Auditory Hallucinations and Reduced Language Lateralization in Schizophrenia: A Meta-analysis of Dichotic Listening Studies

2013 ◽  
Vol 19 (4) ◽  
pp. 410-418 ◽  
Author(s):  
Sebastian Ocklenburg ◽  
René Westerhausen ◽  
Marco Hirnstein ◽  
Kenneth Hugdahl
Keyword(s):  
Effect Size ◽  
Dichotic Listening ◽  
Meta Analysis ◽  
Auditory Hallucinations ◽  
Effect Sizes ◽  
Healthy Controls ◽  
Language Lateralization ◽  
Trait Marker ◽  
Listening Studies ◽  
Meta Analyses

AbstractReduced left-hemispheric language lateralization has been proposed to be a trait marker for schizophrenia, but the empirical evidence is ambiguous. Recent studies suggest that auditory hallucinations are critical for whether a patient shows reduced language lateralization. Therefore, the aim of the study was to statistically integrate studies investigating language lateralization in schizophrenia patients using dichotic listening. To this end, two meta-analyses were conducted, one comparing schizophrenia patients with healthy controls (n = 1407), the other comparing schizophrenia patients experiencing auditory hallucinations with non-hallucinating controls (n = 407). Schizophrenia patients showed weaker language lateralization than healthy controls but the effect size was small (g = −0.26). When patients with auditory hallucinations were compared to non-hallucinating controls, the effect size was substantially larger (g = −0.45). These effect sizes suggest that reduced language lateralization is a weak trait marker for schizophrenia as such and a strong trait marker for the experience of auditory hallucinations within the schizophrenia population. (JINS, 2013, 19, 1–9.)

scholarly journals A Statistical Method for Synthesizing Meta-Analyses

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Liansheng Larry Tang ◽  
Michael Caudy ◽  
Faye Taxman
Keyword(s):  
Statistical Method ◽  
Effect Size ◽  
Meta Analysis ◽  
Effect Sizes ◽  
Weighted Mean ◽  
Summary Effect ◽  
Different Types ◽  
Meta Analyses ◽  
Size Estimates ◽  
Similar Search

Multiple meta-analyses may use similar search criteria and focus on the same topic of interest, but they may yield different or sometimes discordant results. The lack of statistical methods for synthesizing these findings makes it challenging to properly interpret the results from multiple meta-analyses, especially when their results are conflicting. In this paper, we first introduce a method to synthesize the meta-analytic results when multiple meta-analyses use the same type of summary effect estimates. When meta-analyses use different types of effect sizes, the meta-analysis results cannot be directly combined. We propose a two-step frequentist procedure to first convert the effect size estimates to the same metric and then summarize them with a weighted mean estimate. Our proposed method offers several advantages over existing methods by Hemming et al. (2012). First, different types of summary effect sizes are considered. Second, our method provides the same overall effect size as conducting a meta-analysis on all individual studies from multiple meta-analyses. We illustrate the application of the proposed methods in two examples and discuss their implications for the field of meta-analysis.

Can Reliance be Placed on a Single Meta-Analysis?

1990 ◽  
Vol 24 (3) ◽  
pp. 405-415 ◽  
Author(s):  
Nathaniel McConaghy
Keyword(s):  
Literature Review ◽  
Effect Size ◽  
Meta Analysis ◽  
Statistical Significance ◽  
Effect Sizes ◽  
Control Groups ◽  
Consistent Finding ◽  
Placebo Controls ◽  
Effect Of Treatment ◽  
Meta Analyses

Meta-analysis replaced statistical significance with effect size in the hope of resolving controversy concerning evaluation of treatment effects. Statistical significance measured reliability of the effect of treatment, not its efficacy. It was strongly influenced by the number of subjects investigated. Effect size as assessed originally, eliminated this influence but by standardizing the size of the treatment effect could distort it. Meta-analyses which combine the results of studies which employ different subject types, outcome measures, treatment aims, no-treatment rather than placebo controls or therapists with varying experience can be misleading. To ensure discussion of these variables meta-analyses should be used as an aid rather than a substitute for literature review. While meta-analyses produce contradictory findings, it seems unwise to rely on the conclusions of an individual analysis. Their consistent finding that placebo treatments obtain markedly higher effect sizes than no treatment hopefully will render the use of untreated control groups obsolete.

scholarly journals Social anxiety in the eating disorders: a systematic review and meta-analysis

2018 ◽  
Vol 48 (15) ◽  
pp. 2477-2491 ◽  
Author(s):  
Jess Kerr-Gaffney ◽  
Amy Harrison ◽  
Kate Tchanturia
Keyword(s):  
Eating Disorders ◽  
Social Anxiety ◽  
Meta Analysis ◽  
Treatment Strategies ◽  
Self Report ◽  
Effect Sizes ◽  
Healthy Controls ◽  
Comorbid Conditions ◽  
Current Review ◽  
Meta Analyses

AbstractSocial anxiety disorder is one of the most common comorbid conditions in eating disorders (EDs). The aim of the current review and meta-analysis is to provide a qualitative summary of what is known about social anxiety (SA) in EDs, as well as to compare levels of SA in those with EDs and healthy controls. Electronic databases were systematically searched for studies using self-report measures of SA in ED populations. In total, 38 studies were identified, 12 of which were included in the meta-analyses. For both anorexia nervosa (AN) and bulimia nervosa, there were significant differences between ED groups and HCs, with medium to large effect sizes. Findings from the qualitative review indicate that levels of SA are similar across the ED diagnoses, and SA improves with treatment in AN. In addition, high levels of SA are associated with more severe ED psychopathology, but not body mass index. These findings add to the wider literature on socio-emotional functioning in EDs, and may have implications for treatment strategies.

Handedness, language lateralisation and anatomical asymmetry in schizophrenia

2001 ◽  
Vol 178 (4) ◽  
pp. 344-351 ◽  
Author(s):  
Iris Sommer ◽  
André Aleman ◽  
Nick Ramsey ◽  
Anke Bouma ◽  
René Kahn
Keyword(s):  
Strong Evidence ◽  
Lateral Ventricle ◽  
Dichotic Listening ◽  
Planum Temporale ◽  
Healthy Controls ◽  
Left Handedness ◽  
Temporal Horn ◽  
Significant Difference ◽  
Listening Studies ◽  
Meta Analyses

BackgroundCerebral lateralisation appears to be decreased in schizophrenia. Results of studies investigating this, however, are equivocal.AimsTo review quantitatively the literature on decreased lateralisation in schizophrenia.MethodMeta-analyses were conducted on 19 studies on handedness, 10 dichotic listening studies and 39 studies investigating anatomical asymmetry in schizophrenia.ResultsThe prevalence of mixed- and left-handedness (‘non-right-handedness’) was significantly higher in patients with schizophrenia as compared to healthy controls, and also as compared to psychiatric controls. The analysis of dichotic listening studies revealed no significant difference in lateralisation in schizophrenia. However, when analysis was restricted to studies using consonant-vowel or fused word tasks, significantly decreased lateralisation in schizophrenia emerged. Asymmetry of the planum temporale and the Sylvian fissure was significantly decreased in schizophrenia, while asymmetry of the temporal horn of the lateral ventricle was not.ConclusionStrong evidence is provided for decreased cerebral lateralisation in schizophrenia.

Experimental and Quasi-Experimental Studies of Inquiry-Based Science Teaching

2012 ◽  
Vol 82 (3) ◽  
pp. 300-329 ◽  
Author(s):  
Erin Marie Furtak ◽  
Tina Seidel ◽  
Heidi Iverson ◽  
Derek C. Briggs
Keyword(s):  
Science Education ◽  
Education Reform ◽  
Science Teaching ◽  
Effect Size ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Effect Sizes ◽  
Science Education Reform ◽  
Quasi Experimental ◽  
Meta Analyses

Although previous meta-analyses have indicated a connection between inquiry-based teaching and improved student learning, the type of instruction characterized as inquiry based has varied greatly, and few have focused on the extent to which activities are led by the teacher or student. This meta-analysis introduces a framework for inquiry-based teaching that distinguishes between cognitive features of the activity and degree of guidance given to students. This framework is used to code 37 experimental and quasi-experimental studies published between 1996 and 2006, a decade during which inquiry was the main focus of science education reform. The overall mean effect size is .50. Studies that contrasted epistemic activities or the combination of procedural, epistemic, and social activities had the highest mean effect sizes. Furthermore, studies involving teacher-led activities had mean effect sizes about .40 larger than those with student-led conditions. The importance of establishing the validity of the treatment construct in meta-analyses is also discussed.

scholarly journals Comparison of the Effectiveness of Whole Body Vibration in Stroke Patients: A Meta-Analysis

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yoo Jung Park ◽  
Sun Wook Park ◽  
Han Suk Lee
Keyword(s):  
Muscle Strength ◽  
Effect Size ◽  
Meta Analysis ◽  
Whole Body Vibration ◽  
Treatment Method ◽  
Effect Sizes ◽  
Whole Body ◽  
Safe Alternative ◽  
Body Vibration ◽  
Meta Analyses

Objectives. The goals of this study were to assess the effectiveness of WBV (whole body vibration) training through an analysis of effect sizes, identify advantages of WBV training, and suggest other effective treatment methods. Methods. Four databases, namely, EMBASE, PubMed, EBSCO, and Web of Science, were used to collect articles on vibration. Keywords such as “vibration” and “stroke” were used in the search for published articles. Consequently, eleven studies were selected in the second screening using meta-analyses. Results. The total effect size of patients with dementia in the studies was 0.25, which was small. The effect size of spasticity was the greatest at 1.24 (high), followed by metabolism at 0.99 (high), balance, muscle strength, gait, and circulation in the decreasing order of effect size. Conclusions. The effect sizes for muscle strength and balance and gait function, all of which play an important role in performance of daily activities, were small. In contrast, effect sizes for bone metabolism and spasticity were moderate. This suggests that WBV training may provide a safe, alternative treatment method for improving the symptoms of stroke in patients.

scholarly journals Effect Sizes, Power, and Biases in Intelligence Research: A Meta-Meta-Analysis

2018 ◽  
Author(s):  
Michele B. Nuijten ◽  
Marcel A. L. M. van Assen ◽  
Hilde Augusteijn ◽  
Elise Anne Victoire Crompvoets ◽  
Jelte M. Wicherts
Keyword(s):  
Publication Bias ◽  
Effect Size ◽  
Meta Analysis ◽  
Convincing Evidence ◽  
Small Study ◽  
Effect Sizes ◽  
Medium Effect ◽  
Average Effect ◽  
Average Effect Size ◽  
Meta Analyses

In this meta-study, we analyzed 2,442 effect sizes from 131 meta-analyses in intelligence research, published from 1984 to 2014, to estimate the average effect size, median power, and evidence for bias. We found that the average effect size in intelligence research was a Pearson’s correlation of .26, and the median sample size was 60. Furthermore, across primary studies, we found a median power of 11.9% to detect a small effect, 54.5% to detect a medium effect, and 93.9% to detect a large effect. We documented differences in average effect size and median estimated power between different types of in intelligence studies (correlational studies, studies of group differences, experiments, toxicology, and behavior genetics). On average, across all meta-analyses (but not in every meta-analysis), we found evidence for small study effects, potentially indicating publication bias and overestimated effects. We found no differences in small study effects between different study types. We also found no convincing evidence for the decline effect, US effect, or citation bias across meta-analyses. We conclude that intelligence research does show signs of low power and publication bias, but that these problems seem less severe than in many other scientific fields.

Unresolved Heterogeneity in Meta-Analysis: Combined Construct Invalidity, Confounding, and Other Challenges to Understanding Mean Effect Sizes

2020 ◽  
Vol 46 (2-3) ◽  
pp. 343-354 ◽  
Author(s):  
Timothy R Levine ◽  
René Weber
Keyword(s):  
Content Analysis ◽  
Publication Bias ◽  
Effect Size ◽  
Meta Analysis ◽  
Effect Sizes ◽  
Size Distributions ◽  
Questionable Research Practices ◽  
Graphical Displays ◽  
Meta Analyses ◽  
Effect Heterogeneity

Abstract We examined the interplay between how communication researchers use meta-analyses to make claims and the prevalence, causes, and implications of unresolved heterogeneous findings. Heterogeneous findings can result from substantive moderators, methodological artifacts, and combined construct invalidity. An informal content analysis of meta-analyses published in four elite communication journals revealed that unresolved between-study effect heterogeneity was ubiquitous. Communication researchers mainly focus on computing mean effect sizes, to the exclusion of how effect sizes in primary studies are distributed and of what might be driving effect size distributions. We offer four recommendations for future meta-analyses. Researchers are advised to be more diligent and sophisticated in testing for heterogeneity. We encourage greater description of how effects are distributed, coupled with greater reliance on graphical displays. We council greater recognition of combined construct invalidity and advocate for content expertise. Finally, we endorse greater awareness and improved tests for publication bias and questionable research practices.

scholarly journals Effect Sizes, Power, and Biases in Intelligence Research: A Meta-Meta-Analysis

2020 ◽  
Vol 8 (4) ◽  
pp. 36
Author(s):  
Michèle B. Nuijten ◽  
Marcel A. L. M. van Assen ◽  
Hilde E. M. Augusteijn ◽  
Elise A. V. Crompvoets ◽  
Jelte M. Wicherts
Keyword(s):  
Publication Bias ◽  
Effect Size ◽  
Meta Analysis ◽  
Convincing Evidence ◽  
Small Study ◽  
Effect Sizes ◽  
Medium Effect ◽  
Average Effect ◽  
Average Effect Size ◽  
Meta Analyses

In this meta-study, we analyzed 2442 effect sizes from 131 meta-analyses in intelligence research, published from 1984 to 2014, to estimate the average effect size, median power, and evidence for bias. We found that the average effect size in intelligence research was a Pearson’s correlation of 0.26, and the median sample size was 60. Furthermore, across primary studies, we found a median power of 11.9% to detect a small effect, 54.5% to detect a medium effect, and 93.9% to detect a large effect. We documented differences in average effect size and median estimated power between different types of intelligence studies (correlational studies, studies of group differences, experiments, toxicology, and behavior genetics). On average, across all meta-analyses (but not in every meta-analysis), we found evidence for small-study effects, potentially indicating publication bias and overestimated effects. We found no differences in small-study effects between different study types. We also found no convincing evidence for the decline effect, US effect, or citation bias across meta-analyses. We concluded that intelligence research does show signs of low power and publication bias, but that these problems seem less severe than in many other scientific fields.

scholarly journals A Meta-Analysis: Improvement of Students’ Algebraic Reasoning through Metacognitive Training

2018 ◽  
Vol 11 (10) ◽  
pp. 42 ◽  
Author(s):  
Yujin Lee ◽  
Mary M. Capraro ◽  
Robert M. Capraro ◽  
Ali Bicer
Keyword(s):  
Effect Size ◽  
Positive Impact ◽  
Meta Analysis ◽  
Effect Sizes ◽  
Algebraic Reasoning ◽  
Metacognitive Training ◽  
Mathematical Performance ◽  
Meta Analyses ◽  
The Impact

Although algebraic reasoning has been considered as an important factor influencing students’ mathematical performance, many students struggle to build concrete algebraic reasoning. Metacognitive training has been regarded as one effective method to develop students’ algebraic reasoning; however, there are no published meta-analyses that include an examination of the effects of metacognitive training on students’ algebraic reasoning. Therefore, the purpose of this meta-analysis was to examine the impact of metacognitive training on students’ algebraic reasoning. Eighteen studies with 22 effect sizes were selected for inclusion in the present meta-analysis. In the process of the analysis, one study was determined as an outlier; therefore, another meta-analysis was reconstructed without the outlier to calculate more robust results. The findings indicated that the overall effect size without an outlier equaled d=0.973 with SE=0.196. Q=20.201 (p<.05) and I2=0.997, which indicated heterogeneity of the studies. These results showed that the metacognitive training had a statistically significant positive impact on students’ algebraic reasoning.

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