Michael C. Philipp

A preliminary study on how hypohydration affects pain perception

Chronic pain is a prevalent health issue with one in five people suffering from some form of chronic pain, with loss of productivity and medical costs of chronic pain considerable. However, the treatment of pain can be difficult, as pain perception is complex and can be affected by factors other than tissue damage. This study investigated the effect of hypohydration (mild, voluntary dehydration from ∼24 h of limiting fluid intake, mimicking someone drinking less than usual) on a persons pain perception. Seventeen healthy males (age 27 ± 5 years) visited the laboratory on three occasions, once as a familiarization and then twice again while either euhydrated (urine specific gravity: 1.008 ± 0.005) or hypohydrated (urine specific gravity: 1.024 ± 0.003, and -1.4 ± 0.9% body mass). Each visit, they performed a cold pressor test, where their feet were placed in cold water (0-3 °C) for a maximum of 4 min. Measures of hydration status, pain sensitivity, pain threshold, and catastrophization were taken. We found that hypohydration predicted increased pain sensitivity (β = 0.43), trait pain catastrophizing, and baseline pain sensitivity (β = 0.37 and 0.47, respectively). These results are consistent with previous research, and suggest that a persons hydration status may be an important factor in their perception of acute pain.

Mobility, satisfaction with functional capacity and perceived quality of life (PQOL) in older persons with self-reported visual impairment: The pathway between ability to get around and PQOL

Abstract Background: Research shows that ability to get around (AGA) is significantly associated with perceived quality of life (PQOL) among older persons with self-reported visual impairment. Much of this impact, however, is through satisfaction with one’s functional capacity. Satisfaction with functional capacity is a construct composed of five items: satisfaction with (1) activities of daily living, (2) capacity to work, (3) self, (4) health and (5) sleep. At present, it is not known how AGA interacts individually with these items to influence PQOL. Purpose: The purpose of this study is to investigate the extent to which AGA interacts with each of these five items to affect PQOL. Methods: Structural equation modelling was employed in a secondary-analysis of data from 356 persons (aged 56–72) with self-reported visual impairment to identify the pathways by which AGA affects PQOL. Results: Satisfaction with self and health were the only items found to be both directly related to QOL and to provide a significant pathway between AGA and PQOL. Conclusion: AGA significantly affects PQOL both directly and indirectly through its impact on people’s satisfaction with self and health. Lessons may be learnt from this to better focus mobility interventions to enhance PQOL in this population. Implications for Rehabilitation The findings of this study indicate that ability to get around (AGA) has a significant impact on perceived quality of life (PQOL): the stated goal of many rehabilitation programs for older persons who are visually impaired. The study also found that the primary pathway by which AGA influenced PQOL was indirect through its association with both satisfaction with one’s self and health rather than direct. Attempts to enhance PQOL by increasing AGA may be most effective if the focus of intervention was on restoring one’s sense of self and health as opposed to focusing on meeting practical needs.

Sociality of facial expressions in immersive virtual environments: a facial EMG study.

Immersive virtual environment technology is increasingly used by psychologists as a tool for researching social influence in realistic, yet experimentally controllable, settings. The present study demonstrates the validity and reliability of facial electromyography as a marker of affect in immersive virtual environments and further shows that the mere presence of virtual humans is enough to elicit sociality effects on facial expressiveness. Participants viewed pleasant and unpleasant images in a virtual room either alone or with two virtual humans present. The patterns of smiling and frowning activity elicited by positive and negative stimuli in the virtual environment were the same as those found in laboratory settings. Moreover, when viewing positive stimuli, smiling activity was greater when two agents were present than in the alone condition. The results provide new psychophysiological evidence for the potency of social agents in immersive virtual environments.

What Makes for the Most Intense Regrets? Comparing the Effects of Several Theoretical Predictors of Regret Intensity

Several theories have been proposed to account for variation in the intensity of life regrets. Variables hypothesized to affect the intensity of regret include: whether the regretted decision was an action or an inaction, the degree to which the decision was justified, and the life domain of the regret. No previous study has compared the effects of these key predictors in a single model in order to identify which are most strongly associated with the intensity of life regret. In this study, respondents (N = 500) to a postal survey answered questions concerning the nature of their greatest life regret. A Bayesian regression analysis suggested that regret intensity was greater for—in order of importance—decisions that breached participants’ personal life rules, decisions in social life domains than non-social domains, and decisions that lacked an explicit justification. Although regrets of inaction were more frequent than regrets of action, regrets relating to actions were slightly more intense.

Using Bayes Factors to Test Hypotheses in Developmental Research

This article discusses the concept of Bayes factors as inferential tools that can serve as an alternative to null hypothesis significance testing in the day-to-day work of developmental researchers. A Bayes factor indicates the degree to which data observed should increase (or decrease) the credibility of one hypothesis in comparison to another. Bayes factor analyses can be used to compare many types of models but are particularly helpful when comparing a point null hypothesis to a directional or nondirectional alternative hypothesis. A key advantage of this approach is that a Bayes factor analysis makes it clear when a set of observed data is more consistent with the null hypothesis than the alternative. Bayes factor alternatives to common tests used by developmental psychologists are available in easy-to-use software. However, we note that analysis using Bayes factors is a less general approach than Bayesian estimation/modeling, and is not the right tool for every research question.

Who owns a group's proposals: The initiator or the group as a whole?

This study examined who “owns”; a proposal during decision‐making group discussion. There are three potential answers to this question: the member who made the proposal, with that member dominating relevant discussion (the “pet proposal”; possibility), the group as a whole, with different members taking different responsibilities in discussing the proposal (the “role specialization”; possibility), and the group as a whole, with all members sharing in the discussion of the proposal (the “collective responsibility”; possibility). Evidence from a relatively large sample of discussion data supports the collective responsibility possibility, with the proviso that the groups biggest talker tends to dominate discussion no matter whose proposal is being discussed.