Universidad de Talca, Talca, Chile.
Biol Res. 2011;44(3):295-9. Epub 2011 Nov 7.
In an experiment we examined whether the repeated presentation of tones of gradually increasing intensities produces greater decrement in the eyeblink reflex response in humans than the repetition of tones of constant intensities. Two groups of participants matched for their initial level of response were exposed to 110 tones of 100-ms duration. For the participants in the incremental group, the tones increased from 60- to 90- dB in 3-dB steps, whereas participants in the constant group received the tones at a fixed 90-dB intensity. The results indicated that the level of response in the last block of 10 trials, in which both groups received 90-dB tones, was significantly lower in the incremental group than in the constant group. These findings support the data presented by Davis and Wagner (7) with the acoustic response in rats, but differ from several reports with autonomic responses in humans, where the advantage of the incremental condition has not been observed unambiguously. The discussion analyzes theoretical approaches to this phenomenon and the possible involvement of separate neural circuits.
在一项实验中，我们研究了在人类中，逐渐增强强度的音调重复呈现是否比恒定强度的音调重复呈现产生更大的眨眼反射反应衰减。两组参与者根据其初始反应水平相匹配，他们都接受了 110 个持续时间为 100 毫秒的音调。对于递增组的参与者，音调从 60- 到 90- dB 以 3-dB 的步长增加，而恒定组的参与者则以固定的 90-dB 强度接收音调。结果表明，在最后 10 次试验的最后一组中，两组都接受 90-dB 的音调，递增组的反应水平明显低于恒定组。这些发现支持 Davis 和 Wagner（7）在大鼠的声反应中提出的数据，但与人类自主反应的几项报告不同，在这些报告中，递增条件的优势没有得到明确的观察。讨论分析了这种现象的理论方法以及可能涉及的单独的神经回路。
