‘Core Knowledges’: a dissociation between spatiotemporal knowledge and contact‐mechanics in a non‐human primate?

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 primates may exhibit a similar dissociation. Here, I provide the first direct test of this dissociation using a search paradigm with adult rhesus monkeys. Subjects watched as a plum rolled behind one of two opaque barriers. In Experiment 1, subjects had to locate the plum based on the position of a wall that blocked the plum's trajectory. Subjects searched incorrectly, apparently neglecting information about the location of the wall. However, subjects searched correctly in Experiments 2-4 when they were given spatiotemporal information about the plum's movement. Results indicate that adult monkeys use spatiotemporal information, but not contact-mechanical information, to locate hidden objects. This dissociation between contact-mechanical and spatiotemporal knowledge is discussed in light of developmental theories of core knowledge and the literature on object-based attention in human adults.     

Units of visual individuation in rhesus macaques: objects or unbound features?

Vision begins with the processing of unbound visual features, which must eventually be bound together into object representations. Such feature binding is required for coherent visual perception, and accordingly has received a considerable amount of study in several domains. Neurophysiological work, often in monkeys, has revealed the details of how and where feature binding occurs in the brain, but methodological limitations have not allowed this research to elucidate just how feature binding operates spontaneously in real-world situations. In contrast, behavioral work with human infants has demonstrated how we use simpler unbound features to individuate and identify objects over time and occlusion in many types of events, but this work has not typically been able to isolate the role of feature binding in such processing. Here we provide a method for assessing the spontaneity and fidelity of feature binding in non-human primates, as this process is utilized in real-world situations, including simple foraging behaviors. Using both looking-time and manual-search measures in a natural environment, we show that free-ranging rhesus macaques (Macaca mulatta) spontaneously bind features in order to individuate objects across time and occlusion in dynamic events. This pattern of results demonstrates that feature binding is used in subtle ways to guide ecologically relevant behavior in a non-human animal, spontaneously and reliably, in its natural environment.     

Two‐year‐olds’ naîve predictions for horizontal trajectories

Hood recently reported that preschool children overgeneralized the prediction that falling objects travel in a straight line in spite of extensive counter‐evidence that the object had been deviated to a non‐aligned box by a tube. This behaviour was interpreted as a na?^ve theory of gravity resulting from an overgeneralization derived from experience of falling objects. The current study set out to test whether there was also a significant tendency for 2‐year‐olds to predict that objects travel in a straight line in the horizontal plane. This was achieved by comparing search for an invisibly displaced object moving either vertically or horizontally. The findings confirmed a gravity bias for falling events but did not reveal a similar tendency in the horizontal condition. In the horizontal task, children were as likely to search at an incorrect non‐aligned box as an aligned incorrect box. This supports the interpretation of a na?^ve gravity bias present from at least 2 years of age.     

A REFINED COMPUTER HARASSMENT PARADIGM: VALIDATION, AND TEST OF HYPOTHESES ABOUT TARGET CHARACTERISTICS

A refined computer paradigm for assessing sexual harassment is presented, validated, and used for testing substantive hypotheses. Male participants were given an opportunity to send sexist jokes to a computer-simulated female chat partner. In Study 1 ( N = 44), the harassment measure (number of sexist jokes sent) correlated positively with self-reported harassment proclivity. Study 2 ( N = 77) included a more elaborate cover story, variations of the female target's attitude (feminist vs. traditional) and physical attractiveness (low vs. high), and additional measures for construct validation. Results showed that harassment correlated positively with self-reported harassment proclivity, hostile sexism, and male identity. Feminist targets were harassed more than traditional targets, whereas target attractiveness had no effect. Theoretical and applied implications are discussed.     

The egocentric reference for visual exploration and orientation

Clinical signs of damage to the egocentric reference system range from the inability to detect stimuli in the real environment to a defect in recovering items from an internal representation. Despite clinical dissociations, current interpretations consider all symptoms as due to a single perturbation, differentially expressed according to the medium explored (perceptual or representational). We propose an alternative account based on the functional distinction between two separate egocentric mechanisms: one allowing construction of the immediate point of view, the other extracting a required perspective within a mental representation. Support to this claim comes from recent results in the domain of navigation, showing that separate cognitive mechanisms maintain the egocentric reference when actively exploring the visual space as opposed to moving according to an internal map. These mechanisms likely follow separate developmental pathways, seemingly depend on distinct neural pathways and are used independently by healthy adults, reflecting task demands and individual cognitive style. Implications for spatial cognition and social skills are discussed.     

Principal Congruences on Semi-De Morgan Algebras

In this paper we use Hobby's duality for semi-De Morgan algebras, to characterize those algebras having only principal congruences in the classes of semi-De Morgan algebras, demi-pseudocomplemented lattices and almost pseudocomplemented lattices. This work extends some of the results reached by Beazer in [3] and [4].