• 主题
高级搜索  >
历史搜索 清空历史
首页> 美国卫生研究院文献>other >Comparison of fMRI paradigms assessing visuospatial processing: Robustness and reproducibility
【2h】

Comparison of fMRI paradigms assessing visuospatial processing: Robustness and reproducibility

机译：功能磁共振成像范式评估视觉空间加工的比较：鲁棒性和可重复性

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务，本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文，但由于OA文献来源多样且变更频繁，仍可能出现获取不到、文献不完整或与标题不符等情况，如果获取不到我们将提供退款服务。请知悉。
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The development of brain imaging techniques, in particular functional magnetic resonance imaging (fMRI), made it possible to non-invasively study the hemispheric lateralization of cognitive brain functions in large cohorts. Comprehensive models of hemispheric lateralization are, however, still missing and should not only account for the hemispheric specialization of individual brain functions, but also for the interactions among different lateralized cognitive processes (e.g., language and visuospatial processing). This calls for robust and reliable paradigms to study hemispheric lateralization for various cognitive functions. While numerous reliable imaging paradigms have been developed for language, which represents the most prominent left-lateralized brain function, the reliability of imaging paradigms investigating typically right-lateralized brain functions, such as visuospatial processing, has received comparatively less attention. In the present study, we aimed to establish an fMRI paradigm that robustly and reliably identifies right-hemispheric activation evoked by visuospatial processing in individual subjects. In a first study, we therefore compared three frequently used paradigms for assessing visuospatial processing and evaluated their utility to robustly detect right-lateralized brain activity on a single-subject level. In a second study, we then assessed the test-retest reliability of the so-called Landmark task–the paradigm that yielded the most robust results in study 1. At the single-voxel level, we found poor reliability of the brain activation underlying visuospatial attention. This suggests that poor signal-to-noise ratios can become a limiting factor for test-retest reliability. This represents a common detriment of fMRI paradigms investigating visuospatial attention in general and therefore highlights the need for careful considerations of both the possibilities and limitations of the respective fMRI paradigm–in particular, when being interested in effects at the single-voxel level. Notably, however, when focusing on the reliability of measures of hemispheric lateralization (which was the main goal of study 2), we show that hemispheric dominance (quantified by the lateralization index, LI, with |LI| >0.4) of the evoked activation could be robustly determined in more than 62% and, if considering only two categories (i.e., left, right), in more than 93% of our subjects. Furthermore, the reliability of the lateralization strength (LI) was “fair” to “good”. In conclusion, our results suggest that the degree of right-hemispheric dominance during visuospatial processing can be reliably determined using the Landmark task, both at the group and single-subject level, while at the same time stressing the need for future refinements of experimental paradigms and more sophisticated fMRI data acquisition techniques.
机译：脑成像技术的发展，特别是功能磁共振成像（fMRI），使得非侵入性研究大型人群认知脑功能的半球偏侧化成为可能。但是，半球偏侧化的综合模型仍然不见了，不仅应考虑单个大脑功能的半球特化，而且还应解释不同的偏侧化认知过程（例如语言和视觉空间加工）之间的相互作用。这需要鲁棒而可靠的范例来研究各种认知功能的半球偏侧化。尽管已开发出多种语言的可靠成像范例，这些语言代表了最突出的左偏脑功能，但研究典型右偏脑功能（例如视觉空间处理）的成像范例的可靠性受到的关注相对较少。在本研究中，我们旨在建立一个功能强大的核磁共振成像范式，以可靠，可靠地识别单个对象中视觉空间处理引起的右半球激活。因此，在第一项研究中，我们比较了三种常用的评估视觉空间处理的范例，并评估了它们在单个对象水平上稳健地检测右偏脑活动的效用。在第二项研究中，我们然后评估了所谓的Landmark任务的重测可靠性，该模型在研究1中产生了最可靠的结果。在单体素水平上，我们发现视觉空间潜在的大脑激活可靠性较差注意。这表明不良的信噪比可能成为重测可靠性的限制因素。这代表了fMRI范式在一般情况下研究视觉空间注意力的普遍危害，因此强调了需要仔细考虑各个fMRI范式的可能性和局限性，尤其是在对单体素水平的效果感兴趣时。但是，值得注意的是，当关注半球偏侧化措施的可靠性（这是研究2的主要目标）时，我们表明诱发激活的半球优势度（由偏侧化指数LI量化，| LI |> 0.4）可以有力地确定超过62％的对象，如果仅考虑两个类别（即左，右），则可以超过93％的对象。此外，横向强度（LI）的可靠性从“中等”到“良好”。总之，我们的研究结果表明，可以使用Landmark任务在小组和单个对象级别上可靠地确定视觉空间处理过程中右半球的优势程度，同时强调未来对实验范式进行改进的必要性以及更复杂的fMRI数据采集技术。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号