Introduction: Although working memory (WM) dysfunction has been proposed as a schizophrenia (SZ) endophenotype, the specific impaired component (encoding or maintenance) in patients and unaffected relatives remains inconclusive. We compared auditory-verbal and visuospatial WM in patients with SZ, unaffected siblings (USs), and healthy controls under 2 response conditions: immediate (encoding condition) and delayed (maintenance condition). Methods: We included 22 participants per group, similar in age and gender. Three WM tests (Spatial Span, Backward Digit Span, and Letter-Number Span) were administered under both conditions in a counterbalanced manner to all participants. Results: Poorer performance was found in the SZ group for all tests (p #x3c; 0.001). USs showed a better performance than patients, but worse than controls (p #x3c; 0.05), except for the Backward Digit Span test, in which their performance was similar to that of the SZ group. The effect of the delayed response in all tasks was not significant in any group. Conclusion: Our results indicate that WM impairment, including auditory-verbal and visuospatial modalities, corresponds to a stable feature of the disease as it is present in USs, thus confirming its potential endophenotypic property in SZ patients. No effect of the delayed response was observed, suggesting failures in encoding in both patients and USs.
Neuropsychobiology

中文翻译：

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工作记忆障碍作为精神分裂症患者的内表型标志物：编码或维持失败？

简介：虽然工作记忆 (WM) 功能障碍已被提出为精神分裂症 (SZ) 内表型，但患者和未受影响亲属的特定受损成分（编码或维持）仍无定论。我们比较了 SZ 患者、未受影响的兄弟姐妹 (US) 和健康对照在 2 种反应条件下的听觉语言和视觉空间 WM：立即（编码条件）和延迟（维持条件）。方法：我们每组包括 22 名参与者，年龄和性别相似。在两种条件下以平衡的方式对所有参与者进行了三项 WM 测试（空间跨度、后向数字跨度和字母数字跨度）。结果：在所有测试中，SZ 组的表现都较差（ p#x3c; 0.001)。USs 表现出比患者更好的表现，但比对照组差 ( p #x3c; 0.05)，除了后向数字跨度测试，他们的表现与 SZ 组相似。在所有任务中延迟反应的影响在任何组中都不显着。结论：我们的研究结果表明，WM 损伤，包括听觉-语言和视觉空间模式，与 US 中存在的疾病的稳定特征相对应，从而证实了其在 SZ 患者中的潜在内表型特性。没有观察到延迟反应的影响，这表明患者和 US 的编码失败。
神经心理生物学