1,720,986 research outputs found
Neural correlates of apathy in patients with neurodegenerative disorders: an activation likelihood estimation (ALE) meta-analysis
No full textApathy is commonly reported in Alzheimer’s Disease (AD), Fronto-Temporal Dementia (FTD) and Parkinson’s Disease (PD). In our meta-analysis we analysed a total of 41 studies to identify brain patterns associated with apathy. For these purposes we used activation likelihood estimation meta-analyses. Our main overall analysis showed that apathy is associated to hypometabolism and a decreased gray matter volume in the left inferior frontal gyrus (BA 45, 46). Disorder-specific analyses, not performed by means of meta-analysis, because of the small number of studies, but by means a label-based review, revealed an altered brain perfusion and decreased gray matter volume in anterior cingulate cortex (BA 24, 32) in AD patients and a decreased gray matter volume in inferior frontal gyrus (BA 44, 45) and parietal cortex (BA 40) in FTD patients. These findings suggest that apathy is mainly associated with a cortical dysfunction of areas involved in executive-cognitive processing (i.e. action planning) and emotional regulation (auto-activation and reward processing). Knowledge about the neural underpinnings of apathy is crucial for understanding its clinical characteristics in neurodegenerative diseases and for developing novel strategies of treatment in clinical practice
Neural correlates of embodied action language processing: a systematic review and meta-analytic study
No full textThe neural correlates of action language processing are still debated within embodied cognition research and little is known about the flexible involvement of modality-specific pre-motor system and multimodal high-level temporo-parietal regions as a function of explicit and implicit tasks. A systematic review and the Activation likelihood estimation (ALE) meta-analyses on functional neuroimaging studies were performed to identify neural correlates of action language processing activated during explicit and implicit tasks. The contrast ALE meta-analysis revealed activation of modality-specific premotor area and inferior frontal areas during explicit action language tasks while a greater activation of posterior temporo-occipital areas emerged for implicit tasks. The conjunction analysis revealed overlap in the temporo-parietal multimodal high-level regions for both types of tasks. Functional specialization of the middle temporal gyrus was found where the more posterior-occipital part resulted activated during implicit action language tasks whereas the antero-lateral part was involved in explicit tasks. Our findings were discussed within a conceptual flexibility perspective about the involvement of both the modality-specific and multimodal brain system during action language processing depending on different types of tasks
Neuropsychological correlates of theory of mind in chronic migraine
No full textObjective: Theory of mind (ToM), the ability to understand other minds-that is, their beliefs, intentions (cognitive ToM), or emotions (affective ToM)-and its neuropsychological mechanisms in migraine have been poorly investigated. The aim of the study was to explore the deficit of cognitive and affective ToM and its possible associations with cognitive functioning in patients with chronic migraine (CM). Method: Forty participants with CM and 40 age-, education-, and sex-matched healthy controls (HC) underwent clinical assessment, cognitive (the ToM Pictures Sequencing Task and the Advanced Test of ToM) and affective ToM (the Reading the Mind in the Eyes Task and the Emotion Attribution Task) tasks, and a comprehensive neuropsychological battery. Results: Patients with CM significantly reported a lower performance on tasks assessing ToM compared to HC, with an impairment demonstrated for cognitive ToM. Moreover, patients with CM achieved significantly lower scores on tests assessing cognitive flexibility, planning, abstract reasoning, and long-term memory with respect to HC. ToM abilities were significantly related to migraine severity, executive, and memory functions in CM patients. Conclusions: The findings demonstrated that patients with CM present difficulties in inferring others' mental states, which would be related to clinical and cognitive functioning. The clinical importance of these findings, implications for clinical practice, and future research are discussed
Apathy as a herald of cognitive changes in multiple sclerosis: A 2-year follow-up study
No full textBackground: Behavioral symptoms, such as apathy and depression, are common in multiple sclerosis (MS) but their relationship with cognitive and clinical characteristics often remains underinvestigated and not monitored over time. Objective: The aim of this study was to assess the evolution of cognitive profile of patients affected by MS in relation to apathy and depression using a 2-year follow-up study. Methods: Two years after the first assessment, 100 of 125 MS patients were re-evaluated on a comprehensive neuropsychological battery, and on specific scales for assessment of apathy (Apathy Evaluation Scale—Self-reported) and depression (Hamilton Depression Rating Scale). Results: After 2 years (T1), we found a relatively consistent prevalence of apathy (about 40%) and a reduction in prevalence of depression (from 44% to 30%). Higher level of apathy at baseline predicted the progressive cognitive changes at follow-up; and patients with apathy without depression (“pure” apathy) than patients without apathy had poorer performance on the interference task of the Stroop test assessing inhibitory control. Conclusion: The present results suggested that apathy in MS was associated with more severe executive dysfunctions (in particular cognitive control). Apathy rather than depression predicted cognitive impairment in MS over time
The relationship between Impulse Control Disorders and cognitive dysfunctions in Parkinson's Disease: A meta-analysis
No full textImpulse Control Disorders (ICD) are associated with impairment in cognitive flexibility and cortical inhibition. In Parkinson's Disease (PD) the relationship between ICD and cognitive dysfunctions is still unclear: some studies found different cognitive profiles between Parkinsonians with and without ICD, whereas others did not. Moreover, findings from studies on ICD in PD are conflicting on which cognitive function is altered. A meta-analysis of 34 studies was performed to shed light on relationship between ICD and cognitive dysfunctions and to reveal the cognitive function compromised in Parkinsonians with ICD. Data were analysed in global cognitive functioning, memory, executive functions, attention/working memory, language, and visuospatial functions. Significant relationship between ICD and dysfunction of abstraction ability/concept formation, set-shifting, visuospatial/constructional abilities and decision-making was found. These findings suggested that people affected by PD with specific frontal dysfunctions are more vulnerable to develop ICD when they take antiparkinsonian drug. Evaluation of specific cognitive functions in routine clinical practice might help to detect those people with PD susceptible to ICD before treating them with antiparkinsonian drugs
Combining the Inner Self with the Map of the Body: Evidence for White Matter Contribution to the Relation Between Interoceptive Sensibility and Nonaction-oriented Body Representation
No full text: Very recent studies on healthy individuals suggest that changes in the sensibility toward internal bodily sensations across the lifespan affect the ability to mentally represent one's body, in terms of action-oriented and nonaction-oriented body representation (BR). Little is known about the neural correlates of this relation. Here we fill this gap using the neuropsychological model provided by focal brain damage. Sixty-five patients with unilateral stroke (20 with left and 45 with right brain damage, LBD and RBD, respectively) participated in this study. Both action-oriented BR and nonaction-oriented BR were tested; interoceptive sensibility was assessed as well. First, we tested whether interoceptive sensibility predicted action-oriented BR and nonaction-oriented BR, in RBD and LBD separately. Then, a track-wise hodological lesion-deficit analysis was performed in a subsample of twenty-four patients to test the brain network supporting this relation. We found that interoceptive sensibility predicted the performances in the task tapping nonaction-oriented BR. The higher interoceptive sensibility was, the worse patients performed. This relation was associated with the disconnection probability of the corticospinal tract, the fronto-insular tract, and the pons. We expand over the previous findings on healthy individuals, supporting the idea that high levels of interoceptive sensibility negatively affect BR. Specific frontal projections and frontal u-shaped tracts may play a pivotal role in such an effect, likely affecting the development of a first-order representation of the self within the brainstem autoregulatory centers and posterior insula and of a second-order representation of the self within the anterior insula and higher-order prefrontal areas
Neural bases of Impulse Control Disorders in Parkinson's disease: a systematic review and an ALE meta-analysis
No full textImpulse control disorders (ICD) occur in some patients affected by Parkinson's disease (PD). Previous studies revealed an involvement of basal ganglia in ICD, but recent morphological, molecular and functional imaging studies showed that alterations of some extrastriatal regions contribute to development of ICD in PD, with mixed results. To identify the brain regions underlying ICD in PD, a systematic review of morphometric and functional studies was performed, complemented by an ALE meta-analysis of functional studies. The review of structural studies revealed no significant changes in any cortical and subcortical region in patients with ICD. The review of functional studies revealed increased activity in the Ventral Striatum and OrbitoFrontal Cortex and decreased activity in Anterior Cingulate Cortex (ACC). Clusters of hyperactivation in ventral striatum and of hypoactivation in ACC were confirmed by ALE meta-analysis. In conclusion, the present study strongly supported that ICD in PD are related to a dysfunction of limbic divisions of the striatum and of the prefrontal cortex and provided a neurofunctional basis for devising potential therapeutic interventions
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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