Objective. Alzheimer’s disease (AD) is characterized by a slow progressive impairment of episodic memory. Many studies have shown that AD exhibits deterioration of semantic memory during the course of disease progression. We previously reported that AD patients exhibited severe access disorders in the semantic memory system, using the Momentary Presentation Task (20 or 300 ms). In this study, we studied access disorder in patients with AD by the use of object difference (pictures vs words) methods. Methods. 56 patients with probable AD (NINCDS-ADRDA, mean age 79.0 years) and 11 healthy controls (HC) (mean age 67.0 years) were studied. Ten pictures and 10 corresponding Japanese Hiragana words were presented arbitrarily for 20 and 300 ms on the monitor screen which were correctly named at the usual confrontation setting (i.e., semantic memory preserved). They were asked to name the pictures or to read the words or nonsense syllables aloud. Results. The AD group showed significantly lower scores than the HC group, especially for the 20 ms condition. For the type of stimuli, the AD patients had better performances for words > pictures > nonsense syllables, although no differences for the HC group. The effect of AD severity was noted, moderate > severe stage. Conclusions. Our results suggested that the processing speed in AD patients may have reduced, even if the semantic memory were preserved. These data indicated that the difference in the processing speeds by the type of stimuli (pictures, words, and nonsense syllables) may be a character of AD patients.

中文翻译：

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在阿尔茨海默病中，文字处理比图片处理更快。

客观。阿尔茨海默病 (AD) 的特征是情景记忆的缓慢进行性损害。许多研究表明，AD 在疾病进展过程中表现出语义记忆的恶化。我们之前曾报道，AD 患者在语义记忆系统中表现出严重的访问障碍，使用瞬时呈现任务（20 或 300 毫秒）。在这项研究中，我们通过使用对象差异（图片与文字）方法研究了 AD 患者的访问障碍。方法. 研究了 56 名可能患有 AD 的患者（NINCDS-ADRDA，平均年龄 79.0 岁）和 11 名健康对照（HC）（平均年龄 67.0 岁）。10 张图片和 10 个对应的日语平假名单词在监视器屏幕上任意呈现 20 和 300 毫秒，在通常的对抗设置下正确命名（即保留语义记忆）。他们被要求为图片命名或大声朗读单词或无意义的音节。结果。AD 组的分数明显低于 HC 组，尤其是在 20 ms 条件下。对于刺激的类型，AD 患者在单词 > 图片 > 无意义音节方面的表现更好，尽管 HC 组没有差异。注意到AD严重程度的影响，中度>重度阶段。结论. 我们的结果表明，即使保留了语义记忆，AD 患者的处理速度也可能有所降低。这些数据表明，刺激类型（图片、文字和无意义的音节）的处理速度差异可能是 AD 患者的特征。