Boyd E S, Boyd E H, Brown L E
Electroencephalogr Clin Neurophysiol. 1977 Mar;42(3):364-71. doi: 10.1016/0013-4694(77)90172-9.
Changing animals from a schedule on which they had to bar-press after a tone cue to get a food pellet, to a schedule on which the food pellet was presented automatically after the tone cue and the manipulandum was not available, had no effect on the latency, amplitude, or shape of the M-wave evoked by the tone cue. The amplitude of the evoked wave did, however, decrease more rapidly, as a test session progressed, with the latter schedule than with the former schedule. Failure to fast animals before test sessions markedly reduced the amplitude of the M-wave. Variation in the type of food pellet used caused marked variations in the amplitude of the evoked response. In all cases, there was a high degree of correlation between M-wave amplitude and a behavioral indication of the animal's interest in the reward. It was concluded that the M-wave reflects the conditioned incentive value of the cue, or in other words, the level of interest of the animal in the reward.
将动物从必须在音调提示后按压杠杆以获取食物颗粒的程序，改为在音调提示后自动呈现食物颗粒且操作柄不可用的程序，对音调提示诱发的M波的潜伏期、振幅或形状没有影响。然而，随着测试阶段的进行，后一种程序诱发波的振幅比前一种程序下降得更快。在测试阶段之前未对动物进行禁食会显著降低M波的振幅。所用食物颗粒类型的变化导致诱发反应的振幅有显著变化。在所有情况下，M波振幅与动物对奖励的兴趣的行为指标之间都有高度相关性。得出的结论是，M波反映了提示的条件性激励价值，或者换句话说，反映了动物对奖励的兴趣水平。
