A comparison of working memory characteristics in monkeys, apes, and humans.
Working memory is a central component of complex human cognitive abilities such as learning, language comprehension, planning, reasoning, and cognitive control (Engle, 1999; Unsworth & Robison, 2014). 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 (Baddeley & Hitch, 1974; McElree, 2006; Smith, Jonides, & Koeppe, 1996; Unsworth & Engle, 2007). Although working memory has been identified as central to human intelligent behavior (Cole & Braver, 2012; Engle, 1999), little is known about its evolutionary origins and our understanding of how it operates in nonhuman primates is only beginning to emerge (Carruthers, 2013). Thus, comparative studies of working memory are needed to determine what similarities and differences exist in working memory between humans and non-human primates. Indentifying such similarities and differences will elucidate what evolutionary factors such as the development of language, or increased frontal lobe capacity, may have been critical for the development of working memory in humans, and help us understand the origins human-like intelligence more broadly.