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81.
Previous neuroimaging research has documented that patterns of intrinsic (resting state) functional connectivity (FC) among brain regions covary with individual measures of cognitive performance. Here, we examined the relation between intrinsic FC and a reaction time (RT) measure of performance, as a function of age group and task demands. We obtained filtered, event-related functional magnetic resonance imaging data, and RT measures of visual search performance, from 21 younger adults (19–29 years old) and 21 healthy, older adults (60–87 years old). Age-related decline occurred in the connectivity strength in multiple brain regions, consistent with previous findings. Among 8 pairs of regions, across somatomotor, orbitofrontal, and subcortical networks, increasing FC was associated with faster responding (lower RT). Relative to younger adults, older adults exhibited a lower strength of this RT-connectivity relation and greater disruption of this relation by a salient but irrelevant display item (color singleton distractor). Age-related differences in the covariation of intrinsic FC and cognitive performance vary as a function of task demands. 相似文献
82.
C. Rondinoni E. Amaro Jr F. Cendes A.C.dos Santos C.E.G. Salmon 《Brazilian journal of medical and biological research》2013,46(4):359-367
Functional MRI (fMRI) resting-state experiments are aimed at identifying brain
networks that support basal brain function. Although most investigators consider
a ‘resting-state’ fMRI experiment with no specific external stimulation,
subjects are unavoidably under heavy acoustic noise produced by the equipment.
In the present study, we evaluated the influence of auditory input on the
resting-state networks (RSNs). Twenty-two healthy subjects were scanned using
two similar echo-planar imaging sequences in the same 3T MRI scanner: a default
pulse sequence and a reduced “silent” pulse sequence. Experimental sessions
consisted of two consecutive 7-min runs with noise conditions (default or
silent) counterbalanced across subjects. A self-organizing group independent
component analysis was applied to fMRI data in order to recognize the RSNs. The
insula, left middle frontal gyrus and right precentral and left inferior
parietal lobules showed significant differences in the voxel-wise comparison
between RSNs depending on noise condition. In the presence of low-level noise,
these areas Granger-cause oscillations in RSNs with cognitive implications
(dorsal attention and entorhinal), while during high noise acquisition, these
connectivities are reduced or inverted. Applying low noise MR acquisitions in
research may allow the detection of subtle differences of the RSNs, with
implications in experimental planning for resting-state studies, data analysis,
and ergonomic factors. 相似文献
83.
Viola Oertel-Knöchel Britta Reinke Richard Feddern Annika Knake Christian Knöchel David Prvulovic Fabian Fußer Tarik Karakaya Deborah Loellgen Christine Freitag Johannes Pantel David E.J. Linden 《Journal of affective disorders》2013
Background
Episodic memory deficits affect the majority of patients with bipolar disorder (BD).Aims
The study investigates episodic memory performance through different approaches, including behavioural measures, physiological parameters, and the underlying functional activation patterns with functional neuroimaging (fMRI).Methods
26 Remitted BD patients and a matched group of healthy controls underwent a verbal episodic memory test together with monitored autonomic response, psychopathological ratings and functional magnetic resonance imaging (fMRI) during the verbal episodic memory test.Results
Compared to healthy controls, BD patients performed significantly worse during the episodic memory task. The results further indicate that verbal episodic memory deficits in BD are associated with abnormal functional activity patterns in frontal, occipital and limbic regions, and an increase in stress parameters.Limitations
We aimed to minimise sample heterogeneity by setting clear criteria for remission, based on the scores of a depression (BDI II) and mania scale (BRMAS) and on the DSM IV criteria. However, our patients were not symptom-free and scored higher on BDI II scores than the control group.Conclusions
The results are of interest for the treatment of cognitive symptoms in BD patients, as persistent cognitive impairment may hamper full rehabilitation. 相似文献84.
Hongyu Yang Lisa H. Lu Minjie Wu Michael Stevens Ezra Wegbreit Jacklynn Fitzgerald Bryn Levitan Stewart Shankman Mani N. Pavuluri 《Journal of affective disorders》2013
Objective
Activation changes at the interface of affective and cognitive systems are examined over a 3 year period in pediatric bipolar disorder (PBD).Methods
Thirteen participants with PBD and 10 healthy controls (HC) matched on demographics and IQ were scanned at baseline, at 16 weeks, and after 3 years. All patients received pharmacotherapy based on a medication algorithm. A pediatric affective color matching paradigm was used to probe cognitive processing under emotional challenge.Results
At baseline, in response to emotional vs. neutral words, patients with PBD showed greater activation than HC in the right dorsal lateral prefrontal cortex (DLPFC) and amygdala, ventral lateral prefrontal cortex (VLPFC), bilateral anterior cingulate cortex (ACC), and ventral striatum. Increased activation in DLPFC in the PBD group normalized by 16 weeks. By 3 years, normalization was observed in VLPFC, ACC, amygdala, and striatum.Limitations
Small sample size renders the present findings preliminary.Conclusions
Greater activation in fronto-striatal and fronto-limbic circuits were observed in unmedicated patients with PBD. Present findings suggest the possibility that DLPFC is most malleable to pharmacological intervention with systematic pharmacotherapy leading to immediate response, which extended to amygdalostriatal and ventral cortical regions at 3 years. The seminal observation from this study is the prolonged length of recovery time in the normalization of subcortical activity along with their interfacing cortical regions. Findings from this proof of concept study need to be replicated in a larger sample. 相似文献85.
Mayu Harada Takeshi Terao Koji Hatano Kentaro Kohno Yasuo Araki Yoshinori Mizokami Kensuke Kodama Nobuhiko Hoaki Miyano Arasaki Tsuyoshi Shimomura Minoru Fujiki Takanori Kochiyama 《Journal of affective disorders》2013
Background
Hyperthymic temperament has been generally accepted as one of premorbid temperament of bipolar disorders. Although several studies indicate that subjects with hyperthymic temperament receive more illuminance, our recent study suggests that the threshold of brightness and darkness judgment is not different between more and less hyperthymic subjects, and that hyperthymic temperament may be associated with left inferior orbitofrontal cortex, which has been reported to be associated with bipolar disorder. Therefore, at the next stage, it can be hypothesized that hyperthymic subjects may prefer brightness (i.e., heliotropism) and thereby seek illuminance, and that percent signal changes of left inferior orbitofrontal cortex during the preference task may be associated with hyperthymic temperament scores.Methods
We compared brightness preference and un-preference between more and less hyperthymic subjects, and investigated percent signal changes of left inferior orbitofrontal cortex during brightness preference judgment, brightness un-preference judgment, and control task by using functional Magnetic Resonance Imaging (fMRI).Results
There were significant differences in brightness preference judgment and un-preference judgment, showing that more hyperthymic subjects preferred brighter illuminace levels and un-preferred darker illuminance levels than less hyperthymic subjects. Moreover, fMRI signal changes of left inferior orbitofrontal cortex was significantly and negatively associated with hyperthymic temperament scores.Limitations
It is unknown why left but not right inferior orbitofrontal cortex was associated with hyperthymic temperament scores.Conclusions
The present findings suggest that more hyperthymic subjects may prefer brightness and un-prefer darkness than less hyperthymic subjects (i.e., heliotropism), and reconfirm that hyperthymic temperament may be associated with left inferior orbitofrontal cortex, which have been reported to be associated with bipolar disorders. 相似文献86.
Julia Graham Gholamreza Salimi-Khorshidi Cindy Hagan Nicholas Walsh Ian Goodyer Belinda Lennox John Suckling 《Journal of affective disorders》2013
Background
Major Depressive Disorder (MDD) is a leading cause of disease burden worldwide. With the rapid growth of neuroimaging research on relatively small samples, meta-analytic techniques are becoming increasingly important. Here, we aim to clarify the support in fMRI literature for three leading neurobiological models of MDD: limbic–cortical, cortico–striatal and the default mode network.Methods
Searches of PubMed and Web of Knowledge, and manual searches, were undertaken in early 2011. Data from 34 case-control comparisons (n=1165) and 6 treatment studies (n=105) were analysed separately with two meta-analytic methods for imaging data: Activation Likelihood Estimation and Gaussian-Process Regression.Results
There was broad support for limbic–cortical and cortico–striatal models in the case-control data. Evidence for the role of the default mode network was weaker. Treatment-sensitive regions were primarily in lateral frontal areas.Limitations
In any meta-analysis, the increase in the statistical power of the inference comes with the risk of aggregating heterogeneous study pools. While we believe that this wide range of paradigms allows identification of key regions of dysfunction in MDD (regardless of task), we attempted to minimise such risks by employing GPR, which models such heterogeneity.Conclusions
The focus of treatment effects in frontal areas indicates that dysregulation here may represent a biomarker of treatment response. Since the dysregulation in many subcortical regions in the case-control comparisons appeared insensitive to treatment, we propose that these act as trait vulnerability markers, or perhaps treatment insensitivity. Our findings allow these models of MDD to be applied to fMRI literature with some confidence. 相似文献87.
Dreaming occurs during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep, which both are regulated by homeostatic, ultradian, and circadian processes. However, the magnitude of how ultradian REM and NREM sleep and its EEG correlates impact onto dream recall remains fairly unknown. In this review, we address three questions: 1. Is there an ultradian NREM–REM sleep modulation in successful dream recall, which is gated by the circadian clock? 2. What are the key electrophysiological correlates that account for dream recall during NREM and REM sleep and 3. Are there age-related changes in the ultradian and circadian regulation in dream recall and its electrophysiological correlates? Knowledge on the specific frequency and topography NREM and REM sleep differences prior to dream recall may pinpoint to the cerebral correlates that account for this cognitive process, and hint to their possible physiological meaning. 相似文献
88.
89.
In this study, we designed a continuous wins-and-losses task to monitor the mental activities during decision-making and their effects on subsequent decisions in Internet addiction disorder (IAD) subjects. In behavioral performance, IAD subjects show longer response time, lower repeat rate and greater Stroop effect than healthy controls. In neuroimaging results, IAD subjects show increased brain activities in the inferior frontal cortex, insula, anterior cingulate cortex and decreased activation in the caudate and posterior cingulate cortex after continuous wins than healthy controls. In addition, IAD subjects show increased brain activities in the inferior frontal gyrus and decreased brain activation in the posterior cingulate cortex after continuous losses. Thus, we concluded that IAD subjects engage more cognitive activities to finish the decision-making task. As a result, they cannot sufficiently focus on the executive function during this process. They also do not pay adequate attention to considering previous selections and relevant outcomes during decision-making. 相似文献
90.
Johanna M. Jarcho Nathan A. Fox Daniel S. Pine Amit Etkin Ellen Leibenluft Tomer Shechner Monique Ernst 《Biological psychology》2013
The present study is the first to assess whether the neural correlates of cognitive control processes differ in adults with and without a behaviorally inhibited temperament during early childhood. Adults with and without childhood behavioral inhibition completed an emotional conflict task while undergoing functional magnetic resonance imaging scanning. While no group differences in behavior were observed, adults with childhood behavioral inhibition, relative to adults without childhood behavioral inhibition, exhibited greater dorsomedial prefrontal cortex activity during conflict detection and greater putamen activity during conflict adaptation. Lifetime psychopathology predicted behavioral, but not brain-related, differences in conflict adaptation. These data suggest that the brain regions underlying cognitive control processes are differentially influenced by childhood behavioral inhibition, and may be differently related to psychopathology. 相似文献