在消退学习过程中海马的激活可预测在消退回忆中出现的更新效应。
Hippocampal activation during extinction learning predicts occurrence of the renewal effect in extinction recall.
机构信息
Department of Neurology, BG University Hospital Bergmannsheil, Ruhr-Universitaet Bochum, Bochum, Germany.
Department of Neurology, BG University Hospital Bergmannsheil, Ruhr-Universitaet Bochum, Bochum, Germany.
出版信息
Neuroimage. 2013 Nov 1;81:131-143. doi: 10.1016/j.neuroimage.2013.05.025. Epub 2013 May 16.
The renewal effect describes the reoccurrence of a previously extinguished response in situations where the context of extinction differs from that of acquisition, thus illustrating the context-dependency of extinction learning. A number of studies on contextual fear extinction have implicated hippocampus and vmPFC in processing and retrieval of context both during extinction learning and recall of extinction. In this functional magnetic resonance imaging (fMRI) study we explored the neural correlates of the renewal effect in associative learning, using a predictive learning task that required participants to learn relations between cues and outcomes presented in particular contexts. During extinction in a novel context, compared to extinction in a context identical to the acquisition context, participants who exhibited the renewal effect (REN) showed increased activation in brain regions including bilateral posterior hippocampus and left parahippocampal gyrus. This activation pattern was absent in participants that did not show the renewal effect (NOREN). In direct comparisons between the groups, the REN group exhibited higher activation in bilateral hippocampus, while the NOREN group showed higher activation in left dlPFC (BA 46) and right anterior cingulate (BA 32). During extinction recall, stimuli that had been extinguished in a different context were again presented in the context of acquisition. Here both groups exhibited predominantly prefrontal activation, with the REN group's focus upon bilateral OFC (BA 47) and bilateral vmPFC (BA 10), while the NOREN group showed generally more widespread activation, predominantly in large clusters of dlPFC (BA 8,9,45). In a direct comparison, the REN group showed higher activation than the NOREN group in left vmPFC (BA 10), while NOREN participants exhibited more activation in dlPFC (BA 9, 46). Activation in left vmPFC during extinction recall correlated with the number of renewal effect responses, while the dlPFC activation showed a negative correlation with renewal effect responses. These results highlight the differential activation patterns of processes that will eventually produce or not produce a renewal effect, indicating that during extinction learning hippocampus encodes the relation between context and cue-outcome, while in extinction recall vmPFC is active to retrieve this association.
再现效应描述了在与习得时不同的情境中,先前已消退的反应再次出现的现象,从而说明了消退学习的情境依赖性。许多关于情境性恐惧消退的研究表明,海马体和 vmPFC 在消退学习期间以及在对消退的回忆中,都参与了情境的处理和提取。在这项功能磁共振成像 (fMRI) 研究中,我们使用一种需要参与者在特定情境中学习线索和结果之间关系的预测性学习任务,探索了联想学习中再现效应的神经相关性。在新情境中的消退中,与在与习得情境相同的情境中的消退相比,表现出再现效应 (REN) 的参与者在包括双侧后海马体和左侧海马旁回在内的脑区显示出更高的激活。在没有表现出再现效应 (NOREN) 的参与者中,没有观察到这种激活模式。在两组之间的直接比较中,REN 组在双侧海马体中表现出更高的激活,而 NOREN 组在左侧 dlPFC(BA46)和右侧前扣带回(BA32)中表现出更高的激活。在消退回忆期间,在不同情境中被消退的刺激再次在习得情境中呈现。在这里,两组都表现出主要的前额叶激活,REN 组的焦点是双侧 OFC(BA47)和双侧 vmPFC(BA10),而 NOREN 组则表现出更广泛的激活,主要分布在 dlPFC(BA8、9、45)的大簇中。在直接比较中,REN 组在左侧 vmPFC(BA10)中的激活高于 NOREN 组,而 NOREN 组在 dlPFC(BA9、46)中的激活更高。在消退回忆期间,左侧 vmPFC 的激活与再现效应反应的数量相关,而 dlPFC 的激活与再现效应反应呈负相关。这些结果突出了最终产生或不产生再现效应的过程的差异激活模式,表明在消退学习期间,海马体编码了情境与线索-结果之间的关系,而在消退回忆中,vmPFC 活跃以检索这种关联。