Dorothy Fragaszy - US grants

The proposed research evaluates a potentially useful animal model of the acquisition of adaptive motor behavior in socially living individuals. The focus is on the acquisition of manipulative behavior in infant tufted capuchin monkeys (Cebus apella). The work builds upon the principal investigator's previous observations of the development of tool-using and simple tool-making in a breeding group of capuchins, including infants. The unique repertoire of these particular monkeys affords an opportunity to study the ontogeny of manipulative behaviors culminating in tool use in socially-reared monkeys. Observations of the manipulative activity of immature capuchins (newborn to four years) will provide data on the timing and sequence of developmental changes in the form and function of manipulation, the contribution of social context to the development of general and specific motor skills, and the development and extent of lateral preference in this species. Complementary studies address the influence of specific individuals and settings on the expression of variable or novel manipulative behaviors. Our understanding of the relationship in humans between early manual activity and later neurobehavioral organization and motor skills will be enhanced if an adequate nonhuman primate model, one opermitting prospective research, is developed in this domain. Evaluation of monkeys for this purpose has not yet occurred. Capuchin monkeys are an attractive choice for exploratory work on the topic of manipulatory development because of their unusual manipulative propensities, including ready use of tools and the significance of socially mediated learning in their acquisition of certain manipulative skills. They are also relatively small-bodied, easy to keep and breed in captivity, and no species in the genus is yet listed as endangered. At the conclusion of this study, comparisons among humans, apes, and this species can be made on several aspects of manipulative development, allowing assessment of capuchins as a nonhuman primate model of human manipulative development.

The applicant requests continuation of her ADAMHA Research Scientist Development Award (Level II) for its final year and 46 weeks. The award was prematurely terminated in September 1990 upon transfer of the applicant from Washington State University to the University of Georgia. Reinstatement requires application through the competitive renewal procedure. The applicant pursues research in behavioral primatology, specifically on nonhuman models of behavioral development and adaptive manipulative behavior. The chief objectives to be achieved during the final period of the award are, for the applicant, 1) maximal productivity in an ongoing research program on adaptive manipulative behavior and development in capuchin monkeys, 2) significant professional growth through training and collaboration with Duane Rumbaugh in a promising new method of studying sensorimotor functioning using video-formatted tasks, and 3) additional professional growth through strengthening of an existing collaboration with Elisabetta Visalberghi in studies of social learning and tool-using behaviors. The chief objectives for the institution include strengthening the Psychology department's Biopsychology program in areas of interest to ADAMHA. This will be achieved by nurturance of the candidate's research and training program, which complements existing college and departmental strengths in primatology and biopsychology. A second objective for the institution relates to plans for the development of a college-wide facility for primatological research and training, centered upon Biopsychology's programs and facilities. The candidate's participation in the development of this facility will be enhanced by receipt of this award, through released time from other obligations and through more rapid development of collaborative projects with other investigators at UGA and elsewhere.

Instrumental manual activity is a hallmark of behavior in primates. It is an expression of cognitive as well as neuromotor and musculoskeletal function. Nonhuman primate models of such activity afford opportunities for intensive, controlled research not possible with human subjects and provide a comparative perspective that complements the work of developmental psychologists in this area. The five studies of this project focus on assessment of three aspects of instrumental manual activity in children and nonhuman primates: i) spatial competence in such tasks as planning and anticipating movement of the self, single objects, or objects with respect to each other; ii) coordination of bimanual activity, and iii) hierarchical organization of sequences of manual actions. Identical tasks will be presented to children at 11, 16, and 21 months of age, capuchin monkeys Cebus apella), and members of three ape species (bonobo, Pan paniscus; chimpanzee, Pan troglodytes; orangutan, Pongo pygmaeus). Tasks will be presented at the child's home or in the nonhuman subject's home cage or living area during several half-hour to hour-long sessions. Each subject will participate in spontaneous play with a variety of objects as well as in computer-mediated tasks in which joysticks, buttons or dials are used to control an image on a video monitor. Data from each study will be examined for within-group (i.e., monkey, ape, human) norms and between-group contrasts or similarities. The findings of all of the studies, considered jointly, will provide a broad picture of the relations among different aspects of instrumental manual activity in three primate families as well as of ontogenetic changes experienced by humans during their second year of life. It will also allow evaluation of the suitability of using these primate species as models of early instruments competence in humans.

Abstract


Collaborative Research: Perception-Action Foundations of Early Tool Use

Dorothy M. Fragaszy

How do humans learn to use an object as a tool? According to the theory of action/perception coupling, to use a tool, an individual must detect potential relations between objects that allow actions with one to produce change in another (for example, object A can be used to strike object B), and establish these relations through action. To use one object to change another in a specific way (perhaps to use A to crack B open) requires positioning or aligning the objects appropriately and applying the appropriate force. The number of alignments that must be achieved and how precisely movements must be modulated influence the difficulty of mastering a particular tool.

Before they begin to use objects as tools (at about their first birthday), human infants relate objects and surfaces through action, for example, by banging objects together or banging objects on a solid surface. We call these common modes of acting with objects "perception-action routines". Do these routines form the foundation for the appearance over the second year of life of tool use? If so, how are perception-action routines harnessed for this new purpose?

A collaborative project will investigate (1) how tool use emerges from infants' perception-action routines (2) how tool use involves detecting and establishing relations between objects and surfaces (3) how skill with a familiar tool is acquired and (4) how the development of skill with hammer tools in young children differs from how capuchin monkeys (that spontaneously use objects as hammers) acquire skill in the same contexts. Taken together, the results of the proposed experiments will help us better understand how tool use develops in children and to what degree tool use represents an ability that is uniquely human.

Children between 6 and 24 months of age will be videotaped acting singly with objects and surfaces that vary systematically in properties that affect banging (for example, hardness) and in features of handles. Cross-sectional studies of children's activity with unfamiliar objects, and studies of how children at different ages become skilled with practice at using hammers in varying conditions (for example, when the tool object has a handle vs. when it does not, and when they must be more vs. less accurate in where they strike) will also be conducted. These studies will be replicated with 8 adult capuchin monkeys. Capuchins readily use hammer-tools, but we do not know to what extent they master multiple relations in action as humans do.

This work will contribute to knowledge of learning mechanisms that support development of tool-using skills in humans, of age-related changes in learning mechanisms, and of the special qualities of humans in this regard. It contributes to contemporary debates about the continuous or discontinuous origins of tool use in human development and human evolution, and the role of action in learning. Additional broader impacts include involvement of undergraduate and graduate students in research, exposure of the research process to the general public, and the development of a new collaborative relationship between investigators at two institutions and in complementary areas of behavioral study (developmental and comparative psychology).

The capacity to combine objects and employ objects as tools is considered one of the major achievements of our species and figures deeply in our mythological, philosophical, cultural, and academic explanations for the evolution of human intelligence and behavior. Many researchers hold that object manipulation, language, social skills, and brain structure are been linked in human evolution. For the past 40 years capuchins monkeys, New World primates in the genus Cebus, have often been suggested as models for the evolution of intelligence and tool use in humans. Among primates, only only chimpanzees and humans exceed capuchins in the frequency, complexity with which objects are combined and manipulated. Although suggestive observations come from capuchins in captivity, scant evidence from wild populations is available to test hypotheses as to why exceptional manipulative abilities can be advantageous in natural settings and how individuals acquire these skills.

Brown capuchins (Cebus apella) in the Central Suriname Nature Reserve (CSNR) use complex object manipulation at the highest rates yet documented among wild capuchins. More specifically, male capuchins at CSNR employ an array of object combinations and manipulations labeled as percussion: striking sticks or hard fruit against hard surfaces and breaking off tree limbs. Percussion generates mechanical (non-vocal) acoustic sounds that transmit farther and more reliably in this densely forested environment than social signals based on visual displays. Preliminary observations suggest that capuchins evaluate the acoustic structure of the noises males produce in percussion as honest indicators of male strength and vigor important in male-mate competition and female mate choice, i.e., the stronger the male percussing, the louder the noise. This research project evaluates hypotheses about (1) the functions of brown capuchins' percussive behavior, focusing on the relative benefits accruing in sexual selection versus foraging, and (2) the expression of percussion in relation to an individual's developmental status and social circumstances. Whatever the findings, the theoretical implications are important and encompass anthropology, biology, ecology, and psychology.

Percussive behavior will be most fully understood against the distinctive ecological background of capuchin society at CSNR. First, the biota of the Guianan Plateau is characterized by extremely low energy and nutrient flow relative to other Neotropical regions. Second, these regional ecological characteristics are compounded by previously unsuspected landscape earthworks by pre-Columbian Amerindians populations in the area now encompassed by the CSNR. Recent exploratory work by Boinski and colleagues confirms that pervasive archeological features are present in CSNR; these sites covary with the bamboo and liana forest habitats preferentially used by capuchins.

This primate and community ecology research program has been ongoing in the CSNR since 1998 and remains the only multi-year ecological project within Suriname's forested interior since the end of violent civil uprisings (late 1970's - early 1990's). Boinski and her team work with biologists, educators, and wildlife and conservation officials of Suriname, international NGOs, and Peace Corps. Long-term supportive relations have developed between Surinamese Park Service and the research team, leading to educational and conservation outreach and contributions to the scientific infrastructure of Suriname by this project far beyond the immediate research products. Educational videos produced from research tapes will be made freely available on the web. The CSNR project is engaging the Surinamese with provocative questions about the cultural and biological significance of their matchless forests at a moment in history when national and foreign interests seek to expand economic exploitation of these same forests.

This planning visit grant supports travel to Brazil by Drs. M. Madden , T. Jordan, and Dr. D. Fragaszy as well as two graduate students, all from the university of Georgia, to visit colleagues Dr. Rocha, and colleagues at the University of São Paulo, and Dr. D. F. Mendes at the University of Goiás. The purpose of the trip is to plan a collaboration combining geospatial techniques and biological studies of wild capuchin monkeys. The trip will include discussions with collaborators in São Paulo and visits to two or more sites in Goiás and Piauí where the proposed collaborative work would take place to establish the suitability of proposed mapping, habitat sampling and behavioral research techniques. The US and Brazilian collaborators will discuss the details and feasibility of studying variation in the distribution of stone tool use among wild capuchin monkeys in relation to habitat and geographic features.