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PubMed2006

Income inequality and physical and mental health: testing associations consistent with proposed causal pathways.

OBJECTIVES: To test associations between individual health outcomes and ecological variables proposed in causal models of relations between income inequality and health. DESIGN: Regression analysis of a large, nationally representative dataset, linked to US census and other county and state level sources of data on ecological covariates. The regressions control for individual economic and demographic covariates as well as relevant potential ecological confounders. SETTING: The US population in the year 2000. PARTICIPANTS: 4817 US adults about age 40, representative of the US population. MAIN OUTCOME MEASURES: Two outcomes were studied: self reported general health status, dichotomised as "fair" or "poor" compared with "excellent", "very good", or "good", and depression as measured by a score on the Center for Epidemiologic Studies depression instrument >16. RESULTS: State generosity was significantly associated with a reduced odds of reporting poor general health (OR 0.84, 95%CI: 0.71 to 0.99), and the county unemployment rate with reduced odds of reporting depression (OR 0.91, 95%CI: 0.84 to 0.97). The measure of income inequality is a significant risk factor for reporting poor general health (OR 1.98, CI: 1.08 to 3.62), controlling for all ecological and individual covariates. In stratified models, the index of social capital is associated with reduced odds of reporting poor general health among black people and Hispanics (OR 0.40, CI: 0.18 to 0.90), but not significant among white people. The inequality measure is significantly associated with reporting poor general health among white people (OR 2.60, CI: 1.22 to 5.56) but not black people and Hispanics. CONCLUSIONS: The effect of income inequality on health may work through the influence of invidious social comparisons (particularly among white subjects) and (among black subjects and Latinos) through a reduction in social capital. Researchers may find it fruitful to recognise the cultural specificity of any such effects.

Adult↗
PubMed2006

Haplotype structures and large-scale association testing of the 5' AMP-activated protein kinase genes PRKAA2, PRKAB1, and PRKAB2 [corrected] with type 2 diabetes.

AMP-activated protein kinase (AMPK) is a key molecular regulator of cellular metabolism, and its activity is induced by both metformin and thiazolidinedione antidiabetic medications. It has therefore been proposed both as a putative agent in the pathophysiology of type 2 diabetes and as a valid target for therapeutic intervention. Thus, the genes that encode the various AMPK subunits are intriguing candidates for the inherited basis of type 2 diabetes. We therefore set out to test for the association of common variants in the genes that encode three selected AMPK subunits with type 2 diabetes and related phenotypes. Of the seven genes that encode AMPK isoforms, we initially chose PRKAA2, PRKAB1, and PRKAB2 because of their higher prior probability of association with type 2 diabetes, based on previous reports of genetic linkage, functional molecular studies, expression patterns, and pharmacological evidence. We determined their haplotype structure, selected a subset of tag single nucleotide polymorphisms that comprehensively capture the extent of common genetic variation in these genes, and genotyped them in family-based and case/control samples comprising 4,206 individuals. Analysis of single-marker and multi-marker tests revealed no association with type 2 diabetes, fasting plasma glucose, or insulin sensitivity. Several nominal associations of variants in PRKAA2 and PRKAB1 with BMI appear to be consistent with statistical noise.

AMP-Activated Protein Kinases↗
PubMed2005

Validity of the salience asymmetry interpretation of the implicit association test: comment on Rothermund and Wentura (2004).

The Implicit Association Test (IAT) requires responding to category contrasts such as young versus old, male versus female, and pleasant versus unpleasant. In introducing the IAT, A. G. Greenwald, D. E. McGhee, and J. L. K. Schwartz (1998) proposed that IAT measures reflect mental structures involving the nominal features of the IAT's categories (e.g., age, gender, or valence features). In contrast, K. Rothermund and D. Wentura proposed that IAT performance is dominated by salience asymmetries of the IAT's pairs of contrasted categories. To assess relative contributions of nominal feature contrasts versus salience asymmetries, the authors (a) briefly summarize the extensive evidence now available to support construct validity of the IAT as a measure based on nominal category features and (b) present 2 new experiments that yielded results problematic for the salience asymmetry interpretation.

Association Learning↗
PubMed2004

Measuring self-esteem using the implicit association test: the role of the other.

In two experiments, the use of a self-other Implicit Association Test (IAT) as a measure of implicit self-esteem was examined. In Study 1, participants completed two self-other IATs: one in which the other was unspecified and one in which the other was specified to be a close friend. Esteem-IAT scores were significantly higher for the unspecified other-IAT (d = .82), indicating that the content of the other has a considerable influence on the over-all esteem-IAT scores. Study 2 provided a conceptual replication of these results and provided some initial evidence that the valence of an unspecified other is negative. Across both studies, the nature of the mental representation of the self, as measured by an esteem-IAT, changed as a function of the mental representation of the other. The crucial role of the other-associations in the esteem-IAT calls into question its use and interpretation as a measure of self-esteem.

Adult↗
PubMed1992

Quantitative scores of normal and abnormal subjects on Initial-letter Word-association Test.

The quotient of the mean quantitative score on Initial-letter Word-association Test for 193 normal subjects was significantly higher than the quotient of the mean quantitative score of 44 abnormal (psychotic) subjects. This is interpreted as meaning that, in general, the normal subjects have predominantly a positive attitude towards their surrounding world in contradistinction to the abnormal subjects whose attitude was predominantly negative, ambivalent, and repressive. On the other hand, the mean of the quotients of the quantitative scores of the 44 abnormal subjects was higher than the mean of the quotients of the quantitative scores of the normal subjects which suggests increased oral tendencies of the abnormal subjects expressed much as the unwarranted optimism of small children.

Adult↗
PubMed2001

How do indirect measures of evaluation work? Evaluating the inference of prejudice in the Implicit Association Test.

There has been significant interest in indirect measures of attitudes like the Implicit Association Test (IAT), presumably because of the possibility of uncovering implicit prejudices. The authors derived a set of qualitative predictions for people's performance in the IAT on the basis of random walk models. These were supported in 3 experiments comparing clearly positive or negative categories to nonwords. They also provided evidence that participants shift their response criterion when doing the IAT. Because of these criterion shifts, a response pattern in the IAT can have multiple causes. Thus, it is not possible to infer a single cause (such as prejudice) from IAT results. A surprising additional result was that nonwords were treated as though they were evaluated more negatively than obviously negative items like insects, suggesting that low familiarity items may generate the pattern of data previously interpreted as evidence for implicit prejudice.

Attitude↗
PubMed1985

Statistical approach to the word association test.

Six different quantitative single-valued measures for the response domain in free Word Association Test are summarized. The measures are w--the probability of the primary response; K--the number of different responses related to the number of subjects; H--the number of idiosyncratic responses related to the number of subjects; Z--the coefficient proposed by Zinger (1982); Ri--the coefficient of isonymy defined by Lasker (1977); and I--the entropy of the response distribution. These measures are compared on the theoretical level. The results are demonstrated on an experiment in which 175 subjects responded to a list of 40 different stimuli words. The list was presented twice. The measure I is preferred for general application from both theoretical and experimental points of view.

Humans↗
PubMed2006

The psychometric equivalence of two alternate forms of the Controlled Oral Word Association Test.

The equivalence of forms CFL and PRW of the Controlled Oral Word Association Test (COWAT; Benton, de Hamsher, & Sivan; 1994) was examined in samples of healthy college students. Both novel words and qualitative scores (e.g., clusters, switches) were examined using null hypothesis statistical testing (NHST) and inferential confidence intervals (Tryon, 2001). Study 1 used a within-subjects design (n = 66) to examine form equivalence in persons who completed versions CFL and PRW. No mean differences were found for any index, and only one (mean cluster size) differed when examining the standard deviations across forms. Inferential confidence intervals were constructed and Rg (maximum probable difference) values were small and, when compared to prior research, less than the standard error of measure associated with using a single form. In Study 2, we employed a between-subjects design (n = 208) and found that the use of each version generated comparable normative data and correlations among scores. These studies suggest that versions CFL and PRW are best viewed as alternate (rather than parallel) forms at this time; however, they are likely to produce comparable results for most purposes. We discuss the use of inferential confidence intervals to examine form equivalence and directions for future work.

Adolescent↗
PubMed2004

Power estimation of multiple SNP association test of case-control study and application.

At the current stage, a large number of single nucleotide polymorphisms (SNPs) have been deployed in searching for genes underlying complex diseases. A powerful method is desirable for efficient analysis of SNP data. Recently, a novel method for multiple SNP association test using a combination of allelic association (AA) and Hardy-Weinberg disequilibrium (HWD) has been proposed. However, the power of this test has not been systematically examined. In this study, we conducted a simulation study to further evaluate the statistical power of the new procedure, as well as of the influence of the HWD on its performance. The simulation examined the scenarios of multiple disease SNPs among a candidate pool, assuming different parameters including allele frequencies and risk ratios, dominant, additive, and recessive genetic models, and the existence of gene-gene interactions and linkage disequilibrium (LD). We also evaluated the performance of this test in capturing real disease associated SNPs, when a significant global P value is detected. Our results suggest that this new procedure is more powerful than conventional single-point analyses with correction of multiple testing. However, inclusion of HWD reduces the power under most circumstances. We applied the novel association test procedure to a case-control study of preterm delivery (PTD), examining the effects of 96 candidate gene SNPs concurrently, and detected a global P value of 0.0250 by using Cochran-Armitage chi(2)s as "starting" statistics in the procedure. In the following single point analysis, SNPs on IL1RN, IL1R2, ESR1, Factor 5, and OPRM1 genes were identified as possible risk factors in PTD.

Algorithms↗
PubMed2006

Two bases of the compatibility effect in the Implicit Association Test (IAT).

Four experiments are reported, investigating the mechanisms underlying the compatibility effect in the Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998). All experiments involved two IATs: flower IAT, in which the target categories were flowers and insects, and number IAT, involving even and odd numbers as target categories. In Experiment 1, using the standard IAT procedure, the two IATs produced equal IAT effects, despite large differences in rated valence contrast between flowers and insects and between even and odd numbers. Experiment 2 used a procedure developed by Klauer and Mierke (2005) and produced results consistent with the view that valence plays a role in the flower IAT but not in the number IAT. Experiments 3 and 4 used manipulations similar to those developed by Rothermund and Wentura (2004) and showed that these manipulations affected the flower IAT and number IAT differently. The results provide converging evidence that the two types of IAT effects-one based on valence and one based on familiarity-are empirically dissociable. Experiments 1and 2 reported in this paper were conducted as an honours project by Marie Peek-O'Leary under the supervision of Sachiko Kinoshita. Parts of this paper were presented at the 44th Annual Meeting of the Psychonomic Society held in Vancouver, Canada, in November, 2003.

Humans↗
PubMed2004

Incorporating individual error rate into association test of unmatched case-control design.

OBJECTIVES: Genotyping error commonly occurs and could reduce the power and bias statistical inference in genetics studies. In addition to genotypes, some automated biotechnologies also provide quality measurement of each individual genotype. We studied the relationship between the quality measurement and genotyping error rate. Furthermore, we propose two association tests incorporating the genotyping quality information with the goal to improve statistical power and inference. METHODS: 50 pairs of DNA sample duplicates were typed for 232 SNPs by BeadArray technology. We used scatter plot, smoothing function and generalized additive models to investigate the relationship between genotype quality score (q) and inconsistency rate (ĩ) among duplicates. We constructed two association tests: (1) weighted contingency table test (WCT) and (2) likelihood ratio test (LRT) to incorporate individual genotype error rate (epsilon(i)), in unmatched case-control setting. RESULTS: In the 50 duplicates, we found q and ĩ were in strong negative association, suggesting the genotypes with low quality score were more likely to be mistyped. The WCT improved the statistical power and partially corrects the bias in point estimation. The LRT offered moderate power gain, but was able to correct the bias in odds ratio estimation. The two new methods also performed favorably in some scenarios when epsilon(i) was mis-specified. CONCLUSIONS: With increasing number of genetic studies and application of automated genotyping technology, there is a growing need to adequately account for individual genotype error rate in statistical analysis. Our study represents an initial step to address this need and points out a promising direction for further research.

Case-Control Studies↗
PubMed2006

Assessment of implicit personality self-concept using the implicit association test (IAT): concurrent assessment of anxiousness and angriness.

This study explored the psychometric properties of the Implicit Association Test (IAT) when it is employed for the assessment of two personality traits within one sample. The sequence of an anxiousness and an angriness IAT was counterbalanced across 100 participants and the IATs' predictive validity for anxious versus angry behaviour after emotion inductions was examined and compared to direct self-report measures. The anxiousness IAT added incremental validity over direct measures for the prediction of anxious behaviour. The angriness IAT was affected by an order effect. When the angriness IAT was completed after the anxiousness IAT both tests correlated with r=.46 whereas they were not significantly correlated when the angriness IAT was completed first. Direct anxiousness and angriness measures were uncorrelated. Implications for the assessment of multiple implicit personality self-concept dimensions are discussed.

Adult↗
PubMed2000

Using the implicit association test to measure self-esteem and self-concept.

Experiment 1 used the Implicit Association Test (IAT; A. G. Greenwald, D. E. McGhee, & J. L. K. Schwartz, 1998) to measure self-esteem by assessing automatic associations of self with positive or negative valence. Confirmatory factor analysis (CFA) showed that two IAT measures defined a factor that was distinct from, but weakly correlated with, a factor defined by standard explicit (self-report) measures of self-esteem. Experiment 2 tested known-groups validity of two IAT gender self-concept measures. Compared with well-established explicit measures, the IAT measures revealed triple the difference in measured masculinity-femininity between men and women. Again, CFA revealed construct divergence between implicit and explicit measures. Experiment 3 assessed the self-esteem IAT's validity in predicting cognitive reactions to success and failure. High implicit self-esteem was associated in the predicted fashion with buffering against adverse effects of failure on two of four measures.

Adult↗
PubMed2002

Verbal Paired Associates tests limits on validity and reliability.

The Verbal Paired Associates (VPA) subtest from the Wechsler Memory Scale-III (WMS-III) is one of the most widely used instruments for assessing explicit episodic memory performance. The normative data for the VPA subtest in the WMS-III manual show clear evidence of performance ceiling effects that limit the usefulness of this instrument. For this reason, we developed a new 15-item VPA test and we report normative data obtained from a partially stratified sample of 351 healthy adults between 18 and 91 years of age. Only a small fraction of participants obtained perfect scores on our new Paired Associates test. The results show the expected large age-related decline in memory acquisition, indexed by performance on the first study test trial, together with a much smaller age effect on learning across trials. The results also show that performance on the Paired Associates test is related to education, verbal IQ, and to a lesser extent, participants' sex. We provide various equations for precise predictions of Paired Associates test performance.

Journal Article↗
PubMed2001

Attitude measurement using the Implicit Association Test (IAT).

Three years ago, Greenwald, McGhee, and Schwartz (1998) presented a new method to measure differential evaluative association of two target concepts: the Implicit Association Test (IAT). It has been asserted that the IAT allows for the assessment of implicit attitudes by comparing response times in two combined discrimination tasks. Although the distribution and employment of this method has been quite successful, the processes underlying IAT-effects, as well as the psychometric properties of specific IAT-variants, have received relatively little attention up to now. The articles included in the present special issue especially focus on these aspects.

Association↗
PubMed1983

[On the nature of regressive state in hypnosis: a study by word-association-test].

The purpose of this study is to reveal the nature of regressive state in hypnosis by means of word-association-test (WAT). Stimulus words for WAT, pronounced without intonation, was presented to hypnotic, control, and distraction groups. At the first test, all groups were under awaken state, and at the second test, hypnotic group was under hypnosis, distraction group was under distraction. (1) Under hypnosis, more visual images (signifié-images) and clang associations (significant-images) were imagined. The hypnosis was supposed to be a partial, controlled "regression in the service of the ego", and in this state the lexical meaning was not dissolved, but the unity among person, symbol, and referential object in Werner & Kaplan's sense was restored by the images. (2) The results suggest that hypnosis is different from distraction state, and is a state of specific concentration. (3) Since the signifié-image was contrary to the significant-image, these two were regarded as two aspects of regressive state in hypnosis. These two aspects are manifestation of emotional problems and restoration of body-mind unity.

Adolescent↗
PubMed2002

Visual association test to detect early dementia of the Alzheimer type.

BACKGROUND: The visual association test (VAT) is a brief learning task based on imagery mnemonics. The test materials consist of six line drawings of pairs of interacting objects or animals-for example, an ape holding an umbrella. The person is asked to name each object and, later, is presented with one object from the pair and asked to name the other. OBJECTIVE: To verify that the task induces robust incidental or effortless learning (study 1), and to study the efficiency of the test as a discriminator between early dementia of the Alzheimer type (DAT) and non-demented people (study 2) and non-DAT types of dementia (study 3). METHODS: Study 1: two groups of elderly volunteers were administered the VAT. The stimuli were presented in the interactive fashion to group A-for example, a monkey carrying an umbrella (n=83)-and side by side to group B-for example, separate pictures of a monkey alone and an umbrella alone (n=79). Group B received learning instructions, but group A did not. Study 2: three groups of subjects were selected from a population based follow up study: incident DAT cases (n=24), cognitively declining subjects not diagnosed with dementia (n=21), and stable non-demented subjects (n=204). Test performance of the non-demented group at baseline was compared with that of patients with DAT at the time of their diagnosis, of patients with DAT a year before their diagnosis, and of non-demented declining subjects at baseline. Study 3: subjects were patients referred for neuropsychological assessment because of suspected dementia. They were diagnosed by consensus criteria of various dementia syndromes. RESULTS: Study 1: recall was more than twice as high in group A as in group B. Thus interactive presentation, even in the absence of learning instructions, enhances learning. Study 2: at a level of 97.5% specificity, the VAT had a sensitivity of 87.5% for DAT cases at the time of diagnosis and 66.7% one year before diagnosis. The cognitively declining group scored significantly lower on the VAT at baseline than the non-demented group. The VAT discriminated more effectively than both the MMSE and the six item picture learning task from the CAMCOG. Study 3: VAT scores were significantly lower in patients with DAT (n=48) than in patients with vascular dementia (n=37), frontotemporal dementia (n=9), or subcortical dementia (n=15), but not lower than in patients with Lewy body dementia (n=7). Mean mini mental state examination scores of these groups were not significantly different. The VAT discriminated patients with DAT from patients with other types of dementia more effectively than a prose recall test. Sensitivity was 79% and specificity 69%. CONCLUSIONS: The VAT detects with high specificity a sizeable proportion of patients with DAT a year before the diagnosis, and a low VAT score is relatively uncommon in patients with non-DAT dementia.

Aged↗