Bruce V, Burton M, Doyle T, Dench N
Percept Psychophys. 1989 Dec;46(6):528-36. doi: 10.3758/bf03208149.
Mark and Todd (1983) reported an experiment in which the cardioidal strain transformation was extended to three dimensions and applied to a three-dimensional (3-D) representation of the head of a 15-year-old girl in a direction that made the transformed head appear younger to the vast majority of their subjects. The experiments reported here extend this research in order to examine whether subjects are indeed detecting cardioidal strain in three dimensions, rather than detecting changes in head slant or making 2-D comparisons of the shape of the occluding contour. Three-dimensional surfaces were obtained by measuring a real head manually (Experiment 1) and with a laser scanner (Experiment 2), and transformed to different age levels using the 3-D strain transformation described by Mark and Todd (1983). There were no statistically significant differences in the accuracy with which relative age judgments could be made in response to pairs of profiles, pairs of 3/4 views, or pairs of mixed views (profile plus 3/4 view), suggesting that subjects can indeed extract the cardioidal strain level of the head in three dimensions. However, an additional effect that emerged in these studies was that judgments were crucially affected by the instructions given to subjects, which suggests that factors other than cardioidal strain are important in making judgments about rich data structures.
马克和托德（1983年）报告了一项实验，在该实验中，心脏形应变变换被扩展到三维，并应用于一名15岁女孩头部的三维（3-D）表示，其应用方向使变换后的头部在绝大多数受试者看来显得更年轻。此处报告的实验扩展了这项研究，以检验受试者是否确实在三维中检测到心脏形应变，而不是检测头部倾斜的变化或对遮挡轮廓的形状进行二维比较。通过手动测量真实头部（实验1）和使用激光扫描仪（实验2）获得三维表面，并使用马克和托德（1983年）描述的三维应变变换将其转换为不同的年龄水平。对于成对的侧面轮廓、成对的3/4视图或成对的混合视图（侧面轮廓加3/4视图）做出相对年龄判断的准确性，没有统计学上的显著差异，这表明受试者确实可以在三维中提取头部的心脏形应变水平。然而，这些研究中出现的另一个效应是，判断受到给予受试者的指示的关键影响，这表明除了心脏形应变之外，其他因素在对丰富的数据结构进行判断时也很重要。
