Frontotemporal Dementia: What Can the Behavioral Variant Teach Us about Human Brain Organization?
ABSTRACT The behavioral variant of frontotemporal dementia (bvFTD) slowly undermines emotion, social behavior, personal conduct, and decision making. These deficits occur in concert with focal neurodegeneration that can be quantified with modern structural and functional imaging and neuropathological methods. As a result, studies of bvFTD have helped to clarify brain structures, networks, and neurons that prove critical for normal social-emotional functioning. In this article, the authors review the evolving bvFTD literature and propose a simple, testable network-based working model for understanding bvFTD.
SourceAvailable from: Lucina Q Uddin[Show abstract] [Hide abstract]
ABSTRACT: The brain is constantly bombarded by stimuli, and the relative salience of these inputs determines which are more likely to capture attention. A brain system known as the 'salience network', with key nodes in the insular cortices, has a central role in the detection of behaviourally relevant stimuli and the coordination of neural resources. Emerging evidence suggests that atypical engagement of specific subdivisions of the insula within the salience network is a feature of many neuropsychiatric disorders.Nature Reviews Neuroscience 11/2014; DOI:10.1038/nrn3857 · 31.38 Impact Factor
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ABSTRACT: The cognitive estimation test (CET) measures cognitive estimation abilities: it assesses the ability to apply reasoning strategies to answer questions that usually cannot lead to a clear and exact reply. Since it requires the activation of an intricate ensemble of cognitive functions, there is an ongoing debate in the literature regarding whether the CET represents a measurement of global cognitive abilities or a pure measure of executive functions. In the present study, CET together with a neuropsychological assessment focused on executive functions was administered in thirty patients with Parkinson’s disease without signs of dementia. The CET correlated with measures of verbal working memory and semantic knowledge, but not with other dimensions of executive domains, such as verbal phonemic fluency, ability to manage real-world interferences, or visuospatial reasoning. According to our results, cognitive estimation abilities appeared to trigger a defined cognitive path that includes executive functions, namely, working memory and semantic knowledge.Neurological Sciences 03/2015; DOI:10.1007/s10072-015-2158-5 · 1.50 Impact Factor
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ABSTRACT: Objective: Metamemory, or knowledge of one's memory abilities, is often impaired in individuals with Alzheimer's disease (AD), although the basis of this metacognitive deficit has not been fully articulated. Behavioral and imaging studies have produced conflicting evidence regarding the extent to which specific cognitive domains (i.e., executive function; memory) and brain regions contribute to memory awareness. The primary aim of this study was to disentangle the cognitive correlates of metamemory in AD by examining the relatedness of objective metamemory performance to cognitive tasks grouped by domain (executive function or memory) as well as by preferential hemispheric reliance defined by task modality (verbal or nonverbal). Method: Eight-nine participants with mild AD recruited at Columbia University Medical Center and the University of Pennsylvania underwent objective metamemory and cognitive testing. Partial correlations were used to assess the relationship between metamemory and four cognitive variables, adjusted for recruitment site. Results: The significant correlates of metamemory included nonverbal fluency (r = .27, p = .02) and nonverbal memory (r = .24, p = .04). Conclusions: Our findings suggest that objectively measured metamemory in a large sample of individuals with mild AD is selectively related to a set of interdomain nonverbal tasks. The association between metamemory and the nonverbal tasks may implicate a shared reliance on a right-sided cognitive network that spans frontal and temporal regions. (PsycINFO Database Record (c) 2014 APA, all rights reserved).Neuropsychology 05/2014; 28(5). DOI:10.1037/neu0000078 · 3.43 Impact Factor