Journal of Experimental Psychology: Animal Behavior Processes

Rats were tested on an eight-arm maze in a paradigm of sampling with replacement from a known set of items until the entire set was sampled. The first three experiments demonstrated that the animals performed efficiently, choosing an average of more than seven different arms within the first eight choices, and did not utilize intramaze cues or consistent chains of responses in solving the task. The second three experiments examined some characteristics of the rats' memory storage. There was a small but reliable recency effect with the likelihood of a repetition error increasing with the number of choices since the initial instance. This performance decrement was due to interference from choices rather than just to the passage of time. No evidence was found for a primary effect. The data also suggest that there was no tendency to generalize among spatially adjacent arms. The results are discussed in terms of the memory processes involved in this task and human serial learning.