Categoría: Papers con abstracts

Behavioral studies have provided evidence for an action-sentence compatibility effect (ACE) that suggests a coupling of motor mechanisms and action-sentence comprehension. When both processes are concurrent, the action sentence primes the actual movement, and simultaneously, the action affects comprehension. The aim of the present study was to investigate brain markers of bidirectional impact of language comprehension and motor processes. METHODOLOGY/PRINCIPAL FINDINGS: Participants listened to sentences describing an action that involved an open hand, a closed hand, or no manual action. Each participant was asked to press a button to indicate his/her understanding of the sentence. Each participant was assigned a hand-shape, either closed or open, which had to be used to activate the button. There were two groups (depending on the assigned hand-shape) and three categories (compatible, incompatible and neutral) defined according to the compatibility between the response and the sentence. ACEs were found in both groups. Brain markers of semantic processing exhibited an N400-like component around the Cz electrode position. This component distinguishes between compatible and incompatible, with a greater negative deflection for incompatible. Motor response elicited a motor potential (MP) and a re-afferent potential (RAP), which are both enhanced in the compatible condition. CONCLUSIONS/SIGNIFICANCE: The present findings provide the first ACE cortical measurements of semantic processing and the motor response. N400-like effects suggest that incompatibility with motor processes interferes in sentence comprehension in a semantic fashion. Modulation of motor potentials (MP and RAP) revealed a multimodal semantic facilitation of the motor response. Both results provide neural evidence of an action-sentence bidirectional relationship. Our results suggest that ACE is not an epiphenomenal post-sentence comprehension process. In contrast, motor-language integration occurring during the verb onset supports a genuine and ongoing brain motor-language interaction.

Bipolar disorder (BD) and adult attention deficit hyperactivity disorder (ADHD) usually manifest with shared clinical symptoms, proving quite challenging to thoroughly differentiate one from another. Previous research has characterized these two disorders independently, but no study compared both pathologies from a neuropsychological perspective. The aim of this study was to compare the neuropsychological profile of adult ADHD and BD with each other and against a control group, in order to understand the way in which comprehensive cognitive assessment can contribute to their discrimination as distinct clinical entities as well as their differential diagnosis. All groups were successfully matched for age, sex, years of education, and premorbid IQ. Participants were assessed with an extensive neuropsychological battery evaluating multiple domains. Compared to controls, BD patients had a poorer performance on immediate verbal memory tasks. Both clinical groups exhibited significantly lower scores than controls on the recognition phase of verbal and non-verbal memory tasks, as well as on a task of executive functioning with high working memory demand. Noticeably, however, ADHD had significantly better performance than BD on the recognition phase of both the Rey list memory task and the Rey Figure. The better performance of ADHD patients over BD may reflect the crucial role of the executive component on their memory deficits and gives empirical support to further differentiate the neuropsychological profile of BD and adult ADHD patients in clinical practice.

Feedback error-related negativity (fERN) has been referred to as a negative deflection in the event related potential (ERP), which distinguishes between wins and losses in terms of expected and unexpected outcomes. Some studies refer to the «expected outcome » as the probability to win vs. to lose, and others as expected size of rewards. We still do not know much about whether these alternative interpretations of «expected outcome » affect the fERN in a different manner, nor do we know the effect of their interaction in an expected value fashion. We set a gambling task with four game categories; two had the same expected value, while the other two categories were equivalent to the first ones, but alternatively in the size or probability of the offered rewards. Results show that fERN preceded by a P200, and followed by a Pe-like wave differentiates between losing in the category with a higher expected value and the rest of the experimental conditions. fERN differentiates between wins and losses, but changes in the size and probability of rewards impact the fERN amplitude only in win conditions. Results also show greater positivity following win feedback when the size and/or probability of the outcome rewards were higher, so that the higher the expected value the greater the positivity following win feedback. Our findings support the notion that both the probability and size of the offered rewards modulate the motivational value for the win feedback, this being also true for their interaction in an expected value fashion.

From everyday cognition to scientific discovery, analogical processes play an important role: bringing connection, integration, and interrelation of information. Recently, a PFC model of analogy has been proposed to explain many cognitive processes and integrate general functional properties of PFC. We argue here that analogical processes do not suffice to explain the cognitive processes and functions of PFC. Moreover the model does not satisfactorily integrate specific explanatory mechanisms required for the different processes involved. Its relevance would be improved if fewer cognitive phenomena were considered and more specific predictions and explanations about those processes were stated.

Gestures should play a role in second language comprehension, given their importance in conveying contextual information. In this study, the N400 and the LPC were evaluated in a task involving the observation of videos showing utterances accompanied by gestures. Students studying advanced (G-High participants) and basic German (G-Low participants) as a second language were investigated. The utterance-gesture congruence and metaphoric meaning of content were manipulated during the task. As in previous ERP reports with native speakers, metaphorical expressions were sensitive to gestures. In G-Low participants, no modulation in the 300-500 ms window was observed, and only a modest effect was observed for the 500-700 ms window. More subtle differences of verbal expression were not processed in this group. Consistent with previous reports of the same paradigm with native speakers, the N400 from G-High group discriminated both congruent and incongruent gestures as well as literal and metaphorical sentences. Our results suggest that semantic processing is robust in the learning of a second language, although the amplitude modulation and latency of ERPs might depend on the speaker’s proficiency level.

In the last few decades, several works on event related potentials (ERPs hereafter) during sleep have been reported. In spite of numerous studies, clear methodological rules for this kind of study are often missing, making it difficult to valorize the scope of these results. We propose here a description of methodological aspects to be considered when evaluating ERPs during sleep. The use of Rechtschaffen and Kales rules versus automatic methods is assessed, plus the additional use of certain quantitative measures. Additionally, two topics are discussed which must be controlled in ERPs sleep studies: the First Night Effect, and sleep disturbances. Better control of experimental paradigms is relevant for the growth of the neuroscience of sleep.

La demencia es un síndrome que se caracteriza por declinación de la función intelectual, lo bastante severa para interferir en la vida diaria; más de un área cognitiva se ve afectada, hay impacto funcional en las actividades de la vida diaria y, con frecuencia, existen trastornos conductuales. En la actualidad, para poder realizar el diagnóstico de la enfermedad de Alzheimer y otras demencias es necesario combinar los datos de la clínica con la evaluación neuropsicológica, los exámenes de laboratorio y las neuroimágenes. En esta revisión se examinará qué elementos son necesarios para el diagnóstico temprano de las demencias, y se revisará su manejo farmacológico y no farmacológico.

NTRODUCTION: Electroconvulsive therapy (ECT) is an effective, yet controversial treatment. Most patients receiving ECT have depression and it is likely that the majority having this treatment are older adults. However, attitudes towards ECT and knowledge of ECT in this population have never been studied in relation to the patients’ cultural background. OBJECTIVE: To compare the attitudes and knowledge of ECT among older adults depressed patients across three culturally different populations and to explore the relationship between culture, knowledge and attitudes. METHODS: The study was conducted in one centre in each country. A semi-structured survey was used which included three sections: demographics characteristics, attitudes towards and knowledge of ECT. RESULTS: A total of 75 patients were recruited in this study: 30 patients from England; 30 patients from Argentina; and 15 patients from Canada. There was a significant difference in knowledge about ECT across the three countries. No significant difference was found in terms of attitudes. Knowledge was poor in all three countries. The most influential factor shaping subjects’ attitudes and knowledge of ECT differed for the three countries. A weak correlation was found between knowledge of and attitudes towards ECT across all patients from the three different countries. CONCLUSION: Attitudes towards ECT are a very complex phenomenon. We could not find evidence that a particular cultural background affects attitudes towards ECT. Generalising the results of our study is restricted by the fact that this was a pilot study that suffered from limitations including small sample size and number of settings.

NTRODUCTION: In clinical practice it is often difficult to establish whether cognitive impairment is secondary to an affective disorder or a dementing process. AIM: To describe the cognitive performance on the Spanish version of the Addenbrooke’s Cognitive Examination (ACE) of patients with early dementia and depression. SUBJECTS AND METHODS: 77 patients with early dementia (53 Alzheimer disease; 24 frontotemporal dementia), 17 patients with major depression and 54 healthy volunteers were tested with the Spanish version of the ACE. RESULTS: Alzheimer disease and frontotemporal dementia groups were significantly lower than the control group and the major depression group. When the major depression group was compared with the control group no significant differences were found. CONCLUSIONS: The cognitive performance in the ACE is different in patients with early dementia and patient with depression.

Epidemiology of Parkinson’s disease. Autores Kasten M, Chade AR, Tanner CM.  Año 2008 Journal  Kasten M, Chade AR, Tanner CM.  Volumen 2007(83): 129-151 Abstract   Otra información