Potash M, Kelly J
J Comp Physiol Psychol. 1980 Oct;94(5):864-77. doi: 10.1037/h0077819.
The first of two experiments was carried out to examine the tendency of rat infants (13-20 days of age) to approach auditory stimulation. Tests were conducted in a circular maze with a central start area and eight response areas at the periphery. Stimuli were played back over a loudspeaker placed behind one of the eight response areas. Signals included species calls at high and low intensities. A control condition with blank tapes was also used. The subjects showed a clear tendency to approach the low-intensity playback of a species "social" vocalization but did not approach the other stimuli. The aim of the second experiment was to investigate the importance of binaural cues for localization. Rat infants were tested with one ear blocked, both ears blocked, or neither ear blocked. The effect of the ear plug(s) was to attenuate the sound approximately 10 dB. The results indicated that only the binaurally blocked and normal control subjects approached the sound source at above chance levels. The failure of subjects in the monaural group to approach the sound probably resulted from a disruption of binaural cues. The ability of rat infants to localize sounds and process binaural cues is discussed in relation to the onset of hearing and in terms of physiological response that are present early in ontogeny.
两项实验中的第一项旨在研究幼鼠（13 - 20日龄）接近听觉刺激的倾向。实验在一个圆形迷宫中进行，迷宫中央有一个起始区域，周边有八个反应区域。刺激通过放置在八个反应区域之一后面的扬声器播放。信号包括高强度和低强度的物种叫声。还使用了空白磁带的对照条件。实验对象表现出明显倾向于接近物种“社交”叫声的低强度播放，但不接近其他刺激。第二项实验的目的是研究双耳线索对定位的重要性。对幼鼠进行单耳堵塞、双耳堵塞或不堵塞耳朵的测试。耳塞的作用是使声音衰减约10分贝。结果表明，只有双耳堵塞组和正常对照组的实验对象以高于随机水平的概率接近声源。单耳组实验对象未能接近声音可能是由于双耳线索的中断。本文结合听力的开始以及个体发育早期出现的生理反应，讨论了幼鼠定位声音和处理双耳线索的能力。
