Effects of noncontingent reinforcement on problem behavior and stimulus engagement: the role of satiation, extinction, and alternative reinforcement

This study examined the effects of noncontingent reinforcement (NCR) with and without extinction on problem behavior and stimulus engagement (consumption of reinforcement) of 4 participants. Reductions in problem behavior using NCR have frequently been attributed to both satiation of the reinforcer and extinction. In the current study, aspects of the NCR treatment effects were difficult to explain based solely on either a satiation or an extinction account. Specifically, it was found that stimulus engagement remained high throughout the NCR treatment analysis, and that problem behavior was reduced to near-zero levels during NCR without extinction. The implications of these findings are discussed with respect to the satiation and extinction hypotheses frequently described in the applied literature. Findings from basic studies examining the effects of response-independent schedules are presented, and are used as the basis for a matching theory account of NCR-related effects. It is proposed that reductions in problem behavior observed during NCR interventions may be a function of the availability of alternative sources of reinforcement.     

Professional Autonomy and the Normative Structure of Medical Practice

Professional autonomy is often described as a claim of professionalsthat has to serve primarily their own interests. However, it can also beseen as an element of a professional ideal that can function as astandard for professional, i.e. medical practice. This normativeunderstanding of the medical profession and professional autonomy facesthree threats today. 1) Internal erosion of professional autonomy due toa lack of internal quality control by the medical profession; 2)the increasing upward pressure on health care expenses that calls for ahealth care policy that could imply limitations for the professionalautonomy of physicians; 3) a distorted understanding of theprofession as being based on a formal type of knowledge and relatedtechnology, in which other normative dimensions of medical practice areneglected and which frustrates meaningful communication betweenphysicians and patients. To answer these threats a normative structureanalysis of medical practice is presented, that indicates whichprinciples and norms are constitutive for medical practice. It isconcluded that professional autonomy, normatively understood, should bemaintained to avoid the lure of the technological imperative and toprotect patients against third parties' pressure to undertreatment.However, this professional autonomy can only be maintained if members ofthe profession subject their activities and decisions to a criticalevaluation by other members of the profession and by patients and ifthey continue to critically reflect on the values that regulate today'smedicine.     

Resolving the debate over birth order, family size, and intelligence

Hundreds of research articles have addressed the relationship between birth order and intelligence. Virtually all have used cross-sectional data, which are fundamentally flawed in the assessment of within-family (including birth order) processes. Although within-family models have been based on patterns in cross-sectional data, a number of equally plausible between-family explanations also exist. Within-family (preferably intact-family) data are prerequisite for separating within- and between-family causal processes. This observation reframes an old issue in a way that can be easily addressed by studying graphical patterns. Sibling data from the National Longitudinal Survey of Youth are evaluated, and the results are compared with those from other studies using within-family data. It appears that although low-IQ parents have been making large families, large families do not make low-IQ children in modern U.S. society. The apparent relation between birth order and intelligence has been a methodological illusion.     

Counterconditioning in the treatment of spider phobia: effects on disgust, fear and valence

From the perspective that disgust is a core feature of spider phobia, we investigated whether the treatment efficacy could be improved by adding a counterconditioning procedure. Women with a clinically diagnosed spider phobia (N = 34) were randomly assigned to the regular one-session exposure condition (EXP) or to the exposure with counterconditioning condition (CC). In the CC-condition tasty food-items were used during the regular exposure exercises and the participants' favourite music was played. Both treatment conditions appeared very effective in reducing avoidance behaviour and self-reported fear of spiders, strongly attenuated the disgusting properties of spiders and altered the affective evaluations in a positive direction. CC was not more effective in altering the affective valence of spiders than EXP and was not superior with respect to the long term treatment efficacy at 1 year follow up. Apparently, regular exposure treatment is already quite effective in altering the affective-evaluative component of spider phobia and it remains to be seen whether it is possible to further improve treatment outcome by means of procedures which are specifically designed to reduce the spiders' negative affective valence.     

From image segmentation to anti-textons

We apply the 'patchwork engine' (PE; van Tonder and Ejima, 2000 Neural Networks forthcoming) to encode spaces between textons in an attempt to find a suitable feature representation of anti-textons [Williams and Julesz, 1991, in Neural Networks for Perception volume 1: Human and Machine Perception Ed. H Wechsler (San Diego, CA: Academic Press); 1992, Proceedings of the National Academy of Sciences of the USA 89 6531-6534]. With computed anti-textons it is possible to show that tessellation and distribution of anti-textons can differ from that of textons depending on the ratio of texton size to anti-texton size. From this we hypothesise that variability of anti-textons can enhance texture segregation, and test our hypothesis in two psychophysical experiments. Texture segregation asymmetry is the topic of the first test. We found that targets on backgrounds with regular anti-textons segregate more strongly than on backgrounds with highly variable anti-textons. This neatly complements other explanations for texture segregation asymmetry (e.g. Rubenstein and Sagi, 1990 Journal of the Optical Society of America A 7 1632-1643). Second the relative significance of textons and anti-textons in human texture segregation is investigated for a limited set of texture patterns. Subjects consistently judged a combination of texton and anti-texton gradients as more conspicuous than texton-only gradients, and judged texton-only gradients as being more conspicuous than anti-texton-only gradients. In the absence of strong texton gradients the regularity versus irregularity of anti-textons agrees with perceived texture segregation. Using PE outputs as anti-texton features thus enabled the conception of various useful tests on texture segregation. The PE is originally intended as a general image segmentation method based on symmetry axes. With this paper we therefore hope to relate anti-textons with visual processing in a wider sense.     

Differential recall of central and peripheral details of emotional slides is not a stable phenomenon

A number of studies have reported that central information of an emotional scene is well retained, whereas peripheral details of such a scene are poorly recalled. Experiment 1 tested the hypothesis that attentional narrowing is responsible for this phenomenon. In addition, an attempt was made to increase the ecological validity of the experiment by giving extensive self-relevant instructions. Results showed that, although an emotional slide elicited eye-movements consistent with attentional narrowing, the corresponding recall patterns were absent. Experiments 2 and 3 explored some of the variables that might be responsible for the latter result. Experiment 2, relying on the original design of Christianson and E.F. Loftus (1991), found enhanced recall of central information of an emotional scene. Experiment 3 systematically varied stimulus exposure and interstimulus interval durations. However, the results of this experiment were rather complex and did not fully support the predicted differential recall patterns. Possible explanations for these findings are discussed. It is suggested that other methods (e.g. increasing levels of emotion rather than involvement) may be more suitable for testing the attentional narrowing hypothesis of emotional memory.     

The Factor Structure of the Beavers Interactional Scales

Confirmatory factor analysis and regression analyses of the Beavers Interactional Scales did not appear to support the model offered by its developers, namely, several specified family attributes contributing respectively to two global factors of Family Competence and Family Style. Moreover, regression analysis indicated that only three of 12 items predicted raters' assessments of Global Family Health, and one of seven items predicted Global Family Style. Individuals interested in the family dynamic centripetal/centrifugal might best think of that as a unitary entity and rate it accordingly.     

A psychometric analysis of chess expertise

This study introduces the Amsterdam Chess Test (ACT). The ACT measures chess playing proficiency through 5 tasks: a choose-a-move task (comprising two parallel tests), a motivation questionnaire, a predict-a-move task, a verbal knowledge questionnaire, and a recall task. The validity of these tasks was established using external criteria based on the Elo chess rating system. Results from a representative sample of active chess players showed that the ACT is a very reliable test for chess expertise and that ACT has high predictive validity. Several hypotheses about the relationships between chess expertise, chess knowledge, motivation, and memory were tested. Incorporating response latencies in test scores is shown to lead to an increase in criterion validity, particularly for easy items.