Naming of nouns and verbs can be selectively impaired in neurological disorders, but the specificity of the neural and cognitive correlates of such dissociation remains unclear. Functional imaging and stroke research sought to identify cortical regions selectively recruited for nouns versus verbs, yet findings are inconsistent.

The present study investigated this issue in neurodegenerative diseases known to selectively affect different brain networks, thus providing new critical evidence of network specificity. We examined naming performances on nouns and verbs in 146 patients with different neurodegenerative syndromes (Primary Progressive Aphasia – PPA, Alzheimer's disease – AD, and behavioral variant Frontotemporal Dementia – FTD) and 30 healthy adults. We then correlated naming scores with MRI-derived cortical thickness values as well as with performances in semantic and syntactic tasks, across all subjects.

Results indicated that patients with the semantic variant PPA named significantly fewer nouns than verbs. Instead, nonfluent/agrammatic PPA patients named fewer verbs than nouns. Across all subjects, performance on nouns (adjusted for verbs) specifically correlated with cortical atrophy in left anterior temporal regions, and performance on verbs (adjusted for nouns) with atrophy in left inferior and middle frontal, inferior parietal and posterior temporal regions. Furthermore, lower lexical-semantic abilities correlated with deficits in naming both nouns and verbs, while lower syntactic abilities only correlated with naming verbs.

Our results show that different neural and cognitive mechanisms underlie naming of specific grammatical categories in neurodegenerative diseases. Importantly, our findings showed that verb processing depends on a widespread perisylvian networks, suggesting that some regions might be involved in processing different types of action knowledge. These findings have important implications for early differential diagnosis of neurodegenerative disorders.

在神经系统疾病中，名词和动词的命名可能会选择性受损，但这种分离的神经和认知相关性的特异性仍不清楚。功能成像和中风研究试图识别选择性招募名词和动词的皮质区域，但研究结果不一致。

本研究调查了已知选择性影响不同大脑网络的神经退行性疾病中的这个问题，从而为网络特异性提供了新的关键证据。我们检查了 146 名患有不同神经退行性综合征（原发性进行性失语症 – PPA、阿尔茨海默病 – AD 和行为变异型额颞叶痴呆 – FTD）的患者和 30 名健康成年人的名词和动词命名表现。然后，我们将所有受试者的命名分数与 MRI 得出的皮质厚度值以及语义和句法任务的表现相关联。

结果表明，患有语义变体 PPA 的患者命名的名词明显少于动词。相反，不流利/不语法的 PPA 患者说出的动词比名词要少。在所有受试者中，名词的表现（根据动词调整）与左前颞区的皮质萎缩特别相关，而动词的表现（根据名词调整）与左下额叶和中额叶、顶下叶和后颞区的萎缩特别相关。此外，较低的词汇语义能力与命名名词和动词的缺陷相关，而较低的句法能力仅与命名动词相关。

我们的结果表明，不同的神经和认知机制是神经退行性疾病特定语法类别命名的基础。重要的是，我们的研究结果表明，动词处理取决于广泛的perisylvian网络，这表明某些区域可能参与处理不同类型的动作知识。这些发现对于神经退行性疾病的早期鉴别诊断具有重要意义。