da Silva Souza Alessandra, Abreu-Rodrigues Josele, Baumann Ana Amélia
Universidade de Brasília, Brasília, Brazil.
Learn Behav. 2010 Nov;38(4):426-37. doi: 10.3758/LB.38.4.426.
Two experiments evaluated history effects on induced and operant variability. College students typed three-digit sequences on a computer keyboard. Sequence variability was induced (by no reinforcement or variation-independent reinforcement) or reinforced (by variation- or repetition-dependent reinforcement). Conditions with induced and operant variability were presented according to a reverse between-groups design. In Experiment 1, we examined transitions from the variation or repetition contingencies to no reinforcement, and vice versa. In Experiment 2, the variation or repetition contingencies were followed or preceded by variation-independent reinforcement. The results showed that (1) a history of no reinforcement impaired operant variability learning; (2) induced variability levels were higher and lower after a history of reinforcement for variation and repetition, respectively; (3) repetition was more easily disrupted by no reinforcement and independent reinforcement than was variation; and (4) response variability and stability were a function of past and current reinforcement conditions. These results indicate that reinforcement history influences both induced and operant variability levels.
两项实验评估了历史效应对诱发变异性和操作性变异性的影响。大学生在电脑键盘上输入三位数字序列。序列变异性通过无强化或与变异无关的强化来诱发，或者通过与变异或重复相关的强化来强化。根据反向组间设计呈现诱发变异性和操作性变异性的条件。在实验1中，我们考察了从变异或重复偶然性到无强化的转变，反之亦然。在实验2中，变异或重复偶然性之前或之后是与变异无关的强化。结果表明：（1）无强化的历史损害了操作性变异性学习；（2）在经历了变异和重复强化的历史后，诱发变异性水平分别更高和更低；（3）与变异相比，重复更容易被无强化和独立强化所干扰；（4）反应变异性和稳定性是过去和当前强化条件的函数。这些结果表明，强化历史影响诱发变异性和操作性变异性水平。
