General cognitive ability, or general intelligence (g), is central to cognitive science, yet the processes that constitute it remain unknown, in good part because most prior work has relied on correlational methods. Large-scale behavioral and neuroanatomical data from neurologic patients with focal brain lesions can be leveraged to advance our understanding of the key mechanisms of g, as this approach allows inference on the independence of cognitive processes along with elucidation of their respective neuroanatomical substrates. We analyzed behavioral and neuroanatomical data from 402 humans (212 males; 190 females) with chronic, focal brain lesions. Structural equation models (SEMs) demonstrated a psychometric isomorphism between g and working memory in our sample (which we refer to as g/Gwm), but not between g and other cognitive abilities. Multivariate lesion-behavior mapping analyses indicated that g and working memory localize most critically to a site of converging white matter tracts deep to the left temporo-parietal junction. Tractography analyses demonstrated that the regions in the lesion-behavior map of g/Gwm were primarily associated with the arcuate fasciculus. The anatomic findings were validated in an independent cohort of acute stroke patients (n = 101) using model-based predictions of cognitive deficits generated from the Iowa cohort lesion-behavior maps. The neuroanatomical localization of g/Gwm provided the strongest prediction of observed g in the new cohort (r = 0.42, p < 0.001), supporting the anatomic specificity of our findings. These results provide converging behavioral and anatomic evidence that working memory is a key mechanism contributing to domain-general cognition.

SIGNIFICANCE STATEMENT General cognitive ability (g) is thought to play an important role in individual differences in adaptive behavior, yet its core processes remain unknown, in large part because of difficulties in making causal inferences from correlated data. Using data from patients with focal brain damage, we demonstrate that there is a strong psychometric correspondence between g and working memory – the ability to maintain and control mental information, and that the critical neuroanatomical substrates of g and working memory include the arcuate fasciculus. This work provides converging behavioral and neuroanatomical evidence that working memory is a key mechanism contributing to domain-general cognition.

一般认知能力或一般智力（g）对于认知科学至关重要，但是构成认知过程的过程仍然未知，这在很大程度上是因为大多数先前的工作都依赖于相关方法。可以利用来自局灶性脑损伤神经病患者的大规模行为和神经解剖学数据来增进我们对g关键机制的理解，因为这种方法可以推断认知过程的独立性以及阐明其各自的神经解剖学底物。我们分析了来自402例患有慢性局灶性脑部病变的人（男性212名；女性190名）的行为和神经解剖学数据。结构方程模型（SEM）证明了样本中g与工作记忆之间的心理同构（我们称为g / Gwm），但在g与其他认知能力之间没有。多元病变行为映射分析表明，g和工作记忆最关键地定位在会聚的白质束向左颞顶顶交界的深处。断裂谱分析表明，g / Gwm病变行为图中的区域主要与弓形束相关。在独立的急性卒中患者队列中验证了解剖学发现（n = 101），使用基于模型的爱荷华州队列病变行为图生成的认知缺陷预测。g / Gwm的神经解剖学定位提供了在新队列中观察到的g的最强预测（r = 0.42，p <0.001），支持了我们发现的解剖学特异性。这些结果提供了行为和解剖学方面的融合证据，表明工作记忆是促成领域普遍认知的关键机制。

意义声明一般认知能力（g）在适应行为的个体差异中起着重要作用，但其核心过程仍然未知，这在很大程度上是由于难以根据相关数据做出因果推断。使用来自局灶性脑损伤患者的数据，我们证明g与工作记忆之间存在强烈的心理计量对应关系-维持和控制心理信息的能力，并且g和工作记忆的关键神经解剖学基底包括弓形筋膜。这项工作提供了融合的行为和神经解剖学证据，表明工作记忆是促成领域普遍认知的关键机制。