Bahlmann Jörg, Blumenfeld Robert S, D'Esposito Mark
Department of Neurology, University of Lübeck, Lübeck, Germany Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA.
Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA Department of Neurology, University of California, Irvine, CA 92697, USA.
Cereb Cortex. 2015 Jul;25(7):1815-26. doi: 10.1093/cercor/bht419. Epub 2014 Jan 22.
Evidence suggests that lateral frontal cortex implements cognitive control processing along its rostro-caudal axis, yet other evidence supports a dorsal-ventral functional organization for processes engaged by different stimulus domains (e.g., spatial vs. nonspatial). This functional magnetic resonance imaging study investigated whether separable dorsolateral and ventrolateral rostro-caudal gradients exist in humans, while participants performed tasks requiring cognitive control at 3 levels of abstraction with language or spatial stimuli. Abstraction was manipulated by using 3 different task sets that varied in relational complexity. Relational complexity refers to the process of manipulating the relationship between task components (e.g., to associate a particular cue with a task) and drawing inferences about that relationship. Tasks using different stimulus domains engaged distinct posterior regions, but within the lateral frontal cortex, we found evidence for a single rostro-caudal gradient that was organized according to the level of abstraction and was independent of processing of the stimulus domain. However, a pattern of dorsal/ventral segregation of processing engaged by domain-specific information was evident in each separable frontal region only within the most rostral region recruited by task demands. These results suggest that increasingly abstract information is represented in the frontal cortex along distinct rostro-caudal gradients that also segregate along a dorsal-ventral axis dependent on task demands.
有证据表明，外侧额叶皮层沿其前后轴执行认知控制处理，但也有其他证据支持不同刺激域（如空间与非空间）所涉及的过程存在背腹功能组织。这项功能磁共振成像研究调查了在人类中是否存在可分离的背外侧和腹外侧前后梯度，同时参与者执行需要对语言或空间刺激进行三个抽象层次认知控制的任务。通过使用三种关系复杂性不同的不同任务集来操纵抽象程度。关系复杂性是指操纵任务组件之间的关系（例如，将特定线索与任务相关联）并对该关系进行推理的过程。使用不同刺激域的任务涉及不同的后部区域，但在外侧额叶皮层内，我们发现了一个单一的前后梯度的证据，该梯度根据抽象程度进行组织，并且与刺激域的处理无关。然而，仅在任务需求所招募的最前部区域内，每个可分离的额叶区域中由特定域信息所涉及的处理的背/腹分离模式是明显的。这些结果表明，越来越抽象的信息在额叶皮层中沿着不同的前后梯度进行表征，这些梯度也根据任务需求沿着背腹轴分离。
