Department of Psychology, Queens College, The City University of New York, Queens, NY, USA.
Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Cereb Cortex. 2018 Jul 1;28(7):2267-2282. doi: 10.1093/cercor/bhx127.
The Hick-Hyman law describes a linear increase in reaction time (RT) as a function of the information entropy of response selection, which is computed as the binary logarithm of the number of response alternatives. While numerous behavioral studies have provided evidence for the Hick-Hyman law, its neural underpinnings have rarely been examined and are still unclear. In this functional magnetic resonance imaging study, by utilizing a choice reaction time task to manipulate the entropy of response selection, we examined brain activity mediating the input and the output, as well as the connectivity between corresponding regions in human participants. Beyond confirming the Hick-Hyman law in RT performance, we found that activation of the cognitive control network (CCN) increased and activation of the default mode network (DMN) decreased, both as a function of entropy. However, only the CCN, but not the DMN, was involved in mediating the relationship between entropy and RT. The CCN was involved in both stages of uncertainty representation and response generation, while the DMN was mainly involved at the stage of uncertainty representation. These findings indicate that the CCN serves as a core entity underlying the Hick-Hyman law by coordinating uncertainty representation and response generation in the brain.
希克-海曼定律描述了反应时间 (RT) 随响应选择信息熵的线性增加，信息熵是通过对响应选择的替代方案数量的二进制对数计算得出的。虽然许多行为研究已经提供了希克-海曼定律的证据，但该定律的神经基础很少被研究，仍然不清楚。在这项功能磁共振成像研究中，我们利用选择反应时间任务来操纵响应选择的熵，以研究人类参与者的输入和输出以及对应区域之间的连接所介导的大脑活动。除了在 RT 表现中证实希克-海曼定律外，我们还发现认知控制网络 (CCN) 的激活随着熵的增加而增加，而默认模式网络 (DMN) 的激活则减少。然而，只有 CCN 而不是 DMN 参与介导熵和 RT 之间的关系。CCN 参与了不确定性表示和反应生成的两个阶段，而 DMN 主要参与了不确定性表示阶段。这些发现表明，CCN 通过协调大脑中的不确定性表示和反应生成，作为希克-海曼定律的核心实体。
