caa a22 4500 605542015 CHVBK 20210128100919.0 cr unu---uuuuu 210128e20151101xx s 000 0 eng 10.1007/s10071-015-0891-z doi (NATIONALLICENCE)springer-10.1007/s10071-015-0891-z Two-item same/different discrimination in rhesus monkeys ( Macaca mulatta ) [Elektronische Daten] [Benjamin Basile, Emily Moylan, David Charles, Elisabeth Murray] Almost all nonhuman animals can recognize when one item is the same as another item. It is less clear whether nonhuman animals possess abstract concepts of "same” and "different” that can be divorced from perceptual similarity. Pigeons and monkeys show inconsistent performance, and often surprising difficulty, in laboratory tests of same/different learning that involve only two items. Previous results from tests using multi-item arrays suggest that nonhumans compute sameness along a continuous scale of perceptual variability, which would explain the difficulty of making two-item same/different judgments. Here, we provide evidence that rhesus monkeys can learn a two-item same/different discrimination similar to those on which monkeys and pigeons have previously failed. Monkeys' performance transferred to novel stimuli and was not affected by perceptual variations in stimulus size, rotation, view, or luminance. Success without the use of multi-item arrays, and the lack of effect of perceptual variability, suggests a computation of sameness that is more categorical, and perhaps more abstract, than previously thought. Springer-Verlag Berlin Heidelberg (outside the USA), 2015 Categorization nationallicence Concept learning nationallicence Entropy nationallicence Perceptual variability nationallicence Basile Benjamin Section on the Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, NIH, Building 49, Room 1B80, 49 Convent Drive MSC 4415, 20892-4415, Bethesda, MD, USA aut Moylan Emily Section on the Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, NIH, Building 49, Room 1B80, 49 Convent Drive MSC 4415, 20892-4415, Bethesda, MD, USA aut Charles David Section on the Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, NIH, Building 49, Room 1B80, 49 Convent Drive MSC 4415, 20892-4415, Bethesda, MD, USA aut Murray Elisabeth Section on the Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, NIH, Building 49, Room 1B80, 49 Convent Drive MSC 4415, 20892-4415, Bethesda, MD, USA aut Animal Cognition Springer Berlin Heidelberg 18/6(2015-11-01), 1221-1230 1435-9448 18:6<1221 2015 18 10071 https://doi.org/10.1007/s10071-015-0891-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10071-015-0891-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Basile Benjamin Section on the Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, NIH, Building 49, Room 1B80, 49 Convent Drive MSC 4415, 20892-4415, Bethesda, MD, USA aut NATIONALLICENCE 700 1- Moylan Emily Section on the Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, NIH, Building 49, Room 1B80, 49 Convent Drive MSC 4415, 20892-4415, Bethesda, MD, USA aut NATIONALLICENCE 700 1- Charles David Section on the Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, NIH, Building 49, Room 1B80, 49 Convent Drive MSC 4415, 20892-4415, Bethesda, MD, USA aut NATIONALLICENCE 700 1- Murray Elisabeth Section on the Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, NIH, Building 49, Room 1B80, 49 Convent Drive MSC 4415, 20892-4415, Bethesda, MD, USA aut NATIONALLICENCE 773 0- Animal Cognition Springer Berlin Heidelberg 18/6(2015-11-01), 1221-1230 1435-9448 18:6<1221 2015 18 10071