Rhesus monkeys (Macaca mulatta) show robust evidence for memory awareness across multiple generalization tests

• Type of Material: Article
• Authors: Victoria L. Templer, Emory University; Robert Hampton, Emory University
• Language: English
• Date: 2012-05
• Publisher: Springer Verlag (Germany)
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © Springer-Verlag 2011
• Final Published Version (URL): http://link.springer.com/article/10.1007%2Fs10071-011-0468-4
• Title of Journal or Parent Work: Animal Cognition
• ISSN: 1435-9448
• Volume: 15
• Issue: 3
• Start Page: 409
• End Page: 419
• Grant/Funding Information: Additional support was provided by the Yerkes Center base grant No. RR-00165 awarded by the Animal Resources Program of the National Institutes of Health, and the Center for Behavioral Neuroscience under the STC Program of the National Science Foundation under Agreement No. IBN-9876754.; This research was supported by the National Institute of Mental Health Grant No. R01MH082819 and the National Science Foundation Grant No. 0000017475.
• Keywords: monitoring; declarative memory; explicit memory; memory awareness; metacognition
• Research Categories: Psychology, Cognitive

Abstract

The possibility that memory awareness occurs in nonhuman animals has been evaluated by providing opportunity to decline memory tests. Current evidence suggests that rhesus monkeys (Macaca mulatta) selectively decline tests when memory is weak (Hampton, 2001; Smith, Shields, & Washburn, 2003). (R.R. Hampton, 2001; Smith, Shields, & Washburn, 2003). However, much of the existing research in nonhuman metacognition is subject to the criticism that, after considerable training on one test type, subjects learn to decline difficult trials based on associative learning of external test-specific contingencies rather than by evaluating the private status of memory or other cognitive states. We evaluated whether such test-specific associations could account for performance by presenting monkeys with a series of generalization tests across which no single association with external stimuli was likely to adaptively control use of the decline response. Six monkeys performed a four alternative delayed matching to location task and were significantly more accurate on trials with a decline option available than on trials without it, indicating that subjects selectively declined tests when memory was weak. Monkeys transferred appropriate use of the decline response under three conditions that assessed generalization: two tests that weakened memory and one test that enhanced memory in a novel way. Bidirectional generalization indicates that use of the decline response by monkeys is not controlled by specific external stimuli but is rather a flexible behavior based on a private assessment of memory.