Brooks P R, Berg W K
Dev Psychobiol. 1979 Jul;12(4):329-34. doi: 10.1002/dev.420120407.
Twenty alert 16-week-old infants were presented with 20-sec tones at variable intertrial intervals for 10 trials while beat-by-beat heart rate responses were recorded to assess response at offset as well as onset of each stimulus. Consistent with past research, onsets elicited deceleratory responses which habituated and showed some evidence of dishabituation with a change in stimulus frequency on the last 2 trials. Offsets also elicited significant deceleratory responses overall, but inspection of pre-offset heart rate suggested that deceleration in anticipation of the offset event appeared after a few stimulus repetitions and increased in magnitude over trials. However, individual variability was considerable and although the anticipatory response was significant averaged over all trials, the apparent increase over trials did not reach statistical significance. The evidence clearly indicates infants quickly process and act upon temporal information in a stimulus.
20名警觉的16周龄婴儿在可变的试验间隔时间内，每次接受20秒的音调刺激，共进行10次试验，同时记录逐搏心率反应，以评估每次刺激开始和结束时的反应。与以往的研究一致，刺激开始时引发减速反应，这种反应会产生习惯化，并且在最后2次试验中，随着刺激频率的变化，有一些去习惯化的证据。刺激结束时总体上也引发了显著的减速反应，但对刺激结束前心率的检查表明，在几次刺激重复后，预期刺激结束事件的减速反应出现，并在试验过程中幅度增加。然而，个体差异相当大，虽然在所有试验中平均预期反应是显著的，但试验过程中明显的增加并未达到统计学显著性。证据清楚地表明，婴儿能快速处理刺激中的时间信息并据此做出反应。
