Waltz James A, Brown Jaime K, Gold James M, Ross Thomas J, Salmeron Betty J, Stein Elliot A
Department of Psychiatry, University of Maryland School of Medicine, Maryland Psychiatric Research Center, Baltimore, MD;
Neuroimaging Research Branch, National Institute on Drug Abuse - Intramural Research Program, Baltimore, MD.
Schizophr Bull. 2015 Sep;41(5):1115-22. doi: 10.1093/schbul/sbv034. Epub 2015 Apr 1.
It has been proposed that both positive and negative symptoms in schizophrenia (SZ) may derive, at least in part, from a disrupted ability to accurately and flexibly represent the value of stimuli and actions. To assess relationships between dimensions of psychopathology in SZ, and the tendency to devalue food stimuli, on which subjects were fed to satiety, we administered a sensory-specific satiety (SSS) paradigm to 42 SZ patients and 44 controls. In each of 2 sessions, subjects received 16 0.7-ml squirts of each of 2 rewarding foods and 32 squirts of a control solution, using syringes. In between the 2 sessions, each subject was instructed to drink one of the foods until he/she felt "full, but not uncomfortable." At 10 regular intervals, interspersed throughout the 2 sessions, subjects rated each liquid for pleasantness, using a Likert-type scale. Mann-Whitney U-tests revealed group differences in SSS effects. Within-group tests revealed that, while controls showed an effect of satiety that was sensory specific, patients showed an effect of satiety that was not, devaluing the sated and unsated foods similarly. In SZ patients, we observed correlations between the magnitude of SSS effects and measures of both positive and negative symptoms. We argue that the ability to flexibly and rapidly update representations of the value of stimuli and actions figures critically in the ability of patients with psychotic illness to process salient events and adaptively engage in goal-directed behavior.
有人提出，精神分裂症（SZ）的阳性和阴性症状可能至少部分源于准确灵活地表征刺激和行为价值的能力受损。为了评估SZ患者精神病理学维度与食物刺激贬值倾向之间的关系（在让受试者进食至饱腹感的情况下），我们对42名SZ患者和44名对照者实施了感官特异性饱腹感（SSS）范式。在两个阶段的每一个阶段中，受试者使用注射器接受两种奖励性食物各16次0.7毫升的注射以及32次对照溶液的注射。在两个阶段之间，指示每个受试者喝其中一种食物，直到他/她感到“饱了，但不难受”。在贯穿两个阶段的10个固定时间间隔，受试者使用李克特量表对每种液体的愉悦度进行评分。曼-惠特尼U检验揭示了SSS效应的组间差异。组内检验显示，虽然对照组表现出具有感官特异性的饱腹感效应，但患者表现出的饱腹感效应并非如此，对已饱足和未饱足的食物进行了类似的贬值。在SZ患者中，我们观察到SSS效应的大小与阳性和阴性症状的测量之间存在相关性。我们认为，灵活快速更新刺激和行为价值表征的能力在精神病患者处理显著事件和适应性地参与目标导向行为的能力中起着关键作用。
