Lally Níall, Huys Quentin J M, Eshel Neir, Faulkner Paul, Dayan Peter, Roiser Jonathan P
Institute of Cognitive Neuroscience, University College London, Alexandra House, London WC1N 3AZ, United Kingdom,
Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892-9663.
J Neurosci. 2017 Oct 18;37(42):10215-10229. doi: 10.1523/JNEUROSCI.0085-17.2017. Epub 2017 Sep 18.
Important real-world decisions are often arduous as they frequently involve sequences of choices, with initial selections affecting future options. Evaluating every possible combination of choices is computationally intractable, particularly for longer multistep decisions. Therefore, humans frequently use heuristics to reduce the complexity of decisions. We recently used a goal-directed planning task to demonstrate the profound behavioral influence and ubiquity of one such shortcut, namely aversive pruning, a reflexive Pavlovian process that involves neglecting parts of the decision space residing beyond salient negative outcomes. However, how the brain implements this important decision heuristic and what underlies individual differences have hitherto remained unanswered. Therefore, we administered an adapted version of the same planning task to healthy male and female volunteers undergoing functional magnetic resonance imaging (fMRI) to determine the neural basis of aversive pruning. Through both computational and standard categorical fMRI analyses, we show that when planning was influenced by aversive pruning, the subgenual cingulate cortex was robustly recruited. This neural signature was distinct from those associated with general planning and valuation, two fundamental cognitive components elicited by our task but which are complementary to aversive pruning. Furthermore, we found that individual variation in levels of aversive pruning was associated with the responses of insula and dorsolateral prefrontal cortices to the receipt of large monetary losses, and also with subclinical levels of anxiety. In summary, our data reveal the neural signatures of an important reflexive Pavlovian process that shapes goal-directed evaluations and thereby determines the outcome of high-level sequential cognitive processes. Multistep decisions are complex because initial choices constrain future options. Evaluating every path for long decision sequences is often impractical; thus, cognitive shortcuts are often essential. One pervasive and powerful heuristic is aversive pruning, in which potential decision-making avenues are curtailed at immediate negative outcomes. We used neuroimaging to examine how humans implement such pruning. We found it to be associated with activity in the subgenual cingulate cortex, with neural signatures that were distinguishable from those covarying with planning and valuation. Individual variations in aversive pruning levels related to subclinical anxiety levels and insular cortex activation. These findings reveal the neural mechanisms by which basic negative Pavlovian influences guide decision-making during planning, with implications for disrupted decision-making in psychiatric disorders.
重要的现实世界决策往往艰巨，因为它们常常涉及一系列选择，初始选择会影响未来的选项。评估每一种可能的选择组合在计算上是难以处理的，尤其是对于较长的多步决策。因此，人类经常使用启发式方法来降低决策的复杂性。我们最近使用了一个目标导向的规划任务来证明一种这样的捷径的深远行为影响和普遍性，即厌恶修剪，这是一种反射性的巴甫洛夫过程，涉及忽略决策空间中位于显著负面结果之外的部分。然而，大脑如何实现这种重要的决策启发式方法以及个体差异的基础是什么，迄今为止仍然没有答案。因此，我们对正在接受功能磁共振成像（fMRI）的健康男性和女性志愿者进行了同一规划任务的改编版本，以确定厌恶修剪的神经基础。通过计算和标准分类fMRI分析，我们表明，当规划受到厌恶修剪的影响时，膝下扣带回皮质会被强烈激活。这种神经特征与与一般规划和评估相关的特征不同，一般规划和评估是我们的任务引发的两个基本认知成分，但与厌恶修剪互补。此外，我们发现厌恶修剪水平的个体差异与脑岛和背外侧前额叶皮质对遭受重大金钱损失的反应有关，也与亚临床焦虑水平有关。总之，我们的数据揭示了一种重要的反射性巴甫洛夫过程的神经特征，这种过程塑造了目标导向的评估，从而决定了高级顺序认知过程的结果。多步决策很复杂，因为初始选择会限制未来的选项。评估长决策序列的每一条路径通常是不切实际的；因此，认知捷径往往至关重要。一种普遍且强大的启发式方法是厌恶修剪，在这种方法中，潜在的决策途径会因即时负面结果而减少。我们使用神经成像来研究人类如何进行这种修剪。我们发现它与膝下扣带回皮质的活动有关，其神经特征与那些与规划和评估相关的特征不同。厌恶修剪水平的个体差异与亚临床焦虑水平和脑岛皮质激活有关。这些发现揭示了基本的负面巴甫洛夫影响在规划过程中指导决策的神经机制，对精神疾病中决策障碍具有启示意义。
