EFFECTS OF CONTINUOUS NOISE MASKERS ON TONE-EVOKED POTENTIALS IN CAT PRIMARY AUDITORY-CORTEX
EFFECTS OF CONTINUOUS NOISE MASKERS ON TONE-EVOKED POTENTIALS IN CAT PRIMARY AUDITORY-CORTEX
复制标题
DOI：
10.1093/cercor/2.2.134
复制
发表时间：
1992-03-01
期刊：
影响因子：
3.7
通讯作者：
KELLY, JB
中科院分区：
文献类型：
--
作者：
PHILLIPS, DP;KELLY, JB
在9只巴比妥钠麻醉的猫上，研究了对侧耳的皮层诱发电位对连续宽带噪声掩蔽的影响。在五种动物中，在同一只耳朵存在连续噪声掩蔽的情况下，获得了关于音调的输入输出函数。掩蔽者的存在提高了音调阈值，它们密切跟踪掩蔽者的级别，因此掩蔽者级别的增加会带来相同幅度的音调阈值升高。在四只动物中，我们比较了连续口罩呈现给同一只耳朵、另一只耳朵以及同时呈现给两只耳朵的对侧声调反应的影响。在与音调相对的耳朵处，掩蔽物的存在对带有音调的耳朵对刺激的反应具有微小而不同的影响，无论该耳朵是否也存在噪音。对现有的单神经元证据的考虑提供了对这些发现的解释。众所周知，对几乎所有的皮质神经元来说，在耳朵上使用音调掩蔽可以降低信号敏感度，而在与音调相反的耳朵(与大脑皮质同侧)进行掩蔽的效果可能是非常不同的。这很可能是具有不同双耳配置的信号对并发掩蔽器的感知突显存在于神经元元件被激活的位置，而不是在被兴奋的细胞总数中，也许正是由于这个原因，诱发电位仅显示出该掩蔽参数的轻微影响。
In nine barbiturate-anesthetized cats, cortical evoked potentials for tones presented to the contralateral ear were studied for the effects of continuous wideband noise masking. In five animals, input-output functions for tones were obtained in the presence of continuous noise masking at the same ear. Tone thresholds were raised by the presence of the masker, and they closely tracked the level of the masker, such that increments in masker level brought about tone threshold elevations of the same magnitude. In four animals, we compared the effect on responses to contralateral tones of continuous maskers presented to the same ear as the tone, to the opposite ear, and to both ears simultaneously. The presence of the masker at the ear opposite the tone had a small and variable effect on the response to the stimulus at the ear with the tone, whether or not noise was also present at that ear. Consideration of extant single-neuron evidence provides an interpretation of these findings. Whereas maskers at the ear with the tone are known to reduce signal sensitivity for almost all cortical neurons, the effects of masking at the ear opposite the tone (ipsilateral to the cortex) are likely to be very heterogeneous. It is likely that the perceptual salience of signals that have different binaural configurations to concurrent maskers resides in which neuronal elements are activated, rather than in the total number of cells excited, and it is perhaps for this reason that the evoked potentials show only modest effects of this masking parameter.