University of California, Santa Barbara, CA 93106-9660, USA.
Neural Netw. 2012 Aug;32:74-85. doi: 10.1016/j.neunet.2012.02.033. Epub 2012 Feb 20.
Cools (2006) suggested that prefrontal dopamine levels are related to cognitive stability whereas striatal dopamine levels are related to cognitive plasticity. With such a wide ranging role, almost all cognitive activities should be affected by dopamine levels in the brain. Not surprisingly, factors influencing brain dopamine levels have been shown to improve/worsen performance in many behavioral experiments. On the one hand, Nadler, Rabi, and Minda (2010) showed that positive affect (which is thought to increase cortical dopamine levels) improves a type of categorization that depends on explicit reasoning (rule-based) but not another type that depends on procedural learning (information-integration). On the other hand, Parkinson's disease (which is known to decrease dopamine levels in both the striatum and cortex) produces proactive interference in the odd-man-out task (Flowers & Robertson, 1985) and renders subjects insensitive to negative feedback during reversal learning (Cools, Altamirano, & D'Esposito, 2006). This article uses the COVIS model of categorization to simulate the effects of different dopamine levels in categorization, reversal learning, and the odd-man-out task. The results show a good match between the simulated and human data, which suggests that the role of dopamine in COVIS can account for several cognitive enhancements and deficits related to dopamine levels in healthy and patient populations.
库尔兹（2006）提出，前额叶多巴胺水平与认知稳定性有关，而纹状体多巴胺水平与认知可塑性有关。由于多巴胺具有如此广泛的作用，几乎所有的认知活动都应该受到大脑中多巴胺水平的影响。毫不奇怪，影响大脑多巴胺水平的因素已被证明可以改善/恶化许多行为实验中的表现。一方面，纳德勒、拉比和明达（2010）表明积极情绪（被认为会增加皮质多巴胺水平）可以改善一种依赖于明确推理（基于规则）的分类，而不是另一种依赖于程序性学习（信息整合）的分类。另一方面，帕金森病（已知会降低纹状体和皮质中的多巴胺水平）会导致异类任务中的前摄干扰（Flowers & Robertson，1985），并且使受试者在反转学习过程中对负反馈不敏感（Cools、Altamirano 和 D'Esposito，2006）。本文使用 COVIS 分类模型来模拟分类、反转学习和异类任务中不同多巴胺水平的影响。结果表明，模拟数据与人类数据之间具有很好的匹配，这表明多巴胺在 COVIS 中的作用可以解释与健康人群和患者群体中多巴胺水平相关的几种认知增强和缺陷。
