Perceptual differentiation during categorization learning by pigeons.

In Experiment 1, pigeons were trained to categorize two sets of variable stimuli (black and white checkerboard patterns), constructed by random distortions of two prototype patterns. They were subsequently trained on new discriminations, between two new exemplars of their positive category, two new exemplars of their negative category, or two control checkerboard patterns. The new exemplars of their familiar categories were easier to discriminate than the wholly novel stimuli, although this difference was significant only for exemplars of their previously negative category. In Experiment 2, pigeons were initially trained on a discrimination between two prototype checkerboards; they subsequently learned to discriminate between two distortions of their negative prototype more rapidly than between two control patterns. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Care or repair? Home improvement agencies in the UK

Essential reading for those concerned with the provision of housing. The UK experience is well documented by experienced commentators and the development of home-improvement agencies in the UK may provide a valuable example of how to tackle problems which will increasingly come to the fore elsewhere in Europe, especially where governments are pursuing vigorous privatization policies.     

Prototype effects and peak shift in categorization.

People asked to categorize exemplars of 2 categories often respond more accurately to the prototypes of those categories than to other exemplars. The authors suggest that this prototype effect may often have been confounded with a peak shift as is observed when pigeons are trained to discriminate between two wavelengths (S+?=?550 nm and S–?=?560 nm), and the peak of their postdiscrimination gradient lies at 540 or 530 nm rather than at 550 nm. Three experiments established that a similar peak shift can occur when people are asked to categorize 2 sets of stimuli, but the authors also provide evidence of a true prototype effect uncontaminated by any peak shift. These results appear to pose considerable problems for exemplar-based theories of categorization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-empowerment in health promotion: a realistic target?

There have been many calls for nurses to adopt a self-empowerment model for health promotion practice rather than continuing to work from the medical model. Continuing with our series on health promotion, this article examines features of the self-empowerment approach and questions whether its goals are achievable.     

Psychometric intelligence dissociates implicit and explicit learning.

The hypothesis that performance on implicit learning tasks is unrelated to psychometric intelligence was examined in a sample of 605 German pupils. Performance in artificial grammar learning, process control, and serial learning did not correlate with various measures of intelligence when participants were given standard implicit instructions. Under an explicit rule discovery instruction, however, a significant relationship between performance on the learning tasks and intelligence appeared. This finding provides support for Reber's hypothesis that implicit learning, in contrast to explicit learning, is independent of intelligence, and confirms thereby the distinction between the 2 modes of learning. However, because there were virtually no correlations among the 3 learning tasks, the assumption of a unitary ability of implicit learning was not supported. (PsycINFO Database Record (c) 2010 APA, all rights reserved)