EFFECTS OF CONTINUOUS NOISE BACKGROUNDS ON RATE RESPONSE OF AUDITORY-NERVE FIBERS IN CAT
EFFECTS OF CONTINUOUS NOISE BACKGROUNDS ON RATE RESPONSE OF AUDITORY-NERVE FIBERS IN CAT
复制标题
DOI：
10.1152/jn.1984.51.6.1326
复制
发表时间：
1984-01-01
影响因子：
2.5
通讯作者：
GIBSON, DJ
中科院分区：
文献类型：
--
作者：
COSTALUPES, JA;YOUNG, ED;GIBSON, DJ
描述了宽带背景噪声对猫听觉神经纤维最佳频率 (BF) 音调的平均放电率的影响。将暴露于长期连续噪声的影响与与测试音同时打开和关闭的噪声门控的影响进行比较。背景噪声的添加导致音调诱发率与电平函数的动态部分转变为更高的音调强度。噪音水平每增加 1 dB，平均变化率为 0.61 dB。移动速率与最佳频率和自发放电率无关。转变开始时的噪声水平与频率相关，并且与听觉神经纤维调谐曲线的频率相关带宽一致。动态范围的调整与 2 音抑制有很多相似之处。这可能是由于周围频率的噪声中存在的能量抑制了 BF 测试音的响应而引起的。在高噪声水平下，听觉神经纤维响应测试音的能力受到对噪声的速率响应的限制。随着噪声水平的增加，它引起的放电率接近光纤的饱和率，并最终消除光纤响应测试音的能力。低自发率光纤具有更高的阈值和更宽的动态范围，显着更能抵抗高噪声水平的饱和。在测试音调出现之前暴露于宽带噪声会导致响应率总体下降。这种现象类似于短期适应的影响，并且似乎独立于动态范围的变化而发展。在高噪声水平下，先前暴露于噪声会产生小的动态范围变化。这种效果与抑制产生的效果类似，但较小。通过调整抑制产生的灵敏度，可以在连续噪声背景中消除该效应。
The effects of broadband background noise on the average discharge rate to best-frequency (BF) tones of auditory nerve fibers in the cat are described. The effects of exposure to long-term continuous noise are compared to the effects of noise gated on and off simultaneously with test tones. Addition of background noise causes a shift of the dynamic portion of tone-evoked rate versus level functions to higher tone intensities. The shift occurs at a mean rate of 0.61 dB of shift for each 1-dB increment in noise level. The rate of shift is independent of best frequency and spontaneous discharge rate. The noise level at which the shift begins is frequency dependent and is consistent with the frequency-dependent bandwidths of auditory nerve fiber tuning curves. The adjustment of the dynamic range shows many similarities to 2-tone suppression. It is probably caused by suppression of the response to the BF test tone by energy present in the noise at surrounding frequencies. At high noise levels, the ability of auditory nerve fibers to respond to test tones is limited by the rate response to the noise. As noise level increases, the discharge rate it evokes approaches a fiber''s saturation rate and ultimately eliminates the fiber''s ability to respond to test tones. Low spontaneous rate fibers, which have higher thresholds and wider dynamic range are significantly more resistant to saturation by high noise levels. Exposure to broadband noise prior to onset of test tones produces an overall decrement in response rate. This phenomenon is similar to the effects of short-term adaptation and seems to develop independently of the shift of dynamic range. At high noise levels, previous exposure to the noise produces a small dynamic range shift. This effect is similar to that produced by suppression but is smaller. The effect is occluded in continuous noise backgrounds by the adjustment of sensitivity produced by suppression.