Analysis Of Cognitive Data Research Articles

Abstract #1: Cognitive Function Data in Newly Diagnosed AED-Naïve Epilepsy Patients Across a Broad Age Range

Introduction Recent initiatives have resulted in guidelines for the assessment of cognitive function in specific clinical populations including the MATRICS consensus cognitive test battery for schizophrenia and the EMEA guideline on medicinal products for the treatment of Alzheimer s disease and other dementias. There are a number of common criteria that emerge, including assessment of cognition at the level of individual cognitive domains; validation; utility; utility as a repeated measure; and data allowing interpretation of results and understanding of the clinical relevance (i.e., normative/relationship to functional outcomes). It is apparent that such common criteria could usefully be applied to cognitive function assessment in all clinical populations. The publication of normative data is of use in the interpretation of clinical trials data. Methods Five-hundred and seventy (570) patients with newly diagnosed epilepsy, aged 12–75 years, from 21 countries within Europe, Latin America, and Australasia, not previously exposed to AEDs, were recruited to a clinical trial comparing the efficacy and safety of remacemide versus carbamazepine. Patients completed a 30 minute cognitive test battery comprised of the CDR System; Rey auditory verbal learning test; color-word Stroop test; symbol digit modalities test; Lafayette grooved pegboard; digit cancellation test; and the non-verbal matrices subtest of the Kaufman brief intelligence test. Normative data in treatment-naive patients across the studied age range were generated. Results Assessments showed a common relationship with age, with those patients in the younger adult age cohorts tending to perform better on all measures than older patients and also than the youngest age cohort patients. Conclusions These data may be useful in the analysis and interpretation of cognitive assessment data from clinical trials of AEDs and/or studies in similar patient populations. Financial disclosure This study was sponsored by AstraZeneca. None of the authors has a financial relationship with the sponsor.

Cognitive technologies in adaptive models of complex plants

Abstract The paper deals with various aspects of the construction and application of surrogate models in CAD systems, outlines basic data analysis and simulation tasks essential for surrogate model construction, reviews the current state of the art and proposes innovative approaches based on cognitive data analysis and simulation technologies.

Protocolo para Observação do Desenvolvimento Cognitivo e de Linguagem Expressiva - versão revisada (PODCLE-r): proposta de complementação

OBJETIVO: Proposição de complementação do Protocolo para Observação do Desenvolvimento Cognitivo e de Linguagem Expressiva (PODCLE), a partir da inclusão de dois quadros que permitem a análise da diversidade das realizações e produções apresentadas pela criança e um quadro com a síntese das produções relacionadas à linguagem expressiva, organizadas em conjuntos. MÉTODOS: Para a formalização de tal complementação, foram selecionados os indicadores mais significativos em relação ao desenvolvimento cognitivo e de linguagem expressiva, para os quais havia possibilidade de respostas diversificadas. Foi então desenvolvida uma escala de valores e pesos, de acordo com a complexidade das realizações e produções observadas em crianças. O Protocolo, em sua versão revisada, foi aplicado em diferentes populações para verificação de sua viabilidade e levantamento de possíveis dúvidas ou dificuldades durante sua aplicação ou análise dos dados. Juízes foram utilizados tanto para a seleção dos indicadores de desenvolvimento, quanto para a análise dos dados. RESULTADOS: O Protocolo para Observação do Desenvolvimento Cognitivo e de Linguagem Expressiva - versão revisada (PODCLE-r) é composto por sete quadros, contendo os indicadores de desenvolvimento cognitivo e de linguagem expressiva durante o período sensório-motor e início do pré-operatório, que permitem a realização de duas formas de análise: macro e micro. CONCLUSÃO: O PODCLE-r permite ao examinador aprofundar seu olhar quanto ao desenvolvimento cognitivo e de linguagem expressiva da criança, considerando não apenas a presença ou ausência de determinado indicador, mas também a qualidade e diversidade de suas realizações e produções.

Improved EEG source analysis using low‐resolution conductivity estimation in a four‐compartment finite element head model

Bioelectric source analysis in the human brain from scalp electroencephalography (EEG) signals is sensitive to geometry and conductivity properties of the different head tissues. We propose a low-resolution conductivity estimation (LRCE) method using simulated annealing optimization on high-resolution finite element models that individually optimizes a realistically shaped four-layer volume conductor with regard to the brain and skull compartment conductivities. As input data, the method needs T1- and PD-weighted magnetic resonance images for an improved modeling of the skull and the cerebrospinal fluid compartment and evoked potential data with high signal-to-noise ratio (SNR). Our simulation studies showed that for EEG data with realistic SNR, the LRCE method was able to simultaneously reconstruct both the brain and the skull conductivity together with the underlying dipole source and provided an improved source analysis result. We have also demonstrated the feasibility and applicability of the new method to simultaneously estimate brain and skull conductivity and a somatosensory source from measured tactile somatosensory-evoked potentials of a human subject. Our results show the viability of an approach that computes its own conductivity values and thus reduces the dependence on assigning values from the literature and likely produces a more robust estimate of current sources. Using the LRCE method, the individually optimized four-compartment volume conductor model can, in a second step, be used for the analysis of clinical or cognitive data acquired from the same subject.

INFLUENCE OF INDIVIDUAL DIFFERENCES ON THE GROWTH OF LEADERSHIP EFFICACY OVER TIME.

The connections between intelligence, personality, leadership efficacy, and leadership behaviors were explored using Bandura's (1997) framework of social cognitive theory and longitudinal data analysis with random coefficient modeling (Bliese & Ployhart, 2002). Findings indicated that personal leadership efficacy beliefs were positively related to others' assessments of leadership behaviors. Also, leadership efficacy changed within individuals in a meaningful way over time; intelligence and extraversion were significant predictors of individuals' initial leadership efficacy estimates; and emotional stability was a significant predictor of the change in leadership efficacy over time (i.e., slope).

Multi‐state analysis of cognitive ability data: A piecewise‐constant model and a Weibull model

Longitudinal data can be used to estimate transition intensities between healthy and unhealthy states prior to death. When health is defined with respect to cognitive ability during old age, the trajectory of performance is either static or downward. An illness-death model is presented where the intensity of a transition is allowed to change over time by using a piecewise-constant model or by using a Weibull model. Observed improvement of cognitive ability is modelled as misclassification. The methodology is extended to estimate life expectancy with and without cognitive impairment. The measurement of cognitive ability is important as it is an important predictor of future need for care. The models can help to understand how cognitive decline develops over time and which factors play a role. The methods are illustrated using data from the Medical Research Council Cognitive Function and Ageing Study in the U.K. (1991-2005).

Item response theory facilitated cocalibrating cognitive tests and reduced bias in estimated rates of decline

Objective To cocalibrate the Mini-Mental State Examination, the Modified Mini-Mental State, the Cognitive Abilities Screening Instrument, and the Community Screening Instrument for Dementia using item response theory (IRT) to compare screening cut points used to identify cases of dementia from different studies, to compare measurement properties of the tests, and to explore the implications of these measurement properties on longitudinal studies of cognitive functioning over time. Study Design and Setting We used cross-sectional data from three large ( n > 1000) community-based studies of cognitive functioning in the elderly. We used IRT to cocalibrate the scales and performed simulations of longitudinal studies. Results Screening cut points varied quite widely across studies. The four tests have curvilinear scaling and varied levels of measurement precision, with more measurement error at higher levels of cognitive functioning. In longitudinal simulations, IRT scores always performed better than standard scoring, whereas a strategy to account for varying measurement precision had mixed results. Conclusion Cocalibration allows direct comparison of cognitive functioning in studies using any of these four tests. Standard scoring appears to be a poor choice for analysis of longitudinal cognitive testing data. More research is needed into the implications of varying levels of measurement precision.

Analysis of cognitive performance in schizophrenia patients and healthy individuals with unsupervised clustering models

Currently, assignment of cognitive test results to particular cognitive domains is guided by theoretical considerations and expert judgments which may vary. More objective means of classification may advance understanding of the relationships between test performance and the cognitive functions probed. We examined whether “atheoretical” analyses of cognitive test data can help identify potential hidden structures in cognitive performance. Novel data-mining methods which “let the data talk” without a priori theoretically bound constraints were used to analyze neuropsychological test results of 75 schizophrenia patients and 57 healthy individuals. The analyses were performed on the combined sample to maximize the “atheoretical” approach and allow it to reveal different structures of cognition in patients and controls. Analyses used unsupervised clustering methods, including hierarchical clustering, self-organizing maps (SOM), k-means and supermagnetic clustering (SPC). The model revealed two major clusters containing accuracy and reaction time measures respectively. The sensitivity (75% versus 52%) and specificity (95% versus 77% ) of these clusters for diagnosing schizophrenia differed. Downstream branching was influenced by stimulus domain. Predictions arising from this “atheoretical” model are supported by evidence from published studies. This preliminary study suggests that appropriate application of data-mining methods may contribute to investigation of cognitive functions.

Low resolution conductivity estimation to improve source localization

Bioelectric source localization in the brain is sensitive to geometry and conductivity properties of the different head tissues. We propose a method that individually optimizes a realistically-shaped volume conductor with regard to the conductivities using a simulated annealing optimizer in discrete parameter space. We show that the method is able to simultaneously reconstruct two reference sources and a reference skull:brain conductivity ratio even in the presence of realistic noise. The individually optimized head model can then be used for the analysis of clinical or cognitive data.

Translation And Cultural Adaptation Of A Mental Health Outcome Measure: The Basis-R©

Culturally and linguistically appropriate outcome measures are needed to address the needs of Latino consumers of mental health services. The revised Behavior and Symptom Identification Scale (BASIS-R(c)) is an English-language consumer self-report measure designed to assess outcome of behavioral health or substance abuse treatment. This study sought to develop a culturally and linguistically appropriate version of the BASIS-R(c) for Spanish-speaking Latinos. To achieve this goal, the English instrument was translated and adapted into Spanish by an international bilingual committee and tested in four focus groups and 45 cognitive interviews with Puerto Ricans, Dominicans, and Mexicans living in the United States and Puerto Rico. Focus groups and cognitive interviews provided qualitative and quantitative information about the instrument's content and format, and respondents' understanding of the instructions, questionnaire items, time frame, and response options. Respondents' ratings of the clarity and importance of each item were also obtained. Analyses of focus group and cognitive interview data identified items that were confusing or difficult for participants. Findings suggest that the Spanish version of the BASIS-R(c) incorporated the cultural diversity of the three groups of Latinos in this study without compromising the validity of the English version of the BASIS.

Risperidone in the Management of Disruptive Behavior Disorders

Disruptive behavior disorders (DBDs) represent a spectrum of disorders, including conduct disorder and oppositional-defiant disorder. The atypical antipsychotic risperidone may be useful for the management of patients with DBDs. Clinical data on risperidone have demonstrated efficacy and satisfactory tolerability in improving angry, aggressive, self-injurious, and disruptive symptoms and behavior in children with pervasive developmental disorders and mood disorders. This paper reviews the results of recent studies that have evaluated the efficacy and safety of risperidone in the treatment of pediatric patients with DBDs. Because concerns have been raised regarding the safety of atypical antipsychotic treatment in pediatric patients, this paper further evaluates safety risks by presenting newly completed analyses of movement disorders, prolactin concentrations, body weight, and cognitive function data from short- and long-term studies in this patient population. A comprehensive review of all of the findings suggests that risperidone is an effective and well-tolerated treatment option for children and adolescents with DBDs. As with all antipsychotics, practitioners should monitor young patients' growth, weight, sexual maturation, and metabolic parameters.

Trauma-related deficits in working memory

Introduction. The aim of the study was to evaluate trauma-related impairments of working memory in psychiatric outpatients, and the mediating role of processing speed, anxiety and depression in the cognitive decrements. Methods. This research applied a comprehensive assessment protocol including an evaluation of psychopathological and neuropsychological functioning in psychiatric outpatients. Patients with trauma history (n = 33) were compared to patients without such a history (n = 30). We collected information regarding age, gender, culture level, profession level, alcohol abuse, anxiety, and depression symptoms. Working memory and speed processing were assessed with standardised neuropsychological instruments. Data analysis was accomplished using parametric statistics, and a hierarchical multiple regression model was used to regress working memory performance scores against the trauma variable, anxiety-depression scores, and speed processing. Results. The groups differed by gender, not by age, education level, socioeconomic status and alcohol abuse. Analysis of cognitive data revealed specific trauma-related deficits in working memory. Moreover, the trauma-exposed subjects scored higher on anxiety/depression scales, and lower on processing speed tests. The regression revealed significant impairment in working memory partially mediated by speed processing, but not by anxiety or depression. Conclusions. These findings confirmed the trauma-related impairments in working memory and the paramount importance for these impairments of reduced processing speed rather than emotional factors.

Spatial representation and low vision: Two studies on the content, accuracy and utility of mental representations

The paper reports on two studies being conducted with students from Dorton College-Royal London Society for the Blind (RLSB) in Kent. The first experiment will examine the content and accuracy of mental representations of a well-known environment. Students will walk a route around the college campus and learn the position of 10 buildings or structures. They will then be asked to make heading judgments, estimate distances, complete a spatial cued model and sequentially visit a series of locations. The second experiment will examine the strategies and coding heuristics used to explore a complex novel environment. Students will be asked to explore a maze and learn the location of different places. Their search patterns will be digitally tracked, coded and analyzed using GIS software. Students will be tested using the same methods as in the first experiment and their performance level will be correlated with their exploratory patterns. Throughout the paper we are reminded that construct validity can only be secured by employing multiple converging techniques in the collection and analysis of cognitive data. Methods should be designed to test content and accuracy as well as the utility of mental representations.

"MultiPlot": A Graphical Tool to Enhance Cognitive Clinical Data Analysis

"MultiPlot": A Graphical Tool to Enhance Cognitive Clinical Data Analysis

Molarity not modularity: Multivariate genetic analysis of specific cognitive abilities in parents and their 16-year-old children in the colorado adoption project

Previous multivariate genetic analyses suggest substantial genetic overlap among specific cognitive abilities, that is, molarity rather than modularity. We report the first multivariate genetic analysis of specific cognitive ability data from the Colorado Adoption Project when the 16-year-old offspring were administered the same test battery as their parents. The sample included 129 adoptees, sets of adoptive parents, and biological mothers, 24 biological fathers, and 125 nonadopted individuals and their parents. The average phenotypic correlation among verbal, spatial, and perceptual speed is .48, 76% of which is due to genetic influences on average; memory shows lower correlations with these abilities (.27 on average), about half of which are due to genes. These results support the genetic molarity hypothesis: (1) genetic effects on these specific cognitive abilities largely overlap, suggesting a common genetic factor of general cognition; and (2) genetic effects are largely responsible for the phenotypic correlations among these traits.

The Effects of Spatial and Locational Cueing on the Analysis of Aggregate Cognitive Mapping Data

The authors explore the effects of spatial and locational cueing upon the aggregated results of cognitive mapping data. Using four experimental data sets they demonstrate that locational cueing introduces random error into the analysis and that spatial cueing increases the relative and absolute accuracy of spatial products (external representations of spatial knowledge). These effects are consistent regardless of whether individual or place cognition is assessed. As such, location and spatial cueing compromise both construct and convergent validity, and the integrity of the conclusions from previous studies on cognitive mapping are brought into question. It is suggested that a multidata collection, multidata analysis approach should be adopted to highlight and compensate for these methodological weaknesses.

Multivariate path analysis of specific cognitive abilities data at 12 years of age in the Colorado Adoption Project.

A parent-offspring multivariate conditional path model was fitted to specific cognitive abilities data from the Colorado Adoption Project (CAP) when the offspring were 12 years of age. The sample included 175 adoptees, 175 sets of adoptive parents, 175 biological mothers, 34 biological fathers, and 209 nonadopted children and their parents. Consistent with results obtained from multivariate genetic analyses of CAP data obtained at earlier ages, the effects of familial environmental transmission on individual differences in specific cognitive abilities were not significant. Assuming complete isomorphism (i.e., that the genetic and environmental etiologies of individual differences are the same) between the child and the adult measures, the heritability estimates for verbal, spatial, perceptual speed, and visual memory were .26, .35, .38, and .53, respectively. Although the heritability estimate for visual memory is somewhat higher than those for verbal, spatial, and perceptual speed abilities, these estimates are not significantly different. These estimates are higher than those obtained when the adoptees and controls were 4 years old (Rice et al., 1986, 1989); thus, heritabilities of specific cognitive abilities may increase as a function of cognitive development. Alternatively, genetic stability from childhood to adulthood may be greater from 12 years than from 4 years, which would be interpreted as greater heritability by the CAP parent-offspring design. The genetic correlations among the four measures were substantial, ranging from .27 between verbal and spatial abilities to .78 between spatial ability and perceptual speed. However, differences among these correlations are not significant, suggesting that their covariation may be due to general cognitive ability. Finally, estimates of bivariate-heritability indicate that on average about half of the phenotypic correlations among the four specific cognitive ability measures are due to genetic effects.

On the validity of simulating stagewise development by means of PDP networks: Application of catastrophe analysis and an experimental test of rule-like network performance

This article addresses the ability of Parallel Distributed Processing (PDP) networks to generate stagewise cognitive development in accordance with Piaget's theory of cognitive epigenesis. We carried out a replication study of the simulation experiments by McClelland (1989) and McClelland and Jenkins (1991) in which a PDP network learns to solve balance scale problems. In objective tests motivated from catastrophe theory, a mathematical theory of transitions in epigenetical systems, no evidence for stage transitions in network performance was found. It is concluded that PDP networks lack the ability to recover the positive outcomes of analogous catastrophe analyses of real cognitive developmental data. In an attempt to further characterize the learning behaviour of PDP networks, we carried out a second simulation study using the discrimination-shift paradigm. The results thus obtained indicate that PDP learning is compatible with the learning of stimulus-response relationships, not with the acquisition of mediating rules such as conceived in (neo-)Piagetian theory. In closing, we speculate about the feasibility of simulating stagewise development with alternative network architectures.

On the Validity of Simulating Stagewise Development by Means of PDP Networks: Application of Catastrophe Analysis and an Experimental Test of Rule‐Like Network Performance

This article addresses the ability of Parallel Distributed Processing (PDP) networks to generate stagewise cognitive development in accordance with Piaget's theory of cognitive epigenesis. We carried out a replication study of the simulation experiments by McClelland (1989) and McClelland and Jenkins (1991) in which a PDP network learns to solve balance scale problems. In objective tests motivated from catastrophe theory, a mathematical theory of transitions in epigenetical systems, no evidence for stage transitions in network performance was found. It is concluded that PDP networks lack the ability to recover the positive outcomes of analogous catastrophe analyses of real cognitive developmental data. In an attempt to further characterize the learning behaviour of PDP networks, we carried out a second simulation study using the discrimination‐shift paradigm. The results thus obtained indicate that PDP learning is compatible with the learning of stimulus‐response relationships, not with the acquisition of mediating rules such as conceived in (neo‐)Piagetian theory. In closing, we speculate about the feasibility of simulating stagewise development with alternative network architectures.

An exploration of genetic g: Hierarchical factor analysis of cognitive data from the western reserve twin project

Hierarchical factor analyses involving Schmid-Leiman transformations (Schmid & Leiman, 1957) were conducted on specific cognitive abilities data collected in a sample of 148 identical (MZ) and 135 same-sex fraternal (DZ) twin pairs. Two main questions were addressed: First, are genetic influences on specific cognitive abilities simply a reflection of their g loading, or are different sets of genes affecting separate abilities? Second, to the extent that specific cognitive abilities are affected by common genetic variance, how similar is the common genetic factor to a phenotypic factor reflecting g? Model fitting results suggest that genetic influences on specific abilities are a reflection of both general intelligence and genetic influences specific to separate abilities and that loadings on the common genetic factor are more highly correlated with phenotypic g loadings than are common environmental factor loadings.