Yang Huan, Meijer Hil G E, Buitenweg Jan R, van Gils Stephan A
Applied Analysis, MIRA Institute for Technical Medicine and Biomedical Technology, University of Twente Enschede, Netherlands.
Biomedical Signals and Systems, MIRA Institute for Technical Medicine and Biomedical Technology, University of Twente Enschede, Netherlands.
Front Psychol. 2016 Dec 5;7:1884. doi: 10.3389/fpsyg.2016.01884. eCollection 2016.
Healthy or pathological states of nociceptive subsystems determine different stimulus-response relations measured from quantitative sensory testing. In turn, stimulus-response measurements may be used to assess these states. In a recently developed computational model, six model parameters characterize activation of nerve endings and spinal neurons. However, both model nonlinearity and limited information in yes-no detection responses to electrocutaneous stimuli challenge to estimate model parameters. Here, we address the question whether and how one can overcome these difficulties for reliable parameter estimation. First, we fit the computational model to experimental stimulus-response pairs by maximizing the likelihood. To evaluate the balance between model fit and complexity, i.e., the number of model parameters, we evaluate the Bayesian Information Criterion. We find that the computational model is better than a conventional logistic model regarding the balance. Second, our theoretical analysis suggests to vary the pulse width among applied stimuli as a necessary condition to prevent structural non-identifiability. In addition, the numerically implemented profile likelihood approach reveals structural and practical non-identifiability. Our model-based approach with integration of psychophysical measurements can be useful for a reliable assessment of states of the nociceptive system.
伤害性感受子系统的健康或病理状态决定了从定量感觉测试中测得的不同刺激-反应关系。反过来，刺激-反应测量可用于评估这些状态。在最近开发的一个计算模型中，六个模型参数表征神经末梢和脊髓神经元的激活。然而，模型的非线性以及对皮肤电刺激的是/否检测反应中的信息有限，都对估计模型参数构成了挑战。在这里，我们探讨一个问题，即能否以及如何克服这些困难以进行可靠的参数估计。首先，我们通过最大化似然性将计算模型拟合到实验刺激-反应对。为了评估模型拟合与复杂性（即模型参数的数量）之间的平衡，我们评估贝叶斯信息准则。我们发现，在平衡方面，计算模型优于传统的逻辑模型。其次，我们的理论分析表明，改变施加刺激之间的脉冲宽度是防止结构不可识别性的必要条件。此外，数值实现的轮廓似然方法揭示了结构和实际的不可识别性。我们基于模型并结合心理物理学测量的方法，可能有助于对伤害性感受系统的状态进行可靠评估。
