Failure to modulate neural response to increased task demand in mild Alzheimer's disease: fMRI study of visuospatial processing
Alzheimer's disease (AD) is characterized by disturbances of visuospatial cognition. Given that these impairments are closely related to metabolic and neuropathological changes, our study aimed to investigate the functional competency of brain regions in the visuospatial networks responsible fo...
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doaj-d232aafb5e7a403b9cc9356e139cd7612021-03-20T04:55:50ZengElsevierNeurobiology of Disease1095-953X2008-09-01313287297Failure to modulate neural response to increased task demand in mild Alzheimer's disease: fMRI study of visuospatial processingPatrizia Vannini0Christoph Lehmann1Thomas Dierks2Kay Jann3Matti Viitanen4Lars-Olof Wahlund5Ove Almkvist6Department of Neurobiology, Care Sciences and Society, Division of Clinical Geriatrics, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden; Corresponding author. Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Division of Clinical Geriatrics, Novum, level 5/Karolinska University Hospital Huddinge, 14186 Stockholm, Sweden. Fax: +46 8 585 854 70.Department of Psychiatric Neurophysiology, University Hospital of Clinical Psychiatry, Bern, SwitzerlandDepartment of Neurobiology, Care Sciences and Society, Division of Clinical Geriatrics, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden; Department of Psychiatric Neurophysiology, University Hospital of Clinical Psychiatry, Bern, SwitzerlandDepartment of Psychiatric Neurophysiology, University Hospital of Clinical Psychiatry, Bern, SwitzerlandDepartment of Neurobiology, Care Sciences and Society, Division of Clinical Geriatrics, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, SwedenDepartment of Neurobiology, Care Sciences and Society, Division of Clinical Geriatrics, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, SwedenDepartment of Neurobiology, Care Sciences and Society, Division of Clinical Geriatrics, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden; Department of Psychology, Stockholm University, Stockholm, SwedenAlzheimer's disease (AD) is characterized by disturbances of visuospatial cognition. Given that these impairments are closely related to metabolic and neuropathological changes, our study aimed to investigate the functional competency of brain regions in the visuospatial networks responsible for early clinical symptoms in AD using event-related functional magnetic resonance imaging (fMRI). Participants (13AD patients with mild symptoms and 13 age- and education-matched controls) performed an angle discrimination task with varying task demand. Using a novel approach that modeled the dependency of the blood oxygenation level-dependent (BOLD) signal on the subject's reaction time allowed us to investigate task demand-dependent signal changes between the groups. Both groups demonstrated overlapping neural networks engaged in angle discrimination, including the parieto-occipital and frontal regions. In several network regions, AD patients showed a significantly weaker and sometimes no BOLD signal due to increased task demand compared with controls, demonstrating failure to modulate the neural response to increased task demand. A general task demand-independent increase of activation in AD patients compared with controls was found in right middle temporal gyrus. This latter finding may indicate an attempt to compensate for dysfunctional areas in the dorsal visual pathway. These results confirm deficits in visuospatial abilities, which occur early in AD, and offer new insights into the neural mechanisms underlying this impairment.http://www.sciencedirect.com/science/article/pii/S0969996108000909Neurodegenerative diseaseBehaviorReaction timeParametric designNeuroimagingDorsal stream |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Patrizia Vannini Christoph Lehmann Thomas Dierks Kay Jann Matti Viitanen Lars-Olof Wahlund Ove Almkvist |
spellingShingle |
Patrizia Vannini Christoph Lehmann Thomas Dierks Kay Jann Matti Viitanen Lars-Olof Wahlund Ove Almkvist Failure to modulate neural response to increased task demand in mild Alzheimer's disease: fMRI study of visuospatial processing Neurobiology of Disease Neurodegenerative disease Behavior Reaction time Parametric design Neuroimaging Dorsal stream |
author_facet |
Patrizia Vannini Christoph Lehmann Thomas Dierks Kay Jann Matti Viitanen Lars-Olof Wahlund Ove Almkvist |
author_sort |
Patrizia Vannini |
title |
Failure to modulate neural response to increased task demand in mild Alzheimer's disease: fMRI study of visuospatial processing |
title_short |
Failure to modulate neural response to increased task demand in mild Alzheimer's disease: fMRI study of visuospatial processing |
title_full |
Failure to modulate neural response to increased task demand in mild Alzheimer's disease: fMRI study of visuospatial processing |
title_fullStr |
Failure to modulate neural response to increased task demand in mild Alzheimer's disease: fMRI study of visuospatial processing |
title_full_unstemmed |
Failure to modulate neural response to increased task demand in mild Alzheimer's disease: fMRI study of visuospatial processing |
title_sort |
failure to modulate neural response to increased task demand in mild alzheimer's disease: fmri study of visuospatial processing |
publisher |
Elsevier |
series |
Neurobiology of Disease |
issn |
1095-953X |
publishDate |
2008-09-01 |
description |
Alzheimer's disease (AD) is characterized by disturbances of visuospatial cognition. Given that these impairments are closely related to metabolic and neuropathological changes, our study aimed to investigate the functional competency of brain regions in the visuospatial networks responsible for early clinical symptoms in AD using event-related functional magnetic resonance imaging (fMRI). Participants (13AD patients with mild symptoms and 13 age- and education-matched controls) performed an angle discrimination task with varying task demand. Using a novel approach that modeled the dependency of the blood oxygenation level-dependent (BOLD) signal on the subject's reaction time allowed us to investigate task demand-dependent signal changes between the groups. Both groups demonstrated overlapping neural networks engaged in angle discrimination, including the parieto-occipital and frontal regions. In several network regions, AD patients showed a significantly weaker and sometimes no BOLD signal due to increased task demand compared with controls, demonstrating failure to modulate the neural response to increased task demand. A general task demand-independent increase of activation in AD patients compared with controls was found in right middle temporal gyrus. This latter finding may indicate an attempt to compensate for dysfunctional areas in the dorsal visual pathway. These results confirm deficits in visuospatial abilities, which occur early in AD, and offer new insights into the neural mechanisms underlying this impairment. |
topic |
Neurodegenerative disease Behavior Reaction time Parametric design Neuroimaging Dorsal stream |
url |
http://www.sciencedirect.com/science/article/pii/S0969996108000909 |
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