Biomedical Signals and Systems, Technical Medical Centre, University of Twente, PO Box 217, 7500 AE, Enschede, The Netherlands.
Centre for Human Drug Research, Leiden, the Netherlands.
Behav Res Methods. 2020 Aug;52(4):1617-1628. doi: 10.3758/s13428-019-01338-7.
Measuring altered nociceptive processing involved in chronic pain is difficult due to a lack of objective methods. Potential methods to characterize human nociceptive processing involve measuring neurophysiological activity and psychophysical responses to well-defined stimuli. To reliably measure neurophysiological activity in response to nociceptive stimulation using EEG, synchronized activation of nerve fibers and a large number of stimuli are required. On the other hand, to reliably measure psychophysical detection thresholds, selection of stimulus amplitudes around the detection threshold and many stimulus-response pairs are required. Combining the two techniques helps in quantifying the properties of nociceptive processing related to detected and non-detected stimuli around the detection threshold.The two techniques were combined in an experiment including 20 healthy participants to study the effect of intra-epidermal electrical stimulus properties (i.e. amplitude, single- or double-pulse and trial number) on the detection thresholds and vertex potentials. Generalized mixed regression and linear mixed regression were used to quantify the psychophysical detection probability and neurophysiological EEG responses, respectively.It was shown that the detection probability is significantly modulated by the stimulus amplitude, trial number, and the interaction between stimulus type and amplitude. Furthermore, EEG responses were significantly modulated by stimulus detection and trial number. Hence, we successfully demonstrated the possibility to simultaneously obtain information on psychophysical and neurophysiological properties of nociceptive processing. These results warrant further investigation of the potential of this method to observe altered nociceptive processing.
由于缺乏客观方法，测量慢性疼痛中改变的伤害性处理非常困难。用于描述人类伤害性处理的潜在方法包括测量神经生理活动和对明确定义的刺激的心理物理反应。为了使用 EEG 可靠地测量对伤害性刺激的神经生理活动，需要同步激活神经纤维和大量刺激。另一方面，为了可靠地测量心理物理检测阈值，需要选择检测阈值周围的刺激幅度和许多刺激-反应对。将这两种技术结合起来有助于量化与检测和检测阈值周围未检测到的刺激相关的伤害性处理特性。这两种技术在一项包括 20 名健康参与者的实验中结合使用，以研究表皮内电刺激特性（即幅度、单脉冲或双脉冲和试验次数）对检测阈值和顶点电位的影响。广义混合回归和线性混合回归分别用于量化心理物理检测概率和神经生理 EEG 反应。结果表明，刺激幅度、试验次数以及刺激类型与幅度之间的相互作用显著调节了检测概率。此外，EEG 反应也显著受到刺激检测和试验次数的调节。因此，我们成功地证明了同时获得伤害性处理的心理物理和神经生理特性信息的可能性。这些结果进一步证明了这种方法观察改变的伤害性处理的潜力。
