Ornitz E M, Guthrie D, Lane S J, Sugiyama T
Department of Psychiatry, University of California Los Angeles.
Psychophysiology. 1990 May;27(3):298-308. doi: 10.1111/j.1469-8986.1990.tb00385.x.
The startle response to a 104dB (SPL) 50-ms burst of white noise was facilitated by prestimulation with a nonstartling tone sustained for 2 s prior to the startling stimulus in 3, 4, 5, and 8 year old children and young adults. Both startle amplitude and onset latency showed significantly greater facilitation in the preschool children than in the 8-year-olds and adults. The results of this experiment, which used a fixed prestimulation interval, were compared to those of an earlier study in which the prestimulation interval was varied. The maturational changes in startle facilitation in response to the 2-s prestimulation interval were similar in the two experiments. Hence the maturational effect on startle facilitation was independent of the uncertainty (as to when the startling stimulus would be given), which might be associated with variable prestimulation intervals. These findings suggest that the neuronal mechanisms that mediate startle facilitation undergo development during early childhood and mature about 8 years of age, and that this maturational sequence is relatively independent of attentional effects.
在3岁、4岁、5岁、8岁儿童及年轻成年人中，在104分贝（声压级）、持续50毫秒的白噪声突发刺激前，先给予持续2秒的非惊吓性纯音进行预刺激，可增强惊吓反应。与8岁儿童和成年人相比，学龄前儿童的惊吓幅度和起始潜伏期均表现出明显更强的易化作用。本实验采用固定预刺激间隔，其结果与之前一项预刺激间隔可变的早期研究结果进行了比较。在两个实验中，对2秒预刺激间隔的惊吓易化的成熟变化相似。因此，对惊吓易化的成熟效应独立于（与惊吓刺激何时给予相关的）不确定性，而不确定性可能与可变的预刺激间隔有关。这些发现表明，介导惊吓易化的神经机制在幼儿期经历发育，并在约8岁时成熟，且这种成熟顺序相对独立于注意力效应。
