Cognitive Neuroscience Sector, International School for Advanced Studies (SISSA/ISAS), Trieste, Italy.
Neuroimage. 2010 Apr 1;50(2):678-92. doi: 10.1016/j.neuroimage.2009.12.114. Epub 2010 Jan 7.
Episodic retrieval is supported by multiple forms of cognitive control that depend on prefrontal cortex. However, within prefrontal cortex, the regional specificity for different control processes is still largely underspecified. Here we used fMRI to investigate the processes involved in part-list cueing, a phenomenon entailing the reduction of memory performance when some of the "to-be-remembered items" are presented during retrieval. Retrieval inhibition and strategy disruption have been proposed as possible underlying causes of this surprising effect. Critically, different encoding conditions can dissociate these two hypotheses, as this is thought to have a different impact on strategy-related versus inhibition-related processes. Accordingly, we compared part-list versus no part-list retrieval conditions, following high versus low associative encoding conditions. This revealed activation of the left frontopolar and right dorsolateral prefrontal cortex in conditions of part-list cueing retrieval, but only following low associative encoding. These results are consistent with the inhibitory or interference resolution accounts of part-list cueing, suggesting a critical role of between-items competition and high monitoring demands at retrieval. In addition, we also examined brain activation during the encoding phase, specifying further possible anatomo-functional links between encoding and retrieval processes. The results suggest that different encoding conditions induce distinct patterns of activation at retrieval, corroborating the idea that they promote the adoption of different retrieval strategies. The implications of the results are discussed in relation to the cognitive mechanisms of inhibition, interference resolution, and encoding/retrieval strategies for episodic memory.
情景检索由依赖于前额叶皮层的多种形式的认知控制支持。然而，在前额叶皮层中，不同控制过程的区域特异性在很大程度上仍未得到明确说明。在这里，我们使用 fMRI 研究了部分列表提示过程中涉及的过程，当在检索过程中呈现一些“要记住的项目”时，这种现象会导致记忆性能下降。检索抑制和策略破坏被认为是这种惊人效应的可能潜在原因。关键是，不同的编码条件可以区分这两种假设，因为这被认为对策略相关过程和抑制相关过程有不同的影响。因此，我们比较了有部分列表提示和没有部分列表提示的检索条件，分别在高关联编码条件和低关联编码条件下进行。这表明在部分列表提示检索条件下，左额极和右背外侧前额叶皮层被激活，但仅在低关联编码条件下出现。这些结果与部分列表提示的抑制或干扰解决解释一致，表明在检索过程中，项目间竞争和高监控需求具有关键作用。此外，我们还检查了编码阶段的大脑激活情况，进一步明确了编码和检索过程之间可能的解剖功能联系。结果表明，不同的编码条件在检索时会引起不同的激活模式，这支持了它们促进不同检索策略的采用的观点。结果的意义与抑制、干扰解决和情景记忆的编码/检索策略的认知机制有关。
