Department of Psychiatry, University of Maryland School of Medicine, Baltimore,MD 21228, USA.
Schizophr Bull. 2011 Nov;37(6):1295-304. doi: 10.1093/schbul/sbq047. Epub 2010 May 19.
Previous studies have typically found that individuals with schizophrenia (SZ) report levels of emotional experience that are similar to controls (CN) when asked to view a single evocative stimulus and make an absolute judgment of stimulus "value." However, value is rarely assigned in absolute terms in real-life situations, where one alternative or experience is often evaluated alongside others, and value judgments are made in relative terms. In the current study, we examined performance on a preference task that requires individuals to differentiate between the relative values of different stimuli. In this task, subjects were presented with many pairs of moderately positive stimuli and asked to indicate which stimulus they preferred in each pair. Resulting data indicated the rank order of preference across stimuli and the consistency of their transitive mapping (ie, if A > B and B > C, then A should be > C). Individuals with SZ (n = 38) were both less consistent in their rankings of stimuli and more likely to have larger magnitudes of discrepant responses than control subjects (n = 27). Furthermore, CN showed clear differentiation between different valence categories of stimuli (ie, highly positive > mildly positive > mildly negative > highly negative); while individuals with SZ showed the same general pattern of results but with less differentiation between the valence levels. These data suggest that individuals with SZ are impaired in developing or maintaining nuanced representations of the different attributes of a stimulus, thus making stimuli of similar general value easily confusable.
先前的研究通常发现,当被要求观看单一唤起刺激并对刺激“价值”做出绝对判断时,精神分裂症(SZ)个体报告的情绪体验水平与对照组(CN)相似。然而,在现实生活中,价值很少以绝对术语来分配,在这种情况下,通常会对一个替代方案或体验进行评估,并且以相对术语做出价值判断。在当前的研究中,我们检查了在需要个体区分不同刺激的相对价值的偏好任务上的表现。在该任务中,向受试者呈现许多对适度积极的刺激,并要求他们指出每对刺激中他们更喜欢哪一个。结果数据表明了跨刺激的偏好顺序以及它们的传递映射的一致性(即,如果 A>B 且 B>C,则 A 应该>C)。与对照组(n=27)相比,SZ 个体(n=38)的刺激排名一致性较差,并且更有可能出现更大幅度的不一致反应。此外,CN 显示出对不同效价类别的刺激的明显区分(即,高度积极>轻度积极>轻度消极>高度消极);而 SZ 个体表现出相同的一般结果模式,但在效价水平之间的区分较小。这些数据表明,SZ 个体在发展或维持刺激不同属性的细微表示方面存在障碍,从而使具有相似一般价值的刺激容易混淆。