Relations between psychological stress and EEG correlations

In the present study inquiries have been made about the changes EEG cross-correlation in mental activities is subject to. The EEG recordings were made at rest, in visual and acoustical response, when reading and in the solution of an acoustical differentiation problem. In conjunction with plain reflex processes a decline in the intrahemispherical correlation was observed. During complex-structured psycho-request situations dissimilar changes in the EEG correlation have occurred on the scalp. Between the cerebral regions functionally essential for the solution of the problems, an increase in the bio-electric correlation and between other cerebral areas a decline were registered. The findings in conclusion come to realize that the topographic EEG cross-correlation analysis is appropriate to give an insight into the present situation of cerebral functional organization.     

The epistemic status of inter-item correlations in Eysenck's Personality Questionnaire: the a priori versus the empirical in psychological data

Judgements of the semantic relatedness of items in Eysenck's Personality Questionnaire and the corresponding inter-item correlations were found to be significantly related. The results are taken to indicate that the inter-item correlations are knowable a priori and, hence, are not empirical. It is also argued that the reported findings themselves are knowable a priori , and that the study, therefore, is pseudoempirical, that is, attempts to test necessarily true propositions empirically. The study was intended to demonstrate concretely the distinction between a priori and empirical in psychological data, and to indicate the confusion arising when that distinction is not made.     

Canonical correlations with fallible data

The technique of canonical correlation may be used to determine the extent to which two sets of measurements reflect the same underlying traits. However, if the two sets are not perfectly reliable, the unreliability may obscure the fact that they are essentially dependent on similar processes. If we attempt to determine sets of weights so as to maximize the correlation between linear composites after correction for attenuation in the composites, it turns out that the results may be obtained by determining the canonical correlations and canonical regression weights between the true score components of the measures making up the two sets. In addition, formulas are developed for calculating the correlations between the canonical variates and original measures, both corrected and uncorrected for attenuation. A numerical example relating the verbal to the performance subtests of the Wechsler Intelligence Scale for Children is presented.     

Count data in psychological applied research

As some authors have noticed in fields other than psychology, level of measurement and distributional characteristics of count data are commonly not taken into account, so that they are analysed as normally distributed continuous variables, and therefore some general linear model is applied. In this work, we review a random sample of 457 articles published in the last four years in journals with the highest impact factor in the Journal Citation Reports (JCR Social Sciences Edition) of the Institute for Scientific Information. The goals are to know how often count variables appear in psychological applied research and which data analyses are used when dealing with count response variables. Examination showed that there is a notable presence of count variables, especially in some topics in psychology and a remarkable misapplication of the general linear model. One deals with causes and consequences of this approach to data analysis and suggests the use of specific models to analyse count data.     

Planned missing data designs in psychological research

The authors describe 2 efficiency (planned missing data) designs for measurement: the 3-form design and the 2-method measurement design. The 3-form design, a kind of matrix sampling, allows researchers to leverage limited resources to collect data for 33% more survey questions than can be answered by any 1 respondent. Power tables for estimating correlation effects illustrate the benefit of this design. The 2-method measurement design involves a relatively cheap, less valid measure of a construct and an expensive, more valid measure of the same construct. The cost effectiveness of this design stems from the fact that few cases have both measures, and many cases have just the cheap measure. With 3 brief simulations involving structural equation models, the authors show that compared with the same-cost complete cases design, a 2-method measurement design yields lower standard errors and a higher effective sample size for testing important study parameters. With a large cost differential between cheap and expensive measures and small effect sizes, the benefits of the design can be enormous. Strategies for using these 2 designs are suggested.     

Exploring correlations between positive psychological resources and symptoms of psychological distress among hematological cancer patients: a cross-sectional study

Hematological cancer patients experience high levels of psychological distress during diagnoses and intensive treatments. The aim of the present study is to explore the effects of positive psychological resources on depressive and anxiety symptoms in hematological cancer patients. This survey was conducted in a hospital during the period from July 2013 to April 2014. A total of 300 inpatients were recruited and finally 227 of them completed the questionnaires. Questionnaires included demographic and clinical variables, the Center for Epidemiologic Studies Depression Scale, the Self-Rating Anxiety Scale, the Life Orientation Scale-Revised, the General Perceived Self-Efficacy Scale, and the Resilience Scale-14. Results showed that the prevalence of depressive and anxiety symptoms was 66.1 and 45.8%, respectively. Both optimism (β = ?.479, p < .001) and resilience (β = ?.174, p < .05) were negatively associated with depressive symptoms, and optimism (β = ?.393, p < .001) was negatively associated with anxiety symptoms. However, resilience (β = ?.133, p > .05) was not significantly associated with anxiety symptoms, and self-efficacy was not significantly associated with depressive (β = ?.032, p > .05) or anxiety symptoms (β = ?.055, p > .05). The results suggest that hematological cancer patients who possess high levels of positive psychological resources may have fewer symptoms of psychological distress. The findings indicate that enhancing positive psychological resources can be considered in developing intervention strategies for decreasing depressive and anxiety symptoms.     

Resolving legal questions with psychological data.

Psychologists are ever finding new legal arenas for their psychological data and concepts. Findings about the character and operation of stereotyping have been introduced in sex discrimination litigation in the United States. Findings about conformity, obedience to authority, and bystander apathy have been introduced into death penalty cases in South Africa. These concrete and detailed applications of psychological science demonstrate the expanding role that psychology is playing in the legal world.     

Detecting nonlinearity in psychological data: Techniques and applications

Modern graphical and computational techniques for detecting nonlinearity in psychological data sets are presented. These procedures allow researchers to determine the information complexity of temporal data, using physiological and psychological measurements, and to provide evidence for chaos in time series contaminated by measurement noise. Problems with noise reduction and appropriate experimental control, using surrogate time series, are discussed, and applications of the technology are illustrated, using response time, handwriting, and typing data sets. In an experimental application of appropriate nonlinear analysis procedures, the results of a time series prediction experiment confirm that some subjects are sensitive to chaos. In contrast to previous attempts demonstrating sensitivity to chaos, the experiment reported here employs surrogate series to control for linear stochastic aspects of the stimulus sequences, such as autocorrelation. Recommendations for the selection of appropriate software for performing nonlinear analyses are presented, including a comprehensive list of World-Wide Web sites offering such software.     

Estimating correlations with missing data,a bayesian approach

The posterior distribution of the bivariate correlation is analytically derived given a data set wherex is completely observed buty is missing at random for a portion of the sample. Interval estimates of the correlation are then constructed from the posterior distribution in terms of highest density regions (HDRs). Various choices for the form of the prior distribution are explored. For each of these priors, the resulting Bayesian HDRs are compared with each other and with intervals derived from maximum likelihood theory.     

Dimensions in data: testing psychological models using state-trace analysis

Cognitive science is replete with fertile and forceful debates about the need for one or more underlying mental processes or systems to explain empirical observations. Such debates can be found in many areas, including learning, memory, categorization, reasoning and decision-making. Multiple-process models are often advanced on the basis of dissociations in data. We argue and illustrate that using dissociation logic to draw conclusions about the dimensionality of data is flawed. We propose that a more widespread adoption of 'state-trace analysis'--an approach that overcomes these flaws--could lead to a re-evaluation of the need for multiple-process models and to a re-appraisal of how these models should be formulated and tested.     

Fisher transformations for correlations corrected for selection and missing data

The validity of a test is often estimated in a nonrandom sample of selected individuals. To accurately estimate the relation between the predictor and the criterion we correct this correlation for range restriction. Unfortunately, this corrected correlation cannot be transformed using Fisher'sZ transformation, and asymptotic tests of hypotheses based on small or moderate samples are not accurate. We developed a Fisherr toZ transformation for the corrected correlation for each of two conditions: (a) the criterion data were missing due to selection on the predictor (the missing data were MAR); and (b) the criterion was missing at random, not due to selection (the missing data were MCAR). The twoZ transformations were evaluated in a computer simulation. The transformations were accurate, and tests of hypotheses and confidence intervals based on the transformations were superior to those that were not based on the transformations.     

Methods of correcting correlations for indirect restriction of range with non-interval data

A derivation is presented for correcting correlations for indirect restriction of range when correlations between one selection variable and non-interval measures are involved. Following a systematic investigation of special cases, formulas are given for practical application in validation work. Procedures for the case with several selection variables are briefly discussed.This study was initiated when the author was with the Institute of Military Psychology, Sweden.     

Validation of the Narrative Emplotment Scale and its correlations with well‐being and psychological adjustment

Two studies examined correlates of the Narrative Emplotment Scale (NES), which measures the extent to which individuals perceive chance events and unchosen experiences as meaningfully connected. In Study 1 (N=99), the NES demonstrated adequate test–retest stability and good internal reliability. The scale was positively related to paranormal beliefs, mystical experiences, and absorption. In Study 2 (N=342), personality measures indicative of external locus of control, intrinsic religiosity, well‐being, satisfaction with life, and a measure of frequency of coincidence experience were all positively correlated with narrative emplotment, providing further support for the construct validity of the scale. In terms of the question of whether meaning making is predictive of better or worse psychological adjustment, analyses indicated that the relationship between narrative emplotment and psychological adjustment was moderated by individual differences in coping strategies. Path analysis indicated that emplotment was a mediator of the pathway between religiosity and well‐being. Emplotment had a negative effect on well‐being through chance locus of control. These analyses suggest that this type of meaning‐making is an important variable for understanding religious/spiritual beliefs and their influence on psychological adjustment.     

An illustration of issues in factor extraction and identification of dimensionality in psychological assessment data

Structural validity has long been regarded as critical to psychological measurement. However, in practical application, issues central to structural validity are often neglected. The purpose of this study was to illustrate the importance of several crucial choices that face researchers attempting to evaluate the structure of data from a given scale. In this study, I compared the structural solutions derived via principal components analysis and principal axis factoring using eigenvalues, scree plots, and traditional parallel analyses with data from the Purpose in Life Test (Crumbaugh & Maholick, 1964). I discuss the importance of structural validity for overall construct validity and the importance of carefully considering factor analytic methodology. I provide recommendations for uses of factor analysis.     

Tables of event sequences for sequential analyses of data in psychological experiments containing two-class events

Tables of sequences of two-class events are presented for use in programming psychological experiments in which behavior on trial n may be a function of the events of trials n ? 1, n ? 2, and/or n ? 3. Various factors related to schedule generation are discussed, i.e., restrictions on trial-block length which accompany sequential balance, interrelationships of trial blocks in the multiblock experiment, relationships between run length and r-tuple occurrences, and alternation behavior. Following a consideration of various methods of schedule generation for the two-class experiment, it was concluded that no method can result in schedules that possess all properties considered desirable in psychological experiments. However, the present sequences allow for sequential balance and analysis, and thus should prove useful in producing schedules in some contexts that are standard with regard to sequential influences.     

Allowing for correlations between correlations in random-effects meta-analysis of correlation matrices

Practical meta-analysis of correlation matrices generally ignores covariances (and hence correlations) between correlation estimates. The authors consider various methods for allowing for covariances, including generalized least squares, maximum marginal likelihood, and Bayesian approaches, illustrated using a 6-dimensional response in a series of psychological studies concerning prediction of exercise behavior change. Quantities of interest include the overall population mean correlation matrix, the contrast between the mean correlations, the predicted correlation matrix in a new study, and the conflict between the existing studies and a new correlation matrix. The authors conclude that accounting for correlations between correlations is unnecessary when interested in individual correlations but potentially important if concerned with a composite measure involving 2 or more correlations. A simulation study indicates the asymptotic normal assumption appears reasonable. Because of potential instability in the generalized least squares methods, they recommend a model-based approach, either the maximum marginal likelihood approach or a full Bayesian analysis.