The role of item- and category-specific information in the discrimination of people versus nonpeople images by pigeons

Herrnstein and Loveland (1964, pp. 549–551) successfully trained pigeons to discriminate pictures showing humans from pictures that did not. In the present study, a go/no-go procedure was employed to replicate and extend their findings, the primary focus of concern being to reevaluate the role of item- and category-specific information. The pigeons readily acquired the discrimination and were also able to generalize to novel instances of the two classes (Experiment 1). Classification of scrambled versions of the stimuli was based on small and local features, rather than on configural and global features (Experiment 2). The presentation of gray-scale stimuli indicated that color was important for classifying novel stimuli and recognizing familiar ones (Experiments 1 and 2). Finally, the control that could possibly be exerted by irrelevant background features was investigated by presenting the pigeons with images of persons contained in former person-absent pictures (Experiment 3). Classification was found to be controlled by both item- and category- specific features, but only in pigeons that were reinforced on person-present pictures was the latter type of information given precedence over the former.     

Linking logo,levels and language in mathematics

In his book Mindstorms (1980) Papert discusses Turtle Geometry as ego-syntonic or fitting the ways of thinking of the child as a geometric knowledge builder. The van Hiele theory (Wirzup, 1976) looks at geometric knowledge building as occuring through a necessary sequence of levels. Thus if Turtle Geometry is ego-syntonic it would seem that one could apply these van Hiele levels to better describe and understand this form of geometry. It is the first purpose of this paper to provide such an analysis.Using Logo to do Turtle Geometry requires that a child (or learner at any level) do geometry through the deliberate use of language. Thus one ought also to be able to relate theoretically levels of language use to Turtle Geometry. It is a second purpose of this paper to relate a language use framework suggested by the work of Frye (1982) to the language activities of Turtle Geometry.     

Chronisch lymphatische Leuk?mie (CLL)

Ohne Zusammenfassung     

Psychometric Note on the Reliability of the Sport Competition Anxiety Test: Form C

Abstract

Data collected from 736 fourth, fifth, and sixth grade children using Martens SCAT-C yielded moderately high values of split half reliability. Internal consistency coefficients were relatively high (.81 to .85) and similar to the values reported in the Martens test manual when calculated using the appropriate test, eliminating use of the KR-20. The SCAT-C was also found to be generalizable to fourth grade populations even though originally its use was not intended with this age group.     

Would dogs copy irrelevant actions from their human caregiver?

Companion dogs learn easily from humans, including human behavior, human communication, and some aspects of the human-made environment. They benefit from having the opportunity to learn from humans and are able to spontaneously synchronize their behavior with that of their caregiver. Here, we tested whether pet dogs would show a special form of observational learning, one that has been considered uniquely human. Indeed, humans show overimitation, the faithful copying of causally irrelevant actions, but great apes do not. Because in humans this peculiar form of imitation is strongly motivated by social factors, such as affiliation or conformity, we hypothesized that domesticated and enculturated dogs are more likely than apes are to copy such actions, especially if shown by their affiliated caregiver. Indeed, half of the dogs replicated a causally irrelevant action that was demonstrated by their caregiver, and about the same number did this whether they saw only this action being demonstrated or being demonstrated before or after a causally relevant, functional action. The demonstration of a causally relevant action, one that is immediately followed by access to food, thus does not inhibit the copying of an action that is spatially separated and functionally opaque. Given that the copying frequency in this study was low overall, these results suggest evidence for overimitation in dogs, which might challenge the human uniqueness of this type of social learning.