Working memory is a central component of complex human cognitive abilities such as learning, language comprehension, planning, reasoning, and cognitive control [1]. It allows for a limited amount of information to be kept available for processing in the absence of sustained sensory input, and the proficiency with which individuals do so is positively correlated with individual differences in scores of fluid intelligence [2,3]. Although working memory has been identified as central to human intelligent behavior [4], little is known about its evolutionary origins and our understanding of how it operates in nonhuman primates is only beginning to emerge [5]. Yet many of the aspects of human behavior that have been suggested to be unique adaptations in our species, such as social understanding, abstract reasoning, and future planning, rely on working memory - to keep a goal in mind in the face of distraction and formulate mental plans and scenarios. Thus, a comprehensive comparative study of working memory could have wide-reaching implications for the quest to understand what makes the human mind unique. To date working memory in nonhumans has received far less research effort than comparisons of more domain-specific skills. In this proposal I designed a program of work aimed at bringing it under systematic comparative study. The importance of this project lies in its potential for understanding the origins of human complex cognition. The overall objetives were to carry out a series of projects investigating three critical aspects of working memory and comparing them across three separate primate species : humans, chimpanzees, and capuchin monkeys.
