Labudda Kirsten, Woermann Friedrich G, Mertens Markus, Pohlmann-Eden Bernd, Markowitsch Hans J, Brand Matthias
Department of Physiological Psychology, University of Bielefeld, P.O. Box 100131, 33501, Bielefeld, Germany.
Exp Brain Res. 2008 Jun;187(4):641-50. doi: 10.1007/s00221-008-1332-x. Epub 2008 Mar 5.
Recent functional neuroimaging and lesion studies demonstrate the involvement of the orbitofrontal/ventromedial prefrontal cortex as a key structure in decision making processes. This region seems to be particularly crucial when contingencies between options and consequences are unknown but have to be learned by the use of feedback following previous decisions (decision making under ambiguity). However, little is known about the neural correlates of decision making under risk conditions in which information about probabilities and potential outcomes is given. In the present study, we used functional magnetic resonance imaging to measure blood-oxygenation-level-dependent (BOLD) responses in 12 subjects during a decision making task. This task provided explicit information about probabilities and associated potential incentives. The responses were compared to BOLD signals in a control condition without information about incentives. In contrast to previous decision making studies, we completely removed the outcome phase following a decision to exclude the potential influence of feedback previously received on current decisions. The results indicate that the integration of information about probabilities and incentives leads to activations within the dorsolateral prefrontal cortex, the posterior parietal lobe, the anterior cingulate and the right lingual gyrus. We assume that this pattern of activation is due to the involvement of executive functions, conflict detection mechanisms and arithmetic operations during the deliberation phase of decisional processes that are based on explicit information.
近期的功能神经影像学和脑损伤研究表明，眶额/腹内侧前额叶皮层作为决策过程中的关键结构参与其中。当选项与后果之间的偶然联系未知，但必须通过根据先前决策的反馈来学习时（在模糊情况下进行决策），该区域似乎尤为关键。然而，对于在给出概率和潜在结果信息的风险条件下决策的神经关联知之甚少。在本研究中，我们使用功能磁共振成像来测量12名受试者在决策任务期间的血氧水平依赖（BOLD）反应。该任务提供了关于概率和相关潜在奖励的明确信息。将这些反应与在没有奖励信息的对照条件下的BOLD信号进行比较。与先前的决策研究不同，我们在决策后完全去除了结果阶段，以排除先前收到的反馈对当前决策的潜在影响。结果表明，概率和奖励信息的整合导致背外侧前额叶皮层、顶叶后部、前扣带回和右侧舌回内的激活。我们假设这种激活模式是由于在基于明确信息的决策过程的审议阶段执行功能、冲突检测机制和算术运算的参与。
