title: The misbehaviour of a metacognitive monkey.
abstract: Metacognition, the monitoring of one's own mental states, is a fundamental aspect of human intellect. Despite tests in nonhuman animals suggestive of uncertainty monitoring, some authors interpret these results solely in terms of primitive psychological mechanisms and reinforcement regimes, where "reinforcement" is invariably considered to be the delivery and consumption of earned food rewards. Surprisingly, few studies have detailed the trial-by-trial behaviour of animals engaged in such tasks. Here we report ethology-based observations on a rhesus monkey completing sparse-dense discrimination problems, and given the option of escaping trials (i.e., responding "uncertain") at its own choosing. Uncertainty responses were generally made on trials of high objective difficulty, and were characterized by long latencies before beginning visible trials, long times taken for response, and, even after controlling for difficulty, high degrees of wavering during response. Incorrect responses were also common in trials of high objective difficulty, but were characterized by low degrees of wavering. This speaks to the likely adaptive nature of "hesitation," and is inconsistent with models which argue or predict implicit, inflexible information-seeking or "alternative option" behaviours whenever challenging problems present themselves, Confounding models which suggest that nonhuman behaviour in metacognition tasks is driven solely by food delivery/consumption, the monkey was also observed allowing pellets to accumulate and consuming them during and after trials of all response/outcome categories (i.e., whether correct, incorrect, or escaped). This study thus bolsters previous findings that rhesus monkey behaviour in metacognition tasks is in some respects disassociated from mere food delivery/consumption, or even the avoidance of punishment. These and other observations fit well with the evolutionary status and natural proclivities of rhesus monkeys, but weaken arguments that responses in such tests are solely associated with associative mechanisms, and instead suggest more derived and controlled cognitive processing. The latter interpretation appears particularly parsimonious given the neurological adaptations of primates, as well as their highly flexible social and ecological behaviour.
authors.affiliation: Language Research Center, Georgia State University, 3401 Panthersville Rd., Decatur GA 30034, USA.
authors.forename: Ken
authors.initials: K
authors.lastname: Sayers
authors.affiliation: Language Research Center, Georgia State University, 3401 Panthersville Rd., Decatur GA 30034, USA.
authors.forename: Theodore A
authors.initials: TA
authors.lastname: Evans
authors.affiliation: Language Research Center, Georgia State University, 3401 Panthersville Rd., Decatur GA 30034, USA.
authors.forename: Emilie
authors.initials: E
authors.lastname: Menzel
authors.affiliation: Department of Psychology and Center for Cognitive Science, University at Buffalo, the State University of New York, 346 Park Hall, SUNY Buffalo, Buffalo, NY 14260, USA.
authors.forename: J David
authors.initials: JD
authors.lastname: Smith
authors.affiliation: Language Research Center, Georgia State University, 3401 Panthersville Rd., Decatur GA 30034, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Beran
keywords: Macaca mulatta; Morgan’s canon; Old World monkeys; associative learning; ecology; evolution; metacognition; self-reward behaviour