Department of Psychology, Columbia University, Medical Center, New York, NY 10032, USA.
Neuroimage. 2013 Jan 15;65:223-30. doi: 10.1016/j.neuroimage.2012.08.063. Epub 2012 Aug 30.
Real world tasks involving moving targets, such as driving a vehicle, are performed based on continuous decisions thought to depend upon the temporal derivative of the expected utility (∂V/∂t), where the expected utility (V) is the effective value of a future reward. However, the neural mechanisms that underlie dynamic decision-making are not well understood. This study investigates human neural correlates of both V and ∂V/∂t using fMRI and a novel experimental paradigm based on a pursuit-evasion game optimized to isolate components of dynamic decision processes. Our behavioral data show that players of the pursuit-evasion game adopt an exponential discounting function, supporting the expected utility theory. The continuous functions of V and ∂V/∂t were derived from the behavioral data and applied as regressors in fMRI analysis, enabling temporal resolution that exceeded the sampling rate of image acquisition, hyper-temporal resolution, by taking advantage of numerous trials that provide rich and independent manipulation of those variables. V and ∂V/∂t were each associated with distinct neural activity. Specifically, ∂V/∂t was associated with anterior and posterior cingulate cortices, superior parietal lobule, and ventral pallidum, whereas V was primarily associated with supplementary motor, pre and post central gyri, cerebellum, and thalamus. The association between the ∂V/∂t and brain regions previously related to decision-making is consistent with the primary role of the temporal derivative of expected utility in dynamic decision-making.
真实世界中的任务涉及移动物体，例如驾驶车辆，是基于连续决策完成的，这些决策被认为取决于预期效用的时间导数（∂V/∂t），其中预期效用（V）是未来奖励的有效价值。然而，动态决策背后的神经机制尚不清楚。本研究使用 fMRI 技术和一种基于追逐回避游戏的新型实验范式，来研究人类神经与 V 和 ∂V/∂t 的相关性，该范式旨在分离动态决策过程的成分。我们的行为数据表明，追逐回避游戏的玩家采用了指数折扣函数，支持了预期效用理论。连续的 V 和 ∂V/∂t 函数是从行为数据中得出的，并作为 fMRI 分析中的回归因子应用，通过利用大量提供丰富和独立操纵这些变量的试验，实现了超过图像采集采样率的时间分辨率，即超时间分辨率。V 和 ∂V/∂t 都与不同的神经活动相关。具体来说，∂V/∂t 与前扣带皮质和后扣带皮质、顶叶上回和腹侧苍白球有关，而 V 主要与补充运动区、额顶叶和中央后回、小脑和丘脑有关。∂V/∂t 与先前与决策相关的大脑区域之间的关联与预期效用的时间导数在动态决策中的主要作用一致。
