Modeling effects of precursor duration on behavioral estimates of cochlear gain.
Modeling effects of precursor duration on behavioral estimates of cochlear gain.
复制标题
模拟前兆持续时间对耳蜗增益行为估计的影响。
DOI：
10.1007/978-1-4614-1590-9_7
复制
发表时间：
2013
影响因子：
--
通讯作者：
Strickland,ElizabethA
中科院分区：
文献类型：
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作者：
Roverud,ElinM;Strickland,ElizabethA
生理数据表明，前声可通过内侧橄榄耳蜗反射（MOCR）降低耳蜗放大器增益。我们的实验室已经使用前掩蔽作为一种工具来寻找这种影响心理的证据，这使我们重新评估前掩蔽的机制。传统的时间窗口模型（TWM）提出掩蔽是通过整合在时间窗口内的兴奋机制发生的。我们建议，增益降低也可能有助于前向掩蔽。在我们的刺激范例中，掩蔽的增长是用离频前向掩蔽器来测量的，以估计基底膜输入/输出（I/O）功能。当引入通频前兆时，I/O功能的增益降低，这与增益降低假设一致。最近，我们通过研究前体持续时间的影响（Roverud和Strickland），探索了这种估计增益降低的时间过程。在这项研究中，阈值最初随着前驱持续时间的增加而增加，然后随着持续时间的延长而下降。这一结果与单纯的兴奋性掩蔽不一致，但可能反映了MOCR的增益降低。如果前体足够长，它可能会受到它引起的增益降低的影响。在本研究中，我们研究的影响，前体持续时间与频率的前体和频率的前体。如果强度足够大，离频前兆可能会降低信号频率处的增益。然而，假设它在信号处没有增益，它将不受增益降低的影响，而不管其持续时间。我们开发了一种改进的TWM，包括随时间变化的增益减少的前体，从而在适应I/O功能。结果与标准的TWM和TWM与增益降低建模。
Physiological data show that preceding sound can reduce cochlear amplifier gain via the medial olivocochlear reflex (MOCR). Our laboratory has used forward masking as a tool to look for evidence of this effect psychophysically, which has led us to reassess mechanisms of forward masking. The traditional temporal window model (TWM) proposes that masking occurs via an excitatory mechanism that integrates within a temporal window. We propose that gain reduction may also contribute to forward masking. In our stimulus paradigm, growth of masking is measured with an off-frequency forward masker to estimate the basilar membrane input/output (I/O) function. The gain of the I/O function is reduced when an on-frequency precursor is introduced, consistent with a gain reduction hypothesis. Recently we explored the time course of this estimated gain reduction by examining the effect of precursor duration (Roverud and Strickland ). In that study, thresholds initially increased with increasing precursor duration, then decreased for longer durations. This result is not consistent with solely excitatory masking, but may reflect gain reduction by the MOCR. If the precursor is long enough, it could be influenced by the gain reduction it elicited. In the present study, we examine the effect of precursor duration with an on-frequency precursor and an off-frequency precursor. If intense enough, an off-frequency precursor may reduce gain at the signal frequency place. However, assuming it has no gain at the signal place, it would not be influenced by the reduction in gain, regardless of its duration. We developed a modified TWM that includes time-varying gain reduction by the precursor, resulting in an adapting I/O function. Results are modeled with the standard TWM and the TWM with gain reduction.