The perceptual effects of current pulse duration in electrical stimulation of the auditory nerve
The perceptual effects of current pulse duration in electrical stimulation of the auditory nerve
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DOI：
10.1121/1.428052
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发表时间：
1999-08-01
影响因子：
2.4
通讯作者：
McDermott, HJ
中科院分区：
文献类型：
--
作者：
McKay, CM;McDermott, HJ
在采用脉动刺激的耳蜗植入物中，响度由电流幅度和/或脉冲持续时间控制。用耳蜗植入者进行了五个实验，以研究以下假设：除了响度之外，脉冲持续时间从50 μ s到266 μ s的变化引起感知效应。在实验1中，在四个电极位置处测量五个受试者辨别采用不同脉冲持续时间的同等响亮脉冲串的能力。在20例中，有11例受试者可以明显区分这些刺激。在实验2和3中，测量了双电极刺激的辨别力，所述双电极刺激在总体时间模式上不同，但在每个单独电极上具有相等的时间模式（间隔0至9 mm）。歧视进行了比较，采用短或长的脉冲持续时间的刺激，在实验3中，采用不同的脉冲持续时间在每个电极上。当脉冲持续时间较长时，七个受试者中的六个可以在较宽的电极间隔处跨电极位置组合联合收割机时间信息（实验2），或者在相同的电极间隔处具有更好的辨别力（实验3）。这一结果与较长的脉冲持续时间导致比使用较短脉冲持续时间的同等大声刺激更大的兴奋扩散的假设一致。在实验4中，比较了具有不同脉冲持续时间的刺激的脉搏率辨别力，在五分之四的受试者中，脉冲持续时间没有影响。最后，计算了9名受试者（52个电极）阈值和同等声音刺激的脉冲持续时间每增加一倍的电流dB变化。数值范围为-5.9至-2.0 dB/倍，与刺激的绝对强度显著相关。假设该结果是由于神经充电特性与被激发的神经元件距电极的距离之间的关系。(C)1999年美国声学学会。[S0001-4966（99）04708-6]。
In cochlear implants employing pulsatile stimulation, loudness is controlled by current amplitude and/or pulse duration. Five experiments were conducted with cochlear implantees to investigate the hypothesis that perceptual effects other than loudness result from changes in pulse duration for durations from 50 to 266 mu s. In experiment 1, five subjects' ability to discriminate equally loud pulse trains employing differing pulse durations was measured at four electrode positions. In 11 of the 20 cases, subjects could significantly discriminate these stimuli. In experiments 2 and 3, discrimination was measured of dual-electrode stimuli which differed in overall temporal pattern but had an equal temporal pattern on each of the individual electrodes (separated by 0 to 9 mm). Discrimination was compared for stimuli employing short or long pulse durations and, in experiment 3, employing different pulse durations on each electrode. When the pulse duration was longer, six out of seven subjects could either combine temporal information across electrode positions at wider electrode separations (experiment 2) or had better discrimination at the same electrode separation (experiment 3). This result was consistent with the hypothesis that longer pulse durations result in a greater spread of excitation than equally loud stimuli using shorter pulse durations. In experiment 4, pulse rate discrimination was compared for stimuli with differing pulse durations, and in four out of five subjects, there was no effect of pulse duration. Finally, the dB change in current per doubling of pulse duration for threshold and equally loud stimuli was calculated for nine subjects (52 electrodes). Values ranged from -5.9 to -2.0 dB/doubling, and were significantly correlated with the absolute intensity of the stimulus. This result was hypothesized to be due to a relationship between the neural charging characteristics and the distance of the excited neural elements from the electrode. (C) 1999 Acoustical Society of America. [S0001-4966(99)04708-6].