Wormith S J, Pankhurst D, Moffitt A R
Child Dev. 1975 Mar;46(1):272-5.
The nonnutritive sucking of groups of 1-month-old infants was conjugately reinforced with either a 200-H or a 500-H pure tone. Following response acquisition and satiation, the sucking of the experimental groups was reinforced with a new pure tone (either 500 or 200 H) to a criterion of response decrement, after which sucking was reinforced with the original tone. Control groups were reinforced with a single tone (200 or 500 H) throughout the experiment. Frequency of nonnutritive sucking increased significantly in the experimental groups following a shift in frequency of the reinforcing tone but remained unchanged in the control groups, indicating discrimination between 200- and 500-H tones.
对1月龄婴儿组的非营养性吸吮行为，用200赫兹或500赫兹的纯音进行联合强化。在反应习得和满足之后，对实验组的吸吮行为用一种新的纯音（500赫兹或200赫兹）进行强化，直至达到反应递减标准，之后再用原来的纯音进行强化。对照组在整个实验过程中只用一种纯音（200赫兹或500赫兹）进行强化。强化音频率改变后，实验组的非营养性吸吮频率显著增加，而对照组则保持不变，这表明婴儿能够区分200赫兹和500赫兹的声音。
