Department of Psychology, University of Jyvaskyla, P.O. Box 35, 40014, Jyväskylä, Finland.
Hear Res. 2021 Jan;399:107814. doi: 10.1016/j.heares.2019.107814. Epub 2019 Oct 11.
Mismatch negativity (MMN), which is an electrophysiological response demonstrated in humans and animals, reflects memory-based deviance detection in a series of sounds. However, only a few studies on rodents have used control conditions that were sufficient in eliminating confounding factors that could also explain differential responses to deviant sounds. Furthermore, it is unclear if change detection occurs similarly for sinusoidal and complex sounds. In this study, we investigated frequency change detection in urethane-anesthetized rats by recording local-field potentials from the dura above the auditory cortex. We studied change detection in sinusoidal and complex sounds in a series of experiments, controlling for sound frequency, probability, and pattern in a series of sounds. For sinusoidal sounds, the MMN controlled for frequency, adaptation, and pattern, was elicited at approximately 200 ms onset latency. For complex sounds, the MMN controlled for frequency and adaptation, was elicited at 60 ms onset latency. Sound frequency affected the differential responses. MMN amplitude was larger for the sinusoidal sounds than for the complex sounds. These findings indicate the importance of controlling for sound frequency and stimulus probabilities, which have not been fully controlled for in most previous animal and human studies. Future studies should confirm the preference for sinusoidal sounds over complex sounds in rats.
失匹配负波（MMN）是一种在人类和动物中表现出的电生理反应，反映了在一系列声音中基于记忆的偏差检测。然而，只有少数关于啮齿动物的研究使用了充分的对照条件，可以消除也可以解释对偏差声音产生不同反应的混杂因素。此外，对于正弦和复杂声音，变化检测是否相似尚不清楚。在这项研究中，我们通过记录听觉皮层上方硬脑膜的局部场电位，研究了麻醉大鼠的频率变化检测。我们在一系列实验中研究了正弦和复杂声音的变化检测，控制了一系列声音中的声音频率、概率和模式。对于正弦声音，控制了频率、适应和模式的 MMN 在大约 200ms 的起始潜伏期诱发。对于复杂声音，控制了频率和适应的 MMN 在 60ms 的起始潜伏期诱发。声音频率影响了差异反应。正弦声音的 MMN 幅度大于复杂声音。这些发现表明，控制声音频率和刺激概率非常重要，而在大多数以前的动物和人类研究中，这些因素并未得到充分控制。未来的研究应该证实大鼠对正弦声音的偏好超过复杂声音。
