Visual object and face processing in mild-to-moderate Alzheimer's disease: from segmentation to imagination.
Visual object and face processing in mild-to-moderate Alzheimer's disease: from segmentation to imagination.
复制标题
轻度至中度阿尔茨海默病的视觉对象和面部处理：从分割到想象。
DOI：
10.1016/s0028-3932(02)00140-9
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发表时间：
2003
期刊：
影响因子：
2.6
通讯作者：
Farah,MarthaJ
中科院分区：
文献类型：
--
作者：
Tippett,LynetteJ;Blackwood,Kirsty;Farah,MarthaJ
阿尔茨海默病（AD）早期高级视觉感知和视觉心理意象的命运知之甚少。在这项研究中，我们评估了这些能力在一组轻度至中度AD患者使用的任务选择，以满足两个主要标准。首先，他们已经被证明对其他神经系统疾病引起的感知和图像损伤敏感。其次，他们以合理的选择性方式测试视觉感知和认知的特定阶段。这些阶段是（在感知过程中的正常发生顺序）：将视野的不同局部点分割成属于不同对象的区域;在图像中表示这些分割区域的形状;构建更抽象的形状表示，其在大小、位置、方向或照明的变化上具有恒定性。（分别评估面部和物体）;使用这些感知的形状表征来访问存储的形状表征;以及从这些高级视觉表征访问词汇语义表征。额外的任务测试了自上而下的激活早期的视觉表征从语义水平的视觉心理意象。我们的研究结果表明，小，但在大多数情况下可靠的，在视觉感知，这是独立的认知能力下降的程度损害。缺陷的基本形状加工影响性能的一些更高层次的视觉任务，但没有贡献的性能差的面孔处理，或深刻的赤字的对象命名。后者与语义词汇障碍有关。
Little is known about the fate of higher level visual perception and visual mental imagery in the early stages of Alzheimer’s disease (AD). In this study, we assessed these abilities in a group of mild-to-moderate AD patients using tasks selected to satisfy two main criteria. First, they have been shown to be sensitive to impairments of perception and imagery caused by other neurological conditions. Second, they test specific stages of visual perception and cognition in a reasonably selective manner. These stages were (in their normal order of occurrence during perception): the segmentation of different local points of the visual field into regions belonging to distinct objects; the representation of the shapes of these segmented regions in the image; the construction of more abstract shape representations that possess constancy over changes in size, location, orientation or illumination (assessed separately for faces and objects); the use of these perceived shape representations to access stored shape representations; and the access of lexical semantic representations from these high-level visual representations. Additional tasks tested the top–down activation of earlier visual representations from the semantic level in visual mental imagery. Our findings indicate small, but in most cases reliable, impairments in visual perception, which are independent of degree of cognitive decline. Deficits in basic shape processing influenced performance on some higher level visual tasks, but did not contribute to poor performance on face processing, or to the profound deficit on object naming. The latter of these is related to semantic-lexical impairment.