EVENT-RELATED POTENTIAL AND BEHAVIORAL-CORRELATES OF SEMANTIC PROCESSING IN ALZHEIMERS PATIENTS AND NORMAL CONTROLS
EVENT-RELATED POTENTIAL AND BEHAVIORAL-CORRELATES OF SEMANTIC PROCESSING IN ALZHEIMERS PATIENTS AND NORMAL CONTROLS
复制标题
DOI：
10.1006/brln.1995.1002
复制
发表时间：
1995-01-01
影响因子：
2.5
通讯作者：
ROSEN, J
中科院分区：
文献类型：
--
作者：
HAMBERGER, MJ;FRIEDMAN, D;ROSEN, J
在正常年轻人中，N400 幅度与单词被其先前语义上下文启动的程度成反比。根据一系列行为研究，疑似阿尔茨海默氏症患者 (PAD) 的语义记忆组织受到破坏，导致某一类别中的特定项目失去其区别，但上级信息仍然相对完整。本研究检验了在正常年轻人中发现的 N400 梯度是否也反映了 PAD 患者语义相关项目之间区分性的丧失。 10 名正常年轻人、10 名正常老年人和 6 名“轻度”PAD 患者对一系列高度受限的句子上下文的结尾词做出了快速（但准确）有义/无义的决定。终端词属于四种刺激类型之一，其随着与高度期望词的相关性而变化。与我们的预测相反，在年轻的正常组和 PAD 组中，N400 幅度对语义相关性的反应相同，但在正常老年人中的特征不同。鉴于 PAD 患者犯下的错误数量明显增多，我们得出的结论是，他们对语义处理的干扰
In normal young adults, N400 amplitude Varies inversely with the extent to which a word has been primed by its preceding semantic context. Based on a series of behavioral studies, it appears that in Probable Alzheimer's patients (PAD) the organization of semantic memory is disrupted such that specific items within a category lose their distinction, although superordinate information remains relatively intact. The present study examined whether the N400 gradient which has been found with normal young adults would also reflect this loss of discriminability among semantically related items in PAD patients. Ten normal young adults, 10 normal elderly, and 6 ''mild'' PAD patients made speeded (but accurate) sense/nonsense decisions to the terminal words of a series of highly constrained sentence contexts. The terminal words belonged to one of four stimulus types which varied as a function of relatedness to a highly expected word. Counter to our predictions, N400 amplitude was identically responsive to semantic relatedness in the young normal and PAD groups, but was characterized differently in the normal elderly. Given the significantly greater number of errors committed by PAD patients, we concluded that their disruption in semantic processing