Guidance for professionals in health promotion: Keeping it simple–but not too simple

Abstract

People with haemophilia have been infected by HIV through blood products required for the treatment of their bleeds. In a recent study in Scotland their knowledge of HIV/AIDS and their behavioural changes were explored. It was found that people with severe haemophilia were better informed about HIV and AIDS than the mildly/moderately affected, bur only the knowledge of precautions in mildly/moderately affected patients was positively associated with their change of sexual practices. Mildly/moderately affected patients, who were less at risk of contracting HIV, reduced their treatment more than the severely affected patients. Only one third of patients applied safe-sex practices and a greater proportion of those who did not were single men, some of them HIV antibody positive.     

On a simple‐minded definition of creativity

In this study, 909 5th- and 6th-grade children were recruited as participants, and questionnaires were used to investigate the relationships between migration to urban settings and children's creative inclinations. The study was broken down to 2 parts. Study 1 compared scores on measures of creative inclinations among migrant, rural, and urban children, and further compared measures of creative inclinations among children with varying migration durations. Study 2 used path analysis to explore factors potentially mediating the effects of migration on children's creative inclinations. The results suggest that migration to urban settings is meaningfully related to creative inclinations, but the relationship seems more nuanced than initially hypothesized. When openness to new experiences, intelligence, and classroom climate were entered into the prediction equation, migration shows some indirect effects on creative inclinations. The results are discussed in terms of the significance of the study and the need for further research.     

“Backward masking” of simple detection latencies

Simple detection latencies were determined with stimuli that comprised two successive flashes. The second flash either equaled or exceeded the first in luminance, duration, or both. When a low-luminance flash preceded either a low-or a high-luminance flash, the flashes summated, yielding latencies that were shorter than the latency for the first flash alone. In the limit, when the second flash was intense and followed the first by a short time, the latency for the paired flashes behaved as if it was determined by the second flash alone. This limit was analogous to the retroactive interference in studies of the neurophysiological concomitants of backward masking. However, the S in masking studies detects the first flash despite interference by the second, whereas the present S detected the onset of the stimulus light. The need for an analysis of the S’s response under masking is thus indicated.     

Naïve realism: a simple approach

Naïve realism is often characterized, by its proponents and detractors alike, as the view that for a subject to undergo a perceptual experience is for her to stand in a simple two-place acquaintance relation toward an object. However, two of the leading defenders of naïve realism, John Campbell and Bill Brewer, have thought it necessary to complicate this picture, claiming that a third relatum is needed to account for various possible differences between distinct visual experiences of the same object (for example, differences that result from changes in the object’s spatial orientation relative to the subject, or from changes in the intensity with which the subject focuses her attention on the object). This, I argue, is a mistake. Once it is acknowledged that a subject’s visual experience acquaints her with more than just a single object, all of the relevant facts can be explained from within the simpler naïve realist framework.

     

Functionplane—A new approach to simple structure rotation

A new criterion for rotation to an oblique simple structure is proposed. The results obtained are similar to that obtained by Cattell and Muerle's maxplane criterion. Since the proposed criterion is smooth it is possible to locate the local maxima using simple gradient techniques. The results of the application of the Functionplane criterion to three sets of data are given. In each case a better fit to the subjective solution was obtained using the functionplane criterion than was reported for by Hakstian for the oblimax, promax, maxplane, or the Harris-Kaiser methods.This paper is contribution No. 66 from the Program in Ecology and Evolution at the State University of New York, Stony Brook, New York. This work was supported in part by a grant (GB-20496) from the National Science Foundation. The computations were performed on an IBM 360/67 computer at the State University of New York at Stony Brook.     

Is strong inference really superior to simple inference?

The method of strong inference, wherein multiple hypotheses are constructed and a crucial experiment is carried out, is said to have special status in science because it guarantees falsifying results. However, the proposition that strong inference is in any way superior to the method of constructing and testing a single hypothesis is contradicted both by close rational analysis and by the empirical evidence. An experiment is reviewed in which subjects who conduct strong tests are much less likely to discover or approximate the truth than subjects who conduct simple tests of a false hypothesis. It is concluded that a potential to falsify is necessary for a test to have corroborative value; however, arguments as to the general superiority of one type of potentially falsifying test over another have no logical basis. Any claim as to a general superiority of strong tests over simple tests would require access to information about the probability of each strategy to produce various relationships between the truth and whatever explanations are most accessible, and such information is not knowable, even in principle.     

What do the hands externalize in simple arithmetic?

In 4 experiments, the authors examined the use of the hands in simple arithmetic tasks. Experiments 1 and 2 demonstrated that pointing increases both accuracy and speed in counting arrays of items, whether those items are identical or distinctive. Experiment 3 demonstrated that individuals tend to nod their heads when not allowed to point and that nodding is associated with greater accuracy, suggesting that pointing is functional for reasons other than simply providing additional visual information. Experiment 4 examined changes in speech when adding arrays of digits, depending on whether participants were allowed to use their hands to manipulate the tokens on which the digits were presented. Taken together, the results of these experiments are consistent with recent research suggesting that gesture can serve cognitive functions and that the hands can support the binding of representational elements to their functional roles by providing phase markers for cyclic cognitive processes.     

Asperger syndrome: a simple matter of white matter?

Asperger syndrome, one of the Pervasive Developmental Disorders, is formally diagnosed on the basis of a cluster of cognitive, social and motor signs. It is also associated with poor visuo-spatial skills, good verbal performance, gauche social behaviour and clumsiness. Many of the difficulties evident in those with Asperger syndrome are closely associated with right-hemisphere dysfunction. In this respect they also resemble signs used to diagnose what has been labelled Nonverbal Learning Disorder. Here, these are treated as being the same or closely-related disorders with a possible common underlying aetiology; that is, a neurodevelopmental abnormality affecting white matter. This review examines the ability of this approach to account for a wide range of characteristics of the Asperger syndrome, and contrasts this with a theory-of-mind approach, which, although able to account for the primary features of Asperger syndrome, is less successful at explaining some of its secondary features.     

Does the identification of simple features require serial processing?

Several recent studies have shown performance decrements with increasing display size when background texture elements are present in a same-different feature discrimination task--a result that challenges the traditional notion that the identities of simple visual features are processed in parallel, preattentively. Four experiments are reported that explore the implications of these results. Experiment 1 replicates the recent studies but limits the generalizability of the results to small target numbers. Experiments 2 and 3 show that the observed performance decrements are not due to a serial or even limited-capacity, parallel process. Experiment 4 suggests that decision factors idiosyncratic to the use of texture elements in a same-different task are responsible for the effect. It is concluded that the identification of simple visual features proceeds in parallel, with unlimited capacity (i.e., preattentively).     

Backward walking: a simple reversal of forward walking?

The purpose of this study was to determine whether backward walking represented a simple temporal reversal of forward walking and, hence, could be controlled by a reversed cycling of the same group of neurons. Electromyographic (EMG), joint angle, joint moment, and joint muscle power patterns were compared for forward and backward walking, in 6 subjects. The joint angle patterns with the time-base of the backward walking reversed were similar, with the exception of the ankle. The moment patterns were similar except for the knee, whereas the joint muscle powers were almost reversed-polarity images of each other. This suggests that somewhat similar muscle activation patterns could be used to produce both modes of locomotion, but the temporal cycling of muscle contraction would be reversed: Concentric muscle activity in forward walking would become eccentric activity in backward walking, and visa versa. The EMG results generally supported these findings.     

A simple introduction to Markov Chain Monte–Carlo sampling

Markov Chain Monte–Carlo (MCMC) is an increasingly popular method for obtaining information about distributions, especially for estimating posterior distributions in Bayesian inference. This article provides a very basic introduction to MCMC sampling. It describes what MCMC is, and what it can be used for, with simple illustrative examples. Highlighted are some of the benefits and limitations of MCMC sampling, as well as different approaches to circumventing the limitations most likely to trouble cognitive scientists.     

Associative priming in faces: Semantic relatedness or simple co-occurrence?

In two experiments, we explored the effects of co-occurrence and semantic relationships in the associative priming of faces. In Experiment 1, pairs of computer-generated human faces were presented simultaneously (i.e., they co-occurred) with no associated semantic information attached to them. A significant facilitation effect in the subsequent recognition of these paired faces (priming) was observed. Thus, repeatedly presenting faces together while keeping semantic information to a minimum appears to be enough to produce associative priming. In Experiment 2, the computer-generated faces were associated with semantic information and again presented ipairs. Priming effects arising from co-occurrence and semantic relatedness were observed. The results from these experiments show that semantic relatedness is not the sole cause of the association between faces; co-occurrence plays a crucial role too. This conclusion has significant implications for the current computational models of face processing.     

What is learned about nontarget items in simple visual search?

Human sensitivity to correlational structure between nontargets and likelihood of target presence in a visual letter-search task were studied in two experiments. In each of these experiments, the performance of subjects for whom the nontarget information was altered in the final trial block was compared with the performance of subjects for whom the nontarget information did not change. When stimulus strings were presented individually on a computer screen and subjects were required to make a yes-no decision about target presence (Experiment 1), the change in nontarget structure resulted in increased reaction times for target-absent trials. When subjects searched simultaneously for three possible targets (Experiment 2), the change in nontarget structure produced increased error rates and increased reaction times for both target-absent and target-present trials. Correlations between the amount of predictive information in individual stimulus strings and reaction times also showed that both switching and nonswitching subjects were sensitive to the nontarget context. However, neither self-reports of strategy nor postexperiment choices between context-consistent and -inconsistent letter strings indicated any explicit knowledge of the predictive information in the nontarget stimuli. Subjects can thus acquire and benefit from, apparently without awareness, information about subtle correlational structure in nontarget elements in simple visual search.     

Producing simple utterances: How far ahead do we plan?

The subjects were presented pictures depicting a man, woman, girl, or boy touching, kicking, greeting, or standing beside one of the others. The subjects, constrained to using only these names, produced utterances whose lengths and grammatical forms were prespecified. The latencies for subject-verb utterances (e.g., The man is greeting) were longer than for naming the actors (e.g., The man). However, the latencies for subject-verb utterances when the actor was already known were shorter than for naming the actions (e.g., Greeting). Together these results imply that some, but not all, verb selection is performed before subject-verb utterances are initiated. Three control experiments eliminated alternative interpretations. Finally, it was demonstrated that the same degree of advance planning occurs before the initiation of subject-verb-object utterances (e.g., The man is greeting the woman).     

Standardized or simple effect size: What should be reported?

It is regarded as best practice for psychologists to report effect size when disseminating quantitative research findings. Reporting of effect size in the psychological literature is patchy – though this may be changing – and when reported it is far from clear that appropriate effect size statistics are employed. This paper considers the practice of reporting point estimates of standardized effect size and explores factors such as reliability, range restriction and differences in design that distort standardized effect size unless suitable corrections are employed. For most purposes simple (unstandardized) effect size is more robust and versatile than standardized effect size. Guidelines for deciding what effect size metric to use and how to report it are outlined. Foremost among these are: (i) a preference for simple effect size over standardized effect size, and (ii) the use of confidence intervals to indicate a plausible range of values the effect might take. Deciding on the appropriate effect size statistic to report always requires careful thought and should be influenced by the goals of the researcher, the context of the research and the potential needs of readers.