Department of Psychiatry and Psychotherapy, Friedrich-Schiller-University Jena, Jahnstr, Philosophenweg 3, 07740 Jena, Germany.
Neuroimage. 2010 Mar;50(1):223-32. doi: 10.1016/j.neuroimage.2009.12.031. Epub 2009 Dec 16.
In patients with schizophrenia, the ability to learn from reinforcement is known to be impaired. The present fMRI study aimed at investigating the neural correlates of reinforcement-related trial-and-error learning in 19 schizophrenia patients and 20 healthy volunteers. A modified gambling paradigm was applied where each cue indicated a subsequent number which had to be guessed. In order to vary predictability, the cue-number associations were based on different probabilities (50%, 81%, 100%) which the participants were not informed about. Patients' ability to learn contingencies on the basis of feedback and reward was significantly impaired. While in healthy volunteers increasing predictability was associated with decreasing activation in a fronto-parietal network, this decrease was not detectable in patients. Analysis of expectancy-related reinforcement processing yielded a hypoactivation in putamen, dorsal cingulate and superior frontal cortex in patients relative to controls. Present results indicate that both reinforcement-associated processing and reinforcement learning might be impaired in the context of the disorder. They moreover suggest that the activation deficits which patients exhibit in association with the processing of reinforcement might constitute the basis for the learning deficits and their accompanying activation alterations.
在精神分裂症患者中，已知其从强化中学习的能力受损。本 fMRI 研究旨在调查 19 名精神分裂症患者和 20 名健康志愿者在强化相关试错学习中的神经相关性。应用了一种改良的赌博范式，其中每个提示都表示随后要猜测的一个数字。为了改变可预测性，提示-数字的关联基于参与者不知道的不同概率（50%、81%、100%）。患者基于反馈和奖励来学习关联的能力明显受损。虽然在健康志愿者中，可预测性的增加与额顶叶网络的激活减少相关，但在患者中无法检测到这种减少。对与期望相关的强化处理的分析表明，与对照组相比，患者的壳核、背侧扣带回和额上回的激活减少。目前的结果表明，在这种疾病的背景下，强化相关处理和强化学习都可能受损。此外，患者在强化处理过程中表现出的激活缺陷可能构成学习缺陷及其伴随的激活改变的基础。
