Interference

Investigations of animal memory have traditionally been studied in terms of how long animals can remember single items, often in delayed matching-to-sample tasks. Results from some delayed matching-to-sample tasks can be seen in Fig. 1a for capuchin monkeys (filled squares), macaque monkeys (filled circles, diamonds), and pigeons (unfilled circles). These studies all used just two stimuli (See Wright, 2007for references of these studies and further discussion). The sample presented on each trial was one of the two stimuli, followed by a delay and then a choice between these two stimuli for which stimulus matched the sample. With no delay (0s), performance accuracy was more than 80% correct. But performance rapidly declined, reaching 50% correct (chance performance) in 1 min or less. At issue is what do such results tell us about animal memory? Such results are unlikely to convey limits of the animal’s memory because the animals would not be able to survive (e.g., remember food source...