Center for Neuroscience, University of California, Davis, Davis, California.
Center for Neuroscience, University of California, Davis, Davis, California; Departments of Psychology, University of California, Davis, Davis, California.
Biol Psychiatry Cogn Neurosci Neuroimaging. 2023 Jan;8(1):71-78. doi: 10.1016/j.bpsc.2022.05.006. Epub 2022 May 23.
Theories suggest that people with schizophrenia (SZ) have problems generating predictions based on past experiences. The dorsolateral prefrontal cortex (DLPFC) and hippocampus participate in memory-based prediction. We used functional magnetic resonance imaging to investigate DLPFC and hippocampal function in healthy control (HC) subjects and people with SZ during memory-based prediction.
Prior to scanning, HC subjects (n = 54) and people with SZ (n = 31) learned 5-object sequences presented in fixed or random orders on each repetition. During scanning, participants made semantic decisions (e.g., "Can this object fit in a shoebox?") on a continuous stream of objects from fixed and random sequences. Sequence prediction was demonstrated by faster semantic decisions for objects in fixed versus random sequences because memory could be used to anticipate and more efficiently process semantic information about upcoming objects in fixed sequences. Representational similarity analyses were used to determine how each sequence type was represented in the posterior hippocampus and DLPFC.
Sequence predictions were reduced in individuals with SZ relative to HC subjects. Representational similarity analyses revealed stronger memory-based predictions in the DLPFC of HC subjects than people with SZ, and DLPFC representations correlated with more successful predictions in HC subjects only. For the posterior hippocampus, voxel pattern similarity was increased for fixed versus random sequences in HC subjects only, but no significant between-group differences or correlations with prediction success were observed.
Individuals with SZ are capable of learning temporal sequences; however, they are impaired using memory to predict upcoming events as efficiently as HC subjects. This deficit appears related to disrupted neural representation of sequence information in the DLPFC.
理论表明，精神分裂症（SZ）患者在基于过去经验进行预测方面存在问题。背外侧前额叶皮层（DLPFC）和海马体参与基于记忆的预测。我们使用功能磁共振成像来研究健康对照组（HC）受试者和 SZ 患者在基于记忆的预测期间的 DLPFC 和海马体功能。
在扫描之前，HC 受试者（n=54）和 SZ 患者（n=31）在每次重复中学习固定或随机顺序呈现的 5 个物体序列。在扫描过程中，参与者对固定和随机序列中的连续物体流进行语义决策（例如，“这个物体可以放进鞋盒吗？”）。由于可以使用记忆来预测和更有效地处理固定序列中即将到来的物体的语义信息，因此固定序列中的物体的语义决策速度更快，表明存在序列预测。使用代表性相似性分析来确定每个序列类型在海马体后部和 DLPFC 中的表示方式。
与 HC 受试者相比，SZ 患者的序列预测减少。代表性相似性分析表明，HC 受试者的 DLPFC 中基于记忆的预测更强，而只有 HC 受试者的 DLPFC 表示与更成功的预测相关。对于海马体后部，只有 HC 受试者在固定与随机序列之间的神经活动模式相似性增加，但在组间未观察到显著差异或与预测成功的相关性。
SZ 患者能够学习时间序列；然而，他们在使用记忆来预测即将发生的事件方面的效率不如 HC 受试者。这种缺陷似乎与 DLPFC 中序列信息的神经表示受损有关。
