"Play it Again": a new method for testing metacognition in animals.

Putative metacognition data in animals may be explained by non-metacognition models (e.g., stimulus generalization). The primary objective of the present study was to develop a new method for testing metacognition in animals that may yield data that can be explained by metacognition but not by non-metacognition models. Next, we used the new method with rats. Rats were first presented with a brief noise duration which they would subsequently classify as short or long. Rats were sometimes forced to take an immediate duration test, forced to repeat the same duration, or had the choice to take the test or repeat the duration. Metacognition, but not an alternative non-metacognition model, predicts that accuracy on difficult durations is higher when subjects are forced to repeat the stimulus compared to trials in which the subject chose to repeat the stimulus, a pattern observed in our data. Simulation of a non-metacognition model suggests that this part of the data from rats is consistent with metacognition, but other aspects of the data are not consistent with metacognition. The current results call into question previous findings suggesting that rats have metacognitive abilities. Although a mixed pattern of data does not support metacognition in rats, we believe the introduction of the method may be valuable for testing with other species to help evaluate the comparative case for metacognition.