Role of latency jittering correction in motion-onset VEP amplitude decay during prolonged visual stimulation
Role of latency jittering correction in motion-onset VEP amplitude decay during prolonged visual stimulation
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DOI：
10.1007/s10633-012-9321-6
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发表时间：
2012-06-01
影响因子：
1.4
通讯作者：
Szanyi, J.
中科院分区：
文献类型：
--
作者：
Kremlacek, J.;Hulan, M.;Szanyi, J.
运动起始刺激的视觉诱发电位（M-VEP）在检查过程中振幅逐渐衰减。观察到的平均响应下降可能是由单个响应幅度的降低和/或响应延迟的可变性增加（即延迟抖动）引起的。为了阐明刺激重复过程中M-VEP抑制的起源，我们使用相关技术来估计单次扫描可能的潜伏期抖动的上限，并评估其校正对三个M-VEP主峰P1，N2和P3振幅的影响。在长时间的视觉运动刺激中，枕区校正潜伏期偏移的变异性增加（r = 0.35：0.44），枕区和顶叶区对应于平均曲线的单个反应数目减少（r =-0.48：-0.62）。虽然P1峰值振幅没有表现出任何时间特异性行为，但N2振幅表现出29.4%的显著衰减，通过延迟抖动和非对应性校正，在中央枕叶推导中部分降低至16.6%。在P3振幅中观察到最强的衰减（32.7%），并且对校正不太敏感，仅下降到27.9%。对重复运动刺激的反应抑制的主要部分是由幅度下降引起的，并且代表可能对应于疲劳模型的非平稳过程。潜伏期抖动校正变异性的增加和与M-VEP相关的单一反应的减少是与长时间运动刺激相关的重要因素。这些参数与假设的真实响应的关系是不明确的，可能是由响应的时移或信噪比的变化引起的。使用选择性平均和延迟抖动校正，反应抑制的影响被部分消除。
Visual evoked potentials to motion-onset stimulation (M-VEPs) gradually attenuate in amplitude during examination. The observed decline in averaged responses can be caused by decreases in single response magnitudes and/or increased variability in a response delays, that is, latency jittering. To illuminate the origins of the suppression of M-VEPs during stimuli repetition, we used correlation technique to estimate an upper bound of possible latency jittering of single sweeps and we evaluated the effect of its correction on the amplitudes of three M-VEP dominant peaks P1, N2 and P3. During prolonged visual motion stimulation, the variability of corrective latency shifts in the occipital region increased (r = 0.35: 0.44) and the number of single responses corresponding to the average curve declined in occipital and parietal derivations (r = -0.48: -0.62). While the P1 peak amplitude did not exhibit any time-specific behaviour, the N2 amplitude exhibited a significant decay of 29.4 % that was partially reduced to 16.6 % in the central occipital derivation by the latency jitter and non-correspondence corrections. The strongest attenuation (32.7 %) was observed in the P3 amplitude and was less sensitive to the corrections, dropping only to 27.9 %. The main part of the response suppression to repeated motion stimulation was caused by amplitude drop and represents non-stationary process that likely correspond to a fatigue model. The rise of variability in latency jitter correction and the reduction in single responses correlated with the M-VEP were significant factors associated with prolonged motion stimulation. The relation of these parameters to a hypothetical veridical response is ambiguous and can be caused by a time shift of the response or by a change of signal-to-noise ratio. Using selective averaging and latency jitter correction, the effect of response suppression was partially removed.