iMap: a novel method for statistical fixation mapping of eye movement data
iMap: a novel method for statistical fixation mapping of eye movement data
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DOI：
10.3758/s13428-011-0092-x
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发表时间：
2011-09-01
影响因子：
5.4
通讯作者：
Miellet, Sebastien
中科院分区：
文献类型：
--
作者：
Caldara, Roberto;Miellet, Sebastien
眼动数据分析通常基于给定感兴趣区域 (ROI) 中眼跳和注视（及其特征）发生的概率。在本文中，我们介绍了一种计算眼球运动统计注视图的替代方法 - iMap，其灵感来自于功能性磁共振成像方法。重要的是，iMap 不需要先将实验图像分割成 ROI。使用 iMap，首先通过卷积高斯核来平滑注视数据，以生成三维注视图。该过程体现了眼动仪的准确性，但高斯核也可以灵活设置来表示敏锐度或注意力约束。此外，iMap 生成的平滑注视数据符合鲁棒统计随机场理论 (RFT) 方法的假设，此后应用该方法来评估三维注视地图上的显着注视点和差异。 RFT 校正由构成数字图像的大量像素生成的多重统计比较。为了说明 iMap 的处理步骤，我们提供了来自面部、视觉场景和记忆处理的真实眼动数据的示例分析。 iMap MATLAB 工具箱可编辑并可免费在线下载 (www.unifr.ch/psycho/ibmlab/)。
Eye movement data analyses are commonly based on the probability of occurrence of saccades and fixations (and their characteristics) in given regions of interest (ROIs). In this article, we introduce an alternative method for computing statistical fixation maps of eye movements-iMap-based on an approach inspired by methods used in functional magnetic resonance imaging. Importantly, iMap does not require the a priori segmentation of the experimental images into ROIs. With iMap, fixation data are first smoothed by convolving Gaussian kernels to generate three-dimensional fixation maps. This procedure embodies eyetracker accuracy, but the Gaussian kernel can also be flexibly set to represent acuity or attentional constraints. In addition, the smoothed fixation data generated by iMap conform to the assumptions of the robust statistical random field theory (RFT) approach, which is applied thereafter to assess significant fixation spots and differences across the three-dimensional fixation maps. The RFT corrects for the multiple statistical comparisons generated by the numerous pixels constituting the digital images. To illustrate the processing steps of iMap, we provide sample analyses of real eye movement data from face, visual scene, and memory processing. The iMap MATLAB toolbox is editable and freely available for download online (www.unifr.ch/psycho/ibmlab/).