Faculdade de Letras, Universidade Federal de Minas Gerais (UFMG), Av. Pres. Antônio Carlos, 6627 - Pampulha, Belo Horizonte - MG, 31270-901, Brazil.
Laboratório de Neurociências (LIM-27), Faculdade de Medicina, Departamento e Instituto de Psiquiatria, Hospital Das Clínicas HCFMUSP, Universidade de São Paulo, Brazil.
Neuropsychologia. 2022 Sep 9;174:108337. doi: 10.1016/j.neuropsychologia.2022.108337. Epub 2022 Aug 5.
In the present theoretical review we will perform a critical surveillance of linguistic and semantic processing in Mild Cognitive Impairment and Alzheimer's disease, explicitly favouring a neurobiological prism. We conjecture that most linguistic alterations arise from semantic indiscrimination through inhibitory hypofunction. Specifically, a conjoint cluster of cholinergic dysfunction, Aβ load and somatostatin-positive cell loss renders the semantic network disinhibited and overly noisy: fine discriminatory processes in temporal and medial-frontal regions cannot differentiate semantic representations from baseline unconscious activity, which leads to failures in faithful retrieval (preferentially idiosyncratic lexical-semantic links, e.g., proper names), verbal fluency anomalies, semantic interference, dampened N400 effects, and various semiological deviances.
在本理论综述中，我们将对轻度认知障碍和阿尔茨海默病中的语言和语义处理进行批判性监测，特别倾向于采用神经生物学视角。我们推测，大多数语言变化都源于通过抑制功能低下导致的语义辨别力不足。具体而言，胆碱能功能障碍、Aβ 负荷和生长抑素阳性细胞丢失的联合簇会使语义网络去抑制并变得过度嘈杂：颞叶和额内侧区域的精细辨别过程无法将语义表示与基线无意识活动区分开来，从而导致忠实检索失败（优先出现特殊的词汇语义联系，例如，专有名词）、言语流畅性异常、语义干扰、N400 效应减弱以及各种症状偏差。
