Pigeons show metamemory by requesting reduced working memory loads.

Abstract

Citation-Iwasaki, S., Kuroshima, H., & Fujita, K. (2019). Pigeons show metamemory by requesting reduced working memory loads. Animal Behavior and Cognition, 6(4), 247-253. https://doi. Abstract-Even though many studies have demonstrated that pigeons and humans share various properties of memory systems, pigeons have shown only weak evidence of metamemory ability, for example during delayed matching-to-sample. We suspect that this task might be too demanding to allow metamemory processing within pigeons' working memory. Here, we describe our studies in which pigeons have shown metamemory during a task requiring reduced working memory load, a reference memory task. Pigeons solved a simultaneous chaining task, and they were sometimes given the opportunity to ask for ''hints'' about the next correct response in a sequence before or during the task. Some pigeons' hint-seeking behavior varied according to their reference memory states or knowledge states, suggesting that they used metamemory when engaged in a reduced working memory load task. We propose that metamemory ability is dependent on working memory capacity, and that it is important to use suitable cognitive tasks for evaluate metamemory abilities in diverse species. Metamemory is a cognitive function that allows monitoring one's own memory state or trace, and thereby enhanced control of behavior. Humans can report or judge their own memory states verbally. These reports correlate significantly with accuracy on memory tasks (Nelson, 1996). Studies using non-verbal procedures have demonstrated metamemory in other mammals (chimpanzees (Pan troglodytes): investigated metamemory in pigeons (Columba livia) in a delayed matching-to-sample (DMTS) task. In this task, pigeons were required to peck a sample stimulus at the start of trial. After a delay three comparison stimuli including the sample stimulus were presented. When the pigeons pecked the same stimulus as the sample, they got six pellets (a high reward) for a correct response; however, incorrect responses led to a timeout period and no reward. In some trials, pigeons were given an opportunity to choose between taking a test or escaping it before or during presentation of the comparison stimuli. Choosing the escape option always resulted in them receiving only three pellets (a medium reward level). The pigeons' accuracies were lower in longer-delay trials, during which they frequently escaped the test when this option was presented simultaneously with the comparison stimuli. However, when the escape option was presented before the longer-delay trial comparison stimuli, they