Transformation of binaural response properties in the ascending auditory pathway: influence of time-varying interaural phase disparity.
Transformation of binaural response properties in the ascending auditory pathway: influence of time-varying interaural phase disparity.
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上行听觉通路中双耳响应特性的转变：时变耳间相位差的影响。
DOI：
10.1152/jn.1998.80.6.3062
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
Semple,MN
中科院分区：
文献类型：
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作者：
Spitzer,MW;Semple,MN
[2]施皮策，马修W，马尔科姆.塞姆勒.双耳反应特性在上行听觉通路中的变化：时变耳间相位差异的影响.神经生理学杂志.80：3062-3076,1998.以往的研究表明，下丘(IC)神经元对耳间相位差(IPD)的调谐经常受到耳间相位差(IPD)的时间变化的深刻影响，IPD模拟运动声源产生的双耳提示。为了确定IC或双耳加工的早期阶段是否对模拟运动敏感，我们将IC的反应与上橄榄复合体(SOC)中两个主要的IPD敏感神经元的反应进行了比较，这些神经元对纯音刺激的放电是相位锁定的(PL)，而非相位锁定的神经元(NPL)。时变的IPD刺激包括双耳节拍，通过向两只耳朵呈现频率略有不同的音调来产生，以及耳间相位调制(IPM)，通过向一只耳朵呈现纯音，向另一耳呈现相位调制音来产生。IC神经元和NPL-SOC神经元对时变的调谐比对静态IPD的调谐更敏锐，而PL-SOC神经元基本上不受刺激呈现方式的影响。在所有单位种群中，首选IPD对静态和时变IPD的反应通常是相似的。少数IC神经元受模拟运动的方向和速度的影响很大，但大多数IC神经元和所有SOC神经元的主要影响是首选IPD在高速率下的线性移动-归因于反应潜伏期。大多数IC和NPL-SOC神经元受到IPM刺激的强烈影响，模拟运动通过有限的方位范围；通过部分重叠的方位范围模拟运动引起高度不连续的放电轮廓，表明与特定IPD相关的反应依赖于刺激的先前部分。相反，PL-SOC反应跟踪整个模拟运动轨迹的瞬时IPD，导致重叠刺激的高度连续的放电轮廓。这一发现表明，PL-SOC单位对时变IPD的反应仅反映瞬时IPD，而不受动态刺激属性的额外影响。因此，听觉空间信息的神经元表征经历了一次重大的转变，因为耳间延迟最初在SOC中处理，随后在IC中重新处理。IC的运动敏感度来自运动不敏感的输入，这一发现表明，关于位置变化的信息对听觉系统更高水平的空间处理至关重要。
Spitzer, Matthew W. and Malcolm N. Semple.Transformation of binaural response properties in the ascending auditory pathway: influence of time-varying interaural phase disparity.J. Neurophysiol.80: 3062–3076, 1998. Previous studies demonstrated that tuning of inferior colliculus (IC) neurons to interaural phase disparity (IPD) is often profoundly influenced by temporal variation of IPD, which simulates the binaural cue produced by a moving sound source. To determine whether sensitivity to simulated motion arises in IC or at an earlier stage of binaural processing we compared responses in IC with those of two major IPD-sensitive neuronal classes in the superior olivary complex (SOC), neurons whose discharges were phase locked (PL) to tonal stimuli and those that were nonphase locked (NPL). Time-varying IPD stimuli consisted of binaural beats, generated by presenting tones of slightly different frequencies to the two ears, and interaural phase modulation (IPM), generated by presenting a pure tone to one ear and a phase modulated tone to the other. IC neurons and NPL–SOC neurons were more sharply tuned to time-varying than to static IPD, whereas PL–SOC neurons were essentially uninfluenced by the mode of stimulus presentation. Preferred IPD was generally similar in responses to static and time-varying IPD for all unit populations. A few IC neurons were highly influenced by the direction and rate of simulated motion, but the major effect for most IC neurons and all SOC neurons was a linear shift of preferred IPD at high rates—attributable to response latency. Most IC and NPL–SOC neurons were strongly influenced by IPM stimuli simulating motion through restricted ranges of azimuth; simulated motion through partially overlapping azimuthal ranges elicited discharge profiles that were highly discontiguous, indicating that the response associated with a particular IPD is dependent on preceding portions of the stimulus. In contrast, PL–SOC responses tracked instantaneous IPD throughout the trajectory of simulated motion, resulting in highly contiguous discharge profiles for overlapping stimuli. This finding indicates that responses of PL–SOC units to time-varying IPD reflect only instantaneous IPD with no additional influence of dynamic stimulus attributes. Thus the neuronal representation of auditory spatial information undergoes a major transformation as interaural delay is initially processed in the SOC and subsequently reprocessed in IC. The finding that motion sensitivity in IC emerges from motion-insensitive input suggests that information about change of position is crucial to spatial processing at higher levels of the auditory system.