The interpolation of object and surface structure

One of the main theoretical challenges of vision science is to explain how the visual system interpolates missing structure. Two forms of visual completion have been distinguished on the basis of the phenomenological states that they induce. Modal completion refers to the formation of visible surfaces and/or contours in image regions where these properties are not specified locally. Amodal completion refers to the perceived unity of objects that are partially obscured by occluding surfaces. Although these two forms of completion elicit very different phenomenological states, it has been argued that a common mechanism underlies modal and amodal boundary and surface interpolation (the "identity hypothesis"; Kellman & Shipley, 1991; Kellman, 2001). Here, we provide new data, demonstrations, and theoretical principles that challenge this view. We show that modal boundary and surface completion processes exhibit a strong dependence on the prevailing luminance relationships of a scene, whereas amodal completion processes do not. We also demonstrate that the shape of interpolated contours can change when a figure undergoes a transition from a modal to an amodal appearance, in direct contrast to the identity hypothesis. We argue that these and previous results demonstrate that modal and amodal completion do not result from a common interpolation mechanism.     

Hand-scoring error rates in psychological testing

Despite the comprehensive treatment of test validity in most technical manuals, test authors appear to routinely assume that clients and professionals will score their instruments without error. Recently Allard and Faust challenged this assumption by suggesting that error rates "may not be rare or benign" and demonstrated that tests with more complex scoring procedures were associated with a greater number of scoring errors. This study investigated error rates that resulted from hand scoring seven psychometric tests commonly employed in psychological practice. Significant and serious error rates were identified for both psychologist and client scorers across all tests investigated. Scoring complexity was found to predict the base rate of scorer errors. The findings suggest that greater development in and attention to test-scoring procedures is required to restrict the likelihood of scorer error.     

Assessment of cognitive load in multimedia learning using dual-task methodology

In two pilot experiments, a new approach for the direct assessment of cognitive load during multimedia learning was tested that uses dual-task methodology. Using this approach, we obtained the same pattern of cognitive load as predicted by cognitive load theory when applied to multimedia learning: The audiovisual presentation of text-based and picture-based learning materials induced less cognitive load than the visual-only presentation of the same material. The findings confirm the utility of dual-task methodology as a promising approach for the assessment of cognitive load induced by complex multimedia learning systems.     

Acute effects of triazolam on false recognition

Neuropsychological, neuroimaging, and electrophysiological techniques have been applied to the study of false recognition; however, psychopharmacological techniques have not been applied. Benzodiazepine sedative/anxiolytic drugs produce memory deficits similar to those observed in organic amnesia and may be useful tools for studying normal and abnormal memory mechanisms. The present double-blind, placebo-controlled repeated measures study examined the acute effects of orally administered triazolam (Halcion; 0.125 and 0.25 mg/70 kg), a benzodiazepine hypnotic, on performance in the Deese (1959)/Roediger-McDermott (1995) false recognition paradigm in 24 healthy volunteers. Paralleling previous demonstrations in amnesic patients, triazolam produced significant dose-related reductions in false recognition rates to nonstudied words associatively related to studied words, suggesting that false recognition relies on normal memory mechanisms impaired in benzodiazepine-induced amnesia. The results also suggested that relative to placebo, triazolam reduced participants' reliance on memory for item-specific versus list-common semantic information and reduced participants' use of remember versus know responses.     

Kognitive Mobilität. Eine makroskopische Untersuchung der Wanderung von Wissenschaftlern zwischen Forschungsgebieten am Beispiel der Mathematik

Cognitive Mobility, a Macroscopic Investigation of Migration of Scientists between Research Fields Studied by Example of Mathematics. — In history of science, scientific migrations of famous scientists are well-known. Nothing is known, however, about the total of migrations between fields of science, despite the importance of scientific mobility for information transfer and exchange. In the present investigation all migrations between the major 39 subdisciplines of mathematics from 1959 through 1975 are studied in a macroscopic manner. The quantitative importance of migration for the development of mathematical fields is assessed. In an analysis of the relationship between the affinity of fields and mobility between them a „principle of least migration distance” is established. Furthermore, some aspects of a Markov-chain treatment of scientific mobility are discussed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Women Counselor Educators: A Survey of Publication Activity

The authors studied the publication activity of women counselor educators, with respect to the relationship between women's career development in academia and the mentoring process. Possible alternative publishing avenues and networking opportunities pertinent to women counselor educators are suggested.     

Attitudes and attitude change of indigenous teacher trainees in Papua New Guinea

The study reported used the semantic differential as an instrument to collect data for an examination of attitudes and attitude change of indigenous teacher trainees at Port Moresby Teachers College. The sample consisted of three Intakes of students, differing widely in exposure to Western education and experience of the teaching role. Teaching in College was almost entirely the responsibility of Australian academics. Analysis of the results showed a strong similarity between Intakes on pre-test factor patterns. The major factor in each case was clearly identifiable as Osgood's evaluative factor. Two other factors gave evidence of splintering of the evaluative dimension. The basic three factor pattern of Osgood was not established. Ten evaluative scales were identified and used in calculation of pre and posttest attitude scores on the sixty concepts rated. Tests of significance of differences between means and variances were carried out by Intakes and, in the case of one Intake which was made up of males and females, by sex. Results were described and tentative explanations offered taking account of Intake differences, cultural setting and the possible effect of teacher/student cross-cultural differences.