Department of Psychiatry & Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Schizophr Res. 2010 May;118(1-3):6-11. doi: 10.1016/j.schres.2010.02.1029. Epub 2010 Mar 2.
Cognitive processing inefficiency, often measured using digit symbol coding tasks, is a putative vulnerability marker for schizophrenia and a reliable indicator of illness severity and functional outcome. Indeed, performance on the digit symbol coding task may be the most severe neuropsychological deficit patients with schizophrenia display at the group level. Yet, little is known about the contributions of simpler cognitive processes to coding performance in schizophrenia (e.g. decision making, visual scanning, relational memory, motor ability). We developed an experimental behavioral task, based on a computerized digit symbol coding task, which allows the manipulation of demands placed on visual scanning efficiency and relational memory while holding decisional and motor requirements constant. Although patients (n=85) were impaired on all aspects of the task when compared to demographically matched healthy comparison subjects (n=30), they showed a particularly striking failure to benefit from the presence of predictable target information. These findings are consistent with predicted impairments in cognitive processing speed due to schizophrenia patients' well-known memory impairment, suggesting that this mnemonic deficit may have consequences for critical aspects of information processing that are traditionally considered quite separate from the memory domain. Future investigation into the mechanisms underlying the wide-ranging consequences of mnemonic deficits in schizophrenia should provide additional insight.
认知加工效率低下，通常使用数字符号编码任务进行测量，是精神分裂症的潜在脆弱性标志物，也是疾病严重程度和功能结果的可靠指标。事实上，数字符号编码任务的表现可能是精神分裂症患者在群体水平上表现出的最严重的神经心理学缺陷。然而，对于简单认知过程对精神分裂症编码表现的贡献（例如决策、视觉扫描、关系记忆、运动能力）知之甚少。我们开发了一种基于计算机数字符号编码任务的实验行为任务，该任务允许在保持决策和运动要求不变的情况下，操纵对视觉扫描效率和关系记忆的要求。尽管与人口统计学匹配的健康对照组（n=30）相比，患者（n=85）在任务的所有方面都受到了损害，但他们在从可预测的目标信息中获益方面表现出特别明显的失败。这些发现与精神分裂症患者众所周知的记忆障碍导致认知加工速度受损的预测结果一致，这表明这种记忆缺陷可能对传统上被认为与记忆领域完全不同的信息处理的关键方面产生影响。对精神分裂症中记忆缺陷的广泛后果的潜在机制的进一步研究应该提供更多的见解。
