Mechanisms of hemispheric lateralization: How do left- and right-hemispheric regions of the core system of face perception differ functionally?

半球偏侧化的机制：面部感知核心系统的左半球和右半球区域在功能上有何不同？

• 批准号: 401160617
• 负责人: Professor Dr. Andreas Jansen
• 金额: --
• 依托单位: Klinik für Psychiatrie und Psychotherapie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/401160617?language=en
• 关键词: Mechanisms; hemispheric; lateralization; How; do

Face perception relies on computations carried out in face-selective cortical areas. These areas have been intensively studied for two decades. This work has been guided by an influential neural model suggested by Haxby and colleagues in 2000 (“Haxby-model”). This model proposes that face perception is mediated by a distributed, typically right-lateralized neural network. The network is divided into a “core system” and an “extended system”. The core system is comprised of brain regions in the occipitotemporal cortex: the fusiform face area (FFA), the occipital face area (OFA), and the posterior superior temporal sulcus (pSTS). The extended system is comprised of regions that are not specifically dedicated face processing, but are associated with the extraction of additional information from faces, e.g., emotions, biographical information, attractiveness. Despite its indisputable ability to describe important aspects of face processing on the neural systems level, the Haxby-model has a fundamental limitation. Its focus is on the posterior-anterior hierarchy of the face-processing network and neglects aspects of functional lateralization. Apart from the early visual areas (V1 and V2) that have identical functions (but for the left and right halves of the visual field, respectively), it is unlikely that also the neural face processing mechanisms are the same in the left and right hemisphere. In particular in terms of neural resource usage, such duplicated processing would seem puzzling. Also the coupling between core and extended system is likely to be different for the left and right hemisphere.In the present project, we aim to further investigate how the left- and right-hemispheric homologues of the core system of face perceptions differ with regard to their functional roles. For that, we will apply two approaches. In a first approach, we will use network models to test the hypothesis that the right hemisphere is more specialized to process a holistic representation of the face, whereas the left hemisphere relies more on a feature-detection strategy. We expect that the interhemispheric transfer between left and right OFA and/or left and right FFA is associated with the face processing style. The transfer from the left to the right hemisphere is, for instance, hypothesized to be increased when a holistic processing strategy is demanded (e.g., by task instructions) and face stimuli are presented in the right visual hemifield (work package 1). In a second approach, we will investigate how left- and right-hemispheric brain areas of the core system of face processing are coupled to the extended system. We aim to clarify whether the coupling patterns of both hemispheres are similar or not (work packages 2 and 3).

面部感知依赖于面部选择性皮层区域进行的计算。这些领域已经被深入研究了二十年。这项工作受到Haxby及其同事在2000年提出的一个有影响力的神经模型（“Haxby模型”）的指导。该模型提出面部感知是由分布式的、通常是右侧化的神经网络介导的。网络分为“核心系统”和“扩展系统”。核心系统由枕颞皮层的脑区组成：梭状面区（FFA）、枕面区（OFA）和后上级颞沟（pSTS）。该扩展系统由不是专门用于面部处理的区域组成，但是与从面部提取附加信息相关联，例如，情感，传记信息，吸引力尽管其无可争议的能力来描述重要方面的人脸处理的神经系统的水平，哈克斯比模型有一个根本的限制。它的重点是在后-前层次的面孔处理网络和忽视方面的功能偏侧化。除了早期视觉区域（V1和V2）具有相同的功能（但分别针对视野的左半部分和右半部分）之外，神经面部处理机制在左半球和右半球中也不太可能相同。特别是在神经资源使用方面，这种重复处理似乎令人费解。此外，核心和扩展系统之间的耦合可能是不同的左，右半球在本项目中，我们的目标是进一步研究如何左，右半球的同源核心系统的面孔知觉不同方面的功能作用。为此，我们将采用两种方法。在第一种方法中，我们将使用网络模型来测试假设，即右半球更专门处理面部的整体表征，而左半球更多地依赖于特征检测策略。我们认为左右OFA和/或左右FFA之间的半球间传递与面孔加工方式有关。例如，当需要整体处理策略时，从左半球到右半球的转移被假设为增加（例如，通过任务指令），并且面部刺激呈现在右视半视野（工作包1）中。在第二种方法中，我们将研究如何左，右半球的核心系统的大脑区域的面部处理耦合到扩展系统。我们的目标是澄清两个半球的耦合模式是否相似（工作包2和3）。