PDF(Pubmed)
Abstract：
Reward processing is impaired in people with schizophrenia, which may begin in the clinical high-risk (CHR) for psychosis period. The Monetary Incentive Delay (MID) task has been important in understanding the neural correlates of reward processing deficits in various psychiatric disorders. Previous research has found that CHR individuals have an imprecise mental representation of rewards, which leads to a diminished differentiation between rewards, though this has not been observed behaviorally. A total of 19 CHR individuals and 20 controls were given a novel variant of the MID task, designed to examine how modulating reward context may impact responses to reward cues, a process often referred to as \"adaptive coding.\" Both groups appeared to update their behavior in response to the rewards available in this adaptive task. However, when compared to controls who showed a more graded decrease in response time to increasing reward contexts, CHR individuals appeared to have a sharp decrease in response time in the low reward context that is nearly stable across higher reward contexts. This is largely driven by the exponential component of the response time distribution, which is often interpreted to be more cognitively or effortfully influenced. Response times are related to negative symptoms, but not positive symptoms, disorganized symptoms, or estimated intelligence. Although an adaptive coding effect was not observed, these results provide novel insight into the reward processing mechanisms and volitional processes in the CHR population, as this was the first study to observe the diminished differentiation of rewards behaviorally.
摘要：
精神分裂症患者的奖励处理受损，这可能始于精神病期的临床高风险（CHR）。货币激励延迟（MID）任务对于理解各种精神疾病中奖励处理缺陷的神经相关性非常重要。先前的研究发现，CHR个体对奖励的心理表现不精确，这导致奖励之间的差异减少，尽管这还没有从行为上观察到。总共19个CHR个体和20个对照被给予了MID任务的新变体，旨在研究调节奖励环境如何影响对奖励线索的反应，一个通常被称为“自适应编码”的过程。“两组似乎都更新了他们的行为，以响应这一适应性任务中可用的奖励。然而,与对增加的奖励环境的响应时间表现出更分级的减少的对照组相比，CHR个体在低奖励环境中的响应时间似乎急剧下降，在较高奖励环境中几乎是稳定的。这在很大程度上是由响应时间分布的指数分量驱动的，这通常被解释为更多的认知或努力的影响。反应时间与阴性症状有关,但不是阳性症状,杂乱无章的症状，或者估计的智力。尽管没有观察到自适应编码效果，这些结果为CHR群体中的奖励处理机制和意志过程提供了新的见解，因为这是第一项观察行为上奖励差异减弱的研究。
