Categoría: Papers con abstracts

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.

The reported prevalence of asymptomatic atherosclerotic disease of the extracranial internal carotid artery is up to 12.5%. Carotid angioplasty has not yet proven safe and effective enough to prevent ischemic stroke in these patients. Randomized studies showed that carotid endarterectomy is superior to medical therapy in reducing the risk of ischemic stroke when performed by surgical teams with complication rates (stroke or death) of less than 3%. However, recruitment of these patients began more than 25 years ago, when the use of antiplatelet agents was lower than today, the treatment of hypertension was less effective than currently, and statins were not considered as key components of vascular prevention strategies. Optimizing the quality of medical treatment in recent decades has led to a significant reduction in stroke risk in patients not undergoing surgery. Based on these observations and with the exception of specific cases, medical therapy is the treatment of choice for patients with asymptomatic atherosclerotic disease of the extracranial carotid arteries.

BACKGROUND: The Addenbrooke’s Cognitive Examination Revised (ACE-R) is an improved version of the earlier brief screening test which has been validated in English with high sensitivity and specificity to detect cognitive dysfunction. The aim of this study was to validate the Spanish version of the ACE-R in an Argentine population. METHODS: A group of patients with Alzheimer Disease (AD) and patients with behavioural variant Frontotemporal Dementia (bvFTD) paired by age, sex, and years of education with healthy controls were assessed using the ACE-R. Stage of dementia was measured with the Clinical Dementia Rating Scale (CDR). The English version of the ACE-R was first translated into Spanish and then back-translated into English by two blind independent experts. RESULTS: Internal reliability was very good (Cronbach’s alpha=0.89). Concurrent validity, determined by the correlation between total ACE-R and CDR was significant (P<.001) and inter-rater reliability was excellent (Cohen's kappa=0.98). Controls significantly outperformed AD and bvFTD patients on most subdomains of the ACE-R, with significant differences between the dementia groups. With a cut-off score of 85 points, sensitivity was 97.5% and specificity was 88.5%, with a likelihood ratio of 99.3 for the detection of dementia. The ACE-R showed higher sensitivity than the MMSE for the detection of dementia. CONCLUSIONS: The Spanish version of the ACE-R is a brief yet reliable screening tool for the detection of early cognitive impairment and has shown to discriminate between bvFTD and AD.

BACKGROUND: The behavioral variant of frontotemporal dementia (bvFTD) is characterized by progressive changes in personality and social interaction, loss of empathy, disinhibition and impulsivity, most of which generally precede the onset of cognitive deficits. In this study, we investigated decision-making cognition in a group of patients with an early bvFTD diagnosis whose standard neuropsychological performance was within normal range for all variables. METHODS: The Iowa Gambling Task was administered to this group of early bvFTD patients, to a group of early bvFTD patients who had shown impaired performance on the classical neuropsychological battery and to healthy controls. RESULTS: Decision-making was impaired in both bvFTD patient groups, whether they had shown impaired or normal performance in the classical neuropsychological evaluation. CONCLUSIONS: Patients with early bvFTD may perform normally on standard cognitive tests, and yet develop severe deficits in judgment and decision-making. In many current legal systems, early bvFTD patients showing preserved cognitive functioning who commit unlawful acts run the risk of not being able to plead insane or not guilty on the grounds of diminished responsibility beyond reasonable doubt. This represents a unique legal and ethical dilemma. Our findings have important implications for medicolegal decisions relating to capacity and culpability, and regarding the philosophical concept of ‘free will’.

Based on the recent literature and collective experience, an international consortium developed revised guidelines for the diagnosis of behavioural variant frontotemporal dementia. The validation process retrospectively reviewed clinical records and compared the sensitivity of proposed and earlier criteria in a multi-site sample of patients with pathologically verified frontotemporal lobar degeneration. According to the revised criteria, ‘possible’ behavioural variant frontotemporal dementia requires three of six clinically discriminating features (disinhibition, apathy/inertia, loss of sympathy/empathy, perseverative/compulsive behaviours, hyperorality and dysexecutive neuropsychological profile). ‘Probable’ behavioural variant frontotemporal dementia adds functional disability and characteristic neuroimaging, while behavioural variant frontotemporal dementia ‘with definite frontotemporal lobar degeneration’ requires histopathological confirmation or a pathogenic mutation. Sixteen brain banks contributed cases meeting histopathological criteria for frontotemporal lobar degeneration and a clinical diagnosis of behavioural variant frontotemporal dementia, Alzheimer’s disease, dementia with Lewy bodies or vascular dementia at presentation. Cases with predominant primary progressive aphasia or extra-pyramidal syndromes were excluded. In these autopsy-confirmed cases, an experienced neurologist or psychiatrist ascertained clinical features necessary for making a diagnosis according to previous and proposed criteria at presentation. Of 137 cases where features were available for both proposed and previously established criteria, 118 (86%) met ‘possible’ criteria, and 104 (76%) met criteria for ‘probable’ behavioural variant frontotemporal dementia. In contrast, 72 cases (53%) met previously established criteria for the syndrome (P < 0.001 for comparison with 'possible' and 'probable' criteria). Patients who failed to meet revised criteria were significantly older and most had atypical presentations with marked memory impairment. In conclusion, the revised criteria for behavioural variant frontotemporal dementia improve diagnostic accuracy compared with previously established criteria in a sample with known frontotemporal lobar degeneration. Greater sensitivity of the proposed criteria may reflect the optimized diagnostic features, less restrictive exclusion features and a flexible structure that accommodates different initial clinical presentations. Future studies will be needed to establish the reliability and specificity of these revised diagnostic guidelines.

Current research on empathy for pain emphasizes the overlap in the neural response between the first-hand experience of pain and its perception in others. However, recent studies suggest that the perception of the pain of others may reflect the processing of a threat or negative arousal rather than an automatic pro-social response. It can thus be suggested that pain processing of other-related, but not self-related, information could imply danger rather than empathy, due to the possible threat represented in the expressions of others (especially if associated with pain stimuli). To test this hypothesis, two experiments considering subliminal stimuli were designed. In Experiment 1, neutral and semantic pain expressions previously primed with own or other faces were presented to participants. When other-face priming was used, only the detection of semantic pain expressions was facilitated. In Experiment 2, pictures with pain and neutral scenarios previously used in ERP and fMRI research were used in a categorization task. Those pictures were primed with own or other faces following the same procedure as in Experiment 1 while ERPs were recorded. Early (N1) and late (P3) cortical responses between pain and no-pain were modulated only in the other-face priming condition. These results support the threat value of pain hypothesis and suggest the necessity for the inclusion of own- versus other-related information in future empathy for pain research.