features of both MELAS and LS. Whole mitochondrial DNA (mtDNA) sequencing and PCR-RFLP revealed a de novo heteroplasmic m.10197 G > A mutation in the NADH dehydrogenase subunit 3 gene (ND3), which was predicted to cause an alanine to threonine substitution at amino acid 47. Although the mtDNA m.10197 G > A mutation has been reported in association with LS, Leber hereditary optic neuropathy and dystonia, it has never been linked with MELAS/LS overlap syndrome. Our patient therefore expands the phenotypic spectrum of the mtDNA m.10197 G > A mutation.

Delayed action does not always require the ventral stream: a study on a patient with visual form agnosia.

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Hesse, Constanze; Schenk, Thomas

2014-05-01

It has been suggested that while movements directed at visible targets are processed within the dorsal stream, movements executed after delay rely on the visual representations of the ventral stream (Milner & Goodale, 2006). This interpretation is supported by the observation that a patient with ventral stream damage (D.F.) has trouble performing accurate movements after a delay, but performs normally when the target is visible during movement programming. We tested D.F.'s visuomotor performance in a letter-posting task whilst varying the amount of visual feedback available. Additionally, we also varied whether D.F. received tactile feedback at the end of each trial (posting through a letter box vs posting on a screen) and whether environmental cues were available during the delay period (removing the target only vs suppressing vision completely with shutter glasses). We found that in the absence of environmental cues patient D.F. was unaffected by the introduction of delay and performed as accurately as healthy controls. However, when environmental cues and vision of the moving hand were available during and after the delay period, D.F.'s visuomotor performance was impaired. Thus, while healthy controls benefit from the availability of environmental landmarks and/or visual feedback of the moving hand, such cues seem less beneficial to D.F. Taken together our findings suggest that ventral stream damage does not always impact the ability to make delayed movements but compromises the ability to use environmental landmarks and visual feedback efficiently. Copyright © 2014 Elsevier Ltd. All rights reserved.

Color picture drawings without form and eye movements: a case report of visual form agnosia in a girl.

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Kaga, Kimitaka; Shindo, Mitsuko

2012-04-01

The case of an 8-year-old girl who manifested cortical blindness and whose color drawings of faces and objects were without outlines is reported. Her birth was uneventful. When she was 10 months old, she fell down to the floor from a chair, resulting in a subarachnoidal hemorrhage. A repeat brain MRI revealed localized lesions in the visual cortices in the right and left hemispheres. As she grew older she was found to have visual imperceptions. She was found to have difficulties in learning visually the names of objects with form and letters, and in recognizing faces of her family. However, she was able to discriminate well the colors of faces and objects and learn easily the names of the objects with form by touching. She seemed to utilize subcortical vision for seeing colors of faces and objects.

The neuropsychology of the Klüver-Bucy syndrome in children.

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Lippe, S; Gonin-Flambois, C; Jambaqué, I

2013-01-01

The Klüver-Bucy syndrome (KBS) is characterized by a number of peculiar behavioral symptoms. The syndrome was first observed in 1939 by Heinrich Klüver and Paul Bucy in the rhesus monkey following removal of the greater portion of the monkey's temporal lobes and rhinencephalon. The animal showed (a) visual agnosia (inability to recognize objects without general loss of visual discrimination), (b) excessive oral tendency (oral exploration of objects), (c) hypermetamorphosis (excessive visual attentiveness), (d) placidity with loss of normal fear and anger responses, (e) altered sexual behavior manifesting mainly as marked and indiscriminate hypersexuality, and (f) changes in eating behavior. In humans, KBS can be complete or incomplete. It occurs as a consequence of neurological disorders that essentially cause destruction or dysfunction of bilateral mesial temporal lobe structures (i.e., Pick disease, Alzheimer disease, cerebral trauma, cerebrovascular accidents, temporal lobe epilepsy, herpetic encephalopathy, heat stroke). As for epilepsy, complete and incomplete KBS are well documented in temporal lobe epilepsy, temporal lobectomy, and partial status epilepticus. KBS can occur at any age. Children seem to show similar symptoms to adults, although some differences in the manifestations of symptoms may be related to the fact that children have not yet learned certain behaviors. Copyright © 2013 Elsevier B.V. All rights reserved.

Cerebral hemorrhage without manifest motor paralysis. Reports of 5 cases

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Taketani, T.; Dohi, I.; Miyazaki, T.; Handa, A. (Central Hospital of JNR, Tokyo (Japan))

1982-01-01

Before the introduction of computerized tomography (CT) there were some cases of intracerebral bleeding who were wrongly diagnosed as hypertensive encephalopathy or senile psychosis. We here report 5 cases who did not show any sign of motor paralysis. The clinical aspects of these cases were nausea and vomiting with dizziness (case 1), nausea and vomiting with slight headache (case 2), agnosia of left side with several kinds of disorientation (case 3), nausea and vomiting (case 4), and visual disturbance of right, lower quadrant (case 5). All of these cases showed no motor paralysis or abnormal reflex activities. By examination with CT each of them exhibited a high density area in the subcortical area of the right parietal lobe, the subcortical area of the right occipital lobe, the right temporal and parietal lobe, rather small portion of the left putamen and external capsule, and the subcortical area of left occipital lobe, respectively. Patients of cerebral hemorrhage without motor or sensory disturbances might often be taken for some psychic abnormality. We here have emphasized the importance of CT in such a group of patients. But for this technique, most of them would not be given adequate treatment and might be exposed to lifethreatening situations.

Acute parietal lobe infarction presenting as Gerstmann’s syndrome and cognitive decline mimicking senile dementia

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Chen TY

2013-07-01

Full Text Available Tien-Yu Chen,1 Chun-Yen Chen,1,3 Che-Hung Yen,2,3 Shin-Chang Kuo,1,3 Yi-Wei Yeh,1,3 Serena Chang,1 San-Yuan Huang1,31Department of Psychiatry, 2Department of Neurology, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, 3Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of ChinaAbstract: Gerstmann’s syndrome encompasses the tetrad of finger agnosia, agraphia, acalculia, and right-left confusion. An elderly man with a history of several cardiovascular diseases was initially brought to the psychiatric outpatient department by his family because of worsening of recent memory, executive function, and mixed anxious-depressive mood. Gerstmann’s syndrome without obvious motor function impairment and dementia-like features could be observed at first. Emergent brain computed tomography scan revealed new left-middle cerebral artery infarction over the left posterior parietal lobe. This case reminds us that acute cerebral infarction involving the parietal lobe may present as Gerstmann’s syndrome accompanied by cognitive decline mimicking dementia. As a result, emergent organic workups should be arranged, especially for elderly patients at high risk for cerebral vascular accident.Keywords: Gerstmann’s syndrome, dementia, parietal lobe infarction

An MR Brain Images Classifier System via Particle Swarm Optimization and Kernel Support Vector Machine

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Yudong Zhang

2013-01-01

Full Text Available Automated abnormal brain detection is extremely of importance for clinical diagnosis. Over last decades numerous methods had been presented. In this paper, we proposed a novel hybrid system to classify a given MR brain image as either normal or abnormal. The proposed method first employed digital wavelet transform to extract features then used principal component analysis (PCA to reduce the feature space. Afterwards, we constructed a kernel support vector machine (KSVM with RBF kernel, using particle swarm optimization (PSO to optimize the parameters C and σ. Fivefold cross-validation was utilized to avoid overfitting. In the experimental procedure, we created a 90 images dataset brain downloaded from Harvard Medical School website. The abnormal brain MR images consist of the following diseases: glioma, metastatic adenocarcinoma, metastatic bronchogenic carcinoma, meningioma, sarcoma, Alzheimer, Huntington, motor neuron disease, cerebral calcinosis, Pick’s disease, Alzheimer plus visual agnosia, multiple sclerosis, AIDS dementia, Lyme encephalopathy, herpes encephalitis, Creutzfeld-Jakob disease, and cerebral toxoplasmosis. The 5-folded cross-validation classification results showed that our method achieved 97.78% classification accuracy, higher than 86.22% by BP-NN and 91.33% by RBF-NN. For the parameter selection, we compared PSO with those of random selection method. The results showed that the PSO is more effective to build optimal KSVM.

Connecting art and the brain: an artist’s perspective on visual indeterminacy

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Robert ePepperell

2011-08-01

Full Text Available In this article I will discuss the intersection between art and neuroscience from the perspective of a practicing artist. I have collaborated on several scientific studies into the effects of art on the brain and behaviour, looking in particular at the phenomenon of ‘visual indeterminacy’. This is a perceptual state in which subjects fail to recognise objects from visual cues. I will look at the background to this phenomenon, and show how various artists have exploited its effect through the history of art. My own attempts to create indeterminate images will be discussed, including some of the technical problems I faced in trying to manipulate the viewer’s perceptual state through paintings. Visual indeterminacy is not widely studied in neuroscience, although references to it can be found in the literature on visual agnosia and object recognition. I will briefly review some of this work and show how my attempts to understand the science behind visual indeterminacy led me to collaborate with psychophysicists and neuroscientists. After reviewing this work, I will discuss the conclusions I have drawn from its findings and consider the problem of how best to integrate neuroscientific methods with artistic knowledge to create truly interdisciplinary approach.

Cerebral hemorrhage without manifest motor paralysis

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Taketani, Torao; Dohi, Ichiro; Miyazaki, Tadahiko; Handa, Akihisa

1982-01-01

Before the introduction of computerized tomography (CT) there were some cases of intracerebral bleeding who were wrongly diagnosed as hypertensive encephalopathy or senile psychosis. We here report 5 cases who did not show any sign of motor paralysis. The clinical aspects of these cases were nausea and vomiting with dizziness (case 1), nausea and vomiting with slight headache (case 2), agnosia of left side with several kinds of disorientation (case 3), nausea and vomiting (case 4), and visual disturbance of right, lower quadrant (case 5). All of these cases showed no motor paralysis or abnormal reflex activities. By examination with CT each of them exhibited a high density area in the subcortical area of the right parietal lobe, the subcortical area of the right occipital lobe, the right temporal and parietal lobe, rather small portion of the left putamen and external capsule, and the subcortical area of left occipital lobe, respectively. Patients of cerebral hemorrhage without motor or sensory disturbances might often be taken for some psychic abnormality. We here have emphasized the importance of CT in such a group of patients. But for this technique, most of them would not be given adequate treatment and might be exposed to lifethreatening situations. (author)

Important factors influencing the return to work after stroke.

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Wang, Ying-Chih; Kapellusch, Jay; Garg, Arun

2014-01-01

As the field of rehabilitation shifts its focus towards improving functional capacity instead of managing disability, return to work (RTW) and return to the community emerge as key goals in a person's recovery from major disabling illness such as stroke. To compile important factors believed to influence RTW after a stroke. Based on a comprehensive literature review, we clustered similar factors and organized these factors based on the International Classification of Function, Disability and Health (ICF) framework: body functions or structure, activity participation, environmental factors and personal and psychosocial factors. Overall, stroke severity, as assessed by the degree of residual disability such as weakness, neurological deficit or impairments (speech, cognition, apraxia, agnosia), has been shown to be the most consistent negative predictor of RTW. Many factors such as the number of working years remaining until retirement, depression, medical history, and occupation need to be taken into consideration for stroke survivors, as they can influence RTW decision making. Stroke survivors who are flexible and realistic in their vocational goal and emotionally accept their disability appear more likely to return to work. There are many barriers to employment for stroke survivors ranging from physical and cognitive impairments to psychosocial and environmental factors.

Smell of danger: an analysis of LP-gas odorization

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Cain, W.S.; Turk, A.

1985-03-01

LP-gas derives warning properties from the odorants ethyl mercaptan or thiophane. Laboratory tests have implied that the average person has the ability to smell the odors before leaking LP-gas reaches one-fifth its lower limit of flammability. Generally, however, laboratory tests ignore or discard persons with a poor sense of smell, especially the elderly and persons with certain types of hyposmia. Some persons who apparently can smell the warning agents when directed may otherwise fail to notice or identify them. Elderly men seem particularly vulnerable to instances of incidental anosmia and olfactory agnosia. Psychophysical testing of the warning agents has been rather unsophisticated. There exists neither a standard protocol for testing nor adequate specification of the perceptual properties that might make one warning agent better than another. Without such developments, improvement in warning agents will fail to occur. Possible improvements include increases in concentration, the use of blends to insure more uniform delivery of agent and, to decrease the perceptual vulnerability of relatively insensitive people, use of agents with favorable psychophysical (stimulus-response) functions and use of agents with favorable adaptation characteristics. Even without a change in existing products, it seems advisable to learn more about the vulnerability of LP-gas users and to employ educational means to reduce risks.

Aetiology of auditory dysfunction in amusia: a systematic review.

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Casey, Daniel Aj

2013-04-24

Amusia, a music-specific agnosia, is a disorder of pitch interval analysis and pitch direction change recognition which results in a deficit in musical ability. The full range of aetiological factors which cause this condition is unknown, as is each cause's frequency. The objective of this study was to identify all causes of amusia, and to measure each of their frequencies. systematic review was conducted by search of multiple databases for articles related to the aetiology of amusic auditory dysfunction. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for reporting of systematic reviews were followed, utilizing the PRISMA checklist and PRISMA flowchart methodology. Retrospective medical database review. evidence yielded from the systematic review process. The initial search protocol identified 5723 articles. Application of a classification review filter and exclusion of irrelevant or duplicates led to the initial identification of 56 relevant studies which detailed 301 patients. However, these studies were of poor quality. Because of this, synthesis and statistical analysis were not appropriate. Although initially a large number of relevant studies were identified, and might point in future to potential diagnostic categories, it was not appropriate to synthesise and analyse them due to poor quality, considerable heterogeneity and small numbers. This suggests that large, high quality studies focussed directly on understanding the aetiology of amusia are required.

Visuo-Spatial Imagery Impairment in Posterior Cortical Atrophy: A Cognitive and SPECT Study

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Simona Gardini

2011-01-01

Full Text Available This study investigated the cognitive profile and the cerebral perfusion pattern in a highly educated 70 year old gentleman with posterior cortical atrophy (PCA. Visuo-perceptual abilities, spatial memory, spatial representation and navigation, visuo-spatial mental imagery, semantic and episodic-autobiographical memory were assessed. Regional cerebral blood flow (rCBF was imaged with SPECT. Cognitive testing showed visual-perceptual impairment, apperceptive visual and landmark agnosia, topographical disorientation with way-finding deficits, impaired map learning and poor mental image generation. Semantic memory was normal, while episodic-autobiographical memory was impaired. Reduced rCBF was found mainly in the right hemisphere, in the precentral gyrus, posterior cingulate and middle temporal gyri, cuneus and precuneus, in the left superior temporal and lingual gyri and in the parahippocampus bilaterally. Hypoperfusion in occipito-parietal regions was associated with visuo-spatial deficits, whereas deficits in visuo-spatial mental imagery might reflect dysfunction related to hypoperfusion in the parahippocampus and precuneus, structures which are responsible for spatial and imagery processing. Dissociating performance between preserved semantic memory and poor episodic-autobiographical recall is consistent with a pattern of normal perfusion in frontal and anterior temporal regions but abnormal rCBF in the parahippocampi. The present findings indicate that PCA involves visuo-spatial imagery deficits and provide further validation to current neuro-cognitive models of spatial representation and topographical disorientation.

Motor and sensory alalia: diagnostic difficulties

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M. Yu. Bobylova

2017-01-01

Full Text Available Alalia is a speech disorder that develops due to organic brain damage in children with normal hearing and intelligence during the first three year of life. Systemic speech underdevelopment in alalia is characterized by violations in the phonetic, phonemic, lexical, and grammatical structure. Patients with alalia can also have non-speech related impairments, including motor (impaired movement and coordination, sensory (impaired sensitivity and perception, and psychopathological disorders. There are three types of alalia: motor, sensory, and mixed. Children with motor alalia have expressive language disorders, speech praxis, poor speech fluency, impaired articulation, and other focal neurological symptoms; however, they understand speech directed to them. Patients with motor alalia are often left-handed. Regional slowing and epileptiform activity are often detected on their electroencephalogram.  Children with sensory alalia are characterized by poor speech understanding (despite normal hearing resulting in secondary underdevelopment of their own speech. These patients have problems with the analysis of sounds, including speech sounds (impaired speech gnosis, which prevents the development of association between the sound image and the object. Therefore, the child hears, but does not understand the speech directed at him/her (auditory agnosia. Differential diagnosis of alalia is challenging and may require several months of observation. It also implies the exclusion of hearing loss and mental disorders.

CT and MRI findings of cerebral ischemic lesions in the cortical and perforating arterial system

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Kameyama, Masakuni; Udaka, Fukashi; Nishinaka, Kazuto; Kodama, Mitsuo; Urushidani, Makoto; Kawamura, Kazuyuki; Inoue, Haruhisa; Kageyama, Taku [Sumitomo Hospital, Osaka (Japan)

1995-07-01

It is clinically useful to divide the location of infarction into the cortical and perforating arterial system. Computerized tomography (CT) and magnetic resonance imaging (MRI) now make the point of infarction a simple and useful task in daily practice. The diagnostic modality has also demonstrated that risk factors and clinical manifestations are different for infarction in the cortical as opposed to the perforating system. In this paper, we present various aspects of images of cerebral ischemia according to CT and/or MRI findings. With the advance of imaging mechanics, diagnostic capability of CT or/and MRI for cerebral infarction has markedly been improved. We must consider these points on evaluating the previously reported results. In addition, we always consider the pathological background of these image-findings for the precise interpretation of their clinical significance. In some instances, dynamic study such as PET or SPECT is needed for real interpretations of CT and/or MRI images. We paid special reference to lacunar stroke and striatocapsular infarct. In addition, `branch atheromatous disease (Caplan)` was considered, in particular, for their specific clinical significances. Large striatocapsular infarcts frequently show cortical signs and symptoms such as aphasia or agnosia in spite of their subcortical localization. These facts, although have previously been known, should be re-considered for their pathoanatomical mechanism. (author).

CT and MRI findings of cerebral ischemic lesions in the cortical and perforating arterial system

International Nuclear Information System (INIS)

Kameyama, Masakuni; Udaka, Fukashi; Nishinaka, Kazuto; Kodama, Mitsuo; Urushidani, Makoto; Kawamura, Kazuyuki; Inoue, Haruhisa; Kageyama, Taku

1995-01-01

It is clinically useful to divide the location of infarction into the cortical and perforating arterial system. Computerized tomography (CT) and magnetic resonance imaging (MRI) now make the point of infarction a simple and useful task in daily practice. The diagnostic modality has also demonstrated that risk factors and clinical manifestations are different for infarction in the cortical as opposed to the perforating system. In this paper, we present various aspects of images of cerebral ischemia according to CT and/or MRI findings. With the advance of imaging mechanics, diagnostic capability of CT or/and MRI for cerebral infarction has markedly been improved. We must consider these points on evaluating the previously reported results. In addition, we always consider the pathological background of these image-findings for the precise interpretation of their clinical significance. In some instances, dynamic study such as PET or SPECT is needed for real interpretations of CT and/or MRI images. We paid special reference to lacunar stroke and striatocapsular infarct. In addition, 'branch atheromatous disease (Caplan)' was considered, in particular, for their specific clinical significances. Large striatocapsular infarcts frequently show cortical signs and symptoms such as aphasia or agnosia in spite of their subcortical localization. These facts, although have previously been known, should be re-considered for their pathoanatomical mechanism. (author)

Ludwig Edinger (1855-1918): founder of modern neuroanatomy.

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Prithishkumar, Ivan James

2012-03-01

Ludwig Edinger, a German neurologist is considered as one of the founders of modern neuroanatomy. He was conferred the degree of Doctor of Medicine at the University of Strassburg. His observation of small living organisms under a microscope at an early age led him to study medicine. Edinger had many discoveries to his credit. He was the first to describe the ventral and dorsal spinocerebellar tracts, to distinguish between paleo-encephalon and neo-encephalon, and between paleo-cerebellum and neo-cerebellum. He coined the terms "gnosis" and "praxis," which were later adopted in psychological descriptions of agnosia and apraxia. He identified the Edinger-Westphal nucleus in 1885 and was the first to describe the syndrome of thalamic pain. Edinger worked with renowned clinicians and published a large number of papers. He founded the Neurological Institute at the Goethe University in Frankfurt, which is the oldest neurological Institute in Germany. Edinger was a rare combination of a profound scientist, a brilliant teacher, a fine artist, and a noted hypnotist. While at the height of his career, he underwent a surgery and died a few hours later. It was his last will that his brain should be dissected in his own institute. It showed extraordinarily well-developed occipital lobes as well as other unusual features. Copyright © 2011 Wiley-Liss, Inc.

Visual form-processing deficits: a global clinical classification.

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Unzueta-Arce, J; García-García, R; Ladera-Fernández, V; Perea-Bartolomé, M V; Mora-Simón, S; Cacho-Gutiérrez, J

2014-10-01

Patients who have difficulties recognising visual form stimuli are usually labelled as having visual agnosia. However, recent studies let us identify different clinical manifestations corresponding to discrete diagnostic entities which reflect a variety of deficits along the continuum of cortical visual processing. We reviewed different clinical cases published in medical literature as well as proposals for classifying deficits in order to provide a global perspective of the subject. Here, we present the main findings on the neuroanatomical basis of visual form processing and discuss the criteria for evaluating processing which may be abnormal. We also include an inclusive diagram of visual form processing deficits which represents the different clinical cases described in the literature. Lastly, we propose a boosted decision tree to serve as a guide in the process of diagnosing such cases. Although the medical community largely agrees on which cortical areas and neuronal circuits are involved in visual processing, future studies making use of new functional neuroimaging techniques will provide more in-depth information. A well-structured and exhaustive assessment of the different stages of visual processing, designed with a global view of the deficit in mind, will give a better idea of the prognosis and serve as a basis for planning personalised psychostimulation and rehabilitation strategies. Copyright © 2011 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Effect of synapse dilution on the memory retrieval in structured attractor neural networks

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Brunel, N.

1993-08-01

We investigate a simple model of structured attractor neural network (ANN). In this network a module codes for the category of the stored information, while another group of neurons codes for the remaining information. The probability distribution of stabilities of the patterns and the prototypes of the categories are calculated, for two different synaptic structures. The stability of the prototypes is shown to increase when the fraction of neurons coding for the category goes down. Then the effect of synapse destruction on the retrieval is studied in two opposite situations : first analytically in sparsely connected networks, then numerically in completely connected ones. In both cases the behaviour of the structured network and that of the usual homogeneous networks are compared. When lesions increase, two transitions are shown to appear in the behaviour of the structured network when one of the patterns is presented to the network. After the first transition the network recognizes the category of the pattern but not the individual pattern. After the second transition the network recognizes nothing. These effects are similar to syndromes caused by lesions in the central visual system, namely prosopagnosia and agnosia. In both types of networks (structured or homogeneous) the stability of the prototype is greater than the stability of individual patterns, however the first transition, for completely connected networks, occurs only when the network is structured.

Perception, experience and body identity.

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López-Ibor, Juan J; Ortiz, Tomás; López-Ibor, María I

2011-12-01

Physician has to know the patient in the disease and not only the disease in the patient, from the dual perspective of the body as object and the body as subject. This also affects the patient who has to cope with the reality of having a body that bursts into the subject's consciousness as a vital threat, as source of discomfort and inability and being a body (Marcel). The human body in its dual aspect has been and is a great unknown, if not a great outrage in spite of the fact that we are our body and our body is each of us. We sometimes do not feel as we are and thus a confrontation arises, sometimes more normal, others more morbid. This forces the physician to face complex ethics considerations and the scientist to accept a personal identity disorder. Dualism considers that there are two substances in us, one that distinguishes us from other beings and from the rest of the individuals of the human species, the soul, the psychic life, mind or consciousness, and another more insubstancial one, the body. The aim of the first substance is to dominate the body, to survive it after death when it is, already a corpse is meant to become putrefied, is buried, incinerated or thrown to the depth of the sea. This dualism aims to explain the origin of the evil and the attitude to defeat it and it does so efficiently. This anthropology has very ancient roots (the Upvanishads, in the orphic texts, in Plato), it is the core of Gnostic thought and the foundation of the modern science since Descartes. Some monist perspectives are a masked dualism or a mereologic fallacy, according to which, the brain is conscious, when that what is conscious is the subject, although the subject, with the brain could not be conscious. Therefore, a new perspective is proposed, chiasmatic or janicular monism, that considers the adaptive value of focusing on the reality from two perspectives, as physical universe and the world of interpersonal relationships. In the agnosias and in the phantom limb

Sneaking a peek: pigeons use peripheral vision (not mirrors) to find hidden food.

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Ünver, Emre; Garland, Alexis; Tabrik, Sepideh; Güntürkün, Onur

2017-07-01

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. Indeed, we discovered that pigeons can successfully find a hidden food reward using only the reflection, suggesting that pigeons can also use and potentially understand the reflective properties of mirrors, even in the absence of self-recognition. However, tested under monocular conditions, the pigeons approached and attempted to walk through the mirror rather than approach the physical food, displaying similar behavior to patients with mirror agnosia. These findings clearly show that pigeons do not use the reflection of mirrors to locate reward, but actually see the food peripherally with their near-panoramic vision. A re-evaluation of our current understanding of mirror-mediated behavior might be necessary-especially taking more fully into account species differences in visual field. This study suggests that use of reflections in a mirrored surface as a tool may be less widespread than currently thought.

Pathophysiology and Treatment of Alien Hand Syndrome

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Harini Sarva

2014-12-01

Full Text Available Background: Alien hand syndrome (AHS is a disorder of involuntary, yet purposeful, hand movements that may be accompanied by agnosia, aphasia, weakness, or sensory loss. We herein review the most reported cases, current understanding of the pathophysiology, and treatments.Methods: We performed a PubMed search in July of 2014 using the phrases “alien hand syndrome,” “alien hand syndrome pathophysiology,” “alien hand syndrome treatment,” and “anarchic hand syndrome.” The search yielded 141 papers (reviews, case reports, case series, and clinical studies, of which we reviewed 109. Non‐English reports without English abstracts were excluded.Results: Accumulating evidence indicates that there are three AHS variants: frontal, callosal, and posterior. Patients may demonstrate symptoms of multiple types; there is a lack of correlation between phenomenology and neuroimaging findings. Most pathologic and functional imaging studies suggest network disruption causing loss of inhibition as the likely cause. Successful interventions include botulinum toxin injections, clonazepam, visuospatial coaching techniques, distracting the affected hand, and cognitive behavioral therapy.Discussion: The available literature suggests that overlap between AHS subtypes is common. The evidence for effective treatments remains anecdotal, and, given the rarity of AHS, the possibility of performing randomized, placebo‐controlled trials seems unlikely. As with many other interventions for movement disorders, identifying the specific functional impairments caused by AHS may provide the best guidance towards individualized supportive care.

Subgroup differences in the lexical tone mismatch negativity (MMN) among Mandarin speakers with congenital amusia.

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Nan, Yun; Huang, Wan-ting; Wang, Wen-jing; Liu, Chang; Dong, Qi

2016-01-01

The association/dissociation of pitch processing between music and language is a long lasting debate. We examined this music-language relationship by investigating to what extent pitch deficits in these two domains were dissociable. We focused on a special neurodevelopmental pitch disorder - congenital amusia, which primarily affects musical pitch processing. Recent research has also revealed lexical tone deficits in speech among amusics. Approximately one-third of Mandarin amusics exhibits behavioural difficulties in lexical tone perception, which is known as tone agnosia. Using mismatch negativities (MMNs), our current work probed lexical tone encoding at the pre-attentive level among the Mandarin amusics with (tone agnosics) and without (pure amusics) behavioural lexical tone deficits compared with age- and IQ-matched controls. Relative to the controls and the pure amusics, the tone agnosics exhibited reduced MMNs specifically in response to lexical tone changes. Their tone-consonant MMNs were intact and similar to those of the other two groups. Moreover, the tone MMN reduction over the left hemisphere was tightly linked to behavioural insensitivity to lexical tone changes. The current study thus provides the first psychophysiological evidence of subgroup differences in lexical tone processing among Mandarin amusics and links amusics' behavioural tone deficits to impaired pre-attentive tone processing. Despite the overall music pitch deficits, the subgroup differences in lexical tone processing in Mandarin-speaking amusics suggest dissociation of pitch deficits between music and speech. Copyright © 2015 Elsevier B.V. All rights reserved.

Attempted suicide in the elderly: characteristics of suicide attempters 70 years and older and a general population comparison group.

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Wiktorsson, Stefan; Runeson, Bo; Skoog, Ingmar; Ostling, Svante; Waern, Margda

2010-01-01

To identify factors associated with attempted suicide in the elderly. Social, psychological, and psychiatric characteristics were compared in suicide attempters (70 years and older) and a representative population sample. Emergency departments at five hospitals in western Sweden and a representative sample of the elderly population. Persons with Mini Mental State Examination (MMSE) score age 80 years). Comparison subjects matched for gender and age group (N = 408) were randomly selected among participants in our general population studies. Symptoms were rated with identical instruments in cases and comparison subjects. The examination included the MMSE and tests of short- and long-term memory, abstract thinking, aphasia, apraxia, and agnosia. Depressive symptomatology was measured using the Montgomery-Asberg Depression Rating Scale, and major and minor depressions were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, using symptom algorithms. Factors associated with attempted suicide included being unmarried, living alone, low education level, history of psychiatric treatment, and previous suicide attempt. There was no association with dementia. Odds ratios were increased for both major (odds ratio [OR]: 47.4, 95% confidence interval [CI]: 19.1-117.7) and minor (OR: 2.6, 95% CI: 1.5-4.7) depressions. An association was observed between perceived loneliness and attempted suicide; this relationship was independent of depression (OR: 2.8, 95% CI: 1.3-6.1). Observed associations mirrored those previously shown for completed suicide. Results may help to inform clinical decisions regarding suicide risk evaluation in this vulnerable and growing age group.

Mental rotation of faces in healthy aging and Alzheimer's disease.

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Cassandra A Adduri

Full Text Available BACKGROUND: Previous research has shown that individuals with Alzheimer's disease (AD develop visuospatial difficulties that affect their ability to mentally rotate objects. Surprisingly, the existing literature has generally ignored the impact of this mental rotation deficit on the ability of AD patients to recognize faces from different angles. Instead, the devastating loss of the ability to recognize friends and family members in AD has primarily been attributed to memory loss and agnosia in later stages of the disorder. The impact of AD on areas of the brain important for mental rotation should not be overlooked by face processing investigations -- even in early stages of the disorder. METHODOLOGY/PRINCIPAL FINDINGS: This study investigated the sensitivity of face processing in AD, young controls and older non-neurological controls to two changes of the stimuli -- a rotation in depth and an inversion. The control groups showed a systematic effect of depth rotation, with errors increasing with the angle of rotation, and with inversion. The majority of the AD group was not impaired when faces were presented upright and no transformation in depth was required, and were most accurate when all faces were presented in frontal views, but accuracy was severely impaired with any rotation or inversion. CONCLUSIONS/SIGNIFICANCE: These results suggest that with the onset of AD, mental rotation difficulties arise that affect the ability to recognize faces presented at different angles. The finding that a frontal view is "preferred" by these patients provides a valuable communication strategy for health care workers.

CBF tomograms with [/sup 99m/Tc-HM-PAO in patients with dementia (Alzheimer type and HIV) and Parkinson's disease--initial results

International Nuclear Information System (INIS)

Costa, D.C.; Ell, P.J.; Burns, A.; Philpot, M.; Levy, R.

1988-01-01

We present preliminary data on the utility of functional brain imaging with [99mTc]-d,l-HM-PAO and single photon emission computed tomography (SPECT) in the study of patients with dementia of the Alzheimer type (DAT), HIV-related dementia syndrome, and the on-off syndrome of Parkinson's disease. In comparison with a group of age-matched controls, the DAT patients revealed distinctive bilateral temporal and posterior parietal deficits, which correlate with detailed psychometric evaluation. Patients with amnesia as the main symptom (group A) showed bilateral mesial temporal lobe perfusion deficits (p less than 0.02). More severely affected patients (group B) with significant apraxia, aphasia, or agnosia exhibited patterns compatible with bilateral reduced perfusion in the posterior parietal cortex, as well as reduced perfusion to both temporal lobes, different from the patients of the control group (p less than 0.05). SPECT studies of HIV patients with no evidence of intracraneal space occupying pathology showed marked perfusion deficits. Patients with Parkinson's disease and the on-off syndrome studied during an on phase (under levodopa therapy) and on another occasion after withdrawal of levodopa (off) demonstrated a significant change in the uptake of [99mTc]-d,l-HM-PAO in the caudate nucleus (lower on off) and thalamus (higher on off). These findings justify the present interest in the functional evaluation of the brain of patients with dementia. [99mTc]-d,l-HM-PAO and regional cerebral blood flow (rCBF)/SPECT appear useful and highlight individual disorders of flow in a variety of neuropsychiatric conditions

Differential contribution of right and left temporo-occipital and anterior temporal lesions to face recognition disorders

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Guido eGainotti

2011-06-01

Full Text Available In the study of prosopagnosia, several issues (such as the specific or non-specific manifestations of prosopagnosia, the unitary or non-unitary nature of this syndrome and the mechanisms underlying face recognition disorders are still controversial. Two main sources of variance partially accounting for these controversies could be the qualitative differences between the face recognition disorders observed in patients with prevalent lesions of the right or left hemisphere and in those with lesions encroaching upon the temporo-occipital or the (right anterior temporal cortex.Results of our review seem to confirm these suggestions. Indeed, they show that (a the most specific forms of prosopagnosia are due to lesions of a right posterior network including the OFA and the FFA, whereas (b the face identification defects observed in patients with left temporo-occipital lesions seem due to a semantic defect impeding access to person-specific semantic information from the visual modality. Furthermore, face recognition defects resulting from right anterior temporal lesions can usually be considered as part of a multimodal people recognition disorder.The implications of our review are, therefore, the following: (1 to consider the components of visual agnosia often observed in prosopagnosic patients with bilateral temporo-occipital lesions as part of a semantic defect, resulting from left-sided lesions (and not from prosopagnosia proper; (2 to systematically investigate voice recognition disorders in patients with right anterior temporal lesions to determine whether the face recognition defect should be considered a form of ‘associative prosopagnosia’ or a form of the ‘multimodal people recognition disorder’.

Unusual presentations in patients with E200K familial Creutzfeldt-Jakob disease.

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Cohen, O S; Kimiagar, I; Korczyn, A D; Nitsan, Z; Appel, S; Hoffmann, C; Rosenmann, H; Kahana, E; Chapman, J

2016-05-01

Familial Creutzfeldt-Jakob disease (fCJD) in Jews of Libyan ancestry is caused by an E200K mutation in the PRNP gene. The typical presenting symptoms include cognitive decline, behavioral changes and gait disturbances; however, some patients may have an unusual presentation such as a stroke-like presentation, alien hand syndrome or visual disturbances. The aim of this paper is to describe uncommon presentations in our series of consecutive patients with E200K fCJD. The study group included consecutive fCJD patients followed up as part of a longitudinal prospective study ongoing since 2003 or hospitalized since 2005. The clinical diagnosis of probable CJD was based on accepted diagnostic criteria and supported by typical magnetic resonance imaging, electroencephalographic findings, elevated cerebrospinal fluid tau protein levels and by genetic testing for the E200K mutation. Disease symptoms and signs were retrieved from the medical files. The study population included 77 patients (42 men) with a mean age of disease onset of 60.6 ± 7.2 years. The most prevalent presenting symptoms were cognitive decline followed by gait impairment and behavioral changes. However, six patients had an unusual presentation including auditory agnosia, monoparesis, stroke-like presentation, facial nerve palsy, pseudobulbar syndrome and alien hand syndrome. Our case series illustrates the wide phenotypic variability of the clinical presentation of patients with fCJD and widens the clinical spectrum of the disease. A high level of clinical suspicion may prove useful in obtaining early diagnosis and therefore avoiding costly and inefficient diagnostic and therapeutic strategies. © 2016 EAN.

Neural correlates of recognition and naming of musical instruments.

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Belfi, Amy M; Bruss, Joel; Karlan, Brett; Abel, Taylor J; Tranel, Daniel

2016-10-01

Retrieval of lexical (names) and conceptual (semantic) information is frequently impaired in individuals with neurological damage. One category of items that is often affected is musical instruments. However, distinct neuroanatomical correlates underlying lexical and conceptual knowledge for musical instruments have not been identified. We used a neuropsychological approach to explore the neural correlates of knowledge retrieval for musical instruments. A large sample of individuals with focal brain damage (N = 298), viewed pictures of 16 musical instruments and were asked to name and identify each instrument. Neuroanatomical data were analyzed with a proportional MAP-3 method to create voxelwise lesion proportion difference maps. Impaired naming (lexical retrieval) of musical instruments was associated with damage to the left temporal pole and inferior pre- and postcentral gyri. Impaired recognition (conceptual knowledge retrieval) of musical instruments was associated with a more broadly and bilaterally distributed network of regions, including ventromedial prefrontal cortices, occipital cortices, and superior temporal gyrus. The findings extend our understanding of how musical instruments are processed at neural system level, and elucidate factors that may explain why brain damage may or may not produce anomia or agnosia for musical instruments. Our findings also help inform broader understanding of category-related knowledge mapping in the brain, as musical instruments possess several characteristics that are similar to various other categories of items: They are inanimate and highly manipulable (similar to tools), produce characteristic sounds (similar to animals), and require fine-grained visual differentiation between each other (similar to people). (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Lateralized occipital degeneration in posterior cortical atrophy predicts visual field deficits.

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Millington, Rebecca S; James-Galton, Merle; Maia Da Silva, Mari N; Plant, Gordon T; Bridge, Holly

2017-01-01

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. 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. Additional analyses investigated hemispheric asymmetries in these metrics according to the visual field most affected by the disease. Analysis of structural data indicated considerable loss of gray matter in the occipital and parietal cortices, lateralized to the hemisphere contralateral to the visual loss. This lateralized pattern of gray matter loss was also evident in the hippocampus and parahippocampal gyrus. Diffusion-weighted imaging showed considerable effects of PCA on white matter microstructure in the occipital cortex, and in the corpus callosum. The change in white matter was only lateralized in the occipital lobe, however, with greatest change in the optic radiation contralateral to the visual field deficit. Indeed, there was a significant correlation between the laterality of the optic radiation microstructure and visual field loss. Detailed brain imaging shows that the asymmetric visual field deficits in patients with PCA reflect the pattern of degeneration of both white and gray matter in the occipital lobe. Understanding the nature of both visual field deficits and the neurodegenerative brain changes in PCA may improve diagnosis and understanding of this disease.

CBF tomograms with (/sup 99m/Tc-HM-PAO in patients with dementia (Alzheimer type and HIV) and Parkinson's disease--initial results

Energy Technology Data Exchange (ETDEWEB)

Costa, D.C.; Ell, P.J.; Burns, A.; Philpot, M.; Levy, R.

1988-12-01

We present preliminary data on the utility of functional brain imaging with (99mTc)-d,l-HM-PAO and single photon emission computed tomography (SPECT) in the study of patients with dementia of the Alzheimer type (DAT), HIV-related dementia syndrome, and the on-off syndrome of Parkinson's disease. In comparison with a group of age-matched controls, the DAT patients revealed distinctive bilateral temporal and posterior parietal deficits, which correlate with detailed psychometric evaluation. Patients with amnesia as the main symptom (group A) showed bilateral mesial temporal lobe perfusion deficits (p less than 0.02). More severely affected patients (group B) with significant apraxia, aphasia, or agnosia exhibited patterns compatible with bilateral reduced perfusion in the posterior parietal cortex, as well as reduced perfusion to both temporal lobes, different from the patients of the control group (p less than 0.05). SPECT studies of HIV patients with no evidence of intracraneal space occupying pathology showed marked perfusion deficits. Patients with Parkinson's disease and the on-off syndrome studied during an on phase (under levodopa therapy) and on another occasion after withdrawal of levodopa (off) demonstrated a significant change in the uptake of (99mTc)-d,l-HM-PAO in the caudate nucleus (lower on off) and thalamus (higher on off). These findings justify the present interest in the functional evaluation of the brain of patients with dementia. (99mTc)-d,l-HM-PAO and regional cerebral blood flow (rCBF)/SPECT appear useful and highlight individual disorders of flow in a variety of neuropsychiatric conditions.

Finger tapping and verbal fluency post-tap test improvement in INPH: its value in differential diagnosis and shunt-treatment outcomes prognosis.

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Liouta, Evangelia; Gatzonis, Stylianos; Kalamatianos, Theodosis; Kalyvas, Aristotelis; Koutsarnakis, Christos; Liakos, Faidon; Anagnostopoulos, Christos; Komaitis, Spyridon; Giakoumettis, Dimitris; Stranjalis, George

2017-12-01

Idiopathic normal pressure hydrocephalus (INPH) diagnosis is challenging as it can be mimicked by other neurological conditions, such as neurodegenerative dementia and motor syndromes. Additionally, outcomes after lumbar puncture (LP) tap test and shunt treatment may vary due to the lack of a common protocol in INPH assessment. The present study aimed to assess whether a post-LP test amelioration of frontal cognitive dysfunctions, characterizing this syndrome, can differentiate INPH from similar neurological conditions and whether this improvement can predict INPH post-shunt outcomes. Seventy-one consecutive patients referred for INPH suspicion and LP testing, were enrolled. According to the consensus guidelines criteria, 29 patients were diagnosed as INPH and 42 were assigned an alternative diagnosis (INPH-like group) after reviewing clinical, neuropsychological and imaging data, and before LP results. A comprehensive neuropsychological assessment for frontal executive, upper extremity fine motor functions, aphasias, apraxias, agnosias and gait evaluation were administered at baseline. Executive, fine motor functions and gait were re-examined post-LP test in all patients and post-shunt placement in INPH patients. Of the INPH patients, 86.2% showed cognitive amelioration in the post-LP test; in addition, all but one (97%) presented with neurocognitive and gait improvement post-shunt. Verbal phonological fluency and finger tapping task post-LP improvement predicted positive clinical outcome post-shunt. None of the INPH-like group presented with neurocognitive improvement post-LP. Post-LP amelioration of verbal fluency and finger tapping deficits can differentiate INPH from similar disorders and predict positive post-shunt clinical outcome in INPH. This becomes of great importance when gait assessment is difficult to perform in clinical practice.

Remission of progressive multifocal leukoencephalopathy following highly active antiretroviral therapy in a man with AIDS

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Yoganathan K

2012-04-01

Full Text Available Katie Yoganathan1, David Brown2, Kathir Yoganathan31Cardiff Medical School, Cardiff, Wales, UK; 2Virus Reference Department, Microbiology Services, Health Protection Agency, London, UK; 3Singleton Hospital, Abertawe Bro Morgannwg University Health Board, Swansea, UKAbstract: A 43-year-old Caucasian homosexual man with AIDS presented with blurring of vision, change of personality, and memory loss in March 1999. He had first been admitted 2 months previously for treatment of Pneumocystis jiroveci pneumonia. A magnetic resonance imaging scan on admission showed multiple white matter lesions involving both subcortical cerebral hemispheres and cerebellar regions, with no mass effect or surrounding edema. JC virus was detected by nested polymerase chain reaction in the cerebrospinal fluid. These findings were diagnostic of progressive multifocal leukoencephalopathy (PML. His CD4 count was 34 cells/mL, and his HIV ribonucleic acid level was 800,789 copies/mL. He was treated with a combination antiretroviral therapy. He was last reviewed in October 2011. He was fully independent socially and mentally, but he still had some residual neurologic signs with right-sided homonymous hemianopia and visual agnosia. His HIV ribonucleic acid level was undetectable, and his CD4 count was 574 cells/mm3. Although the median survival of patients with PML was poor before the antiretroviral therapy era, our patient, who is now aged 55 years, is still alive 12 years after the diagnosis. The diagnosis of PML and differential diagnosis of focal neurologic signs in HIV-positive patients are discussed in this case report.Keywords: HIV, focal neurologic signs, cerebral toxoplasmosis, primary brain lymphoma, ischaemic stroke

CT classification of small thalamic hemorrhages

International Nuclear Information System (INIS)

Kawahara, Nobutaka; Kaneko, Mitsuo; Tanaka, Keisei; Muraki, Masaaki; Sato, Kengo

1984-01-01

The thalamus is located deep in the cerebral hemispheres, and most of its nuclei have reciprocal fiber connections with specific areas over the cerebral cortex. Localized lesions in the thalamus, therefore, can cause specific neurological deficits, depending on their locations. From this point of view, we reviewed 110 cases, admitted over the past 7 years, with thalamic hemorrhages 37 (34%) of which were small hematomas less than 2 cm in diameter. These small hematomas could be divided into 4 types depending on their locations as follows: antero-lateral type, postero-lateral type, medial type, and dorsal type. Each type had the peculiar clinical features described below: 1) Postero-lateral Type (PL type, 28 cases, 76%): The original symptom was a sudden onset of moderate to severe sensori-motor deficits in most cases. The patients were mostly alert or only slightly confused. 2) Antero-lateral Type (AL type, 4 cases, 11%): The patients of this type first presented with sensori-motor disturbance and prefrontal signs. Both were generally mild and often disappeared early. 3) Medial Type (M type, 3 cases, 8%): The main symptom at onset was either a disturbance of consciousness or dementia. 4) Dorsal Type (D type, 2 cases, 5%): One patient with a right thalamic hematoma of this type showed geographical agnosia and visuo-constructive apraxia. The other patient, with a left-sided hematoma, exhibited transient clumsiness of the right hand and mild dysphasia. In our experience, the above classification of small hematomas clearly delineated the clinical symptoms and neurological signs of the different types; therefore, the symptoms and signs in larger hematoma could be explained by a combination of those of each type. (J.P.N.)

CT classification of small thalamic hemorrhages. Topographic localization and clinical manifestation

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Kawahara, Nobutaka; Kaneko, Mitsuo; Tanaka, Keisei; Muraki, Masaaki; Sato, Kengo (Hamamatsu Medical Center Hospital, Shizuoka (Japan))

1984-06-01

The thalamus is located deep in the cerebral hemispheres, and most of its nuclei have reciprocal fiber connections with specific areas over the cerebral cortex. Localized lesions in the thalamus, therefore, can cause specific neurological deficits, depending on their locations. From this point of view, we reviewed 110 cases, admitted over the past 7 years, with thalamic hemorrhages 37 (34%) of which were small hematomas less than 2 cm in diameter. These small hematomas could be divided into 4 types depending on their locations as follows: antero-lateral type, postero-lateral type, medial type, and dorsal type. Each type had the peculiar clinical features described below: 1) Postero-lateral Type (PL type, 28 cases, 76%): The original symptom was a sudden onset of moderate to severe sensori-motor deficits in most cases. The patients were mostly alert or only slightly confused. 2) Antero-lateral Type (AL type, 4 cases, 11%): The patients of this type first presented with sensori-motor disturbance and prefrontal signs. Both were generally mild and often disappeared early. 3) Medial Type (M type, 3 cases, 8%): The main symptom at onset was either a disturbance of consciousness or dementia. 4) Dorsal Type (D type, 2 cases, 5%): One patient with a right thalamic hematoma of this type showed geographical agnosia and visuo-constructive apraxia. The other patient, with a left-sided hematoma, exhibited transient clumsiness of the right hand and mild dysphasia. In our experience, the above classification of small hematomas clearly delineated the clinical symptoms and neurological signs of the different types; therefore, the symptoms and signs in larger hematoma could be explained by a combination of those of each type.

Neurobiology of consciousness: an overview.

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Delacour, J

1997-05-01

The aim of this review is to connect the phenomenology of consciousness to its neurobiology. A survey of the recent literature revealed the following points. (1) Comprehensive descriptions of consciousness, of its subjective as well as of its objective aspects, are both possible and necessary for its scientific study. An intentionality-modeling structure (an unified and stable ego refers to objects or to itself in the framework of a stable, reproducible, predictable world) accounts for the main features. (2) The material basis of consciousness can be clarified without recourse to new properties of matter or to quantum physics. Current neurobiology appears to be able to handle the problem. In fact, the neurobiology of consciousness is already in progress, and has achieved substantial results. At the system level, its main sources of data are: the neurophysiology of sleep-wakefulness, brain imaging of mental representations, attention and working memory, the neuropsychology of frontal syndrome, and awareness-unawareness dissociations in global amnesia and different forms of agnosia. At an intermediate level of organization, the mechanisms of consciousness may be the formation of a certain kind of neural assembly. (3) Further research may focus on neuropsychology and neurophysiology of object perception and recognition as a natural model of intentionality, perception of time, body schema, interhemispheric communications, 'voluntary' acts and mental images. The synthetic and dynamic views provided by brain imaging may be decisive for discovering the neural correlates of the integrative aspects of consciousness. (4) The neurobiological approach may, beyond the finding of cellular and molecular mechanisms, improve the general concepts of consciousness, overcome their antinomies and, against epiphenomenalism, definitely establish the reality of consciousness.

Gravidez Gemelar com Morte Fetal de Um dos Gêmeos: Avaliação Neurológica dos Gemelares Sobreviventes Neurological Evaluation of the Surviving Twin When One Dies In Utero

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Carolina Araújo Rodrigues Funayama

2002-03-01

Full Text Available Objetivo: verificar as intercorrências pré e perinatais e a evolução neurológica de crianças de gestações gemelares em que um dos fetos apresentou óbito intra-uterino. Métodos: foram avaliados 14 casos de gestações gemelares ocorridas no período de 1988 a 1994 com óbito de um dos fetos, acompanhadas no Setor de Patologia Obstétrica do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da USP. Dados do acompanhamento pré e perinatal, bem como de autópsia dos fetos mortos, foram obtidos. As crianças foram convocadas no ano de 1996 para exame neurológico, sendo avaliados dados evolutivos e sinais patológicos nas áreas motoras, sensitivas, sensoriais e funções corticais superiores, incluindo linguagem, praxias e agnosias. Resultados: do total de 14 casos, 10 retornaram para a avaliação neurológica tardia. Destas, apenas uma criança apresentou alteração no exame neurológico, cursando com paresia espástica de MIE de grau leve, tendo apresentado Apgar 0 no primeiro minuto e 5 no quinto minuto. A avaliação da placentação e idade gestacional mostrou 5 casos (35,7% com placentação monocoriônica e um caso com monoamniótica, 8 casos de pré-termo e 6 casos a termo. O óbito de um dos fetos ocorreu no segundo trimestre em 6 casos (42,8% e os demais no terceiro trimestre. Conclusões: o problema neurológico constatado em um único feto pode ser atribuído às intercorrências perinatais que este recém-nascido apresentou. Não tivemos como resultado outros RN com seqüelas provavelmente pela opção da conduta conservadora, tendo-se resolvido as gestações após a 32ª semana com diminuição das complicações do parto pré-termo extremo.Purpose: to analyze the effects of prenatal and perinatal complications and the neurological development of surviving twins when the other had died in utero. Methods: fourteen cases of twin pregnancies where one of the twins had died during the pregnancy were analyzed

The role of gamma-band activity in the representation of faces: reduced activity in the fusiform face area in congenital prosopagnosia.

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Christian Dobel

2011-05-01

Full Text Available Congenital prosopagnosia (CP describes an impairment in face processing that is presumably present from birth. The neuronal correlates of this dysfunction are still under debate. In the current paper, we investigate high-frequent oscillatory activity in response to faces in persons with CP. Such neuronal activity is thought to reflect higher-level representations for faces.Source localization of induced Gamma-Band Responses (iGBR measured by magnetoencephalography (MEG was used to establish the origin of oscillatory activity in response to famous and unknown faces which were presented in upright and inverted orientation. Persons suffering from congenital prosopagnosia (CP were compared to matched controls.Corroborating earlier research, both groups revealed amplified iGBR in response to upright compared to inverted faces predominately in a time interval between 170 and 330 ms and in a frequency range from 50-100 Hz. Oscillatory activity upon known faces was smaller in comparison to unknown faces, suggesting a "sharpening" effect reflecting more efficient processing for familiar stimuli. These effects were seen in a wide cortical network encompassing temporal and parietal areas involved in the disambiguation of homogenous stimuli such as faces, and in the retrieval of semantic information. Importantly, participants suffering from CP displayed a strongly reduced iGBR in the left fusiform area compared to control participants.In sum, these data stress the crucial role of oscillatory activity for face representation and demonstrate the involvement of a distributed occipito-temporo-parietal network in generating iGBR. This study also provides the first evidence that persons suffering from an agnosia actually display reduced gamma band activity. Finally, the results argue strongly against the view that oscillatory activity is a mere epiphenomenon brought fourth by rapid eye-movements (micro saccades.

Visual attention in posterior stroke and relations to alexia.

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Petersen, A; Vangkilde, S; Fabricius, C; Iversen, H K; Delfi, T S; Starrfelt, R

2016-11-01

Impaired visual attention is common following strokes in the territory of the middle cerebral artery, particularly in the right hemisphere, while attentional effects of more posterior lesions are less clear. Commonly, such deficits are investigated in relation to specific syndromes like visual agnosia or pure alexia. The aim of this study was to characterize visual processing speed and apprehension span following posterior cerebral artery (PCA) stroke. In addition, the relationship between these attentional parameters and single word reading is investigated, as previous studies have suggested that reduced visual speed and span may explain pure alexia. Eight patients with unilateral PCA strokes (four left hemisphere, four right hemisphere) were selected on the basis of lesion location, rather than the presence of any visual symptoms. Visual attention was characterized by a whole report paradigm allowing for hemifield-specific measurements of processing speed and apprehension span. All patients showed reductions in visual span contralateral to the lesion site, and four patients showed bilateral reductions in visual span despite unilateral lesions (2L; 2R). Six patients showed selective deficits in visual span, though processing speed was unaffected in the same field (ipsi- or contralesionally). Only patients with right hemifield reductions in visual span were impaired in reading, and this could follow either right or left lateralized stroke and was irrespective of visual field impairments. In conclusion, visual span may be affected bilaterally by unilateral PCA-lesions. Reductions in visual span may also be confined to one hemifield, and may be affected in spite of preserved visual processing speed. Furthermore, reduced span in the right visual field seems to be related to reading impairment in this group, regardless of lesion lateralization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Post-stroke writing and reading disorders

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Sinanović Osman

2013-03-01

Full Text Available The writing and reading disorders in stroke patients (alexias, agraphias and acalculias are more frequent than verified in routine exam, not only in the less developed but also in large neurological departments. Alexia is an acquired type of sensory aphasia where damage to the brain causes a patient to lose the ability to read. It is also called word blindness, text blindness or visual aphasia. Alexia refers to an acquired inability to read caused by brain damage and must be distinguished from dyslexia, a developmental abnormality in which the individual is unable to learn to read, and from illiteracy, which reflects a poor educational back-ground. Most aphasics are also alexic, but alexia may occur in the absence of aphasia and may occasionally be the sole disability resulting from specific brain lesions. There are different classifications of alexias. Traditionally, the alexias are divided into three categories: pure alexia with agraphia, pure alexia without agraphia, and alexia associated with aphasia ("aphasic alexia". Agraphia is defined as the disruption of previously intact writing skills by brain damage. Writing involves several elements - language processing, spelling, visual perception, visual-spatial orientation for graphic symbols, motor planning, and motor control of writing. A disturbance of any of these processes can impair writing. Agraphia may occur by itself or as association with aphasias, alexia, agnosia and apraxia. Agraphia can also result from "peripheral" involvement of the motor act of writing. Like alexia, agraphia must be distinguished from illiteracy, where writing skills were never developed. Acalculia is a clinical syndrome of acquired deficits in mathematical calculation, either mentally or with paper and pencil. This language disturbances can be classified differently, but there are three principal types of acalculia: acalculia associated with language disturbances, including number paraphasia, number agraphia, or

POST-STROKE WRITING AND READING DISORDERS

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Sinanović Osman

2013-01-01

Full Text Available The writing and reading disorders in stroke patients (alexias, agraphias and acalculias are more frequent than verified in routine exam, not only in the less developed but also in large neurological departments. Alexia is an acquired type of sensory aphasia where damage to the brain causes a patient to lose the ability to read. It is also called word blindness, text blindness orvisual aphasia. Alexia refers to an acquired inability to read caused by brain damage and must be distinguished from dyslexia, a developmental abnormality in which the individual is unable to learn to read, and from illiteracy, which reflects a poor educational back-ground. Most aphasics are also alexic, but alexia may occur in the absence of aphasia and may occasionally be the soledisability resulting from specific brain lesions. There are different classifications of alexias. Traditionally, the alexias are divided into three categories: pure alexia with agraphia, pure alexia without agraphia, and alexia associated with aphasia (“aphasic alexia”. Agraphia is defined as the disruption of previously intact writing skills by brain damage. Writing involves several elements—language processing, spelling, visual perception, visual-spatial orientation for graphic symbols, motor planning, and motor control of writing. A disturbance of any of these processes can impair writing. Agraphia may occur by itself or as association with aphasias, alexia, agnosia and apraxia. Agraphia can also result from “peripheral” involvement of the motor act of writing. Like alexia, agraphia must be distinguished from illiteracy, where writing skills were never developed. Acalculia is a clinical syndrome of acquired deficits in mathematical calculation, either mentally or with paper and pencil. This language disturbances can be classified differently, but there are three principal types of acalculia: acalculia associated with language disturbances, including number paraphasia, number

The Two Visual Systems Hypothesis: new challenges and insights from visual form agnosic patient DF

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Robert Leslie Whitwell

2014-12-01

Full Text Available Patient DF, who developed visual form agnosia following carbon monoxide poisoning, is still able to use vision to adjust the configuration of her grasping hand to the geometry of a goal object. This striking dissociation between perception and action in DF provided a key piece of evidence for the formulation of Goodale and Milner’s Two Visual Systems Hypothesis (TVSH. According to the TVSH, the ventral stream plays a critical role in constructing our visual percepts, whereas the dorsal stream mediates the visual control of action, such as visually guided grasping. In this review, we discuss recent studies of DF that provide new insights into the functional organization of the dorsal and ventral streams. We confirm recent evidence that DF has dorsal as well as ventral brain damage – and that her dorsal-stream lesions and surrounding atrophy have increased in size since her first published brain scan. We argue that the damage to DF’s dorsal stream explains her deficits in directing actions at targets in the periphery. We then focus on DF’s ability to accurately adjust her in-flight hand aperture to changes in the width of goal objects (grip scaling whose dimensions she cannot explicitly report. An examination of several studies of DF’s grip scaling under natural conditions reveals a modest though significant deficit. Importantly, however, she continues to show a robust dissociation between form vision for perception and form vision for action. We also review recent studies that explore the role of online visual feedback and terminal haptic feedback in the programming and control of her grasping. These studies make it clear that DF is no more reliant on visual or haptic feedback than are neurologically-intact individuals. In short, we argue that her ability to grasp objects depends on visual feedforward processing carried out by visuomotor networks in her dorsal stream that function in the much the same way as they do in neurologically

Topographical, autobiographical and semantic memory in a patient with bilateral mesial temporal and retrosplenial infarction.

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Hepner, Ilana J; Mohamed, Armin; Fulham, Michael J; Miller, Laurie A

2007-04-01

According to Consolidation Theory (Squire, 1992, Psychological Review, 99, 195; Squire & Alvarez, 1995, Current Opinion in Neurobiology, 5, 169), the mesial temporal lobes have a time-limited role in the maintenance, storage and retrieval of retrograde declarative memories, such that they are not necessary for recalling remote memories. In contrast, proponents of the Multiple Trace Theory (Fuji, Moscovitch, & Nadel, 2000, Handbook of neuropsychology, 2nd ed., p 223, Amsterdam, New York: Elsevier; Nadel & Moscovitch, 1999, Current Opinion in Neurobiology, 7, 217) posit that the mesial temporal lobe (MTL) is necessary for remembering detailed autobiographical and topographical material from all time periods. A third theory of hippocampal function, the Cognitive Map Theory (O'Keefe & Nadel, 1978, The hippocampus as a cognitive map. Oxford: Clarendon), states that the hippocampus is involved in the processing of allocentric spatial representations. The precise role of the MTL in remote memory has been difficult to elucidate, as the majority of studies present cases with widespread brain damage that often occurred many years prior to testing. We investigated retrograde autobiographical, semantic and topographical memories in a subject (SG) who had recently sustained infarctions confined to the MTL and retrosplenial region bilaterally. Inconsistent with the predictions of Cognitive Map Theory, memory for spatial maps that were learned in the past was preserved. Additional testing indicated that SG suffered from a landmark agnosia, which affected remotely and recently acquired information equally. SG was also poor at imagining which direction he would have to turn his body to move from one landmark to another. In accordance with Consolidation Theory, SG performed similarly to control subjects for remote time periods on various measures of retrograde autobiographical memory and demonstrated intact knowledge regarding famous faces and vocabulary terms that were acquired in

A 58-year-old female with blurred vision and apraxia

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Zhi-hong SHI

2014-07-01

Full Text Available A 58-year-old right handed woman, with 12 years of formal education, had a five-year history of slowly progressive blurred vision and apraxia. Five years before the examination she gradually became blurred vision and had difficulties identifying static objects within the visual field. Then she went to an ophthalmologist and received cataract surgery. However, the symptoms were not improved after surgery. Two years later, she had difficulty doing household chores and was unable to dress herself. She developed an anxiety disorder in the absence of prominent language or memory deficits. Five years after onset, she showed global cognitive decline and abilities of daily life decline. On neurological examination she was alert. Neuropsychological testing revealed a mini-mental state examination (MMSE score of 20/30 with anomia, agraphia, alexia and partial impairment on time orientation. Biochemical investigations for disorders involving thyroid function, vitamin B12, and folate were unremarkable. A brain MRI showed diffuse cortical atrophy and hippocampus atrophy. An 18F-FDG PET scan showed bilateral hypometabolism at the frontal lobes, tempoparietooccipital adjunction, posterior cingulate cortices and precuneus, insular lobes, caudate nuclei and right thalamus. An 11C-PIB PET scan showed bilateral amyloid deposits at bilateral frontal lobes and occipital lobes, left temporal lobe and insular, basal ganglia, bilateral cingulate cortices and precuneus. No PSEN1, PSEN2 or APP mutations were identified. This early-onset patient had an unusual cognitive complaint, including visual agnosia and apraxia. The clinical features, structural and functional imaging findings of this case were compatible with the diagnosis of Posterior Cortical Atrophy (PCA. PCA is a neurodegenerative condition characterized by a progressive, often dramatic and relatively selective decline in visual processing skills and other functions subserved by parietal, occipital and

Caracterização da patologia cerebral, da psicopatologia e da heredologia psiquiátrica na doutrina de Kleist

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Aníbal Silveira

1959-06-01

Full Text Available O ano de 1959 assinala três datas especiais em uma das mais férteis carreiras científicas: completa 80 anos Karl Kleist, nascido em Mülhausen, na Alsácia, a 31 de janeiro de 1879, que comemora o jubileu de venia legendi (1909; e há um quarto de século veio à luz a Gehirnpathologie (1934, que marca a nova era da fisiopatologia cerebral. A construção doutrinária de Kleist combina e aperfeiçoa as diretrizes isoladas de Meynert, de Wernicke e de Kraepelin. Constitui nela uma constante a união da psicopatologia à patologia cerebral; e a pesquisa no domínio clínico se norteia pela patogenia, pela heredologia e pela catamnese sistemática. Na própria patogênese - tanto dos quadros clínicos como dos sintomas - há a considerar a diferente participação do tronco cerebral e da corticalidade. E aqui, a seu turno, é preciso distinguir as funções que dependem de regiões posteriores. Assim, descreveu Kleist, respectivamente, os distúrbios agramáticos e os paragramáticos, os alógicos e os paralógicos, em analogia com os afásicos e os parafásicos. Demonstrou pela primeira vez, em 1905, a existência da afasia de condução e isolou dois novos tipos de apraxia: a apraxia segmentar e a apraxia de construção. Outros quadros psicopatológicos descritos por êle também se tornaram clássicos: a carência de iniciativa, a apraxia de iniciativa, a apraxia de ação coordenada (Handlungsfolge, a cegueira espacial (Ortsblindheit, a agnosia cromática - que depende da noção abstrata de côr e nada tem a ver com o daltonismo - e ainda os quadros psiquiátricos cíngulo-orbitários. Divide a esfera da personalidade em diversos estratos de grande relevância clínico-localizatória (quadro 1. A carta localizatória - plano estrutural e funcional do cérebro - ultrapassa a qualquer empreendimento análogo, tanto pela análise penetrante quanto pela adaptação à realidade clínica (figs. 1 e 2. Sobreleva notar aí que Kleist separa

Delusional misidentifications in a procrustean bed.

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Christodoulou, G N; Margariti, M; Christodoulou, N

2018-01-01

The Delusional Misidentification Syndromes (DMSs) are characterized by defective integration of the normally The Delusional Misidentification Syndromes (DMSs) are characterized by defective integration of the normally fused functions of perception and recognition. The classical sub-types are: the syndromes of Capgras, Fregoli,Intermetamorphosis (mentioned in 3) and Subjective doubles. These syndromes occur in a clear sensorium and shouldbe differentiated from the banal transient misidentifications occurring in confusional states and in mania and from thenon-delusional misidentifications (e.g. prosopagnosia). Joseph Capgras, who described the best-known sub-type, was indecisive on its pathogenesis. In his original report he defined the syndrome as "agnosia of identification" produced by a conflict between affective accompaniments ofsensory and mnemonic images. In his subsequent two publications, he considered the syndrome as a restitution delusionand as a psychopathological mechanism to hide incestuous desires. For more details see the chapter by J.P. Luaute in avolume on DMS. Psychodynamic approaches are, essentially, variants of the formulation that DMSs result from ambivalent feelings resolvedby directing hate feelings onto an imagined double in order to retain the original intact (and thus avoid guilt).These views have been voiced by David Enoch [relevant chapter in (3)] and with variations by many other investigatorsreviewed by Oyebode. Regression to archaic modes of thought (like thinking in terms of doubles and dualisms) due to personality disintegrationproduced by psychotic illness is a fascinating hypothesis by John Todd [mentioned in (1)]. However, if this was thecase, DMS should be much more frequent. Mayer-Gross and Ackner (mentioned in 9) had observed that when there is a delusional development, depersonalization-derealization experiences tend to be included within the delusional system. Such experiences usually precede orcoincide with the onset of DMS