Human and non-human primates share the ability to extract adjacent dependencies and, under certain conditions, non-adjacent dependencies (i.e., predictive relationships between elements that are separated by one or several intervening elements in a sequence). In this study, we explore the online extraction dynamics of non-adjacent dependencies in…

The exhibition of actions that are causally unnecessary to the outcomes with which they are associated is a core feature of human cultural behavior. To enter into the world(s) of their cultural in-group, children must learn to assimilate such unnecessary actions into their own behavioral repertoire. Past research has established the habitual…

Six-month-olds reliably discriminate different monkey and human faces whereas 9-month-olds only discriminate different human faces. It is often falsely assumed that perceptual narrowing reflects a permanent change in perceptual abilities. In 3 experiments, ninety-six 12-month-olds' discrimination of unfamiliar monkey faces was examined. Following…

In a previous study, Adachi, Kuwahata, Fujita, Tomonaga & Matsuzawa demonstrated that infant Japanese macaques (Macaca fuscata) form cross-modal representations of conspecifics but not of humans. However, because the subjects in the experiment were raised in a large social group and had considerably less exposure to humans than to…

A nonverbal false belief task was administered to children (mean age 5 years) and two great ape species: chimpanzees ("Pan troglodytes") and bonobos ("Pan paniscus"). Because apes typically perform poorly in cooperative contexts, our task was competitive. Two versions were run: in both, a human competitor witnessed an experimenter hide a reward in…

How do we come to recognize and represent different kinds of objects in the world? Some developmental psychologists have hypothesized that learning language plays a crucial role in this capacity. If this hypothesis were correct, then non-linguistic animals should lack the capacity to represent objects as kinds. Previous research with rhesus…

In many discrimination-learning tests, spatial separation between stimuli and response loci disrupts performance in rhesus macaques. However, monkeys are unaffected by such stimulus-response spatial discontiguity when responses occur through joystick-based computerized movement of a cursor. To examine this discrepancy, five monkeys were tested on…

Four bonobos, seven gorillas, and six orangutans were presented with two small rectangular boards on a platform. One of the boards had a piece of food under it so that it acquired an inclined orientation whereas the other remained flat on the platform. Subjects preferentially selected the inclined board. In another experiment, subjects were…

This study compared nonverbal numerical processing in 6-year-olds with that in nonhuman animals using a numerical bisection task. In the study, 16 children were trained on a delayed match-to-sample paradigm to match exemplars of two anchor numerosities. Children were then required to indicate whether a sample intermediate to the anchor values was…

We investigated how within-stimulus heterogeneity affects the ability of rhesus monkeys to order pairs of the numerosities 1 through 9. Two rhesus monkeys were tested in a touch screen task where the variability of elements within each visual array was systematically varied by allowing elements to vary in color, size, shape, or any combination of…

The relevance of perirhinal cortical cholinergic and glutamatergic neurotransmission for taste recognition memory and learned taste aversion was assessed by microinfusions of muscarinic (scopolamine), NMDA (AP-5), and AMPA (NBQX) receptor antagonists. Infusions of scopolamine, but not AP5 or NBQX, prevented the consolidation of taste recognition…

Human toddlers demonstrate striking failures when searching for hidden objects that interact with other objects, yet successfully locate hidden objects that do not undergo mechanical interactions. This pattern hints at a developmental dissociation between contact-mechanical and spatiotemporal knowledge. Recent studies suggest that adult non-human…