Performance on patterned string problems by common marmosets (Callithrix jacchus)

Abstract

This experiment examined the performance of common marmosets (Callithrix jacchus) on a series of patterned string problems to assess the marmosets’ understanding of means-ends relationships. One marmoset, Jet, was exposed to a series of problems that were ordered in terms of perceived difficulty during two testings that were separated by one year. In the second testing Jet received problems that had been used during the first testing along with three new problems. Each of the new problems was designed to be an exemplar of the type of problem that Jet had experienced difficulty with in the first testing. A second marmoset, Peaches, was tested on the same set of problems given to Jet in the second testing. Results indicated that the marmosets’ performance on these problems fell into three categories. In one category, some problems were solved without evidence of trial and error learning. In a second category, there were problems in which the marmosets responded at chance levels initially but evidenced improvement as a function of extended testing. In a third category, some problems appeared to be virtually unsolvable even with extended testing. Taken together, these results indicate that the marmosets were able to learn the means-ends connection between pulling a string and obtaining food. This learning was best characterized as a trial and error process for some problem forms, while for others there appeared to be rapid learning that did not require extensive practice. The instances of rapid learning may be the result of the application of a simple spatial proximity rule in which the marmosets chose the string that was closest to an imaginary line drawn between the marmoset and the reinforcer.

Western scrub-jays (Aphelocoma californica) solve multiple-string problems by the spatial relation of string and reward

“…Strategies like the proximity rule, however, may be relatively common across species, e.g. corvids (Bagotskaya et al 2012 ; Taylor et al 2010 ), squirrel monkeys (Cha and King 1969 ), common marmosets (Gagne et al 2012 ), apes (Köhler 1927 ), rhesus monkeys (Mason et al 1956 ) and parrots (Schuck-Paim et al 2008 ). The results of this study seem to suggest that the jays’ remarkable achievements in caching studies may not extend to string-pulling tasks as an example for physical understanding.…”

Of Men and Mice: Modeling the Fragile X Syndrome

“…Though lissencephalic (smooth), their brain shares many features of the human brain, and their cerebral cortex shows the neuronal architecture of all primates (Bendor and Wang, 2005 ; Burman et al, 2006 ; Elston et al, 2006 ; Burman and Rosa, 2009 ; de la Mothe et al, 2012 ; Chaplin et al, 2013 ), from which only humans differ in that neurons of their prefrontal cortex are more spiny and more complex than those of their primate relatives (Elston et al, 2006 ). Consequently, marmosets have the high cognitive abilities characteristic to all primates: they are not only able to perform true imitation (Bugnyar and Huber, 1997 ; Voelkl and Huber, 2007 ), transposition and generalization (Yamazaki et al, 2014 ) but to also solve string problems (Halsey et al, 2006 ; Gagne et al, 2012 ) and to understand physical causality (Yamazaki et al, 2011 ). Considering the weaknesses of FXS individuals in abstract item reasoning and in addressing new problems, the cognitive abilities of marmosets might help to develop tasks which directly translate results between the two species.…”

The common marmoset: An overview of its natural history, ecology and behavior

“…Complex arrangements hindered animals to meet criteria. Gagne et al, 2012 Are those with stronger hand preference better at dealing with two simultaneous tasks?…”