Joan Guàrdia

Neuropsychological long-term sequelae of perinatal asphyxia

Objective : To investigate the long-term neuropsychological consequences of perinatal asphyxia (PA). Methods : A group of adolescents were assessed with antecedents of mild ( n = 8) and moderate ( n = 20) PA, and a matched group of 28 healthy adolescents as a control group. Neuropsychological assessment included tests of memory, perceptual-motor skills, and frontal lobe functions, because these are areas of cognitive functioning susceptible to hypoxic conditions. Results : Subjects with moderate PA showed significant differences from the control group on tests related to delayed recall for both verbal and visual information, perceptual-motor speed, and tests assessing attention and executive functions. Conversely, subjects in the mild PA group exhibited scores which were similar to those of the control group in all the assessed variables. Conclusion : The present findings demonstrate that subtle but persistent neuropsychological deficits were observed in adolescents with antecedents of moderate PA, but not in those classified with mild asphyxia.

MRI and genetic correlates of cognitive function in elders with memory impairment

The present study investigated the relationship between genetic variation, MRI measurements and neuropsychological function in a sample of 58 elders exhibiting memory decline. In agreement with previous reports, we found that the epsilon4 allele of the apolipoprotein E (APOE) and the D allele of the angiotensin converting enzyme (ACE) polymorphisms negatively modulated the cognitive performance. Further, we found an association between the A allele of the apolipoprotein C1 (APOC1) polymorphism and poorer memory and frontal lobe function. No clear associations emerged between MRI measures of white matter lesions (WML) or hippocampal sulcal cavities (HSC) and the cognitive performance after controlling for age effects. Further, the degree of WML or HSC lesions was in general not predisposed genetically except for the presence of the A allele of the APOC1 polymorphism that was related to a higher severity of HSC scores. Our results suggest that WML or HSC do not represent important brain correlates of genetic influences on cognitive performance in memory impaired subjects.

Feature Extraction for Multi-class BCI using Canonical Variates Analysis

To propose a new feature extraction method with canonical solution for multi-class brain-computer interfaces (BCI). The proposed method should provide a reduced number of canonical discriminant spatial patterns (CDSP) and rank the channels sorted by power discriminability (DP) between classes. The feature extractor relays in canonical variates analysis (CVA) which provides the CDSP between the classes. The number of CDSP is equal to the number of classes minus one. We analyze EEG data recorded with 64 electrodes from 4 subjects recorded in 20 sessions. They were asked to execute twice in each session three different mental tasks (left hand imagination movement, rest, and words association) during 7 seconds. A ranking of electrodes sorted by power discriminability between classes and the CDSP were computed. After splitting data in training and test sets, we compared the classification accuracy achieved by linear discriminant analysis (LDA) in frequency and temporal domains. The average LDA classification accuracies over the four subjects using CVA on both domains are equivalent (57.89% in frequency domain and 59.43% in temporal domain). These results, in terms of classification accuracies, are also reflected in the similarity between the ranking of relevant channels in both domains. CVA is a simple feature extractor with canonical solution useful for multi-class BCI applications that can work on temporal or frequency domain.

URBAN SOCIAL IDENTITY AND SUSTAINABILITY BARCELONA’S OLYMPIC VILLAGE

One of the most recent fields of investigation in environmental psychology focuses on the relationship between human behavior and management of environmental resources, aspects related to what is known today as sustainable human development. For the authors, this kind of behavior is linked to the relation that people establish with particular environments, specifically, the processes of socioenvironmental identity that condition the people-environment relationship. The authors present the results of a study conducted in the Olympic Village of Barcelona. The urban social identity of residents was analyzed, focusing on three main factors: identification-satisfaction, image of the neighborhood, and perceived social homogeneity. These three factors were analyzed in relation to a series of items in the initial questionnaire referring to proenvironmental behavior, representation of particular natural resources, and environmental attitudes. The authors expected the answers to these questions would differ significantly according to the degree of identification of residents with their neighborhood.

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, Continous 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.

1H-MR spectroscopy is sensitive to subtle effects of perinatal asphyxia

The authors performed neuropsychological and 1H-MRS studies in 18 subclinical patients with antecedents of perinatal asphyxia (PA) and in 18 matched control subjects. Patients with PA showed reduced values of N-acetylaspartate (NAA) in both the basal ganglia and the midtemporal region (MTR) and reduced NAA/choline values in the MTR. Neuropsychological testing showed group differences in tasks related to attention and memory. These results indicate persistent dysfunctions in cerebral structures vulnerable to hypoxia and demonstrate the utility of MRS for the long-term evaluation of cerebral sequelae of neonatal asphyxia.

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.

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.

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. Practitioner points Internal conflicts have been postulated in clinical psychology for a long time but there is little evidence about its relevance due to the lack of methods to measure them. We developed a method for identifying conflicts using the Repertory Grid Technique. Depressive patients have higher presence and number of conflicts than controls. Conflicts (implicative dilemmas) can be a new target for intervention in depression. Cautions/Limitations A cross-sectional design precluded causal conclusions. The role of implicative dilemmas in the causation or maintenance of depression cannot be ascertained from this study.

A Critical Study of Theoretical Models of Sustainability through Structural Equation Systems

This article presents the results of a comparative analysis of three models: the identification model (IM), the cohesion model (CM), and the general model (GM) proposed by the City-Identity-Sustainability (CIS) Network. These models have been designed for the description of sustainability and all try to explain its relationship with identity and urban development using structural equations. The analyzed items were selected from a longer questionnaire as part of the general CIS Network study. Ten samples from different origins were obtained, with a total of 1, 421 participants. To test the models to the concept of sustainability, the parameters are presented in a comparative way. The indicators show a moderate fit. The IM presents a better fit in samples with high levels of urban development, whereas the CM shows a better fit in samples with less developed areas. The best general fit is in the GM model for all the samples.