scholarly journals Subtraction and beyond: The logic of experimental designs for neuroimaging

2021 ◽  
Author(s):  
Russell Poldrack
Keyword(s):  
Experimental Design ◽  
Functional Neuroimaging ◽  
Experimental Designs ◽  
Factorial Designs ◽  
Subtraction Method ◽  
Mental Processes ◽  
Conjunction Analysis

This chapter focuses on the experimental designs developed for neuroimaging studies. It examines the various forms of experimental design used for functional neuroimaging, with a particular emphasis on the role of these designs in constraining inferences, and presents a discussion on decomposability of the mental processes. The chapter provides detailed information on the subtraction method, including its core problems, advantages, and alternatives to the subtraction approach. It discusses conjunction analysis and several experimental designs, including factorial designs, parametric designs, and priming/adaptation designs.

Everybody Follows the Crowd?

2017 ◽  
Vol 29 (2) ◽  
pp. 1-12 ◽  
Author(s):  
Magdalena Obermaier ◽  
Thomas Koch ◽  
Christian Baden
Keyword(s):  
Experimental Design ◽  
News Coverage ◽  
Personal Characteristics ◽  
Election Campaigns ◽  
Bandwagon Effect ◽  
Political News ◽  
Election Results ◽  
Opinion Polls ◽  
Electoral Preferences

Abstract. Opinion polls are a well-established part of political news coverage, especially during election campaigns. At the same time, there has been controversial debate over the possible influences of such polls on voters’ electoral choices. The most prominent influence discussed is the bandwagon effect: It states that voters tend to support the expected winner of an upcoming election, and use polls to determine who the likely winner will be. This study investigated the mechanisms underlying the effect. In addition, we inquired into the role of past electoral performances of a candidate and analyzed how these (as well as polls) are used as heuristic cues for the assessment of a candidate’s personal characteristics. Using an experimental design, we found that both polls and past election results influence participants’ expectations regarding which candidate will succeed. Moreover, higher competence was attributed to a candidate, if recipients believe that the majority of voters favor that candidate. Through this attribution of competence, both information about prior elections and current polls shaped voters’ electoral preferences.

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

scholarly journals Delta band activity contributes to the identification of command following in disorder of consciousness

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gonzalo Rivera-Lillo ◽  
Emmanuel A. Stamatakis ◽  
Tristan A. Bekinschtein ◽  
David K. Menon ◽  
Srivas Chennu
Keyword(s):  
Functional Neuroimaging ◽  
Brain Activity ◽  
Disorder Of Consciousness ◽  
Fine Grained ◽  
Electrical Brain Activity ◽  
Delta Band ◽  
Delta Modulation ◽  
Command Following ◽  
Band Activity

AbstractThe overt or covert ability to follow commands in patients with disorders of consciousness is considered a sign of awareness and has recently been defined as cortically mediated behaviour. Despite its clinical relevance, the brain signatures of the perceptual processing supporting command following have been elusive. This multimodal study investigates the temporal spectral pattern of electrical brain activity to identify features that differentiated healthy controls from patients both able and unable to follow commands. We combined evidence from behavioural assessment, functional neuroimaging during mental imagery and high-density electroencephalography collected during auditory prediction, from 21 patients and 10 controls. We used a penalised regression model to identify command following using features from electroencephalography. We identified seven well-defined spatiotemporal signatures in the delta, theta and alpha bands that together contribute to identify DoC subjects with and without the ability to follow command, and further distinguished these groups of patients from controls. A fine-grained analysis of these seven signatures enabled us to determine that increased delta modulation at the frontal sensors was the main feature in command following patients. In contrast, higher frequency theta and alpha modulations differentiated controls from both groups of patients. Our findings highlight a key role of spatiotemporally specific delta modulation in supporting cortically mediated behaviour including the ability to follow command. However, patients able to follow commands nevertheless have marked differences in brain activity in comparison with healthy volunteers.

scholarly journals Arousing Motives or Eliciting Stories? On the Role of Pictures in a Picture–Story Exercise

Assessment ◽  
2021 ◽  
pp. 107319112110361
Author(s):  
Philipp Schäpers ◽  
Stefan Krumm ◽  
Filip Lievens ◽  
Nikola Stenzel
Keyword(s):  
Experimental Design ◽  
Experimental Manipulation ◽  
Implicit Motives ◽  
Achievement Motive ◽  
Picture Story Exercise ◽  
Power Motive ◽  
Picture Story ◽  
Measurement Approach

Picture–story exercises (PSE) form a popular measurement approach that has been widely used for the assessment of implicit motives. However, current theorizing offers two diverging perspectives on the role of pictures in PSEs: either to elicit stories or to arouse motives. In the current study, we tested these perspectives in an experimental design. We administered a PSE either with or without pictures. Results from N = 281 participants revealed that the experimental manipulation had a medium to large effect for the affiliation and power motive domains, but no effect for the achievement motive domain. We conclude that the herein chosen pictures cues function differentially across motives, as they aroused the affiliation and power motives, but not the achievement motive.

Reducing misperceptions through news stories with data visualization: The role of readers’ prior knowledge and prior beliefs

Journalism ◽  
2021 ◽  
pp. 146488492110287
Author(s):  
Paul Mena
Keyword(s):  
Experimental Design ◽  
Prior Knowledge ◽  
Data Visualization ◽  
Accurate Information ◽  
Graphical Representations ◽  
Prior Beliefs ◽  
News Stories ◽  
Issue Involvement

Amid the global discussion on ways to fight misinformation, journalists have been writing stories with graphical representations of data to expose misperceptions and provide readers with more accurate information. Employing an experimental design, this study explored to what extent news stories correcting misperceptions are effective in reducing them when the stories include data visualization and how influential readers’ prior beliefs, issue involvement and prior knowledge may be in that context. The study found that the presence of data visualization in news articles correcting misperceptions significantly enhanced the reduction of misperceptions among news readers with less than average prior knowledge about an issue. In addition, it was found that prior beliefs had a significant effect on news readers’ misperceptions regardless of the presence or absence of data visualization. In this way, this research offers some support for the notion that data visualization may be useful to decrease misperceptions under certain circumstances.

THE ROLE OF WHATSAPP IN TEACHING VOCABULARY TO THE STAFFS OF UMBUL PONGGOK KLATEN

2021 ◽  
Vol 5 (2) ◽  
pp. 773
Author(s):  
Lia Ardiana Safitri
Keyword(s):  
Experimental Design ◽  
Foreign Language ◽  
Random Sampling ◽  
Sampling Procedure ◽  
Assessment Instrument ◽  
Vocabulary Test ◽  
Control Groups ◽  
Post Test ◽  
And Control

This study was conducted with the aim of knowing the significant role of WhatsApp in teaching vocabulary, especially staff learning achievement which was limited to vocabulary achievement as measured by a vocabulary test at Umbul Ponggok Klaten. Participants in this study amounted to 30 people consisting of 15 men and 15 women. All participants will learn English as a foreign language using WhatsApp to learn new vocabulary items via their mobile, tablet or laptop. Participants' English level will be measured. Random sampling procedure was carried out. To carry out the research, a true experimental design was used. The participants were assigned to two experimental and control groups. The assessment instrument in this study used a pre-test and post-test. The results showed that the use of the WhatsApp application in teaching vocabulary to the Umbul Ponggok Klaten staff was able to improve the achievement of new English vocabulary mastery of the Umbul Ponggok Klaten staff which was getting better.

scholarly journals Speculations on Quasi-Experimental Design in HIV/AIDS Prevention Research

2012 ◽  
Vol 3 (1) ◽  
pp. 52
Author(s):  
Donald T. Campbell ◽  
Beatrice J. Krauss
Keyword(s):  
Experimental Design ◽  
Hiv Prevention ◽  
Research Design ◽  
Research Community ◽  
Experimental Designs ◽  
Prevention Research ◽  
Quasi Experimental ◽  
Aids Research ◽  
Speculative Discussion ◽  
Hiv Aids

This paper provides a speculative discussion on what quasi-experimental designs might be useful in various aspects of HIV/AIDS research. The first author’s expertise is in research design, not HIV, while the second author has been active in HIV prevention research. It is hoped that it may help the HIV/AIDS research community in discovering and inventing an expanded range of possibilities for valid causal inference. DOI:10.2458/azu_jmmss_v3i1_campbell

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