This study examined whether Parkinson's disease (PD¹) and schizophrenia (SCZ²) share a hypo dopaminergic dysfunction of the prefrontal cortex leading to cognitive impairments in decision processing. 24 medicated PD patients and 28 matched controls performed the Eriksen flanker two-choice reaction time (RT³) task while brain activity was measured throughout, using functional Magnetic Resonance Imaging (fMRI⁴). Results were directly compared to those of 30 SCZ patients and 30 matched controls. Significant differences between SCZ and PD were found, through directly comparing the z-score deviations from healthy controls across all behavioral measures, where only SCZ patients showed deviances from controls. Similarly a direct comparison of z-score activation deviations from controls indicated significant differences in prefrontal and cingulate cortical activation between SCZ and PD, where only SCZ patients showed hypo-activation of these areas compared to controls. The hypo-activation of the dorsolateral prefrontal cortex was related to larger RT variability (ex-Gaussian tau) in SCZ but not PD patients. Overall, the concluding evidence does not support a shared neural substrate of cognitive dysfunction, since the deficit in speeded decision processing and the related cortical hypo-activation observed in SCZ were absent in PD.

这项研究检查了帕金森病 (PD ¹ ) 和精神分裂症 (SCZ ² ) 是否都存在导致决策过程中认知障碍的前额叶皮层多巴胺功能低下的功能障碍。24 名服用药物的 PD 患者和 28 名匹配的对照执行 Eriksen 侧翼二选一反应时间 (RT ³ ) 任务，同时使用功能性磁共振成像 (fMRI ⁴ ) 测量整个大脑活动）。结果直接与 30 名 SCZ 患者和 30 名匹配对照的结果进行比较。通过直接比较所有行为测量中健康对照的 z 分数偏差，发现 SCZ 和 PD 之间存在显着差异，其中只有 SCZ 患者表现出与对照的偏差。类似地，与对照的 z 分数激活偏差的直接比较表明 SCZ 和 PD 之间的前额叶和扣带皮层激活存在显着差异，其中与对照相比，只有 SCZ 患者显示这些区域的低激活。背外侧前额叶皮层的低激活与 SCZ 中较大的 RT 变异性（ex-Gaussian tau）有关，但与 PD 患者无关。总体而言，结论性证据不支持认知功能障碍的共同神经基础，