分类： 心理学 >> 发展心理学 提交时间： 2020-10-10
摘要： Building robust letter-to-sound correspondences is a prerequisite for reading, and such audiovisual integration becomes progressively automatic with development. However, the neural mechanisms underlying the development of audiovisual integration for reading are largely unknown. This study used functional magnetic resonance imaging (fMRI) in a lexical decision task to investigate the changes of brain functional networks that support audiovisual integration for reading between normally developing children (9-12 years old) and adults (20-28 years old). The identified networks were further examined in children with developmental dyslexia (9-12 years old). Results revealed that adults enhanced connectivity in a prefrontal-superior temporal network relative to children, reflecting the attentional modulation to the development of audiovisual integration. Moreover, this network was disrupted in dyslexics, confirming its essential role in audiovisual integration for reading. This study, for the first time, elucidates the neural basis underlying the development of audiovisual integration for reading.
分类： 心理学 >> 认知心理学 提交时间： 2020-06-17
摘要： This study aimed to examine the brain mechanisms underlying the distinctions between automatic and controlled handwriting. Functional magnetic resonance imaging data were collected while adult participants (n = 53) performed a copying task with varying speed control demands. Network analysis showed significant differences in functional connectivity within and between the frontoparietal network (FPN), the default mode network (DMN), the dorsal attention network (DAN), the somatomotor network (SMN) and the visual network (VN) between automatic and speed-controlled handwriting irrespective of written materials, which are thought to reflect general executive control and task-relevant visuomotor operations. However, there were no differences in brain activation between automatic and controlled handwriting. These results suggest that reconfiguration of functional network architecture, rather than regional activation, underlies the dissociations between automatic and controlled handwriting. Our findings shed new light on the neural mechanisms of handwriting mastery and handwriting impairments in individuals with neurological disorders.
分类： 心理学 >> 应用心理学 提交时间： 2017-11-06
Lei Gao
Lijun Bai
Yuchen Zhang
Xi-jian Dai
Rana Netra
Youjiang Min
Fuqing燴hou
Honghan Gong
Ming Zhang
Yijun Liu
摘要： Recent studies have indicated that sleep deprivation (SD) alters intrinsic low-frequency connectivity in the resting brain, mainly focusing on the default mode network (DMN) and its anticorrelated network (ACN). These networks hold key functions in segregating internally and externally directed awareness. However, far less attention has been paid to investigation of the altered amplitude of these low-frequency fluctuations (ALFF) at the whole-brain level and more importantly by what extent the sleep-deprived resting brain pattern can be reproducible and predict individual behavioral performance. The aim of this study was to characterize more clearly the influence of sleep on the whole brain level of ALFF changes and its relation with the performance of a lexical decision task in the sleep deprivation. Sixteen healthy participants underwent fMRI three times: once after a normal night of sleep in the rested wakefulness (RW) state and two following approximately 24 h of total SD separated by an interval of two weeks (SD1 and SD2). Our behavioral results showed that sleep stabilizes performance whereas two sleep deprivation even at an interval of two weeks consistently deteriorates it. Sleep deprivation attenuated the ALFF mainly in the bilateral orbitofrontal cortex (OFC), bilateral dorsolateral prefrontal cortex (DLPFC) and right inferior parietal lobule (IPL). By contrast, the enhanced ALFF emerged in the left sensorimotor cortex (SMA), visual cortex and left fusiform gyrus. Conjunction analysis of SD1 and SD2 versus the control maps and voxel-wise ICC analysis revealed that these SD induced ALFF changes showed a significantly high reliability (ICC＞0.5). Particularly, the attenuation of the right IPL presents a significant negative relation with the behavior performance and can be reproducible for two SD at an interval of two weeks. Our results suggest that ALFF is a stable measure in study of SD, and the right IPL may represent a stable biomarker that responds to sleep loss.
分类： 心理学 >> 应用心理学 提交时间： 2017-11-06
摘要： Brain imaging efforts are being increasingly devoted to decode the functioning of the human brain. Among neuroimaging techniques, resting-state fMRI (R-fMRI) is currently expanding exponentially. Beyond the general neuroimaging analysis packages (e.g., SPM, AFNI and FSL), REST and DPARSF were developed to meet the increasing need of user-friendly toolboxes for R-fMRI data processing. To address recently identified methodological challenges of R-fMRI, we introduce the newly developed toolbox, DPABI, which was evolved from REST and DPARSF. DPABI incorporates recent research advances on head motion control and measurement standardization, thus allowing users to evaluate results using stringent control strategies. DPABI also emphasizes test-retest reliability and quality control of data processing. Furthermore, DPABI provides a user-friendly pipeline analysis toolkit for rat/monkey R-fMRI data analysis to reflect the rapid advances in animal imaging. In addition, DPABI includes preprocessing modules for task-based fMRI, voxel-based morphometry analysis, statistical analysis and results viewing. DPABI is designed to make data analysis require fewer manual operations, be less time-consuming, have a lower skill requirement, a smaller risk of inadvertent mistakes, and be more comparable across studies. We anticipate this open-source toolbox will assist novices and expert users alike and continue to support advancing R-fMRI methodology and its application to clinical translational studies.
分类： 心理学 >> 实验心理学 提交时间： 2017-11-06
摘要： Sharing drafts of scientific manuscripts on preprint hosting services for early exposure and pre-publication feedback is a well-accepted practice in fields such as physics, astronomy, or mathematics. The field of neuroscience, however, has yet to adopt the preprint model. A reason for this reluctance might partly be the lack of central preprint services for the field of neuroscience. To address this issue, we announce the launch of Preprints of the R-fMRI Network (PRN), a community funded preprint hosting service. PRN provides free-submission and free hosting of manuscripts for resting state functional magnetic resonance imaging (R-fMRI) and neuroscience related studies. Submissions will be peer viewed and receive feedback from readers and a panel of invited consultants of the R-fMRI Network. All manuscripts and feedback will be freely available online with citable permanent URL for open-access. The goal of PRN is to supplement the “peer reviewed” journal publication system – by more rapidly communicating the latest research achievements throughout the world. We hope PRN will help the field to embrace the preprint model and thus further accelerate R-fMRI and neuroscience related studies, eventually enhancing human mental health.
分类： 心理学 >> 发展心理学 提交时间： 2023-03-28 合作期刊: 《心理科学进展》
摘要： 在现实生活中, 有效的情绪识别往往依赖于不同通道间的信息整合(如, 面孔、声音)。本文梳理相关研究认为, 面孔表情和声音情绪信息在早期知觉阶段即产生交互作用, 且初级感知觉皮层负责两者信息的编码; 而在晚期决策阶段, 杏仁核、颞叶等高级脑区完成对情绪信息内容的认知评估整合; 此外, 神经振荡活动在多个频段上的功能耦合促进了跨通道情绪信息整合。未来研究需要进一步探究两者整合是否与情绪冲突有关, 以及不一致的情绪信息在整合中是否有优势, 探明不同频段的神经振荡如何促进面孔表情和声音情绪信息整合, 以便更深入地了解面孔表情和声音情绪信息整合的神经动力学基础。
分类： 心理学 >> 实验心理学 提交时间： 2017-11-06
摘要： Various resting-state fMRI (R-fMRI) measures have been developed to characterize intrinsic brain activity. While each of these measures has gained a growing presence in the literature, questions remain regarding the common and unique aspects these indices capture. The present work provided a comprehensive examination of inter-individual variation and intra-individual temporal variation for commonly used measures, including fractional amplitude of low frequency fluctuations, regional homogeneity, voxel-mirrored homotopic connectivity, network centrality and global signal correlation. Regardless of whether examining intra-individual or inter-individual variation, we found that these definitionally distinct R-fMRI indices tend to exhibit a relatively high degree of covariation. When taken as a measure of intrinsic brain function, inter-individual differences in concordance for R-fMRI indices appeared to be stable, and negatively related to age (i.e., functional concordance among indices decreases with age). To understand the functional significance of concordance, we noted that higher concordance was generally associated with higher strengths of R-fMRI indices, regardless of whether looking through the lens of inter-individual (i.e., high vs. low concordance participants) or intra-individual (i.e., high vs. low concordance states identified via temporal dynamic analyses) differences. Finally, temporal dynamics analyses also revealed that high concordance states are characterized by increased within- and between-network functional connectivity, suggesting more general variations in network integration and segregation. The current study draws attention to questions regarding how to select an R-fMRI index for usage in a given study, as well as how to compare findings across studies that examine inter-individual or group differences using different indices. Additionally, our work suggests global neural signals exist in the brain, and their spontaneous variations over time result in fluctuations in the connectedness of brain regions.
分类： 生物学 >> 生物物理学 提交时间： 2016-05-05
Deng, Xiaofeng
Xu, Long
Zhang, Yan
Wang, Shuo
Zhao, Yuanli
Cao, Yong
Zhang, Dong
Wang, Rong
Ye, Xun
Wu, Jun
Zhao, Jizong
Deng, Xiaofeng
Xu, Long
Zhang, Yan
Wang, Shuo
Zhao, Yuanli
Cao, Yong
Zhang, Dong
Wang, Rong
Ye, Xun
摘要： The authors attempted to demonstrate the difference in language cortex reorganization between cerebral malformations (AVMs), cavernous malformations (CMs), and gliomas by blood oxygen level-dependent (BOLD) functional magnetic resonance imaging. Clinical and imaging data of 27 AVM patients (AVM-L group), 29 CM patients (CM-L group), and 20 glioma patients (Glioma-L group) were retrospectively reviewed, with lesions overlying the left inferior frontal gyrus (Broca area). As a control, patients with lesions involving the right inferior frontal gyrus were also enrolled, including 14 AVM patients (AVM-R group), 20 CM patients (CM-R group), and 14 glioma patients (Glioma-R group). All patients were right-handed. Lateralization indices (LI) of BOLD signal activations were calculated separately for Broca and Wernicke areas. In AVM-L group, right-sided lateralization of BOLD signals was observed in 10 patients (37.0 %), including 6 in the Broca area alone, 1 in the Wernicke area alone, and 3 in both areas. Three patients (10.3 %) of CM-L group showed right-sided lateralization in both Broca and Wernicke areas, and 1 patient (5.0 %) of Glioma-L group had right-sided lateralization in the Wernicke area alone. A significant difference of right-sided lateralization was observed between the AVM-L group and CM-L group (P = 0.018) and also between the AVM-L group and Glioma-L group (P = 0.027). No patient in AVM-R, CM-R, or Glioma-R groups showed right-sided lateralization. Language cortex reorganization may occur in AVM, CM, and glioma patients when the traditional language cortex was involved by lesions, but the potential of reorganization for CM and glioma patients seems to be insufficient compared with AVM patients.
分类： 心理学 >> 社会心理学 提交时间： 2023-03-28 合作期刊: 《心理科学进展》
摘要： 本研究筛选了11项采用功能性磁共振成像技术探究言语自闭症人群词义加工的研究, 探讨了该人群与典型人群脑激活模式的差异是否具有跨研究的稳定性。结果表明, 差异的脑激活模式稳定存在, 且表现为主要涉及左额上回的典型脑区激活不足。该结果为言语ASD人群语言加工的神经机制提供了来自词义加工的跨研究激活证据, 在明确“减弱的额叶激活”这一稳定差异表现的基础上, 强调了针对不同语言加工任务开展元分析研究的必要性。
分类： 生物学 >> 生物物理学 提交时间： 2016-05-12
摘要： What is a number? The number sense hypothesis suggests that numerosity is "a primary visual property" like color, contrast, or orientation. However, exactly what attribute of a stimulus is the primary visual property and determines numbers in the number sense? To verify the invariant nature of numerosity perception, we manipulated the numbers of items connected/enclosed in arbitrary and irregular forms while controlling for low-level features (e.g., orientation, color, and size). Subjects performed discrimination, estimation, and equality judgment tasks in a wide range of presentation durations and across small and large numbers. Results consistently show that connecting/enclosing items led to robust numerosity underestimation, with the extent of underestimation increasing monotonically with the number of connected/enclosed items. In contrast, grouping based on color similarity had no effect on numerosity judgment. We propose that numbers or the primitive units counted in numerosity perception are influenced by topological invariants, such as connectivity and the inside/outside relationship. Beyond the behavioral measures, neural tuning curves to numerosity in the intraparietal sulcus were obtained using functional MRI adaptation, and the tuning curves showed that numbers represented in the intraparietal sulcus were strongly influenced by topology.
分类： 心理学 >> 认知心理学 提交时间： 2023-09-13
摘要： 第三方惩罚(third-party punishment, TPP)指个体作为第三方或者观察者为维护社会规范对违规者所实施的惩罚行为。大量研究为揭示TPP行为的神经机制提供了启示，但鲜有研究关注不同功能性脑网络在其中发挥的整体作用。本文综述了近十年来TPP相关的研究，对相关理论模型和脑网络进行总结，并在此基础上提出TPP的认知神经网络模型，系统地对TPP行为背后的神经机制进行解释和整合。在该模型中，情绪系统和奖赏系统是TPP的动力来源，认知系统主要负责责任评估以及惩罚的选择；奖赏网络、突显网络、默认模式网络和中央执行网络分别参与不同认知加工阶段。该模型建立了TPP相关研究在心理层面和认知神经层面上的联系，对TPP行为的发生和发展机制进行了更加整体、全面的解释。未来可以引入元分析或基于机器学习的分析方法，在不同的背景信息和更加复杂的社交情境下探讨第三方干预偏好以及背后的认知神经机制。
分类： 心理学 >> 社会心理学 提交时间： 2023-03-28 合作期刊: 《心理科学进展》
摘要： 自我面孔识别反映了个体通过自我与他人的区分识别出自我面孔的过程。本文采用ALE元分析的方法, 对自我面孔识别的fMRI研究进行系统的定量分析, 探究自我面孔识别的神经基础。结果显示, 自我面孔识别的关键脑区包括顶上小叶、额中回、额下回、脑岛、梭状回、楔前叶和枕叶皮层。另外, 自我面孔识别可能包括两个层面的加工过程：知觉层面的加工整合过程以及由知觉引发的评价和情绪反应过程。知觉加工整合涵盖了自我面孔识别的各个加工阶段, 主要涉及枕叶、梭状回和楔前叶的功能; 而评价加工及情绪反应过程则发生在自我面孔识别的中晚期, 主要涉及顶上小叶、额中回、额下回及脑岛的功能。未来研究可结合时间和空间数据并关注脑区间的协同功能, 考察与内感受的神经关联, 开展临床研究并探索威胁信息的影响机制。
分类： 心理学 >> 认知心理学 提交时间： 2021-05-24
摘要： 自我面孔识别反映了个体通过自我与他人的区分识别出自我面孔的过程。本文采用ALE元分析的方法，对自我面孔识别的fMRI研究进行系统的定量分析，探究自我面孔识别的神经基础。结果显示，自我面孔识别的关键脑区包括顶上小叶、额中回、额下回、脑岛、梭状回、楔前叶和枕叶皮层。另外，自我面孔识别可能包括两个层面的加工过程：知觉层面的加工整合过程以及由知觉引发的评价和情绪反应过程。知觉加工整合涵盖了自我面孔识别的各个加工阶段，主要涉及枕叶、梭状回和楔前叶的功能；而评价加工及情绪反应过程则发生在自我面孔识别的中晚期，主要涉及顶上小叶、额中回、额下回及脑岛的功能。未来研究可结合时间和空间数据并关注脑区间的协同功能，考察与内感受的神经关联，开展临床研究并探索威胁信息的影响机制。
分类： 心理学 >> 社会心理学 提交时间： 2023-03-28 合作期刊: 《心理科学进展》
摘要： 基本情绪理论(basic emotion theory)是情绪科学领域最具代表性的理论, 该理论认为人类情绪是由有限的几种基本情绪组成的, 如恐惧、愤怒、喜悦、悲伤等。基本情绪是为了完成基本生命任务(fundamental life task)进化而来的, 每一种基本情绪都有独特的神经结构和生理基础。尽管基本情绪理论被广泛接受, 但是对于基本情绪的种类却莫衷一是。近几十年来, 许多fMRI研究试图确定各种基本情绪的独特神经结构基础, 而且取得了许多重要发现, 比如厌恶和脑岛有关, 悲伤和前扣带回有关, 杏仁核是与恐惧有关的重要边缘结构等。但是, 最近有人进行了元分析研究, 发现许多基本情绪存在混淆的大脑区域, 因此对基本情绪的特定脑区理论提出质疑, 甚至否定基本情绪理论。通过对基本情绪及其神经基础的探讨, 以及对基本情绪理论的最新功能性磁共振成像研究进行梳理分析, 提出有关基本情绪理论的争论来源于基本情绪种类的确定, 因为许多所谓的不同基本情绪实际上是同一种基本情绪, 提出人类可能只有3种基本情绪。未来研究可以利用机器视觉技术进一步推动基本情绪脑影像研究。
分类： 生物学 >> 生物物理学 提交时间： 2016-05-05
Wei, Zhengde
Yang, Nannan
Yang, Lizhuang
Wang, Ying
Han, Long
Zha, Rujing
Huang, Ruiqi
Zhou, Yifeng
Liu, Ying
Zhang, Peng
Zhang, Xiaochu
Zhang, Xiaochu
Zhang, Xiaochu
摘要： Nicotine addiction is associated with risky behaviors and abnormalities in local brain areas related to risky decision-making such as the dorsal anterior cingulate cortex (dACC), anterior insula (AI), and thalamus. Although these brain abnormalities are anatomically separated, they may in fact belong to one neural network. However, it is unclear whether circuit-level abnormalities lead to risky decision-making in smokers. In the current study, we used task-based functional magnetic resonance imaging (fMRI) and examined resting-state functional connectivity (RSFC) to study how connectivity between the dACC, insula, and thalamus influence risky decision-making in nicotine addicts. We found that an increase in risky decision-making was associated with stronger nicotine dependence and stronger RSFC of the dACC-rAI (right AI), the dACC-thalamus, the dACC-lAI (left AI), and the rAI-lAI, but that risky decision-making was not associated with risk level-related activation. Furthermore, the severity of nicotine dependence positively correlated with RSFC of the dACC-thalamus but was not associated with risk level-related activation. Importantly, the dACC-thalamus coupling fully mediated the effect of nicotine-dependent severity on risky decision-making. These results suggest that circuit-level connectivity may be a critical neural link between risky decision-making and severity of nicotine dependence in smokers.
分类： 生物学 >> 生物物理学 提交时间： 2016-05-15
Zhang, Shaodan
Zhang, Chun
Zhang, Shaodan
Wang, Bo
Zhu, SenHua
Xie, Yuan
Qing, Guoping
Wang, Ningli
Thomas, Ravi
Thomas, Ravi
摘要： PURPOSE. To assess the cortical structure and cerebral blood flow changes in the brain of patients with primary open-angle glaucoma (POAG). METHODS. High-resolution anatomical magnetic resonance imaging (MRI) and arterial spin labeling (ASL)-MRI were performed in 23 POAG patients and 29 controls. Patients were further divided into early-moderate and advanced groups based on mean deviation (MD) cutoff of 12 dB. A baseline scan was obtained and repeated during visual stimulation to the central preserved visual field in the more affected eye of POAG patients and a randomly selected eye of controls. Gray matter volume (GMV) and cerebral blood flow (CBF) throughout the whole brain were compared between patients and controls. RESULTS. Compared to controls, a region with significant reduction of GMV was detected in the anterior calcarine fissure of advanced POAG patients (P < 0.001, voxels = 503, 1698 mm3). Patients with early-moderate POAG had resting CBF similar to that of controls. However, a region with marked CBF decrease was detected in the anterior calcarine fissure of advanced POAG patients (P < 0.001, voxels = 1687, 13,496 mm(3)). The region with CBF reduction in advanced POAG showed good colocalization with the region with GMV decrease in this group. Following visual stimulation, patients with advanced POAG showed significantly lower increase in CBF in the occipital lobes (P < 0.001, voxels = 112, 896 mm(3)) as compared to controls (P < 0.001, voxels = 1880, 15,040 mm(3)) and early-moderate POAG (P < 0.001, voxels = 2233, 17,864 mm(3)). CONCLUSIONS. Primary open-angle glaucoma patients demonstrate a disease severity-dependent retinotopic pattern of cortical atrophy and CBF abnormalities in the visual cortex. Cerebral blood flow may be a potential biomarker for the brain involvement in glaucoma.
分类： 生物学 >> 生物物理学 提交时间： 2016-05-12
摘要： The neural correlates of associative memory in healthy older adults were investigated by examining the correlation of associative memory performance with spontaneous brain oscillations. Eighty healthy older adults underwent a resting-state functional MRI and took a paired-associative learning test (PALT). Correlations between the amplitude of low-frequency fluctuations (ALFF) as well as fractional ALFF (fALFF) in the whole brain and PALT scores were calculated. We found that spontaneous activity as indexed by both ALFF and fALFF in the parahippocampal gyrus (PHG) was significantly positively correlated with associative memory performance, suggesting that the PHG plays a critical role in associative memory in older people.
分类： 心理学 >> 应用心理学 提交时间： 2017-11-06
摘要： Although爈inear trend removing has often been implemented as a routine preprocessing step in resting-state functional magnetic resonance imaging (RS-fMRI) data analysis, the爏patial distribution爋f the magnitude of linear trend is still unclear. Further, it is interesting whether there will be any difference of the linear trend magnitude between different resting-states. For the first aim, we analyzed 5 RS-fMRI datasets from 5 different scanners (namely Beijing-Simens-3T, Cambridge-Siemens-3T, CCBD-GE750-3T, Milwaukee-GE-3T, and Oulu-GE-1.5T). One-sample t-tests on the regression coefficient (i.e., the magnitude of linear trend) were performed for each datasets. For the second aim, we used 2 datasets in each of which different states were compared, one containing eyes-open resting-state (EO-RS) vs. eyes-closed resting-state (EC-RS) and the other containing two steady-state tasks, i.e.,爎eal-time finger force feedback�RT-FFF) and sham finger force feedback (S-FFF) tasks. Paired t-tests were performed between EO-RS and EC-RS, and between RT-FFF and S-FFF. One-sample t-tests showed that the spatial pattern of linear trend of RS-fMRI time series were quite different between different manufactures. The 3T SIEMENS scanners showed positive linear trend in almost all part of the brain, while GE scanners showed primarily negative linear trend in most part of the brain. Paired t-tests showed some differences between paired conditions; differences between EO-RS and EC-RS were mainly in cuneus and eyeballs, and differences between RT-FFF and S-FFF were found in the thalamus, anterior cingulate gyrus, and right sensorimotor cortex. The current study indicated that, while the manufacturer-dependent linear trend of RS-fMRI time series were mostly scanner-related noise, the linear trend may also be physiological noise (eyeballs) or even physiologically meaningful, especially during steady-state tasks.
分类： 生物学 >> 生物物理学 提交时间： 2016-05-12
Rao, Jia-Sheng
Zhao, Can
Liu, Zuxiang
Yang, Zhao-Yang
Li, Xiao-Guang
Ma, Manxiu
Liu, Zuxiang
Yang, Zhao-Yang
Li, Xiao-Guang
摘要： Purpose: To investigate the longitudinal brain regional homogeneity (ReHo) changes in nonhuman primate after spinal cord injury (SCI) by resting-state functional magnetic resonance imaging (fMRI). Methods: Three adult female rhesus monkeys underwent unilateral thoracic cord injury. A resting-state fMRI examination was performed in the healthy stage and 4, 8, and 12 weeks after the injury. The ReHo value of each voxel in the monkey brain was calculated and compared between pre- and post-SCI monkeys with paired t test. The regions of interest (ROIs) in the significantly changed ReHo regions were set. The correlations between the ReHo change and the time after injury were also determined. Results: Compared with those in healthy period, the ReHo values of the left premotor cortex and the anterior cingulate cortex (ACC) in post-SCI rhesus monkeys significantly increased in 4-week follow-up examinations. The ReHo values of posterior cingulate cortex, left precuneus, left temporal parietooccipital area, and bilateral superior parietal lobules decreased at 8-week follow-up examinations. In 12-week follow-up examinations, the ReHo values of the left postcentral gyrus, right caudate nucleus, and superior temporal gyrus increased. Correlation analysis showed positive correlations between left ACC and the postoperative time. Conclusion: SCI can change the regional synchronism of brain activity in sensorimotor system and the default mode network. These findings may help us to understand the potential pathophysiological changes in the central nervous system after SCI. (C) 2015 Elsevier Inc. All rights reserved.
分类： 生物学 >> 生物物理学 >> 神经科学 提交时间： 2016-05-11
Zou, Qihong
Gao, Jia-Hong
Miao, Xinyuan
Liu, Dapeng
Zhuo, Yan
Wang, Danny J. J.
Gao, Jia-Hong
Gao, Jia-Hong
摘要： Blood oxygenation level dependent (BOLD) and arterial spin labeling (ASL) are two predominant resting-state fMRI techniques in mapping spontaneous brain activities. At single voxel level, cerebral blood flow (CBF) measured by ASL and amplitude of low frequency fluctuations (ALFF) of BOLD have been recognized as useful indices to characterize brain function in health and disease. However, no study has directly compared the test-retest reliability between BOLD and CBF contrasts on the same group of subjects at single voxel level. Moreover, both eyes-open and eyes-closed conditions have been employed as resting states, but it is still not clear which state is more reliable. Here we collected BOLD and ASL data during eyes-open and eyes-closed states across three scanning visits on twenty-two healthy young subjects. CBF-mean, BOLD-and CBF-ALFF were computed to characterize corresponding brain activities at single voxel level. Seed-based functional connectivity (FC) with the posterior cingulate cortex (PCC) was further calculated for both BOLD and CBF data. Intra-class correlation was used as the index of long-term reliability between visits 1 and 2 (two months apart) and short-term reliability between visits 2 and 3 (on the same day). Both short-and long-term reliabilities for CBF-mean and BOLD-ALFF were high, but were lower for CBF-ALFF, BOLD-and CBF-FC in both eyes-open and eyes-closed states. Direct comparisons showed that brain regions with the highest reliability of CBF-mean were mainly in the gray matter. The reliability of CBF-ALFF and BOLD-FC was lower than that of BOLD-ALFF, and the reliability of CBF-FC was lower than those of both CBF-ALFF and BOLD-FC. Furthermore, we observed that reliabilities of the eyes-open state were higher than those of the eyes-closed state for both imaging contrasts, though the effect size was small. Voxel-wise comparisons demonstrated that the long-term reliability of BOLD-ALFF was significantly higher with eyes open in the visual system, and both the short-and long-term reliability of BOLD-FC was slightly higher with eyes open in the default mode network. Moreover, we showed that denoising decreased the reliability of both ALFF and FC of both BOLD and ASL contrasts. In conclusion, our results indicated that CBF-mean and BOLD-ALFF could both be used as reliable indices for characterizing resting-state brain activities at single voxel level and recommended the eyes-open state for resting-state studies, especially for those targeting the visual system and default mode network. (C) 2015 Elsevier Inc. All rights reserved.
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