Event-related potential evidence for a specific recognition memory deficit in adult survivors of cerebral hypoxia.
Event-related potential evidence for a specific recognition memory deficit in adult survivors of cerebral hypoxia.
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DOI：
10.1093/brain/121.10.1919
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发表时间：
1998-10
期刊：
影响因子：
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通讯作者：
Axel Mecklinger;D. V. Cramon;G. M. Cramon
中科院分区：
文献类型：
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作者：
Axel Mecklinger;D. V. Cramon;G. M. Cramon
心脏骤停引起的短暂性全身缺血可导致严重的神经心理障碍。最近的研究表明，记忆过程在缺氧脑损伤后特别受损。采用事件相关电位（ERP）和表现数据检测患者的视觉识别记忆功能。8名慢性缺氧患者，与性别和年龄的对照组相匹配，进行了一项视觉识别记忆任务，该任务需要对物体形状或空间位置进行识别判断，以及一项视觉分类（即古怪）任务，该任务对记忆的要求可以忽略不计。患者和对照组都获得了可靠的P300奇球效应，而两组在P300潜伏期和P300头皮地形上存在差异。在记忆任务中，控制组发现了旧/新效应（即先前研究过的项目的ERP波形比未研究过的项目大）。相比之下，在患者中，这些旧/新效应不存在，甚至极性颠倒，而识别表现远高于机会水平，除了一名患者。这些结果表明，在经历过一段时间的短暂性全脑缺血的患者中，基于检索项目研究情节的识别能力下降。鉴于患者的识别表现高于偶然水平，以及对与练习相关的识别表现变化的事后分析结果，我们认为，患者的记忆障碍最好的特征是外显记忆功能的退化，如对学习情节的情景检索。认知技能学习等内隐功能完好无损。
Transient global ischaemia due to cardiac arrest may lead to profound neuropsychological disorders. Recent research indicates that memory processes are particularly impaired after hypoxic brain injury. Visual recognition memory functions were examined in these patients by means of event-related potential (ERP) and performance data. Eight chronic hypoxic patients, matched with controls for sex and age, performed a visual recognition memory task requiring recognition judgements for either object forms or spatial locations and a visual classification (i.e. oddball) task that imposed negligible memory demands. Reliable P300 oddball effects were obtained both for patients and for controls, whereas the two groups differed in P300 latency and P300 scalp topography. In the memory task, old/new effects (i.e. larger ERP waveforms for previously studied than for unstudied items) were found for the controls. In contrast, in patients these old/new effects were absent or even inverted in polarity while recognition performance was well above chance level, except for one patient. These results suggest that recognition, based on the retrieval of an item's study episode, is degraded in patients who have suffered a period of transient global ischaemia. In the light of the patients' above-chance level of recognition performance and the outcome of post hoc analysis of practice-related changes in recognition performance, it is argued that the patients' memory disorders are best characterized as a degradation of explicit memory functions such as episodic retrieval of a study episode. Implicit functions such as cognitive skill learning were intact.