Tan Xiaodan, Fu Qiuyang, Yuan Han, Ding Lei, Wang Tao
School of Biomedical Engineering, Southern Medical University, Guangzhou, China.
Department of Otolaryngology, Guangdong Second Provincial General Hospital, Guangzhou, China.
Front Neurosci. 2017 Dec 12;11:697. doi: 10.3389/fnins.2017.00697. eCollection 2017.
The auditory steady-state response (ASSR) is one of the main approaches in clinic for health screening and frequency-specific hearing assessment. However, its generation mechanism is still of much controversy. In the present study, the linear superposition hypothesis for the generation of ASSRs was investigated by comparing the relationships between the classical 40 Hz ASSR and three synthetic ASSRs obtained from three different templates for transient auditory evoked potential (AEP). These three AEPs are the traditional AEP at 5 Hz and two 40 Hz AEPs derived from two deconvolution algorithms using stimulus sequences, i.e., continuous loop averaging deconvolution (CLAD) and multi-rate steady-state average deconvolution (MSAD). CLAD requires irregular inter-stimulus intervals (ISIs) in the sequence while MSAD uses the same ISIs but evenly-spaced stimulus sequences which mimics the classical 40 Hz ASSR. It has been reported that these reconstructed templates show similar patterns but significant difference in morphology and distinct frequency characteristics in synthetic ASSRs. The prediction accuracies of ASSR using these templates show significant differences ( < 0.05) in 45.95, 36.28, and 10.84% of total time points within four cycles of ASSR for the traditional, CLAD, and MSAD templates, respectively, as compared with the classical 40 Hz ASSR, and the ASSR synthesized from the MSAD transient AEP suggests the best similarity. And such a similarity is also demonstrated at individuals only in MSAD showing no statistically significant difference (Hotelling's test, = 6.96, = 0.80, = 0.592) as compared with the classical 40 Hz ASSR. The present results indicate that both stimulation rate and sequencing factor (ISI variation) affect transient AEP reconstructions from steady-state stimulation protocols. Furthermore, both auditory brainstem response (ABR) and middle latency response (MLR) are observed in contributing to the composition of ASSR but with variable weights in three templates. The significantly improved prediction accuracy of ASSR achieved by MSAD strongly supports the linear superposition mechanism of ASSR if an accurate template of transient AEPs can be reconstructed. The capacity in obtaining both ASSR and its underlying transient components accurately and simultaneously has the potential to contribute significantly to diagnosis of patients with neuropsychiatric disorders.
听觉稳态反应（ASSR）是临床健康筛查和特定频率听力评估的主要方法之一。然而，其产生机制仍存在诸多争议。在本研究中，通过比较经典40Hz ASSR与从三种不同的瞬态听觉诱发电位（AEP）模板获得的三种合成ASSR之间的关系，研究了ASSR产生的线性叠加假说。这三种AEP分别是传统的5Hz AEP以及使用刺激序列通过两种反卷积算法得到的两种40Hz AEP，即连续循环平均反卷积（CLAD）和多速率稳态平均反卷积（MSAD）。CLAD要求序列中的刺激间隔（ISI）不规则，而MSAD使用相同的ISI但刺激序列均匀间隔，这模仿了经典的40Hz ASSR。据报道，这些重建模板在合成ASSR中显示出相似的模式，但在形态上有显著差异且频率特征不同。与经典40Hz ASSR相比，使用这些模板的ASSR预测准确率在传统、CLAD和MSAD模板的ASSR四个周期内的总时间点中分别有45.95%、36.28%和10.84%显示出显著差异（<0.05），并且由MSAD瞬态AEP合成的ASSR显示出最佳相似性。而且这种相似性在个体中也仅在MSAD中得到证明，与经典40Hz ASSR相比无统计学显著差异（Hotelling检验，F = 6.96，p = 0.80，p = 0.592）。本研究结果表明，刺激率和序列因素（ISI变化）都会影响从稳态刺激方案重建瞬态AEP。此外，在三种模板中均观察到听觉脑干反应（ABR）和中潜伏期反应（MLR）对ASSR的组成有贡献，但权重不同。如果能够重建准确的瞬态AEP模板，MSAD实现的ASSR预测准确率的显著提高有力地支持了ASSR的线性叠加机制。准确且同时获取ASSR及其潜在瞬态成分的能力有可能对神经精神疾病患者的诊断做出重大贡献。
