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Research Projects

Michael J. Beran, PhD - Comparative Cognition (Numerical Cognition, Metacognition, Self-Control)

I have studied numerical cognition for the past 15 years in a variety of species.  In particular, I have examined cognitive mechanisms underlying representation of numerosity in animals, and I have advocated that such representation is approximate rather than exact (i.e., similar to estimation) as predicted by an analog magnitude form of representation.  I have found converging lines of evidence for such a mechanism underlying numerical competence through a comparative perspective (studies with monkeys, chimpanzees, adult humans, and children).

I have four additional programs of research for which I have current grant funding from the NIH or NSF.  In the first, I am studying metacognition in monkeys in collaboration with David Smith.  This project focuses on dissociating associative and cognitive aspects of the uncertainty responses that these monkeys will make as well as discerning the extent to which this uncertainty response will generalize across experimental tasks.  In the second, I am investigating the self-control behavior of nonhuman primates through various testing paradigms.  Typically, the animals are presented with situations in which delay of gratification can be examined, as well as behavioral correlates of self-control.  This line of research has provided some interesting similarities and differences between the performance of the animals and that of human children, particularly in the interaction between attention to delayed rewards and delay maintenance (i.e., the ability to stay on track while delaying gratification).  In the third, I am investigating the planning skills of nonhuman primates and also examining whether nonhuman primates show evidence of prospective memories like those of humans.  The final project involves economic tasks given to human and nonhuman primates to examine the evolutionary foundations of cooperative decision making.  For more information on any of these project, see my website at

Sarah F. Brosnan, PhD - Cooperation and Economic Decision-Making

My lab is interested in mechanisms underlying cooperation, reciprocity, inequity, and other economic decisions in nonhuman primates from an evolutionary perspective. This includes, but is not limited to, questions of what decisions individuals make and how they make these decisions, how their social or ecological environments affect their decisions and interactions, and under what circumstances they can alter their behaviors contingent upon these inputs.  Most of our reseach is conducted with the chimpanzees and capuchins at the Language Research Center. In addition, some of our research is done in collaboration with researchers at the Michale E. Keeling Center for Comparative Medicine and Research of the UT/MD Anderson Cancer Center and Zoo Atlanta.  For more detail and copies of lab papers, please see the CEBUS lab website at or my website at

David A. Washburn, PhD - Comparative Cognition

My research emphasizes two parallel lines of inquiry, one from the perspective of comparative psychology (cognition as it is manifest across species) and the other from the perspective of human factors (individual differences in cognition and performance). These two perspectives complement one another in analysis of the psychological processes that I currently study: attention/executive function, and learning/training. Thus, recent experiments include studies of individual and group differences in attention profiles, comparative and psychometric studies of uncertainty monitoring, procedures that improve the effectiveness of computer-based instruction, the effects of spaceflight on behavior and performance, psychophysiological and cognitive predictors of vigilance, and the cognitive profiles of individuals who excel in detecting threat items in X-ray images of airport baggage.