Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran.
Department of Psychology and Educational Sciences, University of Tehran, Tehran, Iran.
Comput Biol Med. 2017 Jul 1;86:113-128. doi: 10.1016/j.compbiomed.2017.05.014. Epub 2017 May 13.
Discovering factors influencing the speed and accuracy of responses in tasks such as "Go/No-Go" is one of issues which have been raised in neurocognitive studies. Mathematical models are considered as tools to identify and to study decision making procedure from different aspects. In this paper, a mathematical model has been presented to show several factors can alter the output of decision making procedure before execution in a "Go/No-Go" task. The dynamic of this model has two stable fixed points, each of them corresponds to the "Press" and "Not-press" responses. This model that focuses on the fronto-striatal-thalamic direct and indirect pathways, receives planned decisions from frontal cortex and sends a regulated output to motor cortex for execution. The state-space analysis showed that several factors could affect the regulation procedure such as the input strength, noise value, initial condition, and the values of involved neurotransmitters. Some probable analytical reasons that may lead to changes in decision-execution regulation have been suggested as well. Bifurcation diagram analysis demonstrates that an optimal interaction between these factors can compensate the weaknesses of some others. It is predicted that abnormalities of response control in different brain disorders such as attention deficit hyperactivity disorder may be resolved by providing treatment techniques that target the regulation of the interaction. The model also suggests a possible justification to show why so many studies insist on the important role of dopamine in some brain disorders.
研究影响“Go/No-Go”等任务中反应速度和准确性的因素是神经认知研究中提出的问题之一。数学模型被认为是从不同角度识别和研究决策过程的工具。本文提出了一个数学模型，表明在“Go/No-Go”任务执行之前，有几个因素可以改变决策过程的输出。该模型的动力学有两个稳定的固定点，每个固定点对应于“按”和“不按”反应。该模型专注于额皮质-纹状体-丘脑直接和间接通路，接收来自额叶皮质的计划决策，并发送调节后的输出到运动皮质进行执行。状态空间分析表明，几个因素可能会影响调节过程，例如输入强度、噪声值、初始条件和涉及的神经递质的值。还提出了一些可能导致决策执行调节变化的分析原因。分叉图分析表明，这些因素之间的最佳相互作用可以弥补其他因素的弱点。可以预测，通过提供针对调节相互作用的治疗技术，可能会解决注意力缺陷多动障碍等不同脑障碍中反应控制异常的问题。该模型还提出了一个可能的解释，说明为什么许多研究都强调多巴胺在某些脑障碍中的重要作用。
