Perceptual Categorization: Connectionist Modelling and Decision Rules

Although it is currently popular to model human associative learning using connectionist networks, the mechanism by which their output activations are converted to probabilities of response has received relatively little attention. Several possible models of this decision process are considered here, including a simple ratio rule, a simple difference rule, their exponential versions, and a winner-take-all network. Two categorization experiments that attempt to dissociate these models are reported. Analogues of the experiments were presented to a single-layer, feed-forward, delta-rule network. Only the exponential ratio rule and the winner-take-all architecture, acting on the networks' output activations that corresponded to responses available on test, were capable of fully predicting the mean response results. In addition, unlike the exponential ratio rule, the winner-take-all model has the potential to predict latencies. Further studies will be required to determine whether latencies produced under more stringent conditions conform to the model's predictions.     

Picking a maintenance service: A user’s view

A guide is provided for selecting small computer maintenance services. Types of available services are described, and a series of questions is answered concerning selection.     

Waving the Flag: National Symbolism,Social Identity,and Political Engagement*

This research examined the psychological underpinnings of concern for national symbols and ritualistic‐ceremonial activities or “symbolic involvement.” We propose and test a distinction between symbolic and “instrumental” involvement or concern for the functionality of national institutions and their capability to provide instrumental benefits to citizens. Items comprising the two constructs were found to be empirically distinct, evidenced by statistically reliable and orthogonal dimensions in exploratory factor analysis. Moreover, evidence based on divergent patterns of relations with various forms of national membership indicates that symbolic and instrumental involvement are rooted in distinct motivational concerns related to identity expression and object appraisal, respectively. These findings suggest that national symbolism evokes a psychological attachment to the nation as an abstracted social entity, but not as a concrete functional system.