Gaze-track representation in high-level visual cortex

当我们看一张脸时，我们会进行独特的眼球运动，导致凝视路径，这很容易与其他物体引起的凝视路径区分开来。众所周知，额叶区和顶叶区支持这种眼球运动的计划和执行。然而，我们最近发现，即使在没有脸或房子的情况下，脸和房子特定的凝视轨迹也可以在梭状回面部区（FFA）和海马体旁区（PPA）被解码。我们的结论是，动作（凝视）模式在高级视觉皮层中表现出来，表明了感知和动作密切互动的潜在神经基础。虽然我们认为我们已经提供了确凿的证据，证明在高级感知区域中复杂凝视模式的反直觉映射，但它们的性质和功能仍然存在许多问题。在本提案的第一个实验中，我们想要调查这个新发现的本质，特别是在什么时候关键信息在凝视轨迹中被表示，以及它是否被编码在序列中，或者更确切地说，是固定的位置。在第二个实验中，我们想了解在识别人脸时所引发的凝视轨迹是否分别在识别面部情绪表达时在不同的感知脑区被表征。最后，我们计划研究在面部观看过程中引发的微扫视是否以与FFA中的扫视相似的方式表示。

When we look at a face, we carry out distinctive eye movements leading to gaze paths that can easily be discriminated from the gaze paths elicited by other objects. It is well-known that frontal and parietal areas support the planning and execution of such eye movements. However, we recently showed that face and house-specific gaze tracks can be decoded in the fusiform face area (FFA) and the parahippocampal place area (PPA) - even in the absence of a face or house to look at. We concluded that action (gaze) patterns are represented in high-level visual cortex, demonstrating a potential neural basis for close interactions of perception and action. While we think we have presented solid evidence for this counterintuitive mapping of complex gaze patterns in high-level perceptual areas, many questions as to their nature and function remain. In the first experiment of the present proposal, we want to investigate the nature of this novel finding, specifically at what time the critical information is represented in a gaze track and if it is coded in the sequence or rather the location of fixations. In a second experiment, we want to learn if the gaze tracks elicited when identifying a face respectively identifying a facial emotion expression are represented in different perceptual brain areas. Finally, we plan to investigate if microsaccades elicited during face viewing are represented in a similar way as saccades in the FFA.