Julie Martin-Malivel and Joël Fagot
Centre de Recherche en Neurosciences Cognitives, CNRS, Marseille

Picture-object equivalence and concept formation were investigated in baboons and humans using intra-modal and cross-modal priming procedures. Subjects were trained to go/no-go sort target pictures of either humans or baboons presented after a prime image. For both species, response times were shorter when the primes and targets were category consistent rather than category inconsistent (Experiment 1). Categorical priming remained in baboons with grayscale or cutout prime pictures (Experiment 2). Further experiments used images as visual primes and vocalizations as auditory targets. Categorical cross-modal priming with either color or grayscale primes was demonstrated in humans and in one of two baboon subjects (Experiments 3-4). Results confirm categorical abilities of baboons and demonstrate that these animals have the ability to process pictures as representations of real humans or baboons. They further suggest the existence of interindividual differences in picture processing modes.