Complex visual disturbances in Alzheimer's disease

Mendez, Mario F.; Méndez, María Andreina; Martin, Richard J; Smyth, Kathleen A.; Whitehouse, Peter J.

doi:10.1212/wnl.40.3_part_1.439

Cited by 314 publications

(155 citation statements)

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“…77.07 (7.62) n.s. Education 14.23 (2.9) [9][10][11][12][13][14][15][16][17][18][19][20] 12.71 (3.8) [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] n.s.…”

Section: Methodsunclassified

“…For instance, individuals suffering from AD have difficulties in color and depth perception [11], visuospatial organization [12], control of visual attention [13] and in visual search tasks with simple stimuli [14]. These low-level visual deficits occur independently of memory problems in AD [15] and may result from the concentration of neuropathology in the visual cortex [16].…”

Section: Introductionmentioning

confidence: 99%

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A Qualitative Impairment in Face Perception in Alzheimer’s Disease: Evidence from a Reduced Face Inversion Effect

Lavallée

Gandini

Rouleau

et al. 2016

JAD

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Short title (running head): face inversion effect in Alzheimer's disease © 2 AbstractPrevalent face recognition difficulties in Alzheimer disease have typically been attributed to the underlying episodic and semantic memory impairment. The aim of the current study was to determine if AD patients are also impaired at the perceptual level for faces, more specifically at extracting a visual representation of an individual face. To address this question, we investigated the matching of simultaneously presented individual faces and of other nonface familiar shapes (cars), at both upright and inverted orientation, in a group of mild AD patients and in a group of healthy older controls matched for age and education. AD patients showed a reduced inversion effect (i.e. larger performance for upright than inverted stimuli) for faces, but not for cars, both in terms of error rates and response times. While healthy participants showed a much larger decrease in performance for faces than for cars with inversion, the inversion effect did not differ significantly for faces and cars in AD. This abnormal inversion effect for faces was observed in a large subset of individual patients with AD. These results suggest that AD patients have deficits in higher-level visual processes, more specifically at perceiving individual faces, a function that relies on holistic representations specific to upright face stimuli. These deficits, combined with their memory impairment, may contribute to the difficulties in recognizing familiar people that are often reported in patients suffering from the disease and by their caregivers.3

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“…77.07 (7.62) n.s. Education 14.23 (2.9) [9][10][11][12][13][14][15][16][17][18][19][20] 12.71 (3.8) [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] n.s.…”

Section: Methodsunclassified

Section: Introductionmentioning

confidence: 99%

A Qualitative Impairment in Face Perception in Alzheimer’s Disease: Evidence from a Reduced Face Inversion Effect

Lavallée

Gandini

Rouleau

et al. 2016

JAD

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“…This condition sometimes presents as an early symptom of neurodegenerative diseases such as Alzheimer's (Cogan, 1985;Mendez et al, 1990;Victoroff et al, 1994). From this data alone, we might suspect that spatial deficits underlie the memory deficits in Alzheimer's.…”

Section: Neuropsychological Datamentioning

confidence: 99%

The Neuropsychology of Autobiographical Memory

Greenberg

Rubin

2003

Cortex

251

151

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This special issue of Cortex focuses on the relative contribution of different neural networks to memory and the interaction of 'core' memory processes with other cognitive processes. In this article, we examine both. Specifically, we identify cognitive processes other than encoding and retrieval that are thought to be involved in memory; we then examine the consequences of damage to brain regions that support these processes. This approach forces a consideration of the roles of brain regions outside of the frontal, medialtemporal, and diencephalic regions that form a central part of neurobiological theories of memory. Certain kinds of damage to visual cortex or lateral temporal cortex produced impairments of visual imagery or semantic memory; these patterns of impairment are associated with a unique pattern of amnesia that was distinctly different from the pattern associated with medial-temporal trauma. On the other hand, damage to language regions, auditory cortex, or parietal cortex produced impairments of language, auditory imagery, or spatial imagery; however, these impairments were not associated with amnesia. Therefore, a full model of autobiographical memory must consider cognitive processes that are not generally considered 'core processes,' as well as the brain regions upon which these processes depend.

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“…It is well established that tasks involving a high load on visual processing-such as visuoconstruction, complex pattern discrimination or visual search-are already affected in early AD [37][38][39][40]. Figure 2 presents an example.…”

Section: Challenges For the Conventional Memory-mentioning

confidence: 99%

A biased competition account of attention and memory in Alzheimer's disease

Finke

Myers

Bublak

et al. 2013

Phil. Trans. R. Soc. B

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The common view of Alzheimer's disease (AD) is that of an age-related memory disorder, i.e. declarative memory deficits are the first signs of the disease and associated with progressive brain changes in the medial temporal lobes and the default mode network. However, two findings challenge this view. First, new model-based tools of attention research have revealed that impaired selective attention accompanies memory deficits from early pre-dementia AD stages on. Second, very early distributed lesions of lateral parietal networks may cause these attention deficits by disrupting brain mechanisms underlying attentional biased competition. We suggest that memory and attention impairments might indicate disturbances of a common underlying neurocognitive mechanism. We propose a unifying account of impaired neural interactions within and across brain networks involved in attention and memory inspired by the biased competition principle. We specify this account at two levels of analysis: at the computational level, the selective competition of representations during both perception and memory is biased by AD-induced lesions; at the large-scale brain level, integration within and across intrinsic brain networks, which overlap in parietal and temporal lobes, is disrupted. This account integrates a large amount of previously unrelated findings of changed behaviour and brain networks and favours a brain mechanism-centred view on AD.

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Complex visual disturbances in Alzheimer's disease

Cited by 314 publications

References 0 publications

A Qualitative Impairment in Face Perception in Alzheimer’s Disease: Evidence from a Reduced Face Inversion Effect

A Qualitative Impairment in Face Perception in Alzheimer’s Disease: Evidence from a Reduced Face Inversion Effect

The Neuropsychology of Autobiographical Memory

A biased competition account of attention and memory in Alzheimer's disease

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