Automatic priming for translation- and scale-invariant representations of object shape

A series of visual search experiments explored whether early visual processes are sensitive to the overall shape of objects. Previous work (Wolfe & Bennett, 1997) has suggested that information concerning overall shape is not coded in early vision. However, in Experiment 1, we demonstrate that these previous findings are explicable in terms of non-target heterogeneity rather than an absence of shape information in early vision. In Experiments 2 and 3, we demonstrate that shape similarity, rather than individual contour similarity, can determine search efficiency. In Experiments 4 and 5, we show that manipulating the contrast polarity of contours and defining shape using texture significantly impeded search for an odd-one-out shape. The implications of these results for shape processing in early vision are discussed.     

Inhibition of return for target discriminations: the effect of repeating discriminated and irrelevant stimulus dimensions

Inhibition of return (IOR) refers to slowed reaction times when a target repeats in the same location as a preceding stimulus. In four experiments, the participants were presented with two successive stimuli, S1 and S2. In Experiments 1 and 2, the participants made a speeded discrimination of the identity or orientation of both S1 and S2 (Experiment 1) or of S2 only (Experiment 2). An IOR effect occurred for the repetition of stimulus location, but a facilitatory effect occurred if the stimulus remained unchanged or if an overt response was repeated. In Experiments 3 and 4, the participants localized S1 and S2 (Experiment 3) or S2 only (Experiment 4) to the left or right of center. In this case, repeating the same stimulus had no effect: IOR occurred any time stimulus location repeated. These results demonstrate that the expression of IOR is modulated by the repetition of a target object, but only when the task requires the discrimination of that object; when no discrimination is required, IOR is unaffected.     

Searching for impossible objects: Processing form and attributes in early vision

In five experiments, we investigated the extent to which form (shape) and metric attributes (three-dimensional, 3-D, orientation), both defined by relations between une elements, are processed in early vision. Search for a target defined by an abstract property of form (i.e., impossibility) was slow and serial. In contrast, search for a 3-D orientation target was considerably easier. Subsequent experiments suggest that this difference reflects the fact that 3-D orientation is derivable from localized sets of lines, whereas impossibility is an idiosyncratic property of the complete set of relations between lines. We conclude that only “gross” aspects of form are available in early vision as the complete set of line relations is not processed preattentively. However, localized processing of line relations is sufficient to derive 3-D orientation.     

Analogy with knowledgeable learners: When analogy confers benefits and exacts costs

Though embedding analogy in a text can improve acquisition of concepts that are relatively unfamiliar to learners (Donnelly & McDaniel, 1993), it remains uncertain how analogy influences learning for learners with some background knowledge for the target material. We develop several theoretical possibilities and report an experiment to test these possibilities. Target concepts familiar to college students were expressed either in literal form or through analogy, and the concepts were presented in a manner that either facilitated or discouraged contact with subjects’ prior knowledge. As revealed by multiple-choice testing, analogy facilitated learning when the targets were presented to discourage contact with prior knowledge. In contrast, analogy decreased performance when the same targets were presented to facilitate contact with prior knowledge. Possible interpretations of this unique finding are discussed.     

Validity of the Perceived Health Competence Scale in a UK primary care setting

The Perceived Health Competence Scale (PHCS) is a measure of self-efficacy regarding general health-related behaviour. This brief paper examines the psychometric properties of the PHCS in a UK context. Questionnaires containing the PHCS, the SF-36 and questions about perceived health needs were posted to 486 patients randomly selected from a GP practice list. Complete questionnaires were returned by 320 patients. Analyses of these responses provide strong evidence for the validity of the PHCS in this setting. Consequently, we conclude that the PHCS is a useful addition to measures of global self-efficacy and measures of self-efficacy regarding specific behaviours in the toolkit of health psychologists. This range of self-efficacy assessment tools will ensure that psychologists can match the level of specificity of the measure of expectancy beliefs to the level of specificity of the outcome of interest.     

Summation relations and portions of stuff

According to the prevalent ‘sum view’ of stuffs, each portion of stuff is a mereological sum of its subportions. The purpose of this paper is to re-examine the sum view in the light of a modal temporal mereology which distinguishes between different varieties of summation relations. While admitting David Barnett’s recent counter-example to the sum view (Barnett, Philos Rev 113:89–100, 2004), we show that there is nonetheless an important sense in which all portions of stuff are sums of their subportions. We use our summation relations to develop, as an alternative to the sum view, an analysis of stuffs that distinguishes between the ways in which different sorts of stuffs are sums of their subportions.

Factors associated with depressed mood among adolescents in Northern Ireland

This paper presents data on the pattern of self‐reported depressed mood among a sample of 887 11–15 year‐old secondary school students living in Northern Ireland. In addition, the paper examines the association between depressed mood and stressful life events, family support and perceived control. Analysis of variance of mean depression scores did not reveal main or interaction effects for age (school year) or sex. However, a school year×sex interaction effect was found when the variation in depression scores due to family cohesiveness (or support) was partialled out in an ANCOVA. In years 1 and 2, males reported higher mean depression scores than females, whereas the pattern was reversed in years 3 and 4. The co‐variates of stressful life events and perceived control did not significantly affect the pattern of mean depression scores. This would tend to suggest that the sex difference in depression found consistently with adults may begin to emerge in middle adolescence; and that the nature and level of family relationships may influence the prevalence and pattern of adolescent depression. The study found a higher mean depression score and a larger proportion of ‘cases’ (27%) than has been recorded in studies of young adolescents living outside Northern Ireland. However, the extent to which higher levels of symptomatology may be related to the politically unsettled nature of Northern Irish society is unclear. Copyright © 1999 John Wiley & Sons, Ltd.