Ananthanarayan A K, Gerken G M
Electroencephalogr Clin Neurophysiol. 1987 Apr;66(4):427-39. doi: 10.1016/0013-4694(87)90212-4.
Alterations in the probe evoked auditory brain-stem response (ABR) were evaluated in 15 normal-hearing subjects using several stimulus configurations in a tone-on-tone forward-masking paradigm. The stimulus parameters manipulated in the study included: masker frequency; relative intensity of the masker; overall intensity of the masker-probe pair; and masker rise-fall time. Latency increases for waves III and V and an amplitude reduction for wave III were observed under some stimulus conditions. These changes were interpreted in terms of partial forward-masking effects. The masking effects were shown: to be maximal for masker frequencies in close proximity to the probe; to increase with increasing level of masker; to be independent of the overall level of the masker-probe pair; and, to decrease with increasing rise-fall time of the masker. Collectively, the forward-masking effects were interpreted as peripheral in origin, although, an additional brain-stem locus was not ruled out. In contrast, the same stimuli which increased wave III and V latencies and reduced wave III amplitude produced a robust amplitude increment in wave V which was termed enhancement. Wave V enhancement was shown: to be maximal for masker frequencies in close proximity to the probe; to decrease with increasing masker level; and, to decrease with faster rise-fall times of the masker. The processes mediating wave V enhancement are not clear, however, it was concluded that wave V enhancement probably reflects the resultant of a complex central neuronal interaction, presumably in the vicinity of the wave V generator(s).
在15名听力正常的受试者中，采用纯音对纯音的前掩蔽范式中的几种刺激配置，评估了探针诱发的听觉脑干反应（ABR）的变化。该研究中操纵的刺激参数包括：掩蔽音频率；掩蔽音的相对强度；掩蔽音 - 探针对的总强度；以及掩蔽音的上升 - 下降时间。在某些刺激条件下，观察到波III和波V的潜伏期增加以及波III的幅度降低。这些变化被解释为部分前掩蔽效应。结果表明，掩蔽效应：在掩蔽音频率与探针频率非常接近时最大；随着掩蔽音强度的增加而增加；与掩蔽音 - 探针对的总强度无关；并且，随着掩蔽音上升 - 下降时间的增加而减小。总体而言，前掩蔽效应被解释为起源于外周，尽管不排除额外的脑干位点。相比之下，相同的刺激增加了波III和波V的潜伏期并降低了波III的幅度，同时却使波V产生了强劲的幅度增加，这被称为增强。结果表明，波V增强：在掩蔽音频率与探针频率非常接近时最大；随着掩蔽音强度的增加而减小；并且，随着掩蔽音上升 - 下降时间的加快而减小。然而，介导波V增强的过程尚不清楚，不过可以得出结论，波V增强可能反映了复杂的中枢神经元相互作用的结果，大概是在波V发生器附近。
