scholarly journals Neurodesign: Optimal Experimental Designs for Task fMRI

2017 ◽  
Author(s):  
Joke Durnez ◽  
Ross Blair ◽  
Russell A. Poldrack
Keyword(s):  
Experimental Design ◽  
Psychological Factors ◽  
Statistical Power ◽  
Experimental Designs ◽  
Web Based ◽  
Estimation Efficiency ◽  
Simulation Based ◽  
Higher Power ◽  
Within Subjects ◽  
User Friendly

1AbstractA recent stream of alarmist publications has questioned the validity of published neuroimaging findings. As a consequence, fMRI teams worldwide have been encouraged to increase their sample sizes to reach higher power and thus increase the positive predictive value of their findings. However, an often-overlooked factor influencing power is the experimental design: by choosing the appropriate experimental design, the statistical power of a study can be increased within subjects. By optimizing the order and timing of the stimuli, power can be gained at no extra cost. To facilitate design optimization, we created a python package and web-based tool called Neurodesign to maximize the detection power or estimation efficiency within subjects, while controlling for psychological factors such as the predictability of the design. We implemented both a simulation-based optimisation, as well as an optimisation using the genetic algorithm, introduced by Wager and Nichols (2003) and further improved by Kao et al. (2009), to optimize the experimental design. The toolbox Neurodesign allows more complex experimental setups than existing toolboxes, while the GUI provides a more user-friendly experience. The toolbox is accessible online at www.neuropowertools.org.

scholarly journals Experimental Design and the Reliability of Priming Effects: Reconsidering the "Train Wreck"

2018 ◽  
Author(s):  
Andrew M Rivers ◽  
Jeff Sherman
Keyword(s):  
Experimental Design ◽  
Statistical Power ◽  
Priming Effect ◽  
Experimental Designs ◽  
Social Psychological ◽  
Priming Effects ◽  
High Profile ◽  
Within Subjects

Failures to replicate high-profile priming effects have raised questions about the reliability of priming phenomena. Studies at the discussion’s center, labeled “social priming,” have been interpreted as a specific indictment of priming that is social in nature. However, “social priming” differs from other priming effects in multiple ways. The present research examines one important difference: whether effects have been demonstrated with within- or between-subjects experimental designs. To examine the significance of this feature, we assess the reliability of four well-known priming effects from the cognitive and social psychological literatures using both between- and within-subjects designs and analyses. All four priming effects are reliable when tested using a within-subjects approach. In contrast, only one priming effect reaches that statistical threshold when using a between-subjects approach. This demonstration serves as a salient illustration of the underappreciated importance of experimental design for statistical power, generally, and for the reliability of priming effects, specifically.

WEB-BASED SOFTWARE FOR REAL-TIME SIMULATION-ASSISTED TRIAL DESIGN IN ALZHEIMER’S DISEASE

2015 ◽  
pp. 1-4
Author(s):  
D. Polhamus ◽  
J. Kang ◽  
J. Rogers ◽  
M. Gastonguay
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Statistical Power ◽  
Operating Characteristics ◽  
Longitudinal Models ◽  
Exclusion Criteria ◽  
Web Based ◽  
Correct Dose ◽  
Time Simulation ◽  
Simulation Based

Clinical trials for Alzheimer’s Disease (AD) are necessarily designed in the presence of substantial quantitative uncertainty. Certain important aspects of this uncertainty can be mitigated by developing longitudinal models for AD progression and by using these models to simulate virtual trials and estimate operating characteristics (such as statistical power, the probability of stopping at an interim analysis, the probability of identifying the correct dose, etc.) as a function of candidate design features, such as inclusion / exclusion criteria. In this brief report we describe the development and deployment of a customized software solution that allows such simulation-based results to be generated “on the fly” in the context of a drug development team meeting. This solution leverages a number of recent practical advances in statistical and scientific computing that could be much more broadly leveraged to assure more quantitatively grounded trial designs in Alzheimer’s Disease.

Mood State Response to Massage and Subsequent Exercise Performance

2005 ◽  
Vol 19 (3) ◽  
pp. 234-250 ◽  
Author(s):  
Dominic Micklewright ◽  
Murray Griffin ◽  
Valerie Gladwell ◽  
Ralph Beneke
Keyword(s):  
Experimental Design ◽  
Exercise Performance ◽  
Psychological Factors ◽  
Mood State ◽  
Mood Disturbance ◽  
Anaerobic Performance ◽  
State Response ◽  
Before And After ◽  
Within Subjects ◽  
The Relationship

A within subjects experimental design (N = 16) was used where participants performed a 30-s Wingate anaerobic cycling test (WAnT) after 30-min rest and after 30-min back massage. Mood State was measured before and after each intervention and after the WAnTs. No significant change in mood was detected following rest or massage. However, WAnT performance was better following massage compared to rest. Mood disturbance increased following the WAnT in both the rest and massage conditions. The results suggest that preperformance massage had no effect on mood state yet seemed to facilitate enhanced WAnT performance. The relationship between massage and anaerobic performance remains unclear, however is almost certainly mediated by preperformance psychological factors other than mood state.

scholarly journals Power to the People: Power, Negative Results and Sample Size

2020 ◽  
Vol 59 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Brianna N Gaskill ◽  
Joseph P Garner
Keyword(s):  
Experimental Design ◽  
Sample Size ◽  
Statistical Power ◽  
Signal To Noise Ratio ◽  
Animal Experiments ◽  
Experimental Studies ◽  
Experimental Designs ◽  
Design Data ◽  
Negative Results ◽  
Ethical Approval

The practical application of statistical power is becoming an increasingly important part of experimental design, data analysis, and reporting. Power is essential to estimating sample size as part of planning studies and obtaining ethical approval for them. Furthermore, power is essential for publishing and interpreting negative results. In this manuscript, we review what power is, how it can be calculated, and reporting recommendations if a null result is found. Power can be thought of as reflecting the signal to noise ratio of an experiment. The conventional wisdom that statistical power is driven by sample size (which increases the signal in the data), while true, is a misleading oversimplification. Relatively little discussion covers the use of experimental designs which control and reduce noise. Even small improvements in experimental design can achieve high power at much lower sample sizes than (for instance) a simple t test. Failure to report experimental design or the proposed statistical test on animal care and use protocols creates a dilemma for IACUCs, because it is unknown whether sample size has been correctly calculated. Traditional power calculations, which are primarily provided for animal number justifications, are only available for simple, yet low powered, experimental designs, such as paired t tests. Thus, in most controlled experimental studies, the only analyses for which power can be calculated are those that inheriently have low statistical power; these analyses should not be used because they require more animals than necessary. We provide suggestions for more powerful experimental designs (such as randomized block and factorial designs) that increase power, and we describe methods to easily calculate sample size for these designs that are suitable for IACUC number justifications. Finally we also provide recommendations for reporting negative results, so that readers and reviewers can determine whether an experiment had sufficient power. The use of more sophisticated designs in animal experiments will inevitably improve power, reproducibility, and reduce animal use.

The Limits of Ego Depletion

2019 ◽  
Vol 50 (5-6) ◽  
pp. 292-304 ◽  
Author(s):  
Mario Wenzel ◽  
Marina Lind ◽  
Zarah Rowland ◽  
Daniela Zahn ◽  
Thomas Kubiak
Keyword(s):  
Research Agenda ◽  
Statistical Power ◽  
Interindividual Variability ◽  
Ego Depletion ◽  
Crossover Design ◽  
Effect Sizes ◽  
Future Research ◽  
Future Research Agenda ◽  
Depletion Effect ◽  
Within Subjects

Abstract. Evidence on the existence of the ego depletion phenomena as well as the size of the effects and potential moderators and mediators are ambiguous. Building on a crossover design that enables superior statistical power within a single study, we investigated the robustness of the ego depletion effect between and within subjects and moderating and mediating influences of the ego depletion manipulation checks. Our results, based on a sample of 187 participants, demonstrated that (a) the between- and within-subject ego depletion effects only had negligible effect sizes and that there was (b) large interindividual variability that (c) could not be explained by differences in ego depletion manipulation checks. We discuss the implications of these results and outline a future research agenda.

The Role of Web Based Accounting Online System 2.0 as the Company's Income and Expense Management

2017 ◽  
Vol 1 (1) ◽  
pp. 44-49
Author(s):  
Nur Azizah ◽  
Dedeh Supriyanti ◽  
Siti Fairuz Aminah Mustapha ◽  
Holly Yang
Keyword(s):  
Financial Management ◽  
Accounting System ◽  
Bank Account ◽  
Web Based ◽  
Online System ◽  
Version 2.0 ◽  
User Friendly ◽  
The Impact ◽  
A Company

In a company, the process of income and expense of money must have a profit-generating goal base. The success of financial management within the company, can be monitored from the ability of the financial management in managing the finances and utilize all the opportunities that exist with as much as possible with the aim to control the company's cash (cash flow) and the impact of generating profits in accordance with expectations. With a web-based online accounting system version 2.0, companies can be given the ease to manage money in and out of the company's cash. It has a user friendly system with navigation that makes it easy for the financial management to use it. Starting from the creation of a company's cash account used as a cash account and corporate bank account on the system, deletion or filing of cash accounts, up to the transfer invoice creation feature, receive and send money. Thus, this system is very effective and efficient in the management of income and corporate cash disbursements.   Keywords:​Accounting Online System, Financial Management, Cash and Bank

Experimental Design as a Retrieval Method for Assessing the Phenomenological Characteristics of Episodic Memories, Episodic Future Thoughts, and Episodic Counterfactual Thoughts

2020 ◽  
Author(s):  
Jared Branch
Keyword(s):  
Experimental Design ◽  
Effect Sizes ◽  
Retrieval Method ◽  
Future Studies ◽  
Within Subjects ◽  
Demand Effects ◽  
Episodic Memories ◽  
Theoretical Considerations

Studies assessing the phenomenological characteristics of episodic memories, episodic future thoughts, and episodic counterfactual thoughts normally utilize a within-subjects design. As such, there are concerns that the observed similarities in phenomenological characteristics are the result of demand effects or other related matters, rather than theoretical considerations. In this study, a within-subjects experimental design was directly compared with a between-subjects experimental design. In both conditions, participants responded to existing questionnaires used to assess phenomenological characteristics of episodic memories, episodic future thoughts, and episodic counterfactual thoughts. The within-subjects design resulted more often in significant findings and larger effect sizes compared to the between-subjects design. The implications for experimental design in future studies is discussed.

Motivating Exercise Through Social Media: Is a Picture Always Worth a Thousand Words?

2018 ◽  
Author(s):  
Caitlyn Johnston ◽  
William E. Davis
Keyword(s):  
Social Media ◽  
Individual Differences ◽  
Experimental Design ◽  
Health Behaviors ◽  
Media Content ◽  
Exercise Motivation ◽  
Positive Health ◽  
Content Type ◽  
Within Subjects

In the present study, we examined how the influence of exercise-related social media content on exercise motivation might differ across content type (with images vs. without images) and account type (individual vs. corporate). Using a 2 × 2 within-subjects experimental design, 229 participants viewed a series of 40 actual social media posts across the four conditions (individual posts with images, corporate posts with images, individual posts without images, and corporate posts without images) in a randomized order. Participants rated the extent to which they felt each social media post motivated them to exercise, would motivate others to exercise, and was posted for extrinsic reasons. Participants also completed other measures of individual differences including their own exercise motivation. Posts with images from individuals were more motivating than posts with images from corporations; however, corporate posts without images were more motivating than posts without images from individuals. Participants expected others to be similarly motivated by the stimuli, and perceived corporate posts as having been posted for more extrinsic reasons than individuals’ posts. These findings enhance our understanding of how social media may be used to promote positive health behaviors.

Web-Based Peer and Self-Assessment System Design and Development for Elementary School Students

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Mehmet EMIN KORTAK
Keyword(s):  
Elementary School ◽  
Elementary School Students ◽  
Primary Schools ◽  
Peer Assessment ◽  
Assessment System ◽  
Assessment Process ◽  
School Students ◽  
Self Assessment ◽  
Web Based ◽  
User Friendly

This research aimed at designing and improving the web-based integrated peer and self- assessment. WesPASS (web-based peer-assessment system), developed in this research, allows students to assess their own or their peers’ performance and project assignments and to report about the result of these assessments so that they correct their assignments. This study employed design-based research. The participants included 102 fourth grade primary school students and their 4 teachers from 2 state and 2 private primary schools in Ankara, Kecioren (Turkey) who employed the system and were engaged in a questionnaire survey to assess its quality. The findings were analyzed through quantitative data analysis. The findings revealed that the system can be used by elementary school students for peer and self-assessment system. The participants stated that WesPASS is simple and user-friendly, and it accelerates the assessment process by employing information technology and allows to share opinions 

scholarly journals The Metano Modeling Toolbox MMTB: An Intuitive, Web-Based Toolbox Introduced by Two Use Cases

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 113
Author(s):  
Julia Koblitz ◽  
Sabine Will ◽  
S. Riemer ◽  
Thomas Ulas ◽  
Meina Neumann-Schaal ◽  
...  
Keyword(s):  
Metabolic Networks ◽  
Point Of View ◽  
Use Cases ◽  
Mathematical Methods ◽  
State Behavior ◽  
Web Based ◽  
Research Fields ◽  
Balance Analysis ◽  
Metabolic Models ◽  
User Friendly

Genome-scale metabolic models are of high interest in a number of different research fields. Flux balance analysis (FBA) and other mathematical methods allow the prediction of the steady-state behavior of metabolic networks under different environmental conditions. However, many existing applications for flux optimizations do not provide a metabolite-centric view on fluxes. Metano is a standalone, open-source toolbox for the analysis and refinement of metabolic models. While flux distributions in metabolic networks are predominantly analyzed from a reaction-centric point of view, the Metano methods of split-ratio analysis and metabolite flux minimization also allow a metabolite-centric view on flux distributions. In addition, we present MMTB (Metano Modeling Toolbox), a web-based toolbox for metabolic modeling including a user-friendly interface to Metano methods. MMTB assists during bottom-up construction of metabolic models by integrating reaction and enzymatic annotation data from different databases. Furthermore, MMTB is especially designed for non-experienced users by providing an intuitive interface to the most commonly used modeling methods and offering novel visualizations. Additionally, MMTB allows users to upload their models, which can in turn be explored and analyzed by the community. We introduce MMTB by two use cases, involving a published model of Corynebacterium glutamicum and a newly created model of Phaeobacter inhibens.

Sign in / Sign up

Export Citation Format

Share Document