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Author Clara, E.; Regolin, L.; Vallortigara, G.; Rogers, L.
Title Perception of the stereokinetic illusion by the common marmoset (Callithrix jacchus) Type Journal Article
Year 2007 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 10 Issue 2 Pages 135-140
Keywords Animals; Behavior, Animal/*physiology; Callithrix/*physiology; Female; Male; *Optical Illusions; Pattern Recognition, Visual/*physiology
Abstract Stereokinetic illusions have never been investigated in non-human primates, nor in other mammalian species. These illusions consist in the perception of a 3D solid object when certain 2D stimuli are rotated slowly in the plane perpendicular to the line of sight. The ability to perceive the stereokinetic illusion was investigated in the common marmoset (Callithrix jacchus). Four adult marmosets were trained to discriminate between a solid cylinder and a solid cone for food reward. Once learning criterion was reached, the marmosets were tested in sets of eight probe trials in which the two solid objects used at training were replaced by two rotating 2D stimuli. Only one of these stimuli produced, at least to the human observer, the stereokinetic illusion corresponding to the solid object previously reinforced. At test, the general behaviour and the total time spent by the marmosets observing each stimulus were recorded. The subjects stayed longer near the stimulus producing the stereokinetic illusion corresponding to the solid object reinforced at training than they did near the illusion corresponding to the previously non-rewarded stimulus. Hence, the common marmosets behaved as if they could perceive stereokinetic illusions.
Address Centre for Neuroscience and Animal Behaviour, University of New England, Armidale, NSW, 2351, Australia. elena.clara@unipd.it
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1435-9448 ISBN Medium (up)
Area Expedition Conference
Notes PMID:16924457 Approved no
Call Number Equine Behaviour @ team @ Serial 2445
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Author Heschl, A.; Burkart, J.
Title A new mark test for mirror self-recognition in non-human primates Type Journal Article
Year 2006 Publication Primates Abbreviated Journal Primates
Volume 47 Issue 3 Pages 187-198
Keywords Animals; *Behavior, Animal; Callithrix/*physiology; Cognition/*physiology; Discrimination (Psychology)/physiology; Female; Male; Photic Stimulation; *Self Concept
Abstract For 30 years Gallup's (Science 167:86-87, 1970) mark test, which consists of confronting a mirror-experienced test animal with its own previously altered mirror image, usually a color mark on forehead, eyebrow or ear, has delivered valuable results about the distribution of visual self-recognition in non-human primates. Chimpanzees, bonobos, orangutans and, less frequently, gorillas can learn to correctly understand the reflection of their body in a mirror. However, the standard version of the mark test is good only for positively proving the existence of self-recognition. Conclusive statements about the lack of self-recognition are more difficult because of the methodological constraints of the test. This situation has led to a persistent controversy about the power of Gallup's original technique. We devised a new variant of the test which permits more unequivocal decisions about both the presence and absence of self-recognition. This new procedure was tested with marmoset monkeys (Callithrix jacchus), following extensive training with mirror-related tasks to facilitate performance in the standard mark test. The results show that a slightly altered mark test with a new marking substance (chocolate cream) can help to reliably discriminate between true negative results, indicating a real lack of ability to recognize oneself in a mirror, from false negative results that are due to methodological particularities of the standard test. Finally, an evolutionary hypothesis is put forward as to why many primates can use a mirror instrumentally – i.e. know how to use it for grasping at hidden objects – while failing in the decisive mark test.
Address Konrad Lorenz Institute for Evolution and Cognition Research, Adolf Lorenz Gasse 2, 3422, Altenberg, Austria. adolf.heschl@uni-graz.at
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0032-8332 ISBN Medium (up)
Area Expedition Conference
Notes PMID:16432640 Approved no
Call Number Equine Behaviour @ team @ Serial 2810
Permanent link to this record