Demanuele Charmaine, Kirsch Peter, Esslinger Christine, Zink Mathias, Meyer-Lindenberg Andreas, Durstewitz Daniel
Department of Theoretical Neuroscience, Bernstein Center for Computational Neuroscience, Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
Department of Theoretical Neuroscience, Bernstein Center for Computational Neuroscience, Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Clinical Psychology, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
PLoS One. 2015 Aug 10;10(8):e0135424. doi: 10.1371/journal.pone.0135424. eCollection 2015.
Discriminating spatiotemporal stages of information processing involved in complex cognitive processes remains a challenge for neuroscience. This is especially so in prefrontal cortex whose subregions, such as the dorsolateral prefrontal (DLPFC), anterior cingulate (ACC) and orbitofrontal (OFC) cortices are known to have differentiable roles in cognition. Yet it is much less clear how these subregions contribute to different cognitive processes required by a given task. To investigate this, we use functional MRI data recorded from a group of healthy adults during a "Jumping to Conclusions" probabilistic reasoning task.
We used a novel approach combining multivariate test statistics with bootstrap-based procedures to discriminate between different task stages reflected in the fMRI blood oxygenation level dependent signal pattern and to unravel differences in task-related information encoded by these regions. Furthermore, we implemented a new feature extraction algorithm that selects voxels from any set of brain regions that are jointly maximally predictive about specific task stages.
Using both the multivariate statistics approach and the algorithm that searches for maximally informative voxels we show that during the Jumping to Conclusions task, the DLPFC and ACC contribute more to the decision making phase comprising the accumulation of evidence and probabilistic reasoning, while the OFC is more involved in choice evaluation and uncertainty feedback. Moreover, we show that in presumably non-task-related regions (temporal cortices) all information there was about task processing could be extracted from just one voxel (indicating the unspecific nature of that information), while for prefrontal areas a wider multivariate pattern of activity was maximally informative.
CONCLUSIONS/SIGNIFICANCE: We present a new approach to reveal the different roles of brain regions during the processing of one task from multivariate activity patterns measured by fMRI. This method can be a valuable tool to assess how area-specific processing is altered in psychiatric disorders such as schizophrenia, and in healthy subjects carrying different genetic polymorphisms.
区分复杂认知过程中信息处理的时空阶段仍是神经科学面临的一项挑战。在额叶前皮质尤其如此，其亚区域，如背外侧前额叶（DLPFC）、前扣带回（ACC）和眶额（OFC）皮质在认知中具有不同作用。然而，这些亚区域如何对给定任务所需的不同认知过程做出贡献却不太清楚。为了对此进行研究，我们使用了功能性磁共振成像（fMRI）数据，这些数据是在一组健康成年人进行“急于下结论”概率推理任务期间记录的。
我们采用了一种新颖的方法，将多变量检验统计与基于自助法的程序相结合，以区分fMRI血氧水平依赖信号模式中反映的不同任务阶段，并揭示这些区域编码的与任务相关信息的差异。此外，我们实施了一种新的特征提取算法，该算法从任何一组对特定任务阶段具有最大联合预测性的脑区中选择体素。
使用多变量统计方法和搜索最大信息体素的算法，我们发现，在“急于下结论”任务期间，DLPFC和ACC对包括证据积累和概率推理的决策阶段贡献更大，而OFC更多地参与选择评估和不确定性反馈。此外，我们表明，在可能与任务无关的区域（颞叶皮质），所有与任务处理有关的信息都可以从仅一个体素中提取（表明该信息的非特异性性质），而对于前额叶区域，更广泛的多变量活动模式具有最大信息量。
结论/意义：我们提出了一种新方法，可从通过fMRI测量的多变量活动模式中揭示大脑区域在一项任务处理过程中的不同作用。该方法可能是一种有价值的工具，用于评估在精神分裂症等精神疾病以及携带不同基因多态性的健康受试者中，特定区域的处理是如何改变的。
