Blough P M
J Exp Anal Behav. 1983 May;39(3):427-35. doi: 10.1901/jeab.1983.39-427.
A three-ply multiple schedule assessed responding in a standard component as a function of the just-preceding schedule. The principal experimental condition was the difference among the wavelengths signaling the schedule components. Only the pigeons working in a narrow wavelength range showed persistent positive local contrast; that is, response rate during the standard component was higher when that component followed extinction than when it followed itself. Birds in both narrow- and medium-range groups showed persistent negative local contrast; that is, rate was lower following a relatively rich component. The dissipation of positive contrast appeared to be most clearly related to the establishment of differential responding. Negative contrast was inversely related to wavelength differences. Theories pertaining to contrast must account for the role of discrimination in both positive and negative types.
一个三层多重强化程序表根据紧接在前的程序表来评估标准成分中的反应。主要的实验条件是标志程序表成分的波长之间的差异。只有在狭窄波长范围内工作的鸽子表现出持续的正性局部对比；也就是说，当标准成分之前是消退时，其反应率高于它之前是自身时。窄波长组和中波长组的鸽子都表现出持续的负性局部对比；也就是说，在相对丰富的成分之后反应率较低。正性对比的消退似乎与差别反应的建立最为明显相关。负性对比与波长差异呈负相关。有关对比的理论必须解释差别在正性和负性两种类型中的作用。
