Uitvlugt Mitchell G, Pleskac Timothy J, Ravizza Susan M
Department of Psychology, Michigan State University, 316 Physics Road, Room 285C, East Lansing, MI, 48824, USA.
Center for Adaptive Rationality, Max Planck Institute for Human Development, Berlin, Germany.
Cogn Affect Behav Neurosci. 2016 Apr;16(2):289-301. doi: 10.3758/s13415-015-0389-9.
Distractions are ubiquitous; our brains are inundated with task-irrelevant information. Thus, to remember successfully, one must actively maintain relevant information and prevent distraction from entering working memory. Researchers suggest the basal ganglia-prefrontal pathways are vital to this process by acting as a working memory gate. Using Parkinson's disease as a model of frontostriatal functioning and with signal detection analyses, the present study aims to better characterize the contribution of frontostriatal pathways of this gating process and to determine how it operates across multiple domains. To achieve this, Parkinson's disease patients and healthy controls completed verbal and spatial working memory tasks consisting of three conditions: low-load without distraction; low-load with distraction; and high-load without distraction. Patients were tested both ON and OFF dopaminergic medication, allowing for assessment of the contribution of dorsal and ventral frontostriatal pathways. The results demonstrate that when medication is withheld, Parkinson's patients have a response bias to answer "NO" across all conditions and domains, supporting our hypothesis that the basal ganglia-prefrontal pathways allow or prevent updates of working memory. Contrastingly, medication status affects d' in the distraction condition but not in the high- or low-load conditions. We attribute this to stimulus valuation processes that were impaired by dopaminergic medication overdosing the ventral pathway. These findings are both consistent with the hypothesis that the working memory gate filters spatial and verbal information before it enters into the working memory system, adding support for the gate being a domain-general mechanism of the central executive.
干扰无处不在；我们的大脑被与任务无关的信息所淹没。因此，为了成功记忆，人们必须积极维持相关信息，并防止干扰进入工作记忆。研究人员认为，基底神经节 - 前额叶通路作为工作记忆的闸门，对这一过程至关重要。本研究以帕金森病作为额纹状体功能的模型，并通过信号检测分析，旨在更好地描述额纹状体通路在这一闸门过程中的作用，并确定其在多个领域的运作方式。为实现这一目标，帕金森病患者和健康对照完成了言语和空间工作记忆任务，这些任务包含三种条件：低负荷无干扰；低负荷有干扰；高负荷无干扰。患者在服用和未服用多巴胺能药物的情况下均接受测试，以便评估背侧和腹侧额纹状体通路的作用。结果表明，在停药时，帕金森病患者在所有条件和领域下都有回答“否”的反应偏向，这支持了我们的假设，即基底神经节 - 前额叶通路允许或阻止工作记忆的更新。相反，药物状态在有干扰的条件下会影响d'，但在高负荷或低负荷条件下则不会。我们将此归因于腹侧通路多巴胺能药物过量导致受损的刺激评估过程。这些发现均与工作记忆闸门在空间和言语信息进入工作记忆系统之前进行过滤的假设一致，进一步支持了该闸门是中央执行系统的一种通用机制的观点。
