Categoría: Papers con abstracts

Previous research on semantic dementia (SD) has demonstrated a link between conceptual representations and ability on a range of ´non-semantic´ tasks, both verbal and nonverbal. In all cases, SD patients perform well on items that conform to the underlying statistical ´surface´ structure of the domain in question but poor performance on items that are atypical with respect to these statistics. For such items, there is a strong tendency for the patients´ erroneous responses to reflect the more typical pattern. To date, most research on this topic has been conducted with English-speaking patients, and where extended to non-English languages, directly comparable aspects of each language have been probed. In this study we tested the generalisation of this theory by probing performance on an aspect of Spanish with no analogue in English (grammatical gender). As predicted, Spanish SD patients provided the correct gender to high frequency words or where the phonology of the noun strongly predicted the gender. For low frequency, atypical nouns, however, the patients made many more errors (preferring the statistically typical gender). As expected, performance on nouns with atypical grammatical gender was strongly correlated with the degree of semantic impairment across the case-series of SD patients.

The results not only provide another example of the critical relationship between semantic memory and ´non-semantic´ cognition, but also indicate that this theoretical framework generalises to novel aspects of non-English languages – suggesting that the phenomenon is based on brain-general mechanisms.

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.

BACKGROUND: Information regarding predisposing factors, frequency, and prognostic implications of new onset atrial fibrillation (NOAF) after carotid endarterectomy (CEA) is scarce. We assessed the frequency, risk factors, and the prognostic impact of NOAF after CEA. METHODS: We assessed every patient undergoing CEA (n = 186) at our academic hospital between 2006 and 2009. Patients underwent continuous electrocardiographic monitoring during surgery and during the rest of hospital stay. We performed univariate and multivariate analyses for identifying variables associated with NOAF and for individualizing variables related to four perioperative adverse outcome measures: a) ischemic stroke; b) ischemic stroke and myocardial infarction, c) ischemic stroke and death, and d) ischemic stroke, myocardial infarction, and death. RESULTS: The study cohort comprised 186 patients. Overall, NOAF was detected in 7 cases (3.8%). The only variable associated with NOAF was intraoperative hypotension (OR 9.6, 95% CI 1.9-47.4, P = .006). There were no perioperative deaths. NOAF was associated with perioperative ischemic stroke and with the combined outcome of ischemic stroke and myocardial infarction. CONCLUSIONS: We found a low frequency of NOAF after CEA. Intraoperative hypotension was associated to a higher risk of NOAF. In turn, NOAF was related to adverse postoperative outcome. Further research is needed to clarify the pathophysiological relation between intraoperative hypotension, NOAF, and adverse CEA outcome.

Language, memory and the temporal lobes. Autores Manes F, Gleichgerrcht E.  Año 2011 Journal  Manes F, Gleichgerrcht E.  Volumen 24(4): 263-264 Abstract   Otra información    

BACKGROUND: Integration of compatible or incompatible emotional valence and semantic information is an essential aspect of complex social interactions. A modified version of the Implicit Association Test (IAT) called Dual Valence Association Task (DVAT) was designed in order to measure conflict resolution processing from compatibility/incompatibly of semantic and facial valence. The DVAT involves two emotional valence evaluative tasks which elicits two forms of emotional compatible/incompatible associations (facial and semantic). METHODS: Behavioural measures and Event Related Potentials were recorded while participants performed the DVAT. RESULTS: Behavioural data showed a robust effect that distinguished compatible/incompatible tasks. The effects of valence and contextual association (between facial and semantic stimuli) showed early discrimination in N170 of faces. The LPP component was modulated by the compatibility of the DVAT. CONCLUSIONS: Results suggest that DVAT is a robust paradigm for studying the emotional interference effect in the processing of simultaneous information from semantic and facial stimuli.

Letter regarding Article “Incidence of Stroke and Socioeconomic Neighborhood Characteristics: An Ecological Analysis of Dijon Stroke Registry». Autores Sposato L, Saposnik G. Año 2011 Journal  Sposato L, Saposnik G. Volumen 42(10): 557-558 Abstract   Otra información    

BACKGROUND: Mitochondrial dysfunction and oxidative stress are pathophysiologic mechanisms implicated in experimental models and genetic forms of Parkinson’s disease (PD). Certain pesticides may affect these mechanisms, but no pesticide has been definitively associated with PD in humans. OBJECTIVES: Our goal was to determine whether pesticides that cause mitochondrial dysfunction or oxidative stress are associated with PD or clinical features of parkinsonism in humans. METHODS: We assessed lifetime use of pesticides selected by mechanism in a case-control study nested in the Agricultural Health Study (AHS). PD was diagnosed by movement disorders specialists. Controls were a stratified random sample of all AHS participants frequency-matched to cases by age, sex, and state at approximately three controls:one case. RESULTS: In 110 PD cases and 358 controls, PD was associated with use of a group of pesticides that inhibit mitochondrial complex I [odds ratio (OR)=1.7; 95% confidence interval (CI), 1.0-2.8] including rotenone (OR=2.5; 95% CI, 1.3-4.7) and with use of a group of pesticides that cause oxidative stress (OR = 2.0; 95% CI, 1.2-3.6), including paraquat (OR=2.5; 95% CI, 1.4-4.7). CONCLUSIONS: PD was positively associated with two groups of pesticides defined by mechanisms implicated experimentally-those that impair mitochondrial function and those that increase oxidative stress-supporting a role for these mechanisms in PD pathophysiology.