Welzl H
Institute of Physiology, Czechoslovak Academy of Sciences, Prague, Czechoslovakia.
Behav Processes. 1976 Dec;1(4):319-26. doi: 10.1016/0376-6357(76)90013-9.
Lick-rate in rats is said to be constant for a given animal, despite variations of internal and external stimuli. On the other hand, small changes can be observed due to changes in the construction of the licking device. However, variations do not exceed 20%. In an attempt to gain operant control over the ILI (interlick interval - the time between two lick-onsets) the delivery of reinforcement (20 μl water) was made dependent on the emission of ILIs of a predetermined length longer than during baseline licking. It could be observed that rats could not shift the peak of their ILI distribution within the reinforced range but - to increase the number of reinforcements - they increased the scatter of the ILI distribution or developed a "harmonic" peak at double ILI length. When the animals were forced in a second experiment to prolong the lick-duration (time of tongue-spout contact) to obtain water, they failed if the restriction from the drinking spout made a closer approach impossible. It is argued that the ability to obtain reinforcement under both schedules is due to postural changes of the animal. The mechanisms controlling licking seem to be relatively constant, which allows good coordination with other behaviours which have to be performed during drinking, such as breathing and swallowing. It can be concluded that the amount of water consumed by rats is controlled by the length of time spent in licking and not by changing the lick-rate.
据说，对于给定的动物，尽管存在内部和外部刺激的变化，大鼠的舔舐速率是恒定的。另一方面，由于舔舐装置结构的变化，可以观察到微小的变化。然而，变化不超过20%。为了对ILI（舔舐间隔——两次舔舐开始之间的时间）进行操作性控制，强化物（20微升水）的递送取决于发出比基线舔舐期间更长的预定长度的ILI。可以观察到，大鼠无法在强化范围内移动其ILI分布的峰值，但为了增加强化物的数量，它们增加了ILI分布的离散度，或者在两倍ILI长度处形成了一个“谐波”峰值。在第二个实验中，当动物被迫延长舔舐持续时间（舌头与饮水口接触的时间）以获取水时，如果饮水口的限制使它们无法更靠近饮水口，它们就会失败。有人认为，在两种实验方案下获得强化物的能力是由于动物的姿势变化。控制舔舐的机制似乎相对恒定，这使得它能够与饮水时必须执行的其他行为（如呼吸和吞咽）很好地协调。可以得出结论，大鼠消耗的水量是由舔舐所花费的时间长度控制的，而不是通过改变舔舐速率。
