Dissociable roles of the inferior longitudinal fasciculus and fornix in face and place perception.
Dissociable roles of the inferior longitudinal fasciculus and fornix in face and place perception.
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DOI：
10.7554/elife.07902
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发表时间：
2015-08-29
期刊：
影响因子：
7.7
通讯作者：
Graham KS
中科院分区：
文献类型：
--
作者：
Hodgetts CJ;Postans M;Shine JP;Jones DK;Lawrence AD;Graham KS
我们检验了一个新的假说，该假说产生于内侧颞叶(MTL)功能的代表性描述，即汇聚在周边皮质(PRC)和海马区(HC)的主要白质束将分别参与不同的面孔和场景知觉。扩散张量成像在健康受试者中应用，同时对动物和人类的PRC和HC病变敏感。下纵束(ILF，连接枕叶和前额叶，包括PRC)和穹隆(HC的主要输入/输出通路)的微结构分别与涉及面孔和场景的奇一出判断的准确性有关。同样，PRC和HC的血氧水平依赖(BOLD)反应在奇特判断中诱发，分别与面部和场景的奇特表现相关。我们还分别在PRC和HC观察到ILF和穹隆微结构与类别选择性BOLD反应之间的关联。这些惊人的三向关联突出了功能上可分离的、结构上实例化的MTL神经认知网络，用于复杂的面部和场景感知。DOI：http://dx.doi.org/10.7554/eLife.07902.001对物体或图片的感知刺激了组成视觉系统的大脑区域的活动。这些区域中的一些区域根据正在查看的内容做出不同的反应：例如，某些区域在查看人脸时更活跃，而其他区域在查看位置时响应更多。一种理论认为，类别敏感的大脑区域不是以一种独立的方式工作，而是更复杂的大脑网络中的元素或节点，专门处理不同类型的视觉刺激。大脑内部包含深色和浅色组织区域。较亮的区域被称为“白质”，含有允许信息在大脑不同部分之间传输的纤维。这些纤维可能在广泛分布的大脑区域的通信中发挥重要作用。为了研究这一点，霍奇茨、波斯斯等人。使用了一种名为扩散磁共振的技术来测量健康志愿者脑白质纤维的结构或连贯性。当志愿者完成一项任务时，他们也测量了大脑活动，在这项任务中，他们需要从面孔或位置的图像中辨认出奇怪的一。霍奇茨、波斯斯等人。研究了白质纤维束的精细结构，称为下纵束(ILF)。这种纤维连接了大脑中参与面部感知的两个部分，称为枕叶和前颞叶。引人注目的是，ILF结构预测了这些区域中与面孔相关的大脑活动，以及一个人辨别面孔的能力，但不能预测地点刺激。相比之下，志愿者区分不同地方(但不是脸)的能力与穹隆的结构有关。穹隆是一束白质纤维，将信息往返于海马体，海马体是一个重要的区域，对于一个人在环境中找到路并在之后记住这样的旅程是很重要的。S等人的发现表明，处理不同视觉类别的系统最好被认为是大规模的分布式网络，而不是大脑中一组单独的、专门的区域。未来，将需要研究来进一步了解白质如何对不同视觉类别的感知做出贡献，并更详细地调查视觉体验如何影响白质通路的结构。DOI：http://dx.doi.org/10.7554/eLife.07902.002
We tested a novel hypothesis, generated from representational accounts of medial temporal lobe (MTL) function, that the major white matter tracts converging on perirhinal cortex (PrC) and hippocampus (HC) would be differentially involved in face and scene perception, respectively. Diffusion tensor imaging was applied in healthy participants alongside an odd-one-out paradigm sensitive to PrC and HC lesions in animals and humans. Microstructure of inferior longitudinal fasciculus (ILF, connecting occipital and ventro-anterior temporal lobe, including PrC) and fornix (the main HC input/output pathway) correlated with accuracy on odd-one-out judgements involving faces and scenes, respectively. Similarly, blood oxygen level-dependent (BOLD) response in PrC and HC, elicited during oddity judgements, was correlated with face and scene oddity performance, respectively. We also observed associations between ILF and fornix microstructure and category-selective BOLD response in PrC and HC, respectively. These striking three-way associations highlight functionally dissociable, structurally instantiated MTL neurocognitive networks for complex face and scene perception. DOI: http://dx.doi.org/10.7554/eLife.07902.001 Perceiving an object or picture stimulates activity in the regions of the brain that make up the visual system. Some of these regions respond differently depending on what is being viewed: for example, some areas are more active when looking at faces, and others respond more when viewing places. One theory is that, rather than working in a self-contained fashion, category-sensitive brain regions are elements or ‘nodes’ within more complex brain networks that are specialised for processing different types of visual stimuli. The inside of the brain contains regions of dark and light tissue. The lighter regions are known as ‘white matter’ and contain fibres that allow information to travel between different parts of the brain. These fibers may play an important role in how widely distributed brain regions communicate. To investigate this, Hodgetts, Postans et al. used a technique called diffusion MRI to measure the structure, or coherence, of white matter fibers in healthy volunteers. Brain activity was also measured while volunteers completed a task in which they needed to spot the odd-one-out from images of either faces or places. Hodgetts, Postans et al. investigated the fine structure of a white matter fibre bundle known as the inferior longitudinal fasciculus (ILF). This fibre links two parts of the brain involved in face perception, called the occipital and anterior temporal lobes. Strikingly, ILF structure predicted both face-related brain activity in these regions and how well an individual could discriminate between faces, but not place stimuli. By contrast, the ability of volunteers to tell apart different places (but not faces) was related to the structure of the fornix. The fornix is a bundle of white matter fibres that carries information to and from the hippocampus, a region that is important for finding one's way around an environment and remembering such journeys afterwards. Hodgetts, Postans et al.'s findings suggest that the systems that process different visual categories are best thought of as large-scale distributed networks rather than a set of individual, specialised regions in the brain. In the future, research will be needed to further understand how white matter contributes to the perception of different visual categories, and to investigate in finer detail how visual experience influences the structure of white matter pathways. DOI: http://dx.doi.org/10.7554/eLife.07902.002