scholarly journals Detecting variable responses within fMRI time-series of volumes-of-interest using repeated measures ANOVA

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 563 ◽  
Author(s):  
Paul M. Macey ◽  
Philip J. Schluter ◽  
Katherine E. Macey ◽  
Ronald M. Harper
Keyword(s):  
Repeated Measures ◽  
A Priori ◽  
Brain Regions ◽  
Response Patterns ◽  
Whole Brain ◽  
Repeated Measures Analysis ◽  
Average Signal Intensity ◽  
Respiratory Challenge ◽  
Post Hoc

We present an approach to analyzing fMRI timetrends from volumes-of-interest (VOI) within and between subject groups using repeated measures analysis of variance (RMANOVA), which allows temporal patterns to be examined without an a priori model of expected timing or pattern of response. The method serves as a complement to whole-brain voxel-based analyses, and is useful for detecting complex responses within pre-determined brain regions, or as a post-hoc analysis of regions of interest identified by whole-brain assessments. We illustrate an implementation of the technique in the statistical software package SAS. VOI timetrends are extracted from conventionally preprocessed fMRI images. A timetrend of average signal intensity across the VOI during the scanning period is calculated for each subject. The values are scaled relative to baseline periods, imported into SAS, and the procedure PROC MIXED implements the RMANOVA. The ensuing results allow determination of significant overall effects, and time-point specific within- and between-group responses relative to baseline. We illustrate the technique using fMRI data from two groups of subjects who underwent a respiratory challenge. RMANOVA allows insight into the timing of responses and response differences between groups, and so is suited to fMRI paradigms eliciting complex response patterns.

scholarly journals Detecting variable responses in time-series using repeated measures ANOVA: Application to physiologic challenges

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 563
Author(s):  
Paul M. Macey ◽  
Philip J. Schluter ◽  
Katherine E. Macey ◽  
Ronald M. Harper
Keyword(s):  
Repeated Measures ◽  
Mixed Model ◽  
A Priori ◽  
Brain Regions ◽  
Single Step ◽  
Response Patterns ◽  
Whole Brain ◽  
Average Signal Intensity ◽  
Respiratory Challenge ◽  
Time Point

We present an approach to analyzing physiologic timetrends recorded during a stimulus by comparing means at each time point using repeated measures analysis of variance (RMANOVA). The approach allows temporal patterns to be examined without an a priori model of expected timing or pattern of response. The approach was originally applied to signals recorded from functional magnetic resonance imaging (fMRI) volumes-of-interest (VOI) during a physiologic challenge, but we have used the same technique to analyze continuous recordings of other physiological signals such as heart rate, breathing rate, and pulse oximetry. For fMRI, the method serves as a complement to whole-brain voxel-based analyses, and is useful for detecting complex responses within pre-determined brain regions, or as a post-hoc analysis of regions of interest identified by whole-brain assessments. We illustrate an implementation of the technique in the statistical software packages R and SAS. VOI timetrends are extracted from conventionally preprocessed fMRI images. A timetrend of average signal intensity across the VOI during the scanning period is calculated for each subject. The values are scaled relative to baseline periods, and time points are binned. In SAS, the procedure PROC MIXED implements the RMANOVA in a single step. In R, we present one option for implementing RMANOVA with the mixed model function “lme”. Model diagnostics, and predicted means and differences are best performed with additional libraries and commands in R; we present one example. The ensuing results allow determination of significant overall effects, and time-point specific within- and between-group responses relative to baseline. We illustrate the technique using fMRI data from two groups of subjects who underwent a respiratory challenge. RMANOVA allows insight into the timing of responses and response differences between groups, and so is suited to physiologic testing paradigms eliciting complex response patterns.

scholarly journals Effect of Educational Workshops on Disaster Risk Perception in Nurses

2020 ◽  
pp. 270-278
Keyword(s):  
Risk Perception ◽  
Repeated Measures ◽  
Intervention Group ◽  
Round Table ◽  
Disaster Risk ◽  
National Standards ◽  
Control Group ◽  
Repeated Measures Analysis ◽  
Post Hoc ◽  
And Control

INTRODUCTION: The enhancement of nurses’ risk perception plays a significant role in their preparedness during disasters and emergencies. Therefore, this study aimed to investigate the effect of educational workshops on disaster risk perception in nurses METHODS: This randomized controlled field trial study included 62 nurses working at Razi Hospital, Birjand, Iran. The participants were divided into intervention and control groups. The intervention group was then requested to participate in a one-day intensive educational workshop based on the current national standards. The workshop content included a combination of lecturing methods, round-table exercises, and film display. The data were collected using the demographic characteristic form and researcher-made questionnaires measuring the nurses’ risk perception during disasters and emergencies. Subsequently, the data were analyzed using independent t-test, repeated measures analysis, and Bonferroni post hoc tests. FINDINGS: The mean total score of risk perception were significantly higher in the intervention group before, immediately, and two months after the workshop session, compared to those in the control group (P˂0.001). CONCLUSION: The implementation of nurses’ national preparation program during disasters and emergencies can result in an increase in the nurses’ risk perception during these events. Therefore, regarding the importance of nurses’ preparedness in confrontation with disasters and emergencies, it seems necessary to integrate the National Preparedness Program into the educational programs immediately after recruitment and in the form of in-service courses.

Effects of Breathy Voice Source on Ratings of Hypernasality

2005 ◽  
Vol 42 (6) ◽  
pp. 641-648 ◽  
Author(s):  
Setsuko Imatomi
Keyword(s):  
Cleft Palate ◽  
Repeated Measures ◽  
Voice Disorder ◽  
Academic Training ◽  
Clinical Experiences ◽  
Point Scale ◽  
Voice Source ◽  
Cleft Palate Speech ◽  
Repeated Measures Analysis ◽  
Post Hoc

Objective To investigate the effects of breathy voice sources on ratings of hypernasality using synthesized speech. Methods Speech samples were obtained from children with cleft palates who demonstrated varying degrees of hypernasality and from a child with a voice disorder. Sources with 6 degrees of breathiness were created: a breathy source and five synthesized sources with lowered harmonics-to-noise ratio (HNR) values by the addition of impulses. These sources and each original (clear) source were combined with three kinds of filters: mild, moderate, and severely hypernasal. Consequently, 21 ([6 + 1] × 3) stimuli for each vowel (/a/ and /i/) were obtained for ratings. Participants Thirteen speech pathologists with academic training and various clinical experiences with cleft palate speech rated hypernasality of the stimuli on a 5-point scale. Main Outcome Measures Ratings of hypernasality for breathy and clear stimuli were analyzed using a repeated measures analysis of variance. Results The effects of breathy source on ratings of hypernasality were significant for the following filters: mild hypernasal /a/, severe hypernasal /a/, mild hypernasal /i/, and moderate hypernasal /i/. A post-hoc comparison test demonstrated that the more breathy sources (BH0 or BH2) generally increased the hypernasality score for mild hypernasal filters and decreased it for moderate and severe hypernasal filters. The less breathy sources (BH3, BH4, and BH5) hardly affected the ratings. Conclusion The effects of breathiness on ratings of hypernasality seem to moderate rather than to mask perceived hypernasality. That is, breathiness raises slight hypernasality, whereas it reduces severe hypernasality.

Using Planned Comparisons in Management Research: A Case for the Bonferroni Procedure

1993 ◽  
Vol 19 (3) ◽  
pp. 707-724 ◽  
Author(s):  
Maria B. Castaiieda ◽  
Joel R. Levin ◽  
Randall B. Dunham
Keyword(s):  
Repeated Measures ◽  
Multivariate Analyses ◽  
A Priori ◽  
Comparison Method ◽  
Multiple Comparison ◽  
Management Research ◽  
Bonferroni Procedure ◽  
Sequential Hypothesis ◽  
Sequential Hypothesis Testing ◽  
Post Hoc

This article describes the Bonferroni multiple-comparison procedure, and makes a case for researchers’ more frequent and appropriate use of it. The procedure is discussed as a test that facilitates investigation of precise and powerful a priori multiple comparisons. Characteristics of the Bonferroni procedure are described in relation to the more familiar Scheffe post hoc multiple-comparison method, and a step-by-step guide for comparing and choosing between the two is provided. The Bonferroni procedure is discussed in detail in the context of one-factor analysis-of-variance designs. Application of the technique is then considered in the context of factorial designs, analyses of covariance, univariate repeated-measures analyses, multivariate analyses of variance, and recent sequential hypothesis-testing extensions. To aid the presentation, an example from the field of management is included.

scholarly journals The Effect of Clinical Pilates on Functional Movement in Recreational Runners

2017 ◽  
Vol 38 (10) ◽  
pp. 776-780 ◽  
Author(s):  
Anna Laws ◽  
Sean Williams ◽  
Cassie Wilson
Keyword(s):  
Repeated Measures ◽  
Functional Movement Screen ◽  
Contributing Factors ◽  
Post Intervention ◽  
Functional Movement ◽  
Repeated Measures Analysis ◽  
Significant Difference ◽  
Movement Ability ◽  
Recreational Runners ◽  
Post Hoc

AbstractBiomechanical imbalances and inefficient functional movements are considered contributing factors to running-related injuries. Clinical Pilates uses a series of exercises focused on retraining normal movement patterns. This study investigated whether a 6-week course of Clinical Pilates improves functional movement and thereby, potentially, reduces the risk of running-related injuries associated with movement dysfunction. A modified functional movement screen was used to analyze the functional movement ability of forty runners. Forty participants completed a 6-week course of Clinical Pilates delivered by a Clinical Pilates instructor. The movement screen was carried out 3 times for each runner: 6 weeks pre-intervention (baseline), within one week pre-intervention (pre) and within one week post-intervention (post). Repeated-measures analysis of variance and post-hoc tests found significant increases in scores between baseline and post (mean±SD; 13.4±2.4 vs. 17.0±1.7, p<0.01) and pre and post (mean±SD; 13.5±2.5 vs. 17.0±1.7, p<0.01), but no significant difference between baseline and pre (p=0.3). A 6-week course of Clinical Pilates significantly improves functional movement in recreational runners, and this may lead to a reduction in the risk of running-related injuries.

scholarly journals Comparison of Placido, Scheimpflug and Combined Dual Scheimpflug-Placido Technologies in Evaluating Anterior and Posterior CLMI, SimK's as well as Kmax, in Keratoconic and Postrefractive Surgery Ectasia

2012 ◽  
Vol 1 (1) ◽  
pp. 44-52 ◽  
Author(s):  
Thomas F Mauger ◽  
Ashraf M Mahmoud ◽  
Cynthia J Roberts ◽  
Lena V Chheda ◽  
Rebecca A Kuennen ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Ohio State University ◽  
State University ◽  
Post Hoc Analysis ◽  
Repeated Measures Analysis ◽  
Financial Interests ◽  
The Difference ◽  
The Ohio State University ◽  
Map Data ◽  
Post Hoc

ABSTRACT Purpose To calculate and compare cone location and magnitude index (CLMI), Kmax and other corneal measures derived from three different technologies, Placido, Scheimpflug, and a combination dual Scheimpflug-Placido device, from the same group of eyes with keratoconus and postrefractive surgery corneal ectasia. Methods Keratoconus (n = 26) eyes of (n = 19) subjects and postrefractive surgery ectasia (n = 5) eyes of (n = 5) subjects were selected to have measurements performed using the Keratron Scout, Pentacam HR and Galilei Dual Scheimpflug Analyzer. Device-generated SimK's and device-specific CLMI and Kmax indices as well as map data, were exported from each device. Index values for multiple exams were averaged. The map data were processed using The Ohio State University Corneal Topography Tool (OSUCTT) to calculate CLMI parameters, Kmax and SimK values using consistent algorithms on all three devices. Maps were averaged before calculation for multiple examinations. Repeated measures analysis of variance and post- hoc analysis were used to identify differences between devices. Results The anterior axial CLMI calculated from the Keratron data was significantly higher than CLMI for the Galilei (p = 0.0443) or Pentacam (p < 0.0004) with keratoconus, 12.23 compared with 11.20 and 11.00 diopters, respectively. Kmax was also significantly higher in the Keratron than the Galilei (p = 0.0063) or the Pentacam (p < 0.0002). Galilei and Pentacam were not significantly different from each other in either CLMI (p = 0.6287) or Kmax (p = 0.2115). The anterior CLMI values for the postrefractive surgery ectasia eyes were not significantly different between devices. Posterior CLMI values were calculated from the Galilei and Pentacam data and were −2.60 and −2.46 diopters (p = 0.1173) for keratoconus and −2.66 and −3.04 diopters (p = 0.2242) for postrefractive surgery ectasia. Conclusion The small cone Placido measured dioptric values that were greater than the pure Scheimpflug system, but the difference was only about 1 diopter, which is not relevant clinically in evaluating and managing ectasia. The combined dual Scheimpflug-Placido system produced measured dioptric values between the other two technologies. The anterior CLMI calculations accurately predicted keratoconus with all three devices. The posterior CLMI in ectasia may be a potentially valuable calculation in demonstrating asymmetric steepening. How to cite this article Mauger TF, Mahmoud AM, Roberts CJ, Chheda LV, Kuennen RA, Hendershot AJ, Lembach RG. Comparison of Placido, Scheimpflug and Combined Dual Scheimpflug-Placido Technologies in Evaluating Anterior and Posterior CLMI, SimK's as well as Kmax, in Keratoconic and Postrefractive Surgery Ectasia. Int J Keratoco Ectatic Corneal Dis 2012;1(1):44-52. • C Roberts is a Consultant for Oculus Optikgerate GmbH and Ziemer Ophthalmic Systems AG, and has an interest in the GALILEI. • A Mahmoud has an interest in the GALILEI. • T Mauger, L Chheda, R Kuennen, A Hendershot, and R Lembach have no financial interests.

Dilutional Effect of Ethylenediaminetetraacetic Acid on Packed Cell Volume in Healthy Dogs

2021 ◽  
Author(s):  
Elizabeth H. Ross ◽  
Amy Dickinson
Keyword(s):  
Cell Volume ◽  
Packed Cell Volume ◽  
Repeated Measures ◽  
Ethylenediaminetetraacetic Acid ◽  
Initial Distribution ◽  
Repeated Measures Analysis ◽  
Red Blood Cell Count ◽  
Dog Blood ◽  
Healthy Dogs ◽  
Post Hoc

ABSTRACT Packed cell volume (PCV) is commonly used to assess and monitor red blood cell count in animals, but the results can be altered if inappropriate ratios of anticoagulant/blood are used. The purpose of this study was to determine the effect of ideally filled, overfilled, and underfilled K3 ethylenediaminetetraacetic acid (EDTA) tubes with various volumes of healthy dog blood on centrifuged PCV. Six milliliters of blood was obtained from 94 blood donors each. Initial distribution was injected into two nonheparinized microhematocrit tubes. The remainder was instilled into 1.3 mL K3 EDTA spray-dried tubes as 1.5 mL, 1.3 mL, 0.75 mL, 0.5 mL, and 0.25 mL aliquots. Normality was determined using the D’agostino–Pearson method and by visual examination of histograms. Data were analyzed using a repeated-measures analysis of variance with post hoc testing using Tukey's test. There is a statistically significant decrease in the PCV between all groups with progressive underfilling of tubes (P &lt; .0001). The closest difference is between 1.5 and 1.3 mL (P = .0138). Our study suggested that underfilling K3 EDTA tubes significantly and negatively influences the PCV in healthy dogs. Using underfilled K3 EDTA tubes result in a lower PCV compared with directly filled microhematocrit tubes without anticoagulant.

Effective Connectivity During an Avoidance-Based Pavlovian-to-Instrumental Transfer Task

2021 ◽  
Author(s):  
Daniel Petrie ◽  
Sy-Miin Chow ◽  
Charles Geier
Keyword(s):  
Effective Connectivity ◽  
A Priori ◽  
Transfer Task ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Response Patterns ◽  
Multiple Model ◽  
Hemodynamic Response Function ◽  
Blood Oxygen Level ◽  
Psychological Phenomena

Pavlovian-to-instrumental transfer (PIT) refers to a phenomenon whereby a classically conditioned stimulus (CS) impacts the motivational salience of instrumental behavior. We examined behavioral response patterns and functional magnetic resonance imaging (fMRI) based effective connectivity during an avoidance-based PIT task. Eleven participants (8 females; Mage = 28.2, SD = 2.8, range = 25-32 years) completed the task. Effective connectivity between a priori brain regions engaged during the task was determined using hemodynamic response function group iterative multiple model estimation (HRF-GIMME). Behaviorally, participants exhibited specific PIT, a CS previously associated with a reinforcing outcome increased instrumental responding directed at the same outcome. We did not find evidence for general PIT; a CS did not significantly increase instrumental responding towards a different but related outcome. Using HRF-GIMME, we recovered effective connectivity maps among corticostriatal circuits engaged during the task. Group-level paths revealed directional effects from left putamen to right insula and from right putamen to right cingulate. Importantly, a direct effect of specific PIT stimuli on blood-oxygen-level-dependent (BOLD) activity in the left putamen was found. Results provide initial evidence of effective connectivity in key brain regions in an avoidance-based PIT task network. This study adds to the literature studying PIT effects in humans and employing GIMME models to understand how psychological phenomena are supported in the brain.

Validation of a Typology of Religious Experience and its Relationship to the Psychotic Experience

1983 ◽  
Vol 11 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Robert D. Margolis ◽  
Kirk W. Elifson
Keyword(s):  
Analysis Of Variance ◽  
Religious Experience ◽  
Repeated Measures ◽  
Religious Experiences ◽  
Psychotic Experiences ◽  
Psychotic Experience ◽  
Repeated Measures Analysis ◽  
Empirical Determination ◽  
Better Than

A typology of religious experience was validated and an empirical determination of the similarities between the religious and psychotic experiences was made. Expert and non-expert raters (n=16) were asked to differentiate religious experiences (n=12), fabricated religious experiences (n=12), and psychotic experiences (n=12) using the typology of religious experience. A split plot, repeated measures analysis of variance yielded three significant findings: (a) Expert raters performed significantly better than non-expert raters at identifying the three types of experiences. (b) Non-expert raters with the typology performed as well as expert raters and significantly better than non-expert raters without the typology. (c) Psychotic experiences were more easily identified than were religious or fabricated experiences.

scholarly journals Correlations in Social Neuroscience Aren't Voodoo: Commentary on Vul et al. (2009)

2009 ◽  
Vol 4 (3) ◽  
pp. 299-307 ◽  
Author(s):  
Matthew D. Lieberman ◽  
Elliot T. Berkman ◽  
Tor D. Wager
Keyword(s):  
Individual Difference ◽  
Meta Analysis ◽  
Brain Regions ◽  
Single Step ◽  
Social Neuroscience ◽  
Regression Analyses ◽  
Step Method ◽  
Whole Brain ◽  
Multiple Tests ◽  
Post Hoc

Vul, Harris, Winkielman, and Pashler (2009) , (this issue) claim that many brain—personality correlations in fMRI studies are “likely … spurious” (p. 274), and “should not be believed” (p. 285). Several of their conclusions are incorrect. First, they incorrectly claim that whole-brain regressions use an invalid and “nonindependent” two-step inferential procedure, a determination based on a survey sent to researchers that only included nondiagnostic questions about the descriptive process of plotting one's data. We explain how whole-brain regressions are a valid single-step method of identifying brain regions that have reliable correlations with individual difference measures. Second, they claim that large correlations from whole-brain regression analyses may be the result of noise alone. We provide a simulation to demonstrate that typical fMRI sample sizes will only rarely produce large correlations in the absence of any true effect. Third, they claim that the reported correlations are inflated to the point of being “implausibly high.” Though biased post hoc correlation estimates are a well-known consequence of conducting multiple tests, Vul et al. make inaccurate assumptions when estimating the theoretical ceiling of such correlations. Moreover, their own “meta-analysis suggests that the magnitude of the bias is approximately .12—a rather modest bias.

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