Grimm Sabine, Escera Carles, Nelken Israel
Cognitive and Biological Psychology, Institute of Psychology, University of Leipzig, Leipzig, Germany.
Institute for Brain, Cognition and Behavior (IR3C), University of Barcelona, Barcelona, Catalonia, Spain; Brainlab-Cognitive Neuroscience Research Group, Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Catalonia, Spain.
Biol Psychol. 2016 Apr;116:23-7. doi: 10.1016/j.biopsycho.2015.11.017. Epub 2015 Dec 2.
Detecting unexpected stimuli in the environment is a critical function of the auditory system. Responses to unexpected "deviant" sounds are enhanced compared to responses to expected stimuli. At the human scalp, deviance detection is reflected in the mismatch negativity (MMN) and in an enhancement of the middle-latency response (MLR). Single neurons often respond more strongly to a stimulus when rare than when common, a phenomenon termed stimulus-specific adaptation (SSA). Here we compare stimulus-specific adaptation with scalp-recorded deviance-related responses. We conclude that early markers of deviance detection in the time range of the MLR could be a direct correlate of cortical SSA. Both occur at an early level of cortical activation, both are robust findings with low-probability stimuli, and both show properties of genuine deviance detection. Their causal relation with the later scalp-recorded MMN is a key question in this field.
检测环境中的意外刺激是听觉系统的一项关键功能。与对预期刺激的反应相比，对意外“偏差”声音的反应会增强。在人类头皮上，偏差检测反映在失匹配负波（MMN）以及中潜伏期反应（MLR）的增强上。单个神经元通常对罕见刺激的反应比对常见刺激的反应更强烈，这一现象被称为刺激特异性适应（SSA）。在这里，我们将刺激特异性适应与头皮记录的偏差相关反应进行比较。我们得出结论，在MLR时间范围内偏差检测的早期标记可能是皮质SSA的直接相关指标。两者都发生在皮质激活的早期阶段，两者都是低概率刺激下的可靠发现，并且都表现出真正偏差检测的特性。它们与后来头皮记录的MMN的因果关系是该领域的一个关键问题。
