Whether reward omission on the sample runs of a delayed alternation task would reduce proactive interference was tested in two experiments. On the first run of a trial, the animal entered one arm of a maze to obtain a food reward; on the second run the reward was available in the opposite arm. Alternation declined across a block of massed trials, but there was less of a decrease when the reward was omitted in the final trial or when another maze was substituted. In a task that required retention of three mazes at a time, alternation again declined across massed trials but was reinstated either by omitting the reward on the final trial or by substituting a different reinforcer. The results suggest that altering the reward outcome can improve memory discriminability of recently visited maze locations and thereby overcome trace confusion in memory.
Terry, William S.
"The Effects of Reward Omission and Change on Proactive Interference in Spatial Alternation,"
The Psychological Record:
1, Article 5.
Available at: http://opensiuc.lib.siu.edu/tpr/vol58/iss1/5