Daselaar S M, Fleck M S, Cabeza R
Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands.
J Neurophysiol. 2006 Oct;96(4):1902-11. doi: 10.1152/jn.01029.2005. Epub 2006 May 31.
Memory for past events may be based on retrieval accompanied by specific contextual details (recollection) or on the feeling that an item is old (familiarity) or new (novelty) in the absence of contextual details. There are indications that recollection, familiarity, and novelty involve different medial temporal lobe subregions, but available evidence is scarce and inconclusive. Using functional magnetic resonance imaging (MRI), we isolated retrieval-related activity associated with recollection, familiarity, and novelty by distinguishing between linear and nonlinear oldness functions derived from recognition confidence levels. Within the medial temporal lobes (MTLs), we found a triple dissociation among the posterior half of the hippocampus, which was associated with recollection, the posterior parahippocampal gyrus, which was associated with familiarity, and anterior half of the hippocampus and rhinal regions, which were associated with novelty. Furthermore, multiple regression analyses based on individual trial activity showed that all three memory signals, i.e., recollection, familiarity, and novelty, make significant and independent contributions to recognition memory performance. Finally, functional dissociations among recollection, familiarity, and novelty were also found in posterior midline, left parietal cortex, and prefrontal cortex regions. This is the first study to reveal a triple dissociation within the MTL associated with distinct retrieval processes. This finding has direct implications for current memory models.
对过去事件的记忆可能基于伴有特定情境细节的提取（回忆），或者基于在缺乏情境细节时对一个项目是旧的（熟悉感）或新的（新奇感）的感觉。有迹象表明，回忆、熟悉感和新奇感涉及不同的内侧颞叶亚区域，但现有证据稀少且尚无定论。我们使用功能磁共振成像（MRI），通过区分从识别置信水平得出的线性和非线性旧性函数，分离出与回忆、熟悉感和新奇感相关的提取相关活动。在内侧颞叶（MTL）内，我们发现海马体后半部与回忆相关，海马旁回后部与熟悉感相关，海马体前半部和鼻周区域与新奇感相关，三者之间存在三重分离。此外，基于个体试验活动的多元回归分析表明，所有三种记忆信号，即回忆、熟悉感和新奇感，对识别记忆表现都有显著且独立的贡献。最后，在中后中线、左侧顶叶皮质和前额叶皮质区域也发现了回忆、熟悉感和新奇感之间的功能分离。这是第一项揭示MTL内与不同提取过程相关的三重分离的研究。这一发现对当前的记忆模型有直接影响。
