Predicting discourse ability in TBI: Cognitive and communicative factors

描述（由申请人提供）：拟议研究的目标是通过识别叙事话语能力背后的认知和沟通过程，提高我们对创伤性脑损伤（TBI）后认知沟通障碍的认识。本研究采用结构方程模型，考察了工作记忆和推理在叙事语篇中的作用，并检验了规范语篇理解的认知模型--结构构建框架（SBF）提出的关键假设。执行功能的各个方面，如工作记忆，已经成为话语的潜在基质。一个相关的因素是推理，这是一种在TBI中经常减弱的能力。语篇产出缺陷在TBI文献中有很好的记载，但关于TBI中语篇理解的数据却很少。话语理解在多大程度上预测话语产出仍不清楚。缺乏一个话语模型来解释神经系统人群的认知沟通障碍，阻碍了理论为基础的话语干预的发展。SBF是一个潜在的候选者，但它的假设需要进行测试，特别是部署的认知过程作为域一般的假设。首先，我们考察了工作记忆和推理对叙事语篇能力的贡献。其次，我们通过使用言语和非言语工作记忆任务来检验语篇依赖于领域一般加工的假设。第三，我们调查了叙事语篇理解对叙事语篇产出的影响程度。分析1使用言语和非言语工作记忆更新和推理任务来预测两个叙事语篇理解任务的成绩。分析2使用与分析1相同的预测因子来预测两个话语产出任务（故事完整性和故事语法）的表现。文献表明，工作记忆是这两种话语模式的基础。如果工作记忆是语篇中的一般域，我们预测，言语工作记忆将无法解释超出非言语工作记忆的语篇理解，反之亦然。如果言语工作记忆和非言语工作记忆的表现高度相关，并且言语工作记忆和非言语工作记忆对语篇任务的解释量相等，则这一假设成立。如果推理在解释了工作记忆后有助于话语能力，这表明推理也会引导其他认知过程。在分析2中，我们预测，工作记忆将进行更多的内容措施，故事完整性的方差比推理，而推理将进行更多的组织措施，故事语法的方差。分析3考察了语篇理解对语篇产出的预测。语篇理解对语篇产出贡献的大小反映了语篇产出对理解的依赖性。更大的关系意味着话语产生和理解可能在同一个系统中运行，而较小的关系则表明理解和产生是平行的系统，它们利用相同的认知过程，但程度不同。 公共卫生相关性：拟议的研究将有助于我们的认知沟通障碍的创伤性脑损伤后，通过识别认知和沟通过程的话语能力。这项研究的结果将有助于修改当前的话语模型或开发新的话语模型，以更好地解释神经系统人群的认知-交际功能。话语能力的工作模式将为有意义和有针对性的话语干预提供坚实的理论基础。

DESCRIPTION (provided by applicant): The goal of the proposed research is to advance our knowledge of cognitive-communicative disorders following traumatic brain injury (TBI) by identifying the cognitive and communicative processes underlying narrative discourse ability. Using structural equation modeling, the proposed research will examine the role of working memory (WM) and inferencing in narrative discourse and test key assumptions posited by the Structure Building Framework (SBF), a cognitive model of normative discourse comprehension. Aspects of executive functions, such as WM, have emerged as potential substrates of discourse. A related factor is inferencing, an often diminished ability in TBI. Discourse production deficits are well-documented in the TBI literature, but data on discourse comprehension in TBI is scarce. The extent to which discourse comprehension predicts discourse production remains unclear. The lack of a discourse model to explain cognitive-communicative breakdowns in neurologic populations hinders the development of theoretically-based discourse interventions. The SBF is a potential candidate, but its assumptions need to be tested, in particular the positing of deployed cognitive processes as domain-general. First, we examine the contributions of WM and inferencing to narrative discourse ability. Second, we test the hypothesis that discourse relies on domain- general processes by using verbal and nonverbal WM tasks. Third, we investigate the extent to which narrative discourse comprehension accounts for narrative discourse production. Analysis 1 uses verbal and nonverbal WM updating and inferencing tasks to predict performance on two narrative discourse comprehension tasks. Analysis 2 uses the same predictors as Analysis 1 to predict performance on two discourse production tasks, story completeness and story grammar. The literature suggests that WM underpins both discourse modes. If WM is domain-general in discourse, we predict that verbal WM will not account for discourse comprehension beyond that of nonverbal WM and vice versa. This hypothesis will hold if performance on verbal and nonverbal WM is highly correlated and the amount of variance in discourse tasks explained by the verbal and nonverbal WM is equivalent. If inferencing contributes to discourse ability after accounting for WM, this suggests that inferencing also marshals other cognitive processes. In Analysis 2, we predict that WM will carry more of the variance in the content measure, story completeness, than inferencing whereas inferencing will carry more of the variance in the organizational measure, story grammar. Analysis 3 examines the prediction of discourse production from discourse comprehension. The magnitude of the contribution of discourse comprehension to discourse production reflects the dependence of production on comprehension. A greater magnitude of the relationship implicates that discourse production and comprehension likely operate in the same system while a smaller one would suggest that comprehension and production operate as parallel systems that draw upon the same cognitive processes but to differing degrees. PUBLIC HEALTH RELEVANCE: The proposed research will contribute to our knowledge of cognitive-communicative disorders following traumatic brain injury by identifying the cognitive and communicative processes underlying discourse ability. The findings from this study will be instrumental in refitting current models of discourse or in developing new ones to better explain cognitive-communicative functioning in neurologic populations. A working model of discourse ability will provide a solid foundation for the development of meaningful and targeted discourse interventions grounded in theory.