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.     

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.     

Apocalyptic Argument and the Anticipation of Catastrophe: the Prediction of Risk and the Risks of Prediction

This essay proposes to extend the model of apocalyptic argument developedin my recent book Arguing the Apocalypse (OLeary, 1994) beyond the study ofreligious discourse, by applying this model to the debate over awell-publicized earthquake prediction that caused a widespread panic in theAmerican midwest in December, 1990. The first section of the essay willsummarize the essential elements of apocalyptic argument as I have earlierdefined them; the second section will apply the model to the case of the NewMadrid, Missouri, earthquake prediction, in order to demonstrate thatcertain patterns of reasoning characteristic of religious apocalyptic arepresent in the discourse over an anticipated local disaster. My ultimatepurpose is to show that predictions of global and local catastrophe mayserve as extreme cases that will illuminate the dynamics of predictiveargument in general. Thus my argument will seek to undercut Daniel Bellsdistinction between prophecy and prediction (Bell, 1973) by establishingthat these discourses share identifiable formal and substantivecharacteristics, and depend for their rhetorical effect on anxiety, hope,far, and excitement as modes of temporal anticipation.     

Imperialism,nationalism and missionaries: Lessons from Sudan for the twenty‐first century

Muslim‐Christian relations in modem Sudanese history involve the tensions created by the transition from imperial rule to independence and by the impact of contemporary processes of globalization. The conflicts between Christian missionaries and the newly‐independent government of Sudan in the early 1960s reflected the tensions between old mission‐station style Christian activities and attempts by a military régime to impose measures of ‘national’ unification. Opportunities for creating institutions for constructive interactions were missed or not even conceived. Lessons from the experiences of the early 1960s emphasize the importance of viewing Muslim‐Christian relations in the 1990s in the context of the actual current conditions rather than imposing out‐of‐date images on existing realities.     

The value of possessions in compulsive hoarding: Patterns of use and attachment

Hoarding behavior, patterns of use of possessions, and emotional attachment to possessions were examined among a sample of female undergraduates and a sample of community volunteers. Hoarding behavior was associated with a decreased frequency of use of possessions and excessive concern about maintaining control over possessions. Furthermore, high scores on the hoarding scale were associated with higher levels of perceived responsibility for: (1) being prepared; and (2) the well-being of the possession. Hoarding was also associated with greater emotional attachment to possessions and to the reliance on possessions for emotional comfort. The implications of these findings for the definition of hoarding are discussed.