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Results for “association testing”

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At least 19 recordsLinked to original sources
PubMed1991

The morphometric histopathology of undescended testes and testes associated with incarcerated inguinal hernia: a comparative study.

The underlying injury to undescended testes may be hormonal, a transient perinatal form fruste of hypogonadotropic hypogonadism characterized by blunting of the surge in gonadotropins normally seen at age 60 to 90 days. Ischemia is the underlying injury to testes associated with incarcerated inguinal hernias. To determine if the histopathology of these 2 injuries is different histomorphometric analyses were performed on semithin microscopic sections of biopsies of 21 control testes, 17 undescended testes and 13 intrascrotal testes associated with incarcerated inguinal hernias. The infants in all groups were 30 to 120 days old. The results showed that, as in previous studies, undescended testes at this age are characterized by hypoplasia of Leydig cells, normal germ cell counts and defective maturation of gonocytes into adult dark spermatogonia. In contrast, testes associated with incarcerated inguinal hernias were characterized by hyperplasia of Leydig cells, reduced germ cell counts and normal maturation of gonocytes into adult dark spermatogonia. One might conclude that the underlying injury of undescended testes, presumably the blunted surge of gonadotropins, causes a primary hypoplasia and hypofunction of Leydig cells, which in turn causes a secondary defect in transformation of gonocytes into spermatogonia. In contrast, ischemia may primarily cause a tubular epithelial lesion leaving the hypothalamic-pituitary-gonadal axis intact and allowing normal transformation of gonocytes into spermatogonia. Reduced gonadotropins and ischemia appear to produce distinctly different primary and secondary pathophysiological effects on the testes.

Biopsy↗
PubMed1992

[Perception of odor quality by Free Image-Association Test].

A method was devised for evaluating odor quality. Subjects were requested to freely describe the images elicited by smelling odors. This test was named the "Free Image-Association Test (FIT)". The test was applied for 20 flavors of various foods, five odors from the standards of T&T olfactometer (Japanese standard olfactory test), butter of yak milk, and incense from Lamaism temples. The words for expressing imagery were analyzed by multidimensional scaling and cluster analysis. Seven clusters of odors were obtained. The feature of these clusters were quite similar to that of primary odors which have been suggested by previous studies. However, the clustering of odors can not be explained on the basis of the primary-odor theory, but the information processing theory originally proposed by Miller (1956). These results support the usefulness of the Free Image-Association Test for investigating odor perception based on the images associated with odors.

Adult↗
PubMed1985

Construction of matched verbal and design continuous paired associate tests.

We developed verbal and figural continuous paired associate tests (CPAT) that are matched on internal consistency and on the distributional properties of mean item difficulty, variance, and skewness. The Verbal CPAT is composed of high frequency nouns, verbs, and adjectives. Selection of the designs was guided by literature on the effects of right-hemisphere damage on memory for designs. One hundred subjects were given 80 items from the verbal CPAT and 80 items from the designs CPAT. Twenty subjects at these five ranges of Wechsler Memory Quotient were evaluated: less than or equal to 79, 80-89, 90-99, 100-109, greater than or equal to 109. The final 40-item version of the Verbal CPAT had a mean of 26.72, a SD of 7.03, and an alpha of .859. The Designs CPAT had a mean of 26.42, a SD of 7.75, and an alpha of .886. Neither test was significantly skewed. These matched tests should be useful in making inferences about differences between verbal and figural memory that are not confounded with the problem of differential test sensitivity.

Adolescent↗
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↗
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↗
PubMed2025

Adjustment for Genotype Imputation Uncertainty Corrects for Inflated Type I Error in Family-Based Association Testing.

Genotype imputation is a widely-used data augmentation approach that is applied to samples of related and/or unrelated individuals. Association testing may then be carried out on the complete data with commonly-used methods. This approach has typically not accounted for the mix of observed and imputed data, although recent work has noted the potential for introduction of confounding in case-control studies. In the Alzheimer's Disease Sequencing Project family sample we found severe inflation of the test statistics in logistic regression analysis following genotype imputation, even after standard covariate adjustments. Here we dissect sources of this inflation, which is driven by three factors: frequency-dependent bias in imputation-induced allele frequencies, differential measurement error, and differential genotyping rates in cases versus controls that introduces confounding. To address the problem, we propose a statistic, imputation deviance (), which can be easily computed from the observed and imputed genotype probabilities. We show that, as an additional fixed-effect covariate, controls the genome-wide inflation in analysis of this family-based sample, and we speculate that use of imputation deviance may also provide a practical approach to correct for genotype imputation effects in other settings, particularly when a data set is unbalanced and includes related individuals.

Humans↗
PubMed1987

Effects of lateralized cerebral dysfunction on the Continuous Paired-Associate Test.

Some authorities have advocated matching tests on several critical psychometric properties before inferring the presence of a differential pattern of deficit. This study examined the effects of lateralized cerebral dysfunction on the matched Verbal and Design subtests of the Continuous Paired-Associate Test (CPAT). Patients with lateralized destructive lesions were studied in Experiment 1. Epileptic patients with lateralized electroencephalographic findings were studied in Experiment 2. Left but not right hemispheric abnormalities impaired performance on the Verbal CPAT, but only for destructive lesions. The Designs CPAT was a nonspecific indicator of cerebral dysfunction. For studies with the goal of predicting laterality of cerebral dysfunction, we advocate a two-step strategy of test development. The first step would make use of the principle of double dissociation in selecting items to compose subtests. The second step would involve an item analysis of subtests to determine the need for matching.

Adolescent↗
PubMed1979

[Word association test in myocardial infarct].

The distinguishing feature of associative reactions of patients with myocardial infarction is the marked predominance of egocentric response and the lesser variance of the reactions to critical verbal stimuli. As compared to patients with myocardial infarction and normal psychic condition and to healthy individuals, patients with psychopathological changes due to myocardial infarction gave disordered associative answers to emotionally meaningful verbal stimuli significantly more frequently and with a more marked affective coloration. These signs may serve in different diagnosis in appraising the psychic status of patients with myocardial infarction.

Adult↗
PubMed1975

[Different responses in word association tests in normotensive and hypertensive subjects].

Activation of latent associations by word stimuli of different emotional relevance as well as the accompanying electrophysiological tracings reveal statistically significantly characteristics in juvenile essential (arterial) hypertensives as compared to normotensives. This applies to the verbal reactions as well as to the electrophysical concomitants. Under additional cognitive demands both groups achieve better performance. This rise is significantly greater, however for hypertensives than for normotensives. Our special recording system permitted exact phonographic registration of the verbal stimulus and reaction as well as of the PGR.

Galvanic Skin Response↗
PubMed1992

Empirical Bayes methods for testing associations with large numbers of candidate genes in the presence of environmental risk factors, with applications to HLA associations in IDDM.

Standard regression models for disease incidence data can be used to test for associations between a disease and measured genetic and environmental factors and their interactions. Complications arise when the gene is not observed, requiring segregation and linkage analysis approaches, or when the candidate gene(s) are found to be highly polymorphic, as in the HLA region. We propose a Bayesian approach to the latter problem, in which the log relative risks for all alleles at a given locus are taken to be independent and exchangeable, assuming there is no preferential zygotic assortment and negligible recombination. Multi-locus problems can be addressed either by adding exchangeable interaction terms or by adopting a multivariate prior for haplotype effects. Some simulations based on our current work on family studies of IDDM are discussed.

Alleles↗