Contribuciones empíricas para la validez de grupos contrastados de la Batería de Tareas de Autorregulación Cognitiva (TAC) / Empirical contributions for contrasting groups validity of the Tareas de Autorregulación Cognitiva (TAC) Battery

Los déficit de las funciones ejecutivas (FE) suelen estar presentes en el Trastorno por Déficit de Atención e Hiperactividad (TDAH). Distintos trabajos mostraron algunas falencias vinculadas a la medición de las FE, como la participación de otros procesos que no constituyen objeto de la evaluación. En el trabajo que se informa se analizaron las diferencias existentes en las FE de niños con y sin diagnóstico de TDAH y se buscó identificar y establecer aquellas variables con mayor poder discriminante para la probabilidad de pertenencia a ambos grupos. Se utilizaron las tareas de la batería denominada Tareas de Autorregulación Cognitiva (TAC), diseñadas ad-hoc para evaluar específica y relativamente en forma independiente cada FE. Se trabajó con una muestra de 49 niños escolarizados de 7 a 12 años de edad, de ambos géneros, divididos en dos grupos, uno clínico de 19 niños con diagnóstico de TDAH, con una media de edad igual a 9.84 años (DE = 1.83) y uno control de 30 niños sin diagnóstico de TDAH con una media de edad igual a 10.27 años (DE = .82), equiparados por género, edad, niveles socioeconómico y educacional. Los resultados mostraron que el análisis discriminante permitió clasificar correctamente al 98% de los participantes. Las tareas mejor discriminadas fueron la de Flexibilidad cognitiva y Control inhibitorio comportamental, con un 98.9% y 97.8%, respectivamente, de casos correctos. Esto muestra que la TAC constituye una batería con adecuada sensibilidad y especificidad para discriminar y detectar casos de TDAH con un elevado nivel de confiabilidad y porcentaje de correctos clasificados.

The executive functions (EF) multidimensional approaches state that EFs consist of a set of processes with relative autonomy and independence: working memory (WM), cognitive flexibility (CF), and inhibition. Regarding the inhibitory operation, three dimensions are distinguished, each with distinct operative features: perceptual, cognitive, and behavioral inhibition. Perceptual inhibition is the process that allows the focus on relevant environmental stimuli through the attenuation of the interference generated by other stimuli present in the context. Cognitive inhibition is involved in the decreased level of activation of the prepotent mental representations of intrusive and irrelevant to the achievement of current goals. Finally, behavioral inhibition handles suppress or cancel behaviors and strong, prepotent and un suitable behaviors. While this last type contributes to the inhibitory control of behavior, the other two processes (cognitive and perceptual inhibition) apply to cognition, as involved in regulating the perceptions and representations. Regarding executive operation in general, empirical evidence suggests that these dimensions are involved in such diverse fields as psychopathology, personality, emotion, attentional control and cognitive development. It has been found that deficits in EFs are usually present in the Attention Deficit Hyper activity Disorder (ADHD). The common practice of treating children with ADHD as an undifferentiated group of participants in behavioral and neuropsychological research may have adverse methodological consequences. Relying on group averaging in comparing the performance of ADHD and control groups may produce misleading results, as it conceals possible effects that may characterize some but not all ADHD participants. According to the previous assumptions, the objectives of this work were (1) analyzing the EF performance in children with or without diagnosed ADHD and (2) identifying and setting the variables with greater discriminant power between the normal and clinical groups. Battery tasks called Tareas de Autorregulación Cognitiva (TAC) ad-hoc and designed to assess EFs operation specifically and with relative independence with each other were used. The sample consisted of 49 school-attending children, aged 7-12 years, of both sexes, divided into two groups: (1) a clinical group of 19 children diagnosed with ADHD combined subtype (M age = 9.84 years, SD =1.83), and (2) a control group of 30 children without ADHD diagnosis (M age = 10.27 years, SD = .82), matched by gender, age, socioeconomic and educational level. By analyzing the results, significant differences were found between verbal and visuospatial WM, CF, behavioral and perceptual inhibition indices. Then, a discriminant analysis was made in order to use the index values with significant differences and make predictions about the probability of a subject to be a member of a certain criteria variable value (clinical or control group condition). Results show that discriminant analysis allows to correctly classifying 98% of the participants. The results indicated that the average RT of the mixed block (Cognitive Flexibility) and the Stop Signal RT (Behavioral Inhibition) are the indices with better sensitivity and specificity for detecting the presence of ADHD in this sample. Considering that the area under the curve indicates the probability to classify correctly a couple of healthy and ill individuals randomly selected, then it is possible to conclude that the values of Cognitive Flexibility and Behavioral Inhibitory control tasks had better discriminant power, as they correctly classified 98.9% and 97.8% of the total cases, respectively. This result shows that the TAC Battery presents adequate sensitivity and specificity to discriminate and detect ADHD with a high level of reliability and classification accuracy. Summarizing, we highlight the importance of having an assessment battery such as the totally computerized TAC, which allows the assessment of EFs independently, with an attractive design and straightforward administering and scoring procedures.

Cognitive conflicts in major depression: between desired change and personal coherence.

OBJECTIVES: The notion of intrapsychic conflict has been present in psychopathology for more than a century within different theoretical orientations. However, internal conflicts have not received enough empirical attention, nor has their importance in depression been fully elaborated. This study is based on the notion of cognitive conflict, understood as implicative dilemma (ID), and on a new way of identifying these conflicts by means of the Repertory Grid Technique. Our aim was to explore the relevance of cognitive conflicts among depressive patients. DESIGN: Comparison between persons with a diagnosis of major depressive disorder and community controls. METHODS: A total of 161 patients with major depression and 110 non-depressed participants were assessed for presence of IDs and level of symptom severity. The content of these cognitive conflicts was also analysed. RESULTS: Repertory grid analysis indicated conflict (presence of ID/s) in a greater proportion of depressive patients than in controls. Taking only those grids with conflict, the average number of IDs per person was higher in the depression group. In addition, participants with cognitive conflicts displayed higher symptom severity. Within the clinical sample, patients with IDs presented lower levels of global functioning and a more frequent history of suicide attempts. CONCLUSIONS: Cognitive conflicts were more prevalent in depressive patients and were associated with clinical severity. Conflict assessment at pre-therapy could aid in treatment planning to fit patient characteristics.

Cognitive reserve as a predictor of two year neuropsychological performance in early onset first-episode schizophrenia.

INTRODUCTION: The concept of cognitive reserve (CR) has been defined as individual differences in the efficient utilization of brain networks which allow some people to cope better than others with brain pathology. CR has been developed mainly in the field of aging and dementia after it was observed that there appears to be no direct relationship between the degree of brain pathology and the severity of clinical manifestations of this damage. The present study applies the concept of CR to a sample of children and adolescents with a first episode of schizophrenia, aiming to assess the possible influence of CR on neuropsychological performance after two year follow-up, controlling for the influence of clinical psychopathology. METHODS: 35 patients meeting DSM-IV criteria for schizophrenia or schizoaffective disorder (SSD) and 98 healthy controls (HC) matched for age and gender were included. CR was assessed at baseline, taking into account premorbid IQ, educational-occupational level and leisure activities. Clinical and neuropsychological assessments were completed by all patients at two year follow-up. RESULTS: The CR proxy was able to predict working memory and attention at two year follow-up. Verbal memory and cognitive flexibility were not predicted by any of the variables included in the regression model. The SSD group obtained lower scores than HC on CR. CR measures correctly classified 79.8% of the sample as being SSD or HC. CONCLUSIONS: Lower scores on CR were observed in SSD than in HC and the CR measure correctly classified a high percentage of the sample into the two groups. CR may predict SSD performance on working memory and attention tasks.

Psychometric properties of the Spanish Human System Audit Short-Scale of transformational leadership.

The aim of this research is to examine the psychometric properties of a Spanish version of the Human System Audit transformational leadership short-scale (HSA-TFL-ES). It is based on the concept of Bass developed in 1985. The HSA-TFL is a part of the wider Human System Audit frame. We analyzed the HSA-TFL-ES in five different samples with a total number of 1,718 workers at five sectors. Exploratory Factor Analysis corroborated a single factor in all samples that accounted for 66% to 73% of variance. The internal consistency in all samples was good (alpha = .92 - .95). Evidence was found for the convergent validity of the HSA-TFL-ES and the Multifactor Leadership Questionnaire. These results suggested that the HSA-TFL short-scale is a psychometrically sound measure of this construct and can be used for a combined and first overall measurement.

Psychometric properties of the Spanish human system audit short-scale of transformational leadership

The aim of this research is to examine the psychometric properties of a Spanish version of the Human System Audit transformational leadership short-scale (HSA-TFL-ES). It is based on the concept of Bass developed in 1985. The HSA-TFL is a part of the wider Human System Audit frame. We analyzed the HSA-TFL-ES in five different samples with a total number of 1,718 workers at five sectors. Exploratory Factor Analysis corroborated a single factor in all samples that accounted for 66% to 73% of variance. The internal consistency in all samples was good (α = .92 - .95). Evidence was found for the convergent validity of the HSA-TFL-ES and the Multifactor Leadership Questionnaire. These results suggested that the HSA-TFL short-scale is a psychometrically sound measure of this construct and can be used for a combined and first overall measurement (AU)

El objetivo de esta investigación es examinar las propiedades psicométricas de la versión española de la escala corta de Liderazgo Transformacional de la Auditoría del Sistema Humano (HSA-TFL-ES). La escala se basa en el concepto de Liderazgo Transformacional desarrollado por Bass en 1985. La HSA-TFL-ES ha sido administrada a un total de 1,718 trabajadores, distribuidos en cinco muestras diferentes correspondientes a distintos sectores empresariales. El análisis factorial exploratorio corroboró la existencia de un solo factor que explica entre 66% y 73% de la varianza. La consistencia interna obtenida ha sido buena (α = .92 - .95). Además, los resultados obtenidos muestran validez convergente entre la escala HSA-TFL-ES y el Cuestionario Multifactorial de Liderazgo (Multifactorial Leadership Questionnaire - MLQ). Los resultados evidencian que la escala corta HSA es una medida psicométricamente adecuada del constructo de Liderazgo Transformacional, por lo que puede ser utilizada para una primera medición global del mismo (AU)

Using artificial neural networks in clinical neuropsychology: high performance in mild cognitive impairment and Alzheimer's disease.

Mild cognitive impairment (MCI) is a transitional state between normal aging and Alzheimer disease (AD). Artificial neural networks (ANNs) are computational tools that can provide valuable support to clinical decision making, classification, and prediction of cognitive functioning. The aims of this study were to develop, train, and explore and develop the ability of ANNs to differentiate MCI and AD, and to study the relevant variables in MCI and AD diagnosis. The sample consisted of 346 controls and 79 MCI and 97 AD patients. A linear discriminant analysis (LDA) and ANNs with 12 input neurons (10 subtests of a neuropsychological test, the abbreviated Barcelona Test; age; and education), 4 hidden neurons, and output neuron (diagnosis) were used to classify the patients. The ANNs were superior to LDA in its ability to classify correctly patients (100-98.33% vs. 96.4-80%, respectively) and showed better predictive performance. Semantic fluency, working and episodic memory and education showed up as the most significant and sensitive variables for classification. Our results indicate that ANNs have an excellent capacity to discriminate MCI and AD patients from healthy controls. These findings provide evidence that ANNs can be a useful tool for the analysis of neuropsychological profiles related to clinical syndromes.

Patient and clinician's ratings of improvement in methadone-maintained patients: Differing perspectives?

BACKGROUND: In the last few years there seems to be an emerging interest for including the patients' perspective in assessing methadone maintenance treatment (MMT), with treatment satisfaction surveys being the most commonly-used method of incorporating this point of view. The present study considers the perspective of patients on MMT when assessing the outcomes of this treatment, acknowledging the validity of this approach as an indicator. The primary aim of this study is to evaluate the concordance between improvement assessment performed by two members of the clinical staff (a psychiatrist and a nurse) and assessment carried out by MMT patients themselves. METHOD: Patients (n = 110) and their respective psychiatrist (n = 5) and nurse (n = 1) completed a scale for assessing how the patient's condition had changed from the beginning of MMT, using the Patient Global Impression of Improvement scale (PGI-I) and the Clinical Global Impression of Improvement scale (CGI-I), respectively. RESULTS: The global improvement assessed by patients showed weak concordance with the assessments made by nurses (Quadratic-weighted kappa = 0.13, p > 0.05) and by psychiatrists (Quadratic-weighted kappa = 0.19, p = 0.0086), although in the latter, concordance was statistically significant. The percentage of improved patients was significantly higher in the case of the assessments made by patients, compared with those made by nurses (90.9% vs. 80%, Z-statistic = 2.10, p = 0.0354) and by psychiatrists (90.9% vs. 50%, Z-statistic = 6.48, p < 0.0001). CONCLUSIONS: MMT patients' perception of improvement shows low concordance with the clinical staff's perspective. Assessment of MMT effectiveness should also focus on patient's evaluation of the outcomes or changes achieved, thus including indicators based on the patient's experiences, provided that MMT aim is to be more patient centred and to cover different needs of patients themselves.

Psychometric data for the revised token test in normally developing Mexican children ages 4-12 years.

Language comprehension is vital to social and educational development but few pediatric tests are available for its assessment. To approach this problem, two versions of the Token Test (TT), "TT short form" (DeRenzi & Faglioni, 1978) and "Revised Token Test" (RTT), were first compared. Using a sample of 88 normally developing Spanish-speaking children, the tests were compared on their: (a) established psychometric development and (b) internal consistency. The RTT was judged to be superior and was selected for additional experimentation. The RTT was compared with a developmental measure of lexical knowledge on a cross-sectional sample of 250 4-12-year-old normally developing Spanish-speaking children. A significant positive and high correlation supports its concurrent validity. Significant differences across the age groups, along with a principal component analysis that yielded a three-factor structure, support its construct validity. Preliminary normative data across the nine age groups are provided.

Using mental tasks transitions detection to improve spontaneous mental activity classification.

This paper presents an algorithm based on canonical variates transformation (CVT) and distance based discriminant analysis (DBDA) combined with a mental tasks transitions detector (MTTD) to classify spontaneous mental activities in order to operate a brain-computer interface working under an asynchronous protocol. The algorithm won the BCI Competition III--Data Set V: Multiclass Problem, Continuous EEG--achieving an averaged classification accuracy over three subjects of 68.65% (79.60, 70.31 and 56.02%, respectively) in a three-class problem.

Multi-episode survival analysis: an application modelling readmission rates of heroin dependents at an inpatient detoxification unit.

The purpose of this study is to describe the characteristics of a statistical technique appropriate for analysing multi-episode data (multi-episode survival analysis), and to show its application in modelling the flow of readmissions at an inpatient detoxification unit. Data are from 784 opioid-dependent patients admitted at an inpatient detoxification unit, who totalled 1,255 admission episodes. Information stored prospectively at the unit database was reviewed for the following variables at the time of each patient discharge: episode serial number, sex, route of heroin administration, reason for discharge, time of discharge, and transition time (re-entry into the inpatient detoxification unit). Cox's semi-parametric regression model seems the most appropriate for describing the series of episodes. Amongst the parametric models, most noteworthy was the superior fit of the Gompertz-Makeham model, suggesting that the transition rate decreases monotonically with time. The influence of the variables assessed differed based on the serial number of the episode. The results suggest that multi-episode survival analysis is a statistical method that can fully address the long-term perspective on treatment utilization.