The Abridgement Paradox

When axiomatizing a body of truths, one first concentrates on obtaining a set of axioms that entail all and only those truths. The theorist expects that this complete system will have some needlessly strong axioms that can later be weakened or even deleted. What happens if the theorist includes in his system recognition of this superfluity? Contradiction! Even admitting the possibility of superfluity dashes all hope of consistency. Any suspicion of superfluous information must be voiced from outside the system.     

Variability and Noise in Continuous Force Production

In the present 3 experiments, the authors examined the hypothesis, derived from information theory, that increases in the variability of motor responses result from increases in perceptual-motor noise. Three different groups of participants (Ns = 10, 9, and 10, respectively, in Experiments 1, 2, and 3) produced continuous isometric force under either low, intermediate, or high target force levels. When considered together, the results showed that force variability (SD) increased exponentially as a function of force level. However, an index of information transmission (M/SD), as well as measures of noise in both the time (approximate entropy) and the frequency (power spectrum) domains, changed according to an inverted-U-shaped function over the range of force levels. The findings provide further evidence that increased information transmission is related to increases, and not to decreases, in the noisiness of the structure of force output.     

Interacting Constraints and the Emergence of Postural Behavior in ACL-Deficient Subjects

In this study, the authors examined how task, informational, and sensorimotor system constraints influence postural control. Postural behavior of subjects with (n = 15) and without (n = 15) a key sensorimotor system constraint, anterior cruciate ligaments (ACLs) in 1 knee, was examined during 1 - and 2-legged stance with and without vision. Postural control was assessed on a commonly used postural sway meter and on a dynamic stabilometer. Data on postural sway characteristics were obtained for 30 s under 6 different conditions: standing, with eyes open and closed, on both legs, on the injured leg, and on the noninjured leg. The interaction of task, informational, and sensorimotor constraints was observed only on the dynamic stabilometer and not the postural sway meter. Vision was the most important informational constraint on postural control for subjects on the dynamic stabilometer, particularly for the ACL-deficient group standing on the injured leg. Under more static task constraints, ACL deficiency did not prove a significant disadvantage, because vision was confirmed as a significant source of exproprioceptive information. The results support the functionality of using dynamic tasks such as a stabilometer in assessing postural behavior of subjects with sensorimotor system constraints.     

Effect of an Audience on Performance of a Motor Task

40 College Ss were placed in 4 groups and tested on a star-tracing task on 2 occasions under the following conditions: spectators-no-spectators; spectators-spectators; no-spectators-no-spectators; no-spectators—spectators. It was found that the presence or absence of spectators had no noticeable effect on the initial learning phase as contrasted to later stages of performance. When conditions remained the same on both testing occasions, less errors were made. Speed was generally quicker under altered task conditions.     

Effects on Face Recognition of Spatial-Frequency Information Contained in Inspection and Test Stimuli

Researchers often assume a critical band of spatial frequencies is required for face recognition. Also, many studies have not measured the contrast required for recognition. On Day 1, observers viewed high-pass-filtered (HP), low-pass-filtered (LP), or unfiltered (UF) faces. On Day 2, they viewed a variety of faces, some of which were LP filtered, HP filtered, and UF. Observers adjusted contrast until they achieved both detection and recognition. Observers were most accurate and sensitive when filtered faces agreed in spatial-frequency content across days. Faces differing in spatial-frequency content were least well recognized. Unfiltered faces always fell between the 2 extremes. Observers generally used less contrast to recognize unfiltered than filtered faces. Correspondence of information between inspection and testing seemed more important than any particular range of frequencies.     

To be or not to be at risk: Spontaneous reactions to risk information

Rheumatoid arthritis (RA) is a chronic disease, which can lead to considerable psychological distress. The present study evaluated anxiety and depression symptoms for this chronic and painful illness within the framework of the conservation of resources (COR) theory. Coping strategies, coping self-efficacy, religiousness and social support are very important personal resources, which have been found to protect individuals from psychological distress. The aim of the present study was to examine the predictive values of socio-demographic and illness-related variables, perceived social support, ways of coping, religiousness, arthritis self-efficacy and resource loss for psychological distress in a sample of 117 RA patients from Turkey, a secular, Islamic, non-western developing country. The results revealed that RA patients experience considerable anxiety and depressive symptoms. The results of the regression analysis showed that gender, helplessness coping and resource loss are significant predictors of anxiety, whereas arthritis self-efficacy and resource loss are significant predictors of depression. Resource loss appeared as an important predictor for both anxiety and depression. This finding was consistent with the COR theory. The clinical implications of these findings are discussed.     

Enhancing the effects of a narrative message through experiential information processing: An experimental study

First-person narratives are becoming a popular means to communicate health risk information. Although studies show they can increase risk perception and motivate health behaviours compared to statistical messages, more research on the conditions in which they are particularly likely to have effects is needed. In this study, we tested a moderator related to how information is processed. Specifically, we hypothesised that thinking in terms of emotions and personal experiences – known as experiential information processing – would increase people’s responsiveness to a narrative. Female college students (N = 138) who reported indoor tanning were randomly assigned to read a first-person narrative message or a statistical message about the risks of skin cancer. Prior to reading the message, the women received instructions that would activate either experiential or rational information processing. Participants then reported their risk perceptions of skin cancer, worry about skin cancer and behaviour intentions related to skin cancer. Analyses showed that message type and information processing interacted to influence risk perceptions and worry. Consistent with hypotheses, participants reported the highest risk perception and worry when they used an experiential information system prior to reading the narrative message. There were no effects on behaviour intentions. Implications of these findings are discussed.     

Autonomy and reactions to health-risk information

It has been suggested that autonomy promotes enhanced reflection on novel information and reduces defensive or biased information processing. This study investigated how autonomy affected people's reactions to known versus novel health-risk information in relation to three behaviours: sun exposure, alcohol consumption and salt intake. Participants (N = 321) completed a measure of autonomy, read either known or novel health-risk information and reported their relative autonomous motivation, attitudes, perceived behavioural control, subjective norm and intentions towards reducing the health-risk behaviour concerned. In line with our hypotheses, the results showed that higher autonomy participants reported greater relative autonomous motivation towards reducing health-risk behaviours than did lower autonomy participants; this effect was mediated by perceptions of the information as less freedom-threatening. The expected interaction between Autonomy and Information Type was not observed. The results indicate that autonomy is associated with greater relative autonomous motivation to engage in health behaviours, and that autonomous motivation may subsequently influence intentions to reduce health-risk behaviour following exposure to health-risk information.     

Perceived responsibility for disease onset affects HIV/AIDS Education

Abstract

Ninety-nine participants were assigned to one of three experimental conditions in which they viewed an AIDS education videotape that systematically manipulated whether or not the educator would be perceived as responsible for HIV infection. Participants were administered pre and post-video affect measures, and an HlV/AIDS knowledge test after watching the video. Participants who viewed the speaker who acquired HIV through a blood transfusion (perceived not responsible) and those who viewed the speaker who did not reveal mode of acquisition (control) performed significantly better on the knowledge test compared to those who viewed the speaker who acquired HIV through unprotected sexual inttrcourse (perceived responsible). In addition. male participants in the perceived responsible condition reported a significant increase in sensation-sceking after viewing the video. Finally, females experienced a significantly greater increase in anxiety as a result of seeing the video than did males. Implications of these tindings for the design and implmentation of AIDS education programs were discussed.     

The effects of scenario-based risk information on perceptions of susceptibility to Chlamydia and HIV

Abstract

Objectives: The Self-Report Habit Index (SRHI) was originally reported as one-dimensional; however, habit has been described as characterised by several features. Moreover, one-dimensional models for the SRHI have demonstrated poor fit. Therefore, we aimed to compare multidimensional models with a one-dimensional model in both snacking and physical activity habits, besides examining further instrument characteristics.

Design: A cross-sectional study was conducted with high school and university students (n?=?555).

Main outcome measure: The SRHI adapted for physical activity and for snaking habits was applied at one time point.

Results: Nested models with one factor, two factors and three factors were compared. Next, a hierarchical second-order model was tested, and further validity issues, as well as invariance between habits, were examined. Three-dimensional models represented a better fit for both habits. However, fit was still inadequate in the snacking version. In addition, discriminant validity concerns emerged for the physical activity SRHI. Moreover, invariance between the snacking and the physical activity versions was not confirmed.

Conclusions: Considering the SRHI as composed by the dimensions of ‘lack of awareness’, ‘lack of control’ and ‘history of behavioural repetition’ seems to be more accurate. Nevertheless, our findings suggest that further research is needed.