Processing spatial information from photographs, video, and scale models: Complex mental representation in children (<i>Homo sapiens</i>) and monkeys (<i>Macaca mulatta</i>)
Much research has focused on the age at which young children are able to use 2- and 3-dimensional stimuli to represent the environment. At 2½ years of age, children do not pass scale-model tasks (using scale models to find a hidden toy in a full-scale room), possibly because they lack dual representation (the ability to understand that model furnishings can simultaneously be both concrete toys and symbols). Experiment 1a of this dissertation tested whether failure on model-tasks by 2½-year-old children is due to an inability to match model furnishings to their full-scale referents. Experiment 1b tested whether children's experience with objects as toys interferes with their ability to use those objects as symbols. Children aged 2½ watched an experimenter hide a small toy in an unfamiliar model and were allowed to search the full-scale apparatus for the large toy hidden in the corresponding location. Children were unable to use the unfamiliar model, indicating that failure on model tasks is due to an inability to use dual representation.
Little is known about the ability of monkeys to solve similar symbolic representation tasks. This dissertation tested rhesus monkeys on three types of task. Monkeys were required to use photographs (Experiment 2) or video images (Experiment 3) to guide their search for a hidden object (a rubber ball or food reward) on a familiar apparatus. In Experiment 4, monkeys were shown the location of a ball on a familiar 4-door apparatus and were allowed to search for a replica ball hidden in the corresponding location on an identical board (1:1 ratio scale model). In Experiments 2 and 3 some monkeys were able to use 2-dimensional stimuli to solve spatial problems (i.e., finding the hidden ball or food on the apparatus). In Experiment 4, rhesus monkeys as a group successfully used a full-sized replica of a familiar apparatus to search in the correct location for a rubber ball. These data provide important insight into the ability of rhesus monkeys to represent their environments using 2- and 3-dimensional stimuli, and may allow for the better formation of animal models of human cognitive development.
0620: Developmental psychology
0633: Cognitive psychology