Development of the optimized approaches to functional magnetic resonance imaging studies(fMRI) in human occipito-temporal cortex

视觉功能磁共振成像（fMRI）实验通常采用梯度回波平面成像（GE-EPI），在枕颞后皮层产生强烈的反应，但在颞叶的下表面和前极有明显的信号丢失。本研究的目的是优化人类枕颞皮质的功能磁共振成像，在保持足够的功能灵敏度和成像速度的同时，最大限度地减少信号损失和失真。发展的多镜头自旋回波平面成像（SE-EPI）提供了不失真的功能图像，覆盖了枕颞皮质。当将SE-EPI应用于皮层视觉处理的研究时，在耳道周围区域检测到类别特异性反应的斑块，而GE-EPI几乎完全失去了信号，没有检测到任何反应。此外，最小的空间扭曲有助于功能和解剖结构的精确匹配。因此，研究结果应该有助于揭示面孔和物体在枕颞皮层中是如何被表征的完整图像。

Visual functional magnetic resonance imaging(fMRI) experiments are commonly conducted with gradient echo echo-planar imaging(GE-EPI), which yields strong responses in the posterior occipito-temporo cortex but suffers from prominent signal loss on the inferior surfaces and anterior poles of the temporal lobes. The aim of the present study was to optimize fMRI of the human occipito-temporal cortex by minimizing signal loss and distortions while maintaining sufficient functional sensitivity and imaging speed. The developed multi-shot spin echo echo-planar imaging(SE-EPI) provided undistorted functional images with a good coverage of the occipital-temporo cortex. When applied to the study of visual processing in the cortex, SE-EPI detected patches of category-specific responses in areas around the ear canal where GE-EPI, suffering form almost complete signal loss, detected no responses. Furthermore, the minimal spatial distortions facilitate precise matching of function and anatomy. The results should thus help reveal a complete image of how faces and objects are represented in the occipito-temporal cortex.