Physical Cognitive Skills Research Articles

Chimpanzees' (Pan troglodytes) problem-solving skills are influenced by housing facility and captive care duration.

Although a large body of primate cognition research is done in captive institutions, little is known about how much individuals from different facilities vary in their experiences and cognitive skills. Here we present the results of an experimental study investigating how physical cognitive skills vary between chimpanzees in relation to captive settings and their time in captivity. We tested 59 chimpanzees housed at two different captive facilities (a rehabilitation center (sanctuary) and a zoo) in three problem-solving tasks. Our results showed that chimpanzees at the two housing facilities significantly differed in overall task performance. On average, the sanctuary chimpanzees outperformed the chimpanzees housed at the zoo in the detour reaching task and the honey trap task. However, the zoo chimpanzees performed slightly better on average in the learning task. We propose that, for this particular sample, the documented differences result from a combination of factors, such as prior experience with cognitive testing, motivation levels and varying degrees of human exposure. Within the sanctuary sample, we found that chimpanzees who arrived at an earlier age at the sanctuary and had therefore spent a larger percentage of their lives in a captive environment, were better problem-solvers than those that arrived at a later age to the sanctuary. Thus, rehabilitation and time in captivity contributed to improved physical cognitive skills in sanctuary chimpanzees. Our results highlight the importance of studying intraspecific variation and the effect that previous experience and living conditions might have on physical cognitive skills in non-human apes. Accordingly, we should be cautious when extrapolating findings of cognitive studies from one population to the species as a whole.

Marine mammal cognition and captive care: A proposal for cognitive enrichment in zoos and aquariums

Marine mammals, particularly cetaceans (whales, dolphins and porpoises) and pinnipeds (seals, sea lions and walruses) are popular in zoos and aquariums worldwide. Bottlenose dolphins and California sea lions have also been popular study species in animal cognition research since the 1950s, and many dolphin cognitive skills are on par with great apes. This paper proposes that ‘cognitive challenges’ can enhance the wellbeing of marine mammals, in line with previous studies on farm animals and great apes. While most captive marine mammals are trained and this challenges their social-cognitive skills to a moderate or high level, their physical-cognitive skills are not being challenged to a high level by floating ‘toys’ in the pool. This paper suggests that tasks originally developed to test the limits of dolphin and sea lion cognitive skill could be modified and implemented as ‘cognitive enrichment’ in zoos and aquariums. To be enriching, cognitive challenges should be relevant, motivating, controllable, and possible to master.

Physical cognition and tool-use: performance of Darwin’s finches in the two-trap tube task

The trap tube is a classic test of causal reasoning abilities in animals in the physical domain. Recently, a modified version of this task improved its diagnostic capacity and allowed testing of non-tool-using animals. We used this modified two-trap tube task to compare the cognition of two Darwin's finch species: the woodpecker finch, Cactospiza pallida, a tool-using species, and the small tree finch, Camarhynchus parvulus, a closely related non-tool-using species. Not all woodpecker finches use tools in nature, and we therefore also tested non-tool-using individuals to assess the effect of experience on trap tube performance. No small tree finches and only two non-tool-using woodpecker finches solved the initial task which was operated using a pre-inserted piston. One tool-using woodpecker finch solved the task when allowed to use its own tool instead of the pre-inserted piston. The fact that none of these subjects transferred their knowledge when the features of the task changed, suggests that in this species, neither experience using tools nor the genetic composition of a tool-user are associated with the general physical cognitive skills required to solve the trap tube task.

Physical and social cognition in domestic dogs: A comparative study

Dogs have shown outstanding social cognitive skills when interacting with humans, especially in situations where social knowledge and communicative skills are needed. On the other hand, when tested on knowledge of objects or understanding of causality, domestic dogs did not prove to be particularly skilled and flexible when compared with other species. Brauer et al. (2006) showed that chimpanzees outperformed dogs in an object choice paradigm when causal cues were provided. However, chimpanzees failed to use social information given by the experimenter, whereas domestic dogs used several social communicative cues to receive a hidden food reward. To test whether these differences in performance hold true over a larger set of cognitive tests covering both physical and social cognition, we tested 97 domestic dogs modifying the Primate Cognition Test Battery (PCTB). This extensive test battery was developed by Herrmann et al. (2007) to investigate the cognitive abilities of great apes and human children and includes tests on knowledge of objects, quantities and causal understanding (physical domain) and social cognitive tasks like social learning, communication and knowledge of others’ actions and minds (social domain). Averaging across all of the tasks in the physical domain, dogs were correct in 45% of the trials, whereas chimpanzees succeeded in 68% of the trials. In the social domain, dogs performed correctly in 34% of the trials, and chimpanzees were correct in 39% of the trials. Statistically, chimpanzees outperformed dogs in physical cognitive tasks as well as in social cognitive tasks. Comparing the particular scales, we did find statistical differences between the species for all 3 scales of physical cognition as well as for tasks requiring knowledge of others’ actions and minds. Although domestic dogs and chimpanzees performed at a similar level over all communicative and social learning tasks, we did find species differences within single tasks. Our results show that chimpanzees outperform dogs not only in causal understanding, but also in a variety of other physical cognitive skills such as knowledge of space and Cognition 49