Boutsen Luc, Humphreys Glyn W
Behavioural Brain Sciences Centre, University of Birmingham, B15 2TT, Birmingham, UK.
Neuropsychologia. 2002;40(13):2305-13. doi: 10.1016/s0028-3932(02)00088-x.
We investigated the role of local and global information on perceptual encoding of faces in patient HJA, who shows prosopagnosia and visual agnosia following occipito-temporal damage. HJA and an age-matched control were tested in a simultaneous matching task which focused on detection of local changes in faces: the inversion of central parts (eyes and mouth) relative to their context (as in the Thatcher illusion). Same-different judgements were made to normal, "that cherised" and mixed type face pairs. Whole faces (Experiment 1), or face parts (Experiment 2), were presented in upright and inverted orientations. Compared to the control, HJA was severely impaired at matching whole faces, but he improved dramatically when face parts were presented in isolation. This suggests an inhibitory influence of face context on HJAs processing of local parts and a relatively intact ability to process part-based information from a face (when context cannot interfere). Face inversion did not affect HJAs performance. A control experiment (Experiment 3) with non-face stimuli (houses) suggested that the inhibitory influence of context on HJAs performance was restricted to faces. These results indicate that contextual information in a face can have an adverse influence on the processing of local part-based information in prosopagnosia.
我们研究了局部和全局信息在患者HJA面部感知编码中的作用，该患者在枕颞叶受损后表现出面孔失认症和视觉失认症。HJA和一名年龄匹配的对照者在一项同步匹配任务中接受测试，该任务聚焦于面部局部变化的检测：面部中央部分（眼睛和嘴巴）相对于其周围环境的倒置（如撒切尔错觉）。对正常、“那种典型的”和混合型面孔对进行相同-不同判断。呈现全脸（实验1）或面部部分（实验2），包括正立和倒置方向。与对照者相比，HJA在匹配全脸时严重受损，但当单独呈现面部部分时，他的表现有显著改善。这表明面部环境对HJA局部部分加工有抑制作用，且其处理基于面部部分信息的能力相对完好（当环境不产生干扰时）。面部倒置并未影响HJA的表现。一项使用非面部刺激（房屋）的对照实验（实验3）表明，环境对HJA表现的抑制作用仅限于面部。这些结果表明，面孔中的背景信息可能会对面孔失认症中基于局部部分的信息处理产生不利影响。
