Configural Frequency Analysis in Applied Psychological Research

L'Analyse de Fréquence des Configurations (AFC) est une méthode de recherche des classes et anticlasses dans les classifications croisées de catégories de variables. Les classes sont des modèles de catégories de variables qui apparaissent plus souvent que le hasard ne le laisse supposes. Les anticlasses sont des modèles de catégorie de variables qui apparaissent moins souvent que le hasard ne le laisse supposes. On présente quatre applications d'AFC: l'AFC de premier ordre, l'AFC prédictive, l'AFC de symétrie axiale, et un modèle d'AFC longitudinale. On examine les caractéristiques de l'AFC en insistant sur les contraintes et l'applicabilité. On compare aussi l'AFC avec d'autres méthodes permettant l'analyse multivariée de catégories de données, en particulier la modèlisation log-linéaire. Des sorties informatiques sont traitées.
Configural Frequency Analysis (CFA) is a method for the search for types and antitypes in cross-classifications of categorical variables. Types are patterns of variable categories that occur more often than expected from chance. Antitypes are patterns of variable categories that occur less often than expected from chance. Four applications of CFA are reviewed: the First Order CFA, the Prediction CFA, Axial Symmetry CFA, and one model of Longitudinal CFA. Characteristics of CFA are discussed, focusing on constraints posed and applicability. Comparisons are made of CFA with other methods for multivariate analysis of categorical data, in particular, log-linear modelling. Computational issues are discussed.     

Neurological soft signs in obsessive compulsive disorder: standardised assessment and comparison with schizophrenia

While several studies have detected raised levels of neurological soft signs in patients with obsessive compulsive disorder (OCD), the specificity of these abnormalities remains uncertain. This study used a new standardised measure, the Cambridge Neurological Inventory (CNI), to assess soft signs in 51 subjects with OCD. Comparison was made with data on patients with schizophrenia and a non-clinical control group from a previously reported study. Individuals with OCD showed raised levels of soft signs compared with non-clinical controls in many categories of the CNI: Motor Coordination, Sensory Integration, Primitive Reflexes, Extrapyramidal Signs, and Failure of Suppression. Compared with patients with schizophrenia, the OCD group had lower levels of neurological signs in some CNI categories: Hard Signs, Motor Co-ordination, Tardive Dyskinesia, Catatonic Signs, and Extrapyramidal Signs. However, levels of soft signs in the OCD group did not significantly differ from those in the schizophrenia group in other CNI categories: Sensory Integration, Primitive Reflexes and Failure of Suppression. The significance of these patterns of findings is discussed.     

Approximate entropy and point correlation dimension of heart rate variability in healthy subjects

The contribution of nonlinear dynamics to heart rate variability in healthy humans was examined using surrogate data analysis. Several measures of heart rate variability were used and compared. Heart rates were recorded for three hours and original data sets of 8192 R-R intervals created. For each original data set (n=34), three surrogate data sets were made by shuffling the order of the R-R intervals while retaining their linear correlations. The difference in heart rate variability between the original and surrogate data sets reflects the amount of nonlinear structure in the original data set. Heart rate variability was analyzed by two different nonlinear methods, point correlation dimension and approximate entropy. Nonlinearity, though under 10 percent, could be detected with both types of heart rate variability measures. More importantly, not only were the correlations between these measures and the standard deviation of the R-R intervals weak, the correlation among the nonlinear measures themselves was also weak (generally less than 0.6). This suggests that in addition to standard linear measures of heart rate variability, the use of multiple nonlinear measures of heart rate variability might be useful in monitoring heart rate dynamics.     

Ratio requirement and reinforcer effects in concurrent fixed-interval fixed-ratio schedules

The fixed-ratio requirement was varied in concurrent fixed-interval fixed-ratio schedules. Fixed-interval responding was reinforced by food. In different phases, fixed-ratio responding was reinforced by food or water. There was a direct relation between the ratio requirement and interval response rates when both responses were reinforced with food, but essentially no relation when the reinforcers were different. The role of reinforcers in concurrent schedules merits detailed study.     

An objective test of goodness of fit of the continuous strength model in STM

The continuous strength model of recognition memory was evaluated in a task where Ss were tested for recognition of 10-number lists using a rating procedure. Maximum likelihood estimates of the parameters of the model were obtained by an iterative method on a high-speed computer, and a chi-square goodness-of-fit test was performed for individual Ss. For 15 of 20 Ss, the chi-square values were nonsignificant, p < .05, indicating that the model provided a good fit to the data. Although the model gave a good fit to the data, the Δm measure of sensitivity was highly correlated with a true recognition score computed by subtracting false alarmsfrom correct recognitions.     

An investigation of the relationships between problem solving strategies, representation and memory

There has been considerable debate in recent years about the status of “imagery” in problem solving. The present experiment attempts to show that while subjects may employ representational strategies when they first encounter a class of problems, they abandon such strategies as they gain experience with the problems. It does this by asking subjects to answer unexpected questions which are based upon the information which they have just used to solve a problem. The hypothesis, which is supported by the results, is that increasing experience with problems will be paralleled by a decreasing ability to answer unexpected questions. The experiment also shows that such effects are not attributable to a build-up in proactive interference.