Categoría: Papers con abstracts

A commentary on ERP investigation of study-test back- ground mismatch during face recognition in schizophrenia by Guillaume et al. (2012). Schizophr. Res. 134, 101–109.

La interocepción como censado del estado homeostático y visceral, ha sido recientemente postulada como requisito para la conciencia de estados emocionales corporales (Craig, 2009). Vías parasimpáticas y espinotalámicas que codifican esta información corporal tienen relevo en la corteza insular. Simultáneamente, han sido descriptas otras funciones insulares implicadas en procesos conscientes, como la intencionalidad, la toma de decisiones, la conciencia sensorio-motora, la percepción temporal, reconocer la imagen visual de uno mismo o percibir confiables a otros individuos (Craig, 2009; Ibanez, Gleichgerrcht, & Manes, 2010). Esta evidencia, sumada a resultados de estudios de lesión y neuroimágenes funcionales, sugiere que la corteza insular anterior (IA) sería la encargada de integrar señales multimodales cognitivas, emocionales y sociales para dirigir las conductas motivacionales que entrañan la supervivencia del individuo. En esta revisión analizamos el cúmulo de evidencia que involucran a la interocepción y al procesamiento insular integrativo en el surgimiento de estados emocionales conscientes, a través de estudios de lesiones y de técnicas de conectividad funcional en resonancia magnética funcional (RMF).

Atrial fibrillation (AF) is the major cause of cardioembolic stroke. It often remains occult when asymptomatic and paroxysmal. We hypothesized that the detection of AF after acute ischemic stroke (AIS) or transient ischemic attack (TIA) could be improved by using continuous cardiac monitoring (CCM) immediately after admission. We sought to determine the detection rate of AF by immediate in-hospital CCM after cryptogenic and noncryptogenic AIS or TIA in patients without a previous diagnosis of AF. We retrospectively studied a cohort of 155 patients with cryptogenic and noncryptogenic AIS or TIA without known AF. We compared the detection rates of newly diagnosed AF (NDAF) in patients admitted to areas with CCM and those never admitted to these areas. We developed a multiple logistic regression model for identifying predictors of NDAF. We characterized NDAF episodes and analyzed how the availability of CCM data changed secondary prevention strategies. We detected NDAF in 21 patients (13.5%). Diagnostic rates of NDAF in patients who underwent CCM and those who did not undergo CCM were 18.2% and 2.2%, respectively (P = .005). The median time from admission to recognition of NDAF was 2.0 days. Most NDAFs were paroxysmal (95.2%) and lasted less than 1 hour (85.7%). Diabetes mellitus and infarct size were predictors of NDAF. Detection of NDAF prompted the initiation of anticoagulation therapy in 8.2% of the patients admitted to areas with CCM availability. Our findings suggest that immediate and prolonged CCM significantly improves the detection of NDAF after cryptogenic and noncryptogenic AIS or TIA, and that diabetes mellitus and infarct size are significantly associated with NDAF.

Several case reports have linked solvent exposure to Parkinson disease (PD), but few studies have assessed associations with specific agents using an analytic epidemiologic design. We tested the hypothesis that exposure to specific solvents is associated with PD risk using a discordant twin pair design. METHODS: Ninety-nine twin pairs discordant for PD ascertained from the National Academy of Sciences/National Research Council World War II Veteran Twins Cohort were interviewed regarding lifetime occupations and hobbies using detailed job task-specific questionnaires. Exposures to 6 specific solvents selected a priori were estimated by expert raters unaware of case status. RESULTS: Ever exposure to trichloroethylene (TCE) was associated with significantly increased risk of PD (odds ratio [OR], 6.1; 95% confidence interval [CI] 1.2-33; p = 0.034), and exposure to perchloroethylene (PERC) and carbon tetrachloride (CCl(4) ) tended toward significance (respectively: OR, 10.5; 95% CI, 0.97-113; p = 0.053; OR, 2.3; 95% CI, 0.9-6.1; p = 0.088). Results were similar for estimates of exposure duration and cumulative lifetime exposure. INTERPRETATION: Exposure to specific solvents may increase risk of PD. TCE is the most common organic contaminant in groundwater, and PERC and CCl(4) are also ubiquitous in the environment. Our findings require replication in other populations with well-characterized exposures, but the potential public health implications are substantial.

Several lines of experimental evidence support an association between facial processing and social cognition, but no direct link between cortical markers of facial processing and complex cognitive processes has been reported until now. In the current study, we tested the hypothesis that cortical electrophysiological markers for the processing of facial emotion are associated with individual differences in executive and social cognition skills. We tested for correlations between the amplitude of event-related potentials (N170) in a dual valence task and participants’ scores on three neuropsychological assessments (general neuropsychology, executive functioning, and social cognition). N170 was modulated by the stimulus type (face versus word) and the valence of faces (positive versus negative). The neural source of N170 was estimated to be the fusiform gyrus. Robust correlations were found between neuropsychological markers and measures of facial processing. Social cognition skills (as measured by three tests: the Reading the Mind in the Eyes test, the Faux Pas test, and the Iowa Gambling Task) correlated with cortical measures of emotional discrimination. Executive functioning ability also correlated with the cortical discrimination of complex emotional stimuli. Our findings suggest that the cortical processing of facial emotional expression is associated with social cognition skills.

The goal of this study is to assess the role of membership and valence effects on errors performed in a racial implicit association test indexed by event-related potentials (ERPs). Non-indigenous participants performed an implicit association test (IAT) paradigm emphasizing the feedback of error due to misclassification of ingroup (non-indigenous) and outgroup (indigenous) faces as well as positive and negative words. As expected, participants responded to the compatible task with higher accuracy than to incompatible tasks. This is the first report demonstrating that IAT errors produce electrophysiological ERP modulation. Our results suggest that medial frontal negativity is modulated not only by IAT error of membership and valence classifications but also by IAT compatible and incompatible tasks. These results provide a basis for the future use of the misclassification error in the IAT recorded simultaneously with ERPs in other classic social psychology contexts.

The lifespan of people with severe mental illness (SMI) is shorter compared to the general population. This excess mortality is mainly due to physical illness. We report prevalence rates of different physical illnesses as well as important individual lifestyle choices, side effects of psychotropic treatment and disparities in health care access, utilization and provision that contribute to these poor physical health outcomes. We searched MEDLINE (1966 – August 2010) combining the MeSH terms of schizophrenia, bipolar disorder and major depressive disorder with the different MeSH terms of general physical disease categories to select pertinent reviews and additional relevant studies through cross-referencing to identify prevalence figures and factors contributing to the excess morbidity and mortality rates. Nutritional and metabolic diseases, cardiovascular diseases, viral diseases, respiratory tract diseases, musculoskeletal diseases, sexual dysfunction, pregnancy complications, stomatognathic diseases, and possibly obesity-related cancers are, compared to the general population, more prevalent among people with SMI. It seems that lifestyle as well as treatment specific factors account for much of the increased risk for most of these physical diseases. Moreover, there is sufficient evidence that people with SMI are less likely to receive standard levels of care for most of these diseases. Lifestyle factors, relatively easy to measure, are barely considered for screening; baseline testing of numerous important physical parameters is insufficiently performed. Besides modifiable lifestyle factors and side effects of psychotropic medications, access to and quality of health care remains to be improved for individuals with SMI.

The major goal of evoked related potential studies arise in source localization techniques to identify the loci of neural activity that give rise to a particular voltage distribution measured on the surface of the scalp. In this paper we evaluate the effect of the head model adopted in order to estimate the N170 component source in attention deficit hyperactivity disorder (ADHD) patients and control subjects, considering faces and words stimuli. The standardized low resolution brain electromagnetic tomography algorithm (sLORETA) is used to compare between the three shell spherical head model and a fully realistic model based on the ICBM-152 atlas. We compare their variance on source estimation and analyze the impact on the N170 source localization. Results show that the often used three shell spherical model may lead to erroneous solutions, specially on ADHD patients, so its use is not recommended. Our results also suggest that N170 sources are mainly located in the right occipital fusiform gyrus for faces stimuli and in the left occipital fusiform gyrus for words stimuli, for both control subjects and ADHD patients. We also found a notable decrease on the N170 estimated source amplitude on ADHD patients, resulting in a plausible marker of the disease.

The present study compares the occurrence of depressive symptoms evaluated by the Calgary Depression Scale for Schizophrenia (CDSS) in patients of Multiplex (MS) and Simplex Schizophrenia families (SS). The Positive and Negative Syndrome Scale (PANSS) was used to evaluate psychopathology. A total of 206 paranoid schizophrenia patients were studied according DSM-IV criteria. The Family Interview for Genetic Studies (FIGS) was used to study the families. A result in the FIGS for a positive family history of schizophrenia was referred as MS (patients); its lack as SS (patients). CDSS scores were compared among MS and SS patients and possible sex differences intra- and inter-groups were explored. In the analysis of our sample (30) 19% of the total persons with schizophrenia group was depressed. The depressive symptoms measured by the CDSS were higher in females and the MS males group. Males from MS group showed more depressive symptoms than males from SS group. No differences with females from both groups were found. Findings in this study underscore the importance of gender and family history in understanding the heterogeneity of schizophrenia. This study suggests that sex and familiar history are important to consider in studying depressive symptoms.

The present study is the first to investigate the relationship between vagal tone level and event-related potentials (ERPs) in adults. Numerous studies have shown a relationship between vagal tone and the individual differences between a variety of psychophysiological, affective, and social outcomes. This suggests that vagal tone can be related to how people process relevant affective social information at the brain level. This study aimed to assess whether the ERP response varies between high and low vagal tone groups, in the face of salient affective information. In the experimental cohort, two groups were separated according to their vagal tone level. ERPs were recorded while individuals performed an affective picture task that included positive, neutral, and negative emotional stimuli. Differences between the high and low vagal tone groups were observed at the early posterior negativity for both positive and negative valences, and at the late positive potential for all the categories. It can be concluded that differences between high and low vagal tone levels are related to differences in the ERPs at early, middle, and late latencies. The results are discussed with respect to the effect of differences between the vagal tone conditions on various stages of information-processing.