Differential impact of parenting sick infants

Parenting a newborn infant has been identified as a significant stressor, and parenting a sick infant evokes an even greater stress. This study evaluated the differential impact of parenting infants with interrupted infantile apnea vs. extremely low birth weight infants. These infants were compared to normal infants on the Bayley Scales of Infant Assessment and the Parenting Stress Index when the infants were 6 months old. Significant effects on the mental index revealed that the low birthweight infants performed more poorly than did the other groups. A stepwise multiple discriminant analysis on the Parenting Stress Index suggested that child adaptability, maternal restrictions, isolation, and health were significant stressors. Mothers of apneic infants were affected most severely by their child's illness. The lower educational level of these mothers may have influenced these findings.     

A factor simplicity index

We propose an index for assessing the degree of factor simplicity in the context of principal components and exploratory factor analysis. The new index, which is called Loading Simplicity, is based on the idea that the communality of each variable should be related to few components, or factors, so that the loadings in each variable are either zero or as far from zero as possible. This index does not depend on the scale of the factors, and its maximum and minimum are only related to the degree of simplicity in the loading matrix. The aim of the index is to enable the degree of simplicity in loading matrices to be compared.The author would like to thank the review team for their insights and recommendations. This work was supported by a grant SEC2001-3821-C05-C02 from the Spanish Ministry of Science and Technology.     

Need to train your rat? There is an App for that: A touchscreen behavioral evaluation system

The increasing demand for highly automated and flexible tasks capable of assessing visual learning and memory in nonhuman animals has led to the exciting development of a wide array of prefabricated touchscreen-equipped systems. However, the high cost of these prefabricated systems has led many researchers to develop or modify their own preexisting equipment. We developed a freely downloadable App, the Touchscreeen Behavioral Evaluation System (TBES) for use in conjunction with an iPad (Apple, Cupertino, California) as an alternative to prefabricated touchscreen systems. TBES allows for stimulus presentation and data collection on an iPad. The touchscreen technology offered by the iPad is attractive to researchers due to its affordability, reliability, and resistance to false inputs. We highlight these, as well as the feasibility and procedural flexibility of TBES, in an effort to promote our system as a competitive alternative to those currently available.     

FACTOR: A computer program to fit the exploratory factor analysis model

Exploratory factor analysis (EFA) is one of the most widely used statistical procedures in psychological research. It is a classic technique, but statistical research into EFA is still quite active, and various new developments and methods have been presented in recent years. The authors of the most popular statistical packages, however, do not seem very interested in incorporating these new advances. We present the program FACTOR, which was designed as a general, user-friendly program for computing EFA. It implements traditional procedures and indices and incorporates the benefits of some more recent developments. Two of the traditional procedures implemented are polychoric correlations and parallel analysis, the latter of which is considered to be one of the best methods for determining the number of factors or components to be retained. Good examples of the most recent developments implemented in our program are (1) minimum rank factor analysis, which is the only factor method that allows one to compute the proportion of variance explained by each factor, and (2) the simplimax rotation method, which has proved to be the most powerful rotation method available. Of these methods, only polychoric correlations are available in some commercial programs. A copy of the software, a demo, and a short manual can be obtained free of charge from the first author.     

NFACOM: A new program for relating solutions in exploratory factor analysis

A new version of the program FACOM (comparison of exploratory factor analysis solutions) is presented. The new version (NFACOM) greatly extends the possibilities of the previous versions. It is now possible to use congruence as well as least squares comparisons in both orthogonal and oblique situations. What is more, n solutions, not just two, can be compared. Recently developed algorithms have been implemented; others, which have proved not to be theoretically well founded, have been omitted.     

A General Approach for Fitting Pure Exploratory Bifactor Models

This article proposes a procedure for fitting a pure exploratory bifactor solution in which the general factor is orthogonal to the group factors, but the loadings on the group factors can satisfy any orthogonal or oblique rotation criterion. The proposal combines orthogonal Procrustes rotations with analytical rotations and consists of a sequence of four steps. The basic input is a semispecified target matrix that can be (a) defined by the user, (b) obtained by using Schmid-Leiman orthogonalization, or (c) automatically built from a conventional unrestricted solution based on a prescribed number of factors. The relevance of the proposal and its advantages over existing procedures is discussed and assessed via simulation. Its feasibility in practice is illustrated with two empirical examples in the personality domain.     

Stability of the factor structure of Barrat's Impulsivity Scales for children across cultures: a comparison of Spain and Colombia

Despite the great importance of impulsivity in many childhood and adolescence disorders, there are few self-reports on child impulsivity. Recently, a modified version of Barratt's BIS-11 questionnaire adapted for children has been developed, which may be useful in assessing this personality dimension. The present study reports an adaptation of this questionnaire in a different culture (Colombia) and assesses the degree of convergence between the factor structures of both adaptations using consensus oblimin rotation. The results indicate not only that the factor structure of the test remains stable across both adaptations, and that two of the three scales in the Colombian version show acceptable reliabilities, but also that cultural and linguistic issues are important in test adaptation even when the same language is used.     

Expectation and temperament moderate amygdala and dorsal anterior cingulate cortex responses to fear faces

A chronic tendency to avoid novelty is often the result of a temperamental bias called inhibited temperament, and is associated with increased risk for anxiety disorders. Neuroimaging studies have demonstrated that an inhibited temperament is associated with increased amygdalar blood-oxygenation-level-dependent (BOLD) response to unfamiliar faces that were not expected; however, the effects of variations in expectancy remain unknown. Using functional magnetic resonance imaging (fMRI), we studied BOLD response to infrequently encountered fear faces that were either expected or not expected in 42 adults with an inhibited or an uninhibited temperament. Individuals with an inhibited temperament had greater amygdala, but less dorsal anterior cingulate cortex (dACC), BOLD response when the stimuli were expected. In contrast, those with an uninhibited temperament had a smaller amygdala but larger dorsal anterior cingulate cortex BOLD response when expecting to see fear faces. These findings demonstrate temperament differences in expectancy effects and provide preliminary evidence for the dACC as a neural substrate mediating differences in inhibited temperament. Enhanced amygdala sensitivity coupled with weak inhibitory control from the dACC may form a neural circuit mediating behaviors characteristic of inhibited temperament and risk for anxiety disorders.