Hower Kylie H, Wixted John, Berryhill Marian E, Olson Ingrid R
Temple University, Department of Psychology, Philadelphia, PA 19122, USA.
University of California at San Diego, Department of Psychology, La Jolla, CA 92093, USA.
Neuropsychologia. 2014 Apr;56:409-17. doi: 10.1016/j.neuropsychologia.2014.02.014. Epub 2014 Feb 22.
In studies of episodic memory retrieval, recognition paradigms are known to elicit robust activations in the inferior parietal lobe. However, damage to this region does not produce severe deficits in episodic memory performance as indexed by typical accuracy measures. Rather, because problems with memory confidence are frequently reported, the observed deficits may be best described as "metamemory" or subjective memory deficits. Here, we further investigated the inferior parietal lobe's role in recognition memory as well as metamemory. We tested the hypothesis that the inferior parietal lobe gauges the perceived oldness of items, given several neuroimaging findings suggesting that a portion of the left inferior parietal lobe is sensitive to perceived oldness. We tested two patients with bilateral parietal lobe lesions and matched controls on an old/new recognition task. From these data we constructed receiver operating characteristic (ROC) curves by fitting the data with the unequal-variance signal-detection (UVSD) model. The results revealed no memory impairment in terms of patients' accuracy. However, patients exhibited lower hit rates and false alarms rates at high confidence levels. Further, patients and controls differed in how they set decision criteria for making recognition responses. Patients' decision criteria for "old" responses were shifted in a conservative fashion such that they were unwilling to endorse recognized target items with high levels of confidence. These findings provide constraints on models of inferior parietal lobe contributions to episodic memory retrieval.
在情景记忆检索的研究中，已知识别范式会在顶下小叶引发强烈激活。然而，该区域受损并不会导致情景记忆表现出现严重缺陷，这是由典型的准确性测量指标所反映的。相反，由于经常报告存在记忆信心方面的问题，观察到的缺陷可能最好被描述为“元记忆”或主观记忆缺陷。在此，我们进一步研究了顶下小叶在识别记忆以及元记忆中的作用。鉴于多项神经影像学研究结果表明左侧顶下小叶的一部分对感知到的旧性敏感，我们测试了顶下小叶衡量项目感知旧性的假设。我们让两名双侧顶叶病变患者和匹配的对照组完成一项新旧识别任务。根据这些数据，我们通过用不等方差信号检测（UVSD）模型拟合数据构建了接受者操作特征（ROC）曲线。结果显示，就患者的准确性而言，不存在记忆损害。然而，患者在高信心水平下的命中率和误报率较低。此外，患者和对照组在设定识别反应的决策标准方面存在差异。患者对“旧”反应的决策标准以保守的方式发生了偏移，以至于他们不愿意高度自信地认可已识别的目标项目。这些发现为顶下小叶对情景记忆检索贡献的模型提供了限制条件。
