Short-term memory binding deficits in Alzheimers disease
Short-term memory binding deficits in Alzheimers disease
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DOI：
10.1093/brain/awp036
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发表时间：
2009-04-01
期刊：
影响因子：
14.5
通讯作者：
Della Sala, Sergio
中科院分区：
文献类型：
--
作者：
Parra, Mario A.;Abrahams, Sharon;Della Sala, Sergio
老年痴呆症损害相关事件的长期记忆（例如有名字的面孔），而不是单个事件（例如面孔或名字列表）。这种关联或结合缺陷是否也存在于短期记忆中，目前还没有研究。在两个实验中，我们研究了阿尔茨海默病的言语短期记忆的结合缺陷。实验一：23例老年性痴呆患者和23例年龄、文化程度相匹配的健康老年人。参与者研究了视觉阵列的对象（六个健康老年人和四个阿尔茨海默病患者），颜色（六个健康老年人和四个阿尔茨海默病患者），未绑定的对象和颜色（三个健康老年人和两个阿尔茨海默病患者在这两个类别中的每一个），或对象绑定颜色（三个健康老年人和两个阿尔茨海默病患者）。然后，他们被要求口头回忆这些项目。老年痴呆症患者的记忆与颜色绑定的对象显着不如单一或未绑定的功能，而健康的老年人的记忆绑定和未绑定的功能没有差异。实验二：21例阿尔茨海默病患者和20例健康老年人。健康老年组的记忆负荷增加到8个项目的条件下评估记忆的单一或未绑定的功能和4个项目的条件下评估记忆的这些功能的绑定。对于老年痴呆症患者来说，任务仍然是一样的。这种操作允许在评估单个或未绑定特征的记忆的条件下，将各组的表现等同起来。在阿尔茨海默病患者在回忆实验1中报告的绑定对象的损害被复制。结合成本大于在健康老年人组中观察到的结合成本，健康老年人组在结合和未结合特征方面的表现没有差异。老年痴呆症严重损害了负责在言语短期记忆中保持完整对象的机制。
Alzheimers disease impairs long term memories for related events (e.g. faces with names) more than for single events (e.g. list of faces or names). Whether or not this associative or binding deficit is also found in short-term memory has not yet been explored. In two experiments we investigated binding deficits in verbal short-term memory in Alzheimers disease. Experiment 1 : 23 patients with Alzheimers disease and 23 age and education matched healthy elderly were recruited. Participants studied visual arrays of objects (six for healthy elderly and four for Alzheimers disease patients), colours (six for healthy elderly and four for Alzheimers disease patients), unbound objects and colours (three for healthy elderly and two for Alzheimers disease patients in each of the two categories), or objects bound with colours (three for healthy elderly and two for Alzheimers disease patients). They were then asked to recall the items verbally. The memory of patients with Alzheimers disease for objects bound with colours was significantly worse than for single or unbound features whereas healthy elderlys memory for bound and unbound features did not differ. Experiment 2 : 21 Alzheimers disease patients and 20 matched healthy elderly were recruited. Memory load was increased for the healthy elderly group to eight items in the conditions assessing memory for single or unbound features and to four items in the condition assessing memory for the binding of these features. For Alzheimers disease patients the task remained the same. This manipulation permitted the performance to be equated across groups in the conditions assessing memory for single or unbound features. The impairment in Alzheimers disease patients in recalling bound objects reported in Experiment 1 was replicated. The binding cost was greater than that observed in the healthy elderly group, who did not differ in their performance for bound and unbound features. Alzheimers disease grossly impairs the mechanisms responsible for holding integrated objects in verbal short-term memory.