Document Type



The condition where S must successively learn two responses to the same stimulus has been assumed to provide optimal conditions for generating interference during the learning of the second response. The empirical evidence in support of this assumption is not strong. When compared to a control group this condition tends only to result in fewer correct responses in the early stages of relearning. In addition, this tendency is observed only for lower levels of training on the first task for, with increases in training it diminishes until eventually facilitation is clearly evident. Recently, however, Porter and Duncan (5) following a suggestion by Gagne, Baker and Foster (2) found evidence for interference with this condition in a verbal paired-associate learning task where the stimuli and responses involved in the first task were required to be re-paired in the second task. That is, the stimuli and responses of both tasks were identical, the second task being constructed by pairing each response with a stimulus different from that with which it was paired in the first task. It was also found that the frequency of intrusions, i.e., an error consisting of the response that was learned to a stimulus in the first task being made to that same stimulus in the second task, was related to the number of times that response had been correctly made in the first task. This latter finding would be consistent with the assumption that the degree to which the first learned response competes successfully with the learning of the new response is a positive function of its associative strength. However, in a study of motor learning employing this same basic procedure and in which the amount of first task training was one of variables studied, Duncan (1) found facilitation in the learning of the second task with the amount of facilitation being positively related to the amount of first task training. Similar results have been more recently obtained by Mandler (3) with this procedure.

Publication Date


Journal Title

Proceedings of the Iowa Academy of Science





First Page


Last Page



©1955 Iowa Academy of Science, Inc.



File Format




To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.