Distinct Memory Signatures in the Hippocampus: Intentional States Distinguish Match and Mismatch Enhancement Signals
Distinct Memory Signatures in the Hippocampus: Intentional States Distinguish Match and Mismatch Enhancement Signals
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DOI：
10.1523/jneurosci.2998-08.2009
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发表时间：
2009-01-07
影响因子：
5.3
通讯作者：
Davachi, Lila
中科院分区：
文献类型：
--
作者：
Duncan, Katherine;Curtis, Clayton;Davachi, Lila
与存储表征匹配或不匹配的传入事件被认为会影响海马体在记忆编码和检索模式之间切换的能力。电生理学工作已经分离了猴子嗅周皮层中的匹配和失配信号，其中匹配信号对于与目标状态的匹配是选择性的，而失配信号不受意图的调节（米勒和Desimone，1994）。为了研究海马体中理论上重要的关系匹配和不匹配信号是否受到目标状态的调制，我们完全跨越了探针刺激是否与先前感知的图像或目标状态关系匹配或不匹配。受试者进行了两个工作记忆任务，他们要么回答“是“的探针是相同的，以前的样本场景，或者，在执行一个关系操纵的场景，回答“是“，只有一个探针，这是相同的感知新的图像。使用功能性磁共振成像，我们发现证据的关系匹配增强双边在海马体之间的探针刺激和目标状态的匹配是有选择性的，但不调制的目标是否是感知新颖的。此外，我们发现的证据互补海马不匹配的增强，是由刺激包含显着的知觉操纵。我们的研究结果为海马体中的并行记忆特征提供了证据：一个受控的匹配信号可以检测到与内部生成的目标状态的匹配，一个自动的失配信号可以识别出不可预测的感知新奇性。
Incoming events that match or mismatch stored representations are thought to influence the ability of the hippocampus to switch between memory encoding and retrieval modes. Electrophysiological work has dissociated match and mismatch signals in the monkey perirhinal cortex, where match signals were selective for matches to goal states, whereas mismatch signals were not modulated by intention (Miller and Desimone, 1994). To investigate whether the theoretically important relational match and mismatch signals in the hippocampus are modulated by goal states, we fully crossed whether a probe stimulus relationally matched or mismatched a previously perceived image or goal state. Subjects performed two working memory tasks in which they either responded "yes"to probes that were identical to the previous sample scene or, after performing a relational manipulation of the scene, responded "yes"only to a probe that was identical to this perceptually novel image. Using functional magnetic resonance imaging, we found evidence for relational match enhancements bilaterally in the hippocampus that were selective for matches between the probe stimulus and goal state, but were not modulated by whether that goal was perceptually novel. Moreover, we found evidence for a complementary hippocampal mismatch enhancement that was triggered by stimuli containing salient perceptual manipulations. Our results provided evidence for parallel memory signatures in the hippocampus: a controlled match signal that can detect matches to internally generated goal states and an automatic mismatch signal that can identify unpredicted perceptual novelty.