Understanding the processes underlying normal, impaired, and recovered language performance has been a long-standing goal for cognitive and clinical neuroscience. Many verbally described hypotheses about language lateralization and recovery have been generated. However, they have not been considered within a single, unified, and implemented computational framework, and the literatures on healthy participants and patients are largely separated. These investigations also span different types of data, including behavioral results and functional MRI brain activations, which augment the challenge for any unified theory. Consequently, many key issues, apparent contradictions, and puzzles remain to be solved. We developed a neurocomputational, bilateral pathway model of spoken language production, designed to provide a unified framework to simulate different types of data from healthy participants and aphasic patients. The model encapsulates key computational principles (differential computational capacity, emergent division of labor across pathways, experience-dependent plasticity-related recovery) and provides an explanation for the bilateral yet asymmetric lateralization of language in healthy participants, chronic aphasia after left rather than right hemisphere lesions, and the basis of partial recovery in patients. The model provides a formal basis for understanding the relationship between behavioral performance and brain activation. The unified model is consistent with the degeneracy and variable neurodisplacement theories of language recovery, and adds computational insights to these hypotheses regarding the neural machinery underlying language processing and plasticity-related recovery following damage.

了解正常、受损和恢复的语言表现背后的过程一直是认知和临床神经科学的长期目标。已经产生了许多关于语言偏侧化和恢复的口头描述的假设。然而，它们并没有被考虑在一个单一的、统一的和实施的计算框架内，关于健康参与者和患者的文献在很大程度上是分开的。这些研究还涵盖了不同类型的数据，包括行为结果和功能性 MRI 大脑激活，这增加了任何统一理论的挑战。因此，许多关键问题、明显矛盾和困惑仍有待解决。我们开发了一种口语产生的神经计算双边通路模型，旨在提供一个统一的框架来模拟来自健康参与者和失语症患者的不同类型的数据。该模型包含了关键的计算原理（差异计算能力、跨路径的紧急分工、与经验相关的可塑性恢复），并为健康参与者的双侧但不对称的语言偏侧化、左脑而非右脑后的慢性失语症提供了解释病变部位，是患者部分康复的基础。该模型为理解行为表现和大脑激活之间的关系提供了正式的基础。统一模型与语言恢复的退化和可变神经位移理论一致，