Heterogeneous heterogeneity by default: Testing categorical moderators in mixed-effects meta-analysis

Categorical moderators are often included in mixed-effects meta-analysis to explain heterogeneity in effect sizes. An assumption in tests of categorical moderator effects is that of a constant between-study variance across all levels of the moderator. Although it rarely receives serious thought, there can be statistical ramifications to upholding this assumption. We propose that researchers should instead default to assuming unequal between-study variances when analysing categorical moderators. To achieve this, we suggest using a mixed-effects location-scale model (MELSM) to allow group-specific estimates for the between-study variance. In two extensive simulation studies, we show that in terms of Type I error and statistical power, little is lost by using the MELSM for moderator tests, but there can be serious costs when an equal variance mixed-effects model (MEM) is used. Most notably, in scenarios with balanced sample sizes or equal between-study variance, the Type I error and power rates are nearly identical between the MEM and the MELSM. On the other hand, with imbalanced sample sizes and unequal variances, the Type I error rate under the MEM can be grossly inflated or overly conservative, whereas the MELSM does comparatively well in controlling the Type I error across the majority of cases. A notable exception where the MELSM did not clearly outperform the MEM was in the case of few studies (e.g., 5). With respect to power, the MELSM had similar or higher power than the MEM in conditions where the latter produced non-inflated Type 1 error rates. Together, our results support the idea that assuming unequal between-study variances is preferred as a default strategy when testing categorical moderators.     

The effect of microlevel and macrolevel signaling on learning with 360° videos

The application of 360° videos raised the attention of educators and researchers, as it appears to be an approachable option to mediate complete environments in educational settings. However, challenges emerge from the perspective of educational psychology. Learning irrelevant cognitive strains might be imposed because it is necessary to navigate through spherical material. However, these potential downsides could be compensated for using signaling techniques. In a two (macrolevel vs. no macrolevel signaling) × two (microlevel vs. no microlevel signaling) factorial between-subjects design plus control group, 215 fifth-and sixth-grade students will watch a 360° video about visual and behavioral characteristics of animals. Learning outcomes, cognitive load, disorientation, and presence will be investigated. It is expected that macrolevel signaling will enhance learning and presence and reduce cognitive load and disorientation. Microlevel signaling will have comparable advantages, but these effects will be more pronounced when macrolevel signaling is implemented.     

Behavioral consequences of intergroup sensitivity

Communication of criticism between groups is important to productive societal discourse, but may serve to inflame conflict. The defensive rejection of intergroup, relative to intragroup, criticism (intergroup sensitivity effect [ISE]) may contribute to such divides. The ISE has been observed in self-report measures, but such measures are weak and biased predictors of actual (divisive) behavior. We review recent research demonstrating that the ISE does have costly behavioral consequences. We next consider the debate concerning whether the ISE reflects defense of a valued social identity or enforcement of a conversational norm. We therefore review recent evidence for an ISE among individuals lacking identification with the target of the criticism. Third, we examine how the ISE may affect a variety of behaviors relevant to societal divisions, including political reconciliation, environmental sustainability, and vaccination. Lastly, we outline future research that can clarify the underlying mechanisms of the ISE and promote conciliatory intergroup behavior.     

Pain in the eye of the beholder: Variations in pain visual representations as a function of face ethnicity and culture

Pain experienced by Black individuals is systematically underestimated, and recent studies have shown that part of this bias is rooted in perceptual factors. We used Reverse Correlation to estimate visual representations of the pain expression in Black and White faces, in participants originating from both Western and African countries. Groups of raters were then asked to evaluate the presence of pain and other emotions in these representations. A second group of White raters then evaluated those same representations placed over a neutral background face (50% White; 50% Black). Image-based analyses show significant effects of culture and face ethnicity, but no interaction between the two factors. Western representations were more likely to be judged as expressing pain than African representations. For both cultural groups, raters also perceived more pain in White face representations than in Black face representations. However, when changing the background stimulus to the neutral background face, this effect of face ethnic profile disappeared. Overall, these results suggest that individuals have different expectations of how pain is expressed by Black and White individuals, and that cultural factors may explain a part of this phenomenon     

Choice behavior and the accessibility of the reinforcer

In Experiment 1, matching of relative response rates to relative rates of reinforcement was obtained in concurrent variable-interval schedules when the absolute values of the two concurrent variable-interval schedules varied from 6 sec and 12 sec to 600 sec and 1200 sec. Increases in the duration of the changeover delay, however, produced decreases in the relative response rates and, consequently, some deviation from matching. In Experiment 2, matching of relative response rates to the relative duration of the reinforcer failed to occur when the equal variable-interval schedules arranging access to the two different reinforcer durations (1.5 and 6 sec) were varied in size from concurrent variable-interval 10-sec schedules to concurrent variable-interval 600-sec schedules.     

Differential-psychologische Untersuchungen zum Vigilanzverhalten

Zusammenfassung Mit Hilfe von Korrelationsmethoden wurden inter-individuelle Leistungsunterschiede in einer ein- und einer mehrflächigen Vigilanzaufgabe untersucht. In beiden Aufgaben korrelieren bestimmte Vigilanzscores mit Interferenzindikatoren im Stroop-Versuch. In der mehrflächigen Anordnung zeigte sich eine negative Korrelation zwischen der Entdeckungswahrscheinlichkeit und der Rate der falschen Alarme. Hinsichtlich der zeitlichen Merkmale der Vigilanzleistung ergab sich, daß die Vpn den geringsten Abfall der Entdeckungswahrscheinlichkeit erkennen lassen, die zu Beginn der Vigilanzaufgabe die Rate der falschen Alarme am stärksten reduzieren konnten. Die Ergebnisse wurden im Rahmen des detection-Modells interpretiert.

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Experiments in individual differences of vigilance behavior

Summary This paper is concerned with individual differences of vigilance performance in a simple and a complex vigilance task. In both tasks certain aspects of vigilance behavior were correlated with interference in the Color Word Test by Stroop. In the complex vigilance task there was a negative correlation between the probabilities of signal detections and false alarms rates. With regard to the temporal characteristics of vigilance behavior it was found out that subjects with the least decrease of detection rate showed the greatest reduction of their false alarms rate to the beginning of the vigilance task. The results were discussed in the context of the detection model.

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Teil II der Dissertation, die im Januar 1969 der Philosophischen Fakultät der Freien Universität Berlin vorgelegt wurde.     

Gallbladder distention and the effects of several drugs on heart rate,respiratory movements and cortical potentials in cats with hypothalamic lesions

The effects of chronic hypothalamic lesions and various drugs on the viscero-visceral reflexes of cats have been investigated, utilizing measurement of the bioelectrical activity of the cerebral cortex. After coagulation of the posterolateral hypothalamus the heart rate decreased by 40–60 beats per minute, but eventually it regained its initial value. The viscero-visceral reflexes from the gallbladder to the heart were preserved after the operative procedure. Chlorpromazine and atropine blocked both arousal and the cardiorespiratory response to stimulation of the gallbladder. Similar effects were produced by novocaine and pantocaine.