Cue- versus probe-dependent prefrontal cortex activity during contextual remembering
Cue- versus probe-dependent prefrontal cortex activity during contextual remembering
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DOI：
10.1162/jocn.2006.18.9.1439
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发表时间：
2006-09-01
影响因子：
3.2
通讯作者：
Han, Sanghoon
中科院分区：
文献类型：
--
作者：
Dobbins, Ian G.;Han, Sanghoon
情景记忆和项目记忆的功能神经影像学比较在情景特异性记忆的恢复过程中经常涉及左前额叶皮层（PFC）。然而，由于提示和探针通常同时出现，这种活动可能反映了涉及计划检索的操作，或者反映了依赖于记忆探针本身的后续操作，例如对探针唤起的回忆的评估。更重要的是，计划相关的活动，其中受试者恢复细节概述所期望的记忆的性质，应该发生在上下文记忆线索的响应，甚至在检索探针可用之前。使用事件相关的功能性磁共振成像，我们通过在情境记忆中分离线索与探针相关的活动来测试这一点。提示预警情景记忆要求在左侧中央前回、额上回中线和右侧额极皮层产生比预警项目记忆更多的活动。因此，这些预期的、基于线索的激活表明，即将到来的探测决定是否需要上下文特定的记忆。相比之下，左背外侧/中腹外侧和前腹外侧PFC区域在探针实际呈现之前没有表现出不同的活动，表明上下文比项目记忆探针更活跃。直接比较左PFC近端区域表明，在线索和探测期间，外侧中央前区域和背外侧区域的反应谱在质量上是不同的。这些结果可能会将上下文记忆计划相关的过程与随后的过程（如回忆的评估）隔离开来，这些过程必然依赖于单个探针特征。他们还证明，情境记忆招募了多个功能不同的PFC过程。
Functional neuroimaging comparisons of context and item memory frequently implicate the left prefrontal cortex (PFC) during the recovery of contextually specific memories. However, because cues and probes are often presented simultaneously, this activity could reflect operations involved in planning retrieval or instead reflect later operations dependent upon the memory probes themselves, such as evaluation of probe-evoked recollections. More importantly, planning-related activity, wherein subjects reinstate details outlining the nature of desired remembrances, should occur in response to contextual memory cues even before retrieval probes are available. Using event-related functional magnetic resonance imaging, we tested this by dissociating cue- from probe-related activity during context memory for pictures. Cues forewarning contextual memory demands yielded more activity than those forewarning item memory in the left lateral precentral gyrus, midline superior frontal gyrus, and right frontopolar cortex. Thus, these anticipatory, cue-based activations indicated whether upcoming probe decisions would require contextually specific memories or not. In contrast, the left dorsolateral/midventrolateral and anterior ventrolateral PFC areas did not show differential activity until the probes were actually presented, demonstrating greater activity for context than for item memory probes. Direct comparison of proximal left PFC regions demonstrated qualitatively different response profiles across cue versus probe periods for lateral precentral versus dorsolateral regions. These results potentially isolate contextual memory-planning-related processes from subsequent processes such as the evaluation of recollections, which are necessarily dependent on individual probe features. They also demonstrate that contextual remembering recruits multiple, functionally distinct PFC processes.