Are there nontrivial constraints on colour categorization?

In this target article the following hypotheses are discussed: (1) Colour is autonomous: a perceptuolinguistic and behavioural universal. (2) It is completely described by three independent attributes: hue, brightness, and saturation: (3) Phenomenologically and psychophysically there are four unique hues: red, green, blue, and yellow; (4) The unique hues are underpinned by two opponent psychophysical and/or neuronal channels: red/green, blue/yellow. The relevant literature is reviewed. We conclude: (i) Psychophysics and neurophysiology fail to set nontrivial constraints on colour categorization. (ii) Linguistic evidence provides no grounds for the universality of basic colour categories. (iii) Neither the opponent hues red/green, blue/yellow nor hue, brightness, and saturation are intrinsic to a universal concept of colour. (iv) Colour is not autonomous.     

Hippocampal synaptic plasticity during instrumental learning

present research examined the role of hippocampal NMDA-dependent synaptic potentiation on appetitive instrumental conditioning under a continuous reinforcement schedule. In the first experiment, low (.025 mg.kg) or moderate (.05 mg/kg) dosages of the NMDA receptor antagonist, MK801, failed to increase the number of training days required to reach acquisition criterion; number of training days required to reach criterion for extinction were also unaffected. In the second experiment, a higher dosage (.10 mg/kg) of MK801 or induction of long-term potentiation failed to alter the number of responses occurring during acquisition. These data suggest that hippocampal synaptic potentiation does not play a prominent role in instrumental learning with simple contingency conditions. It is suggested that hippocampal LTP reflects a perceptual process that contributes differentially to spatial cognition, classical and instrumental conditioning.     

Neural Network Models and Mechanisms of Strategy Development

The focus of this paper is mechanisms that may be responsible for intellectual and developmental differences in the cognitive strategies of typical and atypical children, including those with mental retardation. The discussion of these mechanisms is based on behavioral experiments on external memory strategies and on a set of neural network models designed for these tasks. Following the review of the external memory research, the rationale for using neural network models, how they have been used in other research, and their specific application to intellectual and developmental differences in external memory, including the results of several simulations, are reviewed. This is followed by a discussion of the mechanisms of intellectual differences and developmental change included in the models and some challenges for this type of modeling. Neural network modeling is discussed as an asset to research on cognitive development.     

Multiple information sources in interceptive timing

This study was designed to explore the limitations of tau (τ) as an explanatory construct for the timing of interceptive action. This was achieved by examining the effects of environmental structure and binocular vision on the timing of the grasp in a simple one-handed catch. In two experiments, subjects were required to catch luminous balls of different diameters (4, 6, 8 and 10 cm) in a completely darkened room. In the first experiment the influence of the presence vs. absence of an environmental background structure (both under monocular viewing) was tested, and in the second experiment the influence of monocular vs. binocular vision was examined. It was found that irrespective of the presence of environmental structure, an effect of ball size occurred in the monocular viewing conditions. That is, in monocular viewing conditions the grasp was initiated and completed earlier for the larger balls as compared to the smaller ones, while in the binocular viewing condition subjects behaved in accordance with a constant time to contact strategy: no effects of ball size were found. It is concluded that under binocular viewing a binocular information source is used, while in the monocular viewing condition a lower order information source like image size or image velocity is probably involved.     

Gender role stereotyping in Australian radio commercials

Most previous research into gender role stereotypes in the mass media has concentrated on television or print. Only one content analysis (Furnham & Schofield, 1986) has examined radio content, finding patterns of bias in British radio commercials consistent with, though less marked than, those in television commercials. The present study sought to determine whether similar patterns obtain in another Western country’s radio commercials collected approximately a decade later. Over 100 Australian radio ads were content analyzed, and results very similar to those of the earlier study were obtained. The findings are discussed in terms of their implications for studies of gender role development and audience reactions to media content. We are grateful to Elyse Frankel and Jason Low for assistance in data coding and checking, and to two anonymous reviewers for constructive commentaries on an earlier version.     

Hippocampal synaptic plasticity during instrumental learning

present research examined the role of hippocampal NMDA-dependent synaptic potentiation on appetitive instrumental conditioning under a continuous reinforcement schedule. In the first experiment, low (.025 mg.kg) or moderate (.05 mg/kg) dosages of the NMDA receptor antagonist, MK801, failed to increase the number of training days required to reach acquisition criterion; number of training days required to reach criterion for extinction were also unaffected. In the second experiment, a higher dosage (.10 mg/kg) of MK801 or induction of long-term potentiation failed to alter the number of responses occurring during acquisition. These data suggest that hippocampal synaptic potentiation does not play a prominent role in instrumental learning with simple contingency conditions. It is suggested that hippocampal LTP reflects a perceptual process that contributes differentially to spatial cognition, classical and instrumental conditioning.     

THE CREDIBLE SHRINKING ROOM:

Abstract— Becoming a proficient symbol user is a universal developmental last in the first years of life, but delecting and mentally representing symbolic relations can be quite challenging for young children To test the extent to which symbolic reasoning per se is problematic, we compared the performance of 2-year-olds in symbolic and nonsymbolic versions of a search task. The children had to use their knowledge of the location of a toy hidden in a room to draw an inference about where to find a miniature toy in a scale model of the room (and vice versa) Children in the nonsymbolic condition believed a shrinking machine had caused the room to become the model They were much more successful than children in the symbolic condition, for whom the model served as a symbol of the room The symbol understanding and use.     

The Development of a Clinical Rating Scale the McMaster Model of Family Functioning

This article describes the development and validation of the McMaster Clinical Rating Scale (MCRS). The MCRS is a 7-item scale designed to be completed by a trained rater after completion of an in-depth interview of the family. We present data from four new studies and review previously published articles concerning the reliability, validity, and clinical utility of the MCRS. Adequate interrater reliability and rater stability were obtained. The MCRS was found to correlate significantly with the self-report Family Assessment Device and to discriminate between families in different phases of a depressive disorder.