Department of Psychiatry, University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong, China.
Centre for Brain and Education. Department of Education and Human Development, The Education University of Hong Kong, 10 Lo Ping Road, Tai Po N.T., Hong Kong, China.
Schizophr Res. 2018 Feb;192:294-299. doi: 10.1016/j.schres.2017.04.008. Epub 2017 Apr 6.
Deficits in verbal working memory (VWM) have consistently been observed in schizophrenia, ranging from impairments in capacity, encoding, to irregular semantic organisation. However, syntactic deficits are less well-characterised, despite its crucial role in language construction. This study examines the role of simple syntactic structure (basis of the "sentence superiority effect") in VWM of patients with psychotic disorders.
Patients with schizophrenia-spectrum disorders (n=40) and healthy controls matched on age, sex and education (n=40) were administered an auditory serial recall task containing word lists with low semantic coherence and either syntactically familiar structure (noun-verb-noun sequence) or syntactically unfamiliar structure. Other neurocognitive measures, symptoms and social functioning of patients were also assessed.
A 4-way analysis of variance (group×version×list type×serial position) indicated that patients had significantly worse performance overall, suggesting a generalised verbal memory impairment. In addition, a significant interaction was found for list type and Group, demonstrating that healthy controls, but not patients, had superior performance in syntactically familiar word lists. A subgroup analysis of high-performing patients revealed that the interaction was not an artefact of poor verbal memory, but a selective deficit in syntactic facilitation.
Our findings may suggest segregated mechanisms for maintenance and computational aspects of VWM, and show that even simple syntactic structure facilitates recall of syntactically unfamiliar words lists. Additionally, schizophrenic patients show difficulty utilising syntactic information, which highlights the need to understand the neuropsychological basis of working memory and linguistic impairments in psychosis.
精神分裂症患者的言语工作记忆（VWM）存在缺陷，表现在容量、编码和不规则语义组织等方面。然而，语法缺陷的特征描述较少，尽管语法在语言构建中起着至关重要的作用。本研究探讨了简单语法结构（“句子优势效应”的基础）在精神病患者 VWM 中的作用。
对精神分裂症谱系障碍患者（n=40）和年龄、性别和教育程度相匹配的健康对照者（n=40）进行了听觉系列回忆任务测试，任务中包含低语义连贯性的单词列表，以及语法上熟悉的结构（名词-动词-名词序列）或语法上不熟悉的结构。还评估了患者的其他神经认知测量、症状和社会功能。
4 组方差分析（组×版本×列表类型×序列位置）表明，患者的整体表现明显较差，表明存在一般性的言语记忆损伤。此外，列表类型和组之间存在显著的交互作用，表明健康对照组而不是患者在语法熟悉的单词列表中表现更好。对表现较好的患者进行的亚组分析表明，这种交互作用不是由于言语记忆差造成的，而是语法促进作用的选择性缺陷。
我们的研究结果可能表明 VWM 的维持和计算方面存在分离的机制，并且表明即使是简单的语法结构也能促进对语法不熟悉的单词列表的回忆。此外，精神分裂症患者表现出难以利用语法信息的困难，这突出了理解精神疾病中工作记忆和语言障碍的神经心理学基础的必要性。
