Recollection versus strength as the primary determinant of hippocampal engagement at retrieval
Recollection versus strength as the primary determinant of hippocampal engagement at retrieval
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DOI：
10.1073/pnas.0908651106
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发表时间：
2009-12-29
影响因子：
11.1
通讯作者：
McAndrews, Mary Pat
中科院分区：
文献类型：
--
作者：
Cohn, Melanie;Moscovitch, Morris;McAndrews, Mary Pat
我们研究了海马体的活动是否与记忆的强度或回忆的经验有关，这是一个目前有相当大争议的问题。参与者研究单词对，然后对每个项目进行两次连续的识别决策：首先是未提示的目标，然后是与研究的提示词一起呈现的目标。我们比较了这些决定的功能磁共振成像激活的回忆和熟悉模式。重要的是，我们的分析试图以两种方式来等同感知记忆强度，同时改变可用的关联信息。首先，活动的目标判断熟悉线索前进行了对比与活动相同的项目在第二个决定的功能，是否转换为回忆或保持熟悉的目标时，提供的上下文线索。我们发现海马活动增加后，提示只有回忆转换。其次，我们研究了海马活动是否受到线索项目的额定熟悉强度的调制，或者它是否在回忆中独特地增加。海马激活不调制参数熟悉的强度和回忆的项目与更大的活动相对于高度熟悉的项目。总之，我们的研究结果支持了这样一种观点，即在提取时海马参与的基础是对背景的回忆，而不是记忆强度。
We examined whether hippocampal activity in recognition relates to the strength of the memory or to recollective experience, a subject of considerable current debate. Participants studied word pairs and then made two successive recognition decisions on each item: first on the uncued target and then on the target presented with the studied cue word. We compared recollection and familiarity patterns of activation in fMRI for these decisions. Critically, our analyses attempted in two ways to equate perceived memory strength while varying the associative information available. First, activity for targets judged familiar before cueing was contrasted with activity for the same items in the second decision as a function of whether the targets converted to recollection or remained familiar when the context cues were provided. We found increased hippocampal activity following cueing only with recollective conversion. Second, we investigated whether hippocampal activity was modulated by the rated familiarity strength of cued items or whether it increased uniquely in recollection. Hippocampal activation was not modulated parametrically by familiarity strength and recollected items were associated with greater activity relative to highly familiar items. Together, our results support the notion that it is recollection of context, rather than memory strength, that underlies hippocampal engagement at retrieval.