Cyber Buddy is Better than No Buddy: A Test of the Köhler Motivation Effect in Exergames.

Objective: Although exergames are popular, few people take advantage of the potential of group dynamics to motivate play (and achieve associated health bene?ts). One motivation gain phenomenon has shown promise for motivating greater effort in partnered exergames: The Koehler effect (working at a task with a more capable partner where one’s performance is indispensable to the group). This article examines whether a Koehler effect can be demonstrated in an exergame by exercising with a moderately superior humanoid, software-generated partner. Materials and Methods: Male and female (n = 120; mean age, 19.41 years) college students completed a series of plank exercises using ‘‘CyBuddy Exercise,’’ a program developed speci?cally for this study. In a lab in an academic building, participants completed the exercises individually and, after a rest, were randomly assigned to complete the same exercises again, but with a ‘‘live’’ human partner (HP) presented virtually, a nearlyhuman-like, humanoid partner (NHP), a hardly human-like, software-generated partner (HHP), or a no-partner control condition (IC), with equal numbers in each group (i.e., n = 30). Exercise persistence, perceived exertion, self-ef?cacy beliefs, enjoyment, and intentions to exercise were recorded and analyzed. Results: A 4X2 analysis of variance on the (Block 2 – Block 1) difference scores showed that a signi?cant Koehler motivation gain was observed in all partner conditions (compared with IC), but persistence was signi?cantly greater with HPs than with either NHP or HHP humanoid partners (P < 0.05). By the conclusion of the study, there were no signi?cant differences among the partnered conditions in perceived exertion, self-ef?cacy, enjoyment, or future intentions to exercise. Conclusions: These results suggest that a software-generated partner can elicit the Koehler motivation gain in exergames, but not as strongly as a partner who is thought to be human

A Conceptual Model of Referee Efficacy

This paper presents a conceptual model of referee efficacy, defines the concept, proposes sources of referee specific efficacy information, and suggests consequences of having high or low referee efficacy. Referee efficacy is defined as the extent to which referees believe they have the capacity to perform successfully in their job. Referee efficacy beliefs are hypothesized to be influenced by mastery experiences, referee knowledge/education, support from significant others, physical/mental preparedness, environmental comfort, and perceived anxiety. In turn, referee efficacy beliefs are hypothesized to influence referee performance, referee stress, athlete rule violations, athlete satisfaction, and co-referee satisfaction

Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe

To pay or not to pay?: Do extrinsic incentives alter the Köhler group motivation gain?

The Köhler effect is an increase in task motivation that occurs in performance groups when one is (a) less capable than one’s fellow group members, and (b) one’s efforts are particularly indispensible for group success. Recently, it has been shown that the Köhler effect can dramatically increase one’s motivation to exercise. The present study examines the potential moderating effect of the provision of extrinsic incentives on such Köhler motivation gains. When participants were offered such an extrinsic incentive for persisting at an exercise task, a robust Köhler effect was observed—participants who thought they were the less capable member of a dyad working at a conjunctive group exercise task persisted 26% longer than comparable individual exercisers. But an even stronger effect (a 43% improvement) was observed when no such incentive was on offer. Possible explanations and boundary conditions for this moderating effect are discussed

“…been down so long…”: perpetual vs. intermittent inferiority and the Köhler group motivation gain in exercise groups

Prior research has documented the Köhler motivation gain effect-- working with a more capable partner at a task that makes one’s performance indispensible for the group can boost task motivation. Recent research has shown that the Köhler effect can boost one’s persistence exercising in groups, but that always being the group’s “weak link” can eventually undermine these motivation gains. An experiment is reported which contrasts having a partner that is more capable on all/both exercise tasks with one that is more capable on the focal task, but inferior on the second task. The Köhler effect on the focal task was replicated and unmoderated by the uniformity of the partner’s exercise superiority. Implications for further research and application are discussed

Silence is Golden: Effect of Encouragement in Motivating the Weak Link in an Online Exercise Video Game

Background: Despite the physical and mental health benefits, few adults meet US Department of Health and Human Services physical activity guidelines for exercise frequency, intensity, and duration. One strategy that may increase physical activity duration is exercising with an Internet partner (ie, someone who is virtually present, as in video chat). Internet partners help people overcome many barriers associated with face-to-face exercise groups (eg, time, coordinating schedules, social physique anxiety). Past research examining individual performance in groups suggests that an increase in effort occurs when performing a task conjunctively, ie, when a participant is (1) less capable than fellow group members, and (2) participants efforts are particularly indispensable for group success (ie, where the group’s potential productivity is equal to the productivity of its least capable member). This boost in effort is more commonly known as the Köhler effect, named after the German psychologist who first observed the effect. While encouragement between group members is common practice in face-to-face group exercise, the effect of encouragement between partners exercising conjunctively across the Internet is unknown. Objective: To examine the impact of exercising alone, compared to exercising conjunctively with an Internet partner, both with and without encouragement, on exercise persistence (primary outcomes) and secondary psychosocial outcomes (self-efficacy, enjoyment, exercise intention). Methods: Participants were recruited online and face-to-face from the campus of Michigan State University. With the assistance of the experimenter, participants (n=115) played an exercise video game in a laboratory, performing a series of five abdominal plank exercises where they were asked to hold the plank for as long as possible (Time 1). They were then randomized to a condition (Individual, Partner-without-encouragement, or Partner-with-encouragement), where they performed the exercises again (Time 2). The impact of condition on the primary outcome measures and secondary outcome measures were evaluated using a 2 (Gender) x 3 (Condition) ANOVA on change scores (Time 2-Time 1). Results: Those who exercised in online teams (n=80) exercised significantly longer (time=78.8s, P<.001) than those who worked individually (n=35). However, exercise duration was shorter when one’s more capable partner gave verbal encouragement (n=55) than when s/he did not (n=25) (a mean difference of 31.14s). These increases in effort were not accompanied by altered task self-efficacy, enjoyment of the task, or intention to exercise in the future. Conclusions: Exercising conjunctively with an Internet partner can boost one’s duration of exercise. However, encouragement from the stronger to the weaker member can mitigate these gains, especially if one perceives such comments being directed at someone other than themselves. To boost exercise duration, Internet-based physical activity interventions involving group interaction should make relative abilities of participants known and communication clear

Aerobic exercise is promoted when individual performance affects the group: a test of the Kohler motivation gain effect

Background: A key barrier to achieving recommended intensity and duration of physical activity is motivation. Purpose: We investigated whether a virtually-present partner would influence participants’ motivation (duration) during aerobic exercise. Method: Fifty-eight females (M[subscript age] = 20.54 ± 1.86) were randomly assigned to either a coactive condition (exercising along side another person, independently), a conjunctive condition (performance determined by whichever partner stops exercising first) where they exercised with a superior partner, or to an individual condition. Participants exercised on a stationary bike at 65% of heart rate reserve on 6 separate days. Results: Across sessions, conjunctive condition participants exercised significantly longer (M = 21.89 min, SD = ±10.08 min) than those in coactive (M = 19.77 min, SD = ± 9.00 min) and individual (M = 10.6 min, SD = ± 5.84 min) conditions (p < 0.05). Conclusion: Exercising with a virtually-present partner can improve performance on an aerobic exercise task across multiple sessions