Institute of Cognitive Neuroscience, University College London, London, UK.
J Cogn Neurosci. 2011 Jan;23(1):168-82. doi: 10.1162/jocn.2010.21439.
Severe capacity limits, closely associated with fluid intelligence, arise in learning and use of new task rules. We used fMRI to investigate these limits in a series of multirule tasks involving different stimuli, rules, and response keys. Data were analyzed both during presentation of instructions and during later task execution. Between tasks, we manipulated the number of rules specified in task instructions, and within tasks, we manipulated the number of rules operative in each trial block. Replicating previous results, rule failures were strongly predicted by fluid intelligence and increased with the number of operative rules. In fMRI data, analyses of the instruction period showed that the bilateral inferior frontal sulcus, intraparietal sulcus, and presupplementary motor area were phasically active with presentation of each new rule. In a broader range of frontal and parietal regions, baseline activity gradually increased as successive rules were instructed. During task performance, we observed contrasting fronto-parietal patterns of sustained (block-related) and transient (trial-related) activity. Block, but not trial, activity showed effects of task complexity. We suggest that, as a new task is learned, a fronto-parietal representation of relevant rules and facts is assembled for future control of behavior. Capacity limits in learning and executing new rules, and their association with fluid intelligence, may be mediated by this load-sensitive fronto-parietal network.
严重的能力限制与流体智力密切相关，出现在学习和使用新任务规则时。我们使用 fMRI 研究了一系列涉及不同刺激、规则和反应键的多规则任务中的这些限制。在呈现指令期间和之后的任务执行期间分析数据。在任务之间，我们操纵任务指令中指定的规则数量，在任务内部，我们操纵每个试验块中操作的规则数量。复制以前的结果，规则失败强烈预测流体智力，并随操作规则数量的增加而增加。在 fMRI 数据中，指令期的分析表明，双侧额下回、顶内沟和补充运动区随着每个新规则的呈现而呈阶段性活跃。在更广泛的额顶区域，随着连续规则的指示，基线活动逐渐增加。在任务执行期间，我们观察到持续（块相关）和瞬态（试验相关）活动的额顶模式相反。块，而不是试验，活动显示出任务复杂性的影响。我们认为，随着新任务的学习，与未来行为控制相关的规则和事实的额顶表示被组装起来。学习和执行新规则的能力限制及其与流体智力的关联可能由这个负载敏感的额顶网络介导。
