VA San Francisco Healthcare System, Mental Health Service, San Francisco, California; Department of Psychiatry and Behavioral Sciences, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, California.
VA San Francisco Healthcare System, Mental Health Service, San Francisco, California; Department of Psychiatry and Behavioral Sciences, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, California.
Biol Psychiatry Cogn Neurosci Neuroimaging. 2023 May;8(5):551-559. doi: 10.1016/j.bpsc.2022.12.015. Epub 2023 Jan 9.
Alterations in the brain's reward system may underlie motivation and pleasure deficits in schizophrenia (SZ). Neuro-oscillatory desynchronization in the alpha band is thought to direct resource allocation away from the internal state, to prioritize processing salient environmental events, including reward feedback. We hypothesized reduced reward-related alpha event-related desynchronization (ERD) in SZ, consistent with less externally focused processing during reward feedback.
Electroencephalography was recorded while participants with SZ (n = 54) and healthy control participants (n = 54) played a simple slot machine task. Total alpha band power (8-14 Hz), a measure of neural oscillation magnitude, was extracted via principal component analysis and compared between groups and reward outcomes. The clinical relevance of hypothesized alpha power alterations was examined by testing associations with negative symptoms within the SZ group and with trait rumination, dimensionally, across groups.
A group × reward outcome interaction (p = .018) was explained by healthy control participants showing significant posterior-occipital alpha power suppression to wins versus losses (p < .001), in contrast to participants with SZ (p > .1). Among participants with SZ, this alpha ERD was unrelated to negative symptoms (p > .1). Across all participants, less alpha ERD to reward outcomes covaried with greater trait rumination for both win (p = .005) and loss (p = .002) outcomes, with no group differences in slope.
These findings demonstrate alpha ERD alterations in SZ during reward outcome processing. Additionally, higher trait rumination was associated with less alpha ERD during reward feedback, suggesting that individual differences in rumination covary with external attention to reward processing, regardless of reward outcome valence or group membership.
大脑奖励系统的改变可能是精神分裂症（SZ）动机和愉悦缺失的基础。alpha 频段的神经振荡去同步化被认为可以将资源从内部状态中分配出来，优先处理突出的环境事件，包括奖励反馈。我们假设 SZ 患者的奖励相关 alpha 事件相关去同步化（ERD）减少，这与奖励反馈期间较少的外部聚焦处理一致。
在 SZ 患者（n=54）和健康对照参与者（n=54）玩简单老虎机任务时记录脑电图。通过主成分分析提取总 alpha 频段功率（8-14 Hz），作为神经振荡幅度的度量，并在组间和奖励结果之间进行比较。通过在 SZ 组中测试与阴性症状的关联，并在组间维度上测试与特质沉思的关联，检验了假设的 alpha 功率改变的临床相关性。
组×奖励结果的交互作用（p=0.018）可以解释为健康对照组在获胜与失败时显示出明显的后枕部 alpha 功率抑制（p<0.001），而 SZ 患者则相反（p>0.1）。在 SZ 患者中，这种 alpha ERD 与阴性症状无关（p>0.1）。在所有参与者中，奖励结果的 alpha ERD 与特质沉思呈负相关，无论是获胜（p=0.005）还是失败（p=0.002），而斜率在组间没有差异。
这些发现表明 SZ 在奖励结果处理过程中存在 alpha ERD 改变。此外，较高的特质沉思与奖励反馈期间的 alpha ERD 减少相关，这表明，无论奖励结果的效价或群体成员如何，特质沉思的个体差异与对奖励处理的外部注意相关。
