健康与遗传心理学研究室知识库

轻度认知损伤(Mild Cognitive Impairment, MCI)老年人的记忆力比同龄人有显著衰退，但并没有达到痴呆程度。本研究从一记忆的编码和提取过程，以及情节记忆的内容和来源两个方面出发，通过三个实验探讨了轻度认知损伤老年人的情节一记忆损伤特点以及他们利用认知支持提高记忆成绩的能力。被试分为两组，年龄、性别、受教育年限和职业均匹配，MCI组31名(平均73.7岁)，正常对照(Normal Control, NC)组31名(平均74.0岁)。三个实验分别测查图像、数字和词组记忆。测查内容记忆时，要求被试对图像和数字进行自由回忆和再认，对词组进行自由回忆、线索回忆和再认。测查来源记忆时，被试在再认图像和数字的同时回忆学习时的呈现位置;再认词组时，测验一回忆学习时词组的颜色，测验二回忆学习时对词组进行的认知加工。字词编码条件有言语、想象和做动作，提取条件有自由回忆、线索回忆和再认。
本研究的主要结论如下:
    1 MCI组的图像、数字和字词记忆成绩都显著低于NC组，表现出普遍损伤，表明MCI老年人情节记忆的内容受损。
    2 MCI组只有在编码支持和提取支持都较强时，记忆成绩才能有较大的提高，其利用认知支持能力不如NC组老年人。
    3不同识记材料的来源记忆结果不一致。MCI组在图像和字词来源记忆测验中表现出损伤，而数字条件性来源记忆成绩和NC组成绩差异不显著。
    MCI老年人外部来源记忆和内容记忆损伤一致，而内部来源记忆损伤小于内容记忆损伤。

    Cognitive abilities of aged persons are range from normal, to mild impairment, to obvious dementia. The term mild cognitive impairment (MCI) refers to the state that memory is not normal but do not meet conventional criteria for dementia. Previous research demonstrates that MCI is specifically characterized by deficits of episodic memory.
    Current study is designed to explore the characters of item memory and source memory in the elderly with mild cognitive impairment. Thirty-one mild cognitive impairment elderly and thirty-one normal control elderly were selected as subjects with homogeneous age, sex, educational level and profession of the two groups. Three experiments examine picture, digit and words memory separately. For the item memory, subjects are asked to free recall and recognize pictures and digits and to free recall, cued recall and recognize words. As to the source memory tasks, subjects are asked to retrieve the position of the picture and digit when it was presented in learning. Subjects retrieved the color of the words in one task and retrieval the cognitive process (image/enact) in another task in two words source memory tasks. Words episodic memory tasks vary in terms of the level of cognitive support provided. Such variation may be seen with regard to the encoding conditions (words versus imaging versus action), and the retrieval conditions (free recall versus cued recall. Versus recognition).
    It was demonstrated by the study that,
    1 Memory deterioration of all three materials (picture, digit and words) are all significant for mild cognitive impairment subjects compared with normal subjects.
    2 When encoding support combined with retrieval support, normal control subjects showed stronger ability of benefit from cognitive support. Mild cognitive impairment subjects can improve their memory performance only through strong encoding together with strong retrieval supports.
    3 As for the source memory of subjects with mild cognitive impairment, different materials showed different results. There are significant deficits in source memory of picture and words but no difference in source memory of digit between mild cognitive impairment subjects and normal control subjects.
    Outer source memory is not as same as inner source memory, which is less sensitive to impairment than item memory of mild cognitive impairment elderly.