Long-term memory of real-world episodes is independent of recency effects: magic tricks as ecological tasks.

How episodic memories decay is an unresolved question in cognitive neuroscience. The role of short-term mechanisms regarding the decay of episodic memories is circumscribed to set the maximum recall from which a monotonic decay occurs. However, this sequential view from the short to the long-term is not compulsory, as short-term dependent memory gains (like recency effects when memorizing a list of elements; serial-position effects) may not be translated into long-term memory differences. Moreover, producing memorable events in the laboratory faces important challenges, such as recreating realistic conditions with elevated recall, or avoiding spontaneous retrievals during memory retention (sociocultural hooks). The current study proposes the use of magic to enhance the study of memory. We designed a sequence of magic tricks performed live on stage to evaluate the interaction between memory decay and serial-position effects of those tricks. The audience was asked to freely recall the tricks at four different timepoints: just after the show, 10 days, 1.5 months and 4.5 months. We discovered serial-position differences after the show that were no longer present later on, suggesting that short-term memory gains do not translate into the long-term. Illustrating the power of naturalistic stimuli to study long-term memory while interrogating the interaction between short-term and long-term mechanisms, this work is, to our knowledge, the first scientific study of the memorability of magic tricks.

On the cognitive bases of illusionism.

Cognitive scientists have paid very little attention to magic as a distinctly human activity capable of creating situations that are considered impossible because they violate expectations and conclude with the apparent transgression of well-established cognitive and natural laws. This illusory experience of the "impossible" entails a very particular cognitive dissonance that is followed by a subjective and complex "magical experience". Here, from a perspective inspired by visual neuroscience and ecological cognition, we propose a set of seven fundamental cognitive phenomena (from attention and perception to memory and decision-making) plus a previous pre-sensory stage that magicians interfere with during the presentation of their effects. By doing so, and using as an example the deconstruction of a classic trick, we show how magic offers novel and powerful insights to study human cognition. Furthermore, live magic performances afford to do so in tasks that are more ecological and context-dependent than those usually exploited in artificial laboratory settings. We thus believe that some of the mysteries of how the brain works may be trapped in the split realities present in every magic effect.

Higher prevalence of cerebral white matter hyperintensities in homozygous APOE-ɛ4 allele carriers aged 45-75: Results from the ALFA study.

Cerebral white matter hyperintensities are believed the consequence of small vessel disease and are associated with risk and progression of Alzheimer's disease. The ɛ4 allele of the APOE gene is the major factor accountable for Alzheimer's disease heritability. However, the relationship between white matter hyperintensities and APOE genotype in healthy subjects remains controversial. We investigated the association between APOE-ɛ4 and vascular risk factors with white matter hyperintensities, and explored their interactions, in a cohort of cognitively healthy adults (45-75 years). White matter hyperintensities were assessed with the Fazekas Scale from magnetic resonance images (575 participants: 74 APOE-ɛ4 homozygotes, 220 heterozygotes and 281 noncarriers) and classified into normal (Fazekas < 2) and pathological (≥2). Stepwise logistic regression was used to study the association between pathological Fazekas and APOE genotype after correcting for cardiovascular and sociodemographic factors. APOE-ɛ4 homozygotes, but not heterozygotes, bear a significantly higher risk (OR 3.432; 95% CI [1.297-9.082]; p = 0.013) of displaying pathological white matter hyperintensities. As expected, aging, hypertension and cardiovascular and dementia risk scales were also positively associated to pathological white matter hyperintensities, but these did not modulate the effect of APOE-ɛ4/ɛ4. In subjects at genetic risk of developing Alzheimer's disease, the control of modifiable risk factors of white matter hyperintensities is of particular relevance to reduce or delay dementia's onset.

Ethical challenges in preclinical Alzheimer's disease observational studies and trials: Results of the Barcelona summit.

Alzheimer's disease (AD) is among the most significant health care burdens. Disappointing results from clinical trials in late-stage AD persons combined with hopeful results from trials in persons with early-stage suggest that research in the preclinical stage of AD is necessary to define an optimal therapeutic success window. We review the justification for conducting trials in the preclinical stage and highlight novel ethical challenges that arise and are related to determining appropriate risk-benefit ratios and disclosing individuals' biomarker status. We propose that to conduct clinical trials with these participants, we need to improve public understanding of AD using unified vocabulary, resolve the acceptable risk-benefit ratio in asymptomatic participants, and disclose or not biomarker status with attention to study type (observational studies vs clinical trials). Overcoming these challenges will justify clinical trials in preclinical AD at the societal level and aid to the development of societal and legal support for trial participants.

The ALFA project: A research platform to identify early pathophysiological features of Alzheimer's disease.

INTRODUCTION: The preclinical phase of Alzheimer's disease (AD) is optimal for identifying early pathophysiological events and developing prevention programs, which are shared aims of the ALFA project, including the ALFA registry and parent cohort and the nested ALFA+ cohort study. METHODS: The ALFA parent cohort baseline visit included full cognitive evaluation, lifestyle habits questionnaires, DNA extraction, and MRI. The nested ALFA+ study adds wet and imaging biomarkers for deeper phenotyping. RESULTS: A total of 2743 participants aged 45 to 74 years were included in the ALFA parent cohort. We show that this cohort, mostly composed of cognitively normal offspring of AD patients, is enriched for AD genetic risk factors. DISCUSSION: The ALFA project represents a valuable infrastructure that will leverage with different studies and trials to prevent AD. The longitudinal ALFA+ cohort will serve to untangle the natural history of the disease and to model the preclinical stages to develop successful trials.

Reference Data of the Spanish Memory Binding Test in a Midlife Population from the ALFA STUDY (Alzheimer's and Family).

BACKGROUND: The Memory Binding Test (MBT) is a novel test based on the learning of two lists of words, developed to detect early memory impairment suggestive of Alzheimer's disease (AD). OBJECTIVE: To present and provide reference data of the Spanish MBT in a midlife population of mainly first-degree descendants of AD patients. METHODS: 472 cognitively unimpaired subjects, aged 45 to 65 and participants of the ALFA STUDY, were included. Raw scores were transformed to scaled scores on which multivariate regression analysis was applied adjusting by age, gender, and education level. A standard linear regression was employed to derive the scaled score adjusted. Sociodemographic corrections were applied and an adjustment table was constructed. RESULTS: Performance was heterogeneously influenced by sociodemographic factors. Age negatively influenced free recall. Education tends to have an influence in the results showing lower performance with lower education level. Women tend to outperform men in the learning of the first list and total recall. Only a few variables were unaffected by sociodemographic factors such as those related to semantic proactive interference (SPI) and to the retention of learned material. Our results point out that some vulnerability to SPI is expectable in cognitively healthy subjects. Close to 100% of the learned material was maintained across the delay interval. CONCLUSION: This study contributes with reference data for the MBT providing the necessary adjustments for sociodemographic characteristics. Our data may prove to be useful for detecting asymptomatic at-risk candidates for secondary prevention studies of AD.

Human pharmacology of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) after repeated doses taken 4 h apart Human pharmacology of MDMA after repeated doses taken 4 h apart.

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is a popular psychostimulant, frequently associated with multiple administrations over a short period of time. Repeated administration of MDMA in experimental settings induces tolerance and metabolic inhibition. The aim is to determine the acute pharmacological effects and pharmacokinetics resulting from two consecutive 100mg doses of MDMA separated by 4h. Ten male volunteers participated in a randomized, double-blind, crossover, placebo-controlled trial. The four conditions were placebo plus placebo, placebo plus MDMA, MDMA plus placebo, and MDMA plus MDMA. Outcome variables included pharmacological effects and pharmacokinetic parameters. After a second dose of MDMA, most effects were similar to those after a single dose, despite a doubling of MDMA concentrations (except for systolic blood pressure and reaction time). After repeated MDMA administration, a 2-fold increase was observed in MDMA plasma concentrations. For a simple dose accumulation MDMA and MDA concentrations were higher (+23.1% Cmax and +17.1% AUC for MDMA and +14.2% Cmax and +10.3% AUC for MDA) and HMMA and HMA concentrations lower (-43.3% Cmax and -39.9% AUC for HMMA and -33.2% Cmax and -35.1% AUC for HMA) than expected, probably related to MDMA metabolic autoinhibition. Although MDMA concentrations doubled after the second dose, most pharmacological effects were similar or slightly higher in comparison to the single administration, except for systolic blood pressure and reaction time which were greater than predicted. The pharmacokinetic-effects relationship suggests that when MDMA is administered at a 4h interval there exists a phenomenon of acute tolerance to its effects.

La experimentación animal y el progreso de la medicina / Animal experimentation and progress in medicine

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Caracterización bibliométrica de la producción bibliográfica de los grupos de investigación cardio-cerebrovascular, España 1996-2004 / Identification and bibliometric characterization of research groups in the cardio-cerebrovascular field, Spain 1996-2004

Introducción y objetivos. La abundancia de estudios macro sobre la producción en biomedicina en España pone de manifiesto la escasez de estudios micro que informan sobre la actividad de grupos de investigación, unidad básica del sistema de ciencia-tecnología. Entre las dificultades que explicarían dicha escasez, cuentan la ambigüedad del concepto de «grupo de investigación» y la existencia de firmas bibliográficas sinónimas y homónimas que falsean la correspondencia entre firmas bibliográficas y autores. El objetivo del presente estudio es caracterizar la producción bibliográfica en el campo cardio-cerebrovascular e identificar los grupos de investigación en esta área de estudio. Métodos. Empleando la base de datos National Citation Report for Spain de Thomson-Reuters y el tesauro Medical Subject Headings de la National Library of Medicine, se definió el área cardio-cerebrovascular, y posteriormente se identificó los grupos de investigación mediante el análisis de coautorías y el concurso de un experto. Los grupos se caracterizaron bibliométricamente empleando indicadores de actividad y visibilidad. Resultados. Se identificó un total de 93 grupos, formados por 772 autores distintos, a partir de un subconjunto inicial de 6.540 publicaciones en tema cardio-cerebrovascular. Los grupos detectados procedieron principalmente del sector sanitario y universitario, y se concentraron en las comunidades de Cataluña y Madrid. La producción científica atribuible a los grupos presentó indicadores de visibilidad superiores a la media del ámbito de biomedicina. Conclusiones. La colaboración entre los sectores sanitario y universitario predominó en el área cardio-cerebrovascular; por el contrario, la colaboración internacional es una asignatura pendiente, con índices bajos en comparación con la media de biomedicina (AU)

Introduction and objectives. The abundance of macro-level studies on scientific production in the field of biomedicine in Spain only serves to highlight the scarcity of micro-level studies reporting on the activity of research groups - the basic units of the science and technology system. This lack of information may well be explained by the ambiguity inherent in the "research group" concept and by the existence of synonymous and homonymous bibliographic signatures that confuse the correspondence between these and the real authors. The aim of this study is to describe bibliographic production in cardio-cerebrovascular research and identify research groups active in the field. Methods. Using Thomson-Reuters’ National Citation Report for Spain database and the National Library of Medicine Medical Subject Headings thesaurus, we defined the field of cardio-cerebrovascular research and identified research groups through coauthorship analysis supported by the opinions of an expert. Groups were described in terms of bibliometric indicators of activity and visibility. Results. Ninety-three groups made up of 772 different authors were identified from an initial subset of 6540 publications on cardio-cerebrovascular research. The groups we identified came mainly from the healthcare sector and the universities and were mostly located in the autonomous regions of Catalonia and the Community of Madrid. The scientific production attributable to the groups presented indicators of visibility above the mean for biomedicine. Conclusions. Collaboration between the healthcare sector and the universities dominated cardio-cerebrovascular research, although international collaboration rates were poor, standing at levels below the mean for biomedicine (AU)

Identification and bibliometric characterization of research groups in the cardio-cerebrovascular field, Spain 1996-2004.

INTRODUCTION AND OBJECTIVES: The abundance of macro-level studies on scientific production in the field of biomedicine in Spain only serves to highlight the scarcity of micro-level studies reporting on the activity of research groups-the basic units of the science and technology system. This lack of information may well be explained by the ambiguity inherent in the "research group" concept and by the existence of synonymous and homonymous bibliographic signatures that confuse the correspondence between these and the real authors. The aim of this study is to describe bibliographic production in cardio-cerebrovascular research and identify research groups active in the field. METHODS: Using Thomson-Reuters' National Citation Report for Spain database and the National Library of Medicine Medical Subject Headings thesaurus, we defined the field of cardio-cerebrovascular research and identified research groups through co-authorship analysis supported by the opinions of an expert. Groups were described in terms of bibliometric indicators of activity and visibility. RESULTS: Ninety-three groups made up of 772 different authors were identified from an initial subset of 6540 publications on cardio-cerebrovascular research. The groups we identified came mainly from the healthcare sector and the universities and were mostly located in the autonomous regions of Catalonia and the Community of Madrid. The scientific production attributable to the groups presented indicators of visibility above the mean for biomedicine. CONCLUSIONS: Collaboration between the healthcare sector and the universities dominated cardio-cerebrovascular research, although international collaboration rates were poor, standing at levels below the mean for biomedicine.

¿Es necesario modificar la normativa sobre investigaciones médicas en las que los medicamentos no son el objetivo de estudio? / Is it necessary to change the regulation in which drugs are not the objective of the medical research?

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Is there an association between the quality of hospitals' research and their quality of care?

OBJECTIVE: It is often claimed that hospitals that are leaders in biomedical research provide higher health care quality, or vice versa. Although several studies have shown a relationship between teaching status and quality of care, none has analysed the association between research output and hospital outcomes. Our aim was to determine whether there is a relationship between bibliometric measures of research output in acute hospitals and hospital mortality for two common cardiac conditions. METHODS: A cross-sectional analysis of secondary data of in-hospital risk-adjusted mortality for congestive heart failure and acute myocardial infarction (2002-2004) and several bibliometric measures of publications (1996-2004) in cardiovascular disease. The setting was 50 acute Spanish public hospitals, voluntarily participating in an external quality initiative, with more than 30 medical cases of congestive heart failure and acute myocardial infarction per year, and more than five citable papers in the field of heart disease. Spearman's rho non-parametric correlation coefficient was used to assess association. RESULTS: There was a low-to-moderate negative correlation between the risk-adjusted mortality ratio and the weighted citations ratio: -0.43 (95% CI -0.17 to -0.63) for congestive heart failure and -0.37 (-0.10 to -0.59) for acute myocardial infarction. Teaching status and the technological level of the hospital had a stronger correlation with hospital mortality. CONCLUSIONS: Measures of research output could be considered for incorporation into comparisons of the quality of hospitals. A weighted citations ratio is the most suitable measure of research output, but more research is needed on the interplay between research and practice as complementary ways of developing medical knowledge.

Creating a transatlantic research enterprise for preventing Alzheimer's disease.

In recognition of the global problem posed by Alzheimer's disease and other dementias, an international think-tank meeting was convened by Biocat, the Pasqual Maragall Foundation, and the Lou Ruvo Brain Institute in February 2009. The meeting initiated the planning of a European Union-North American collaborative research enterprise to expedite the delay and ultimate prevention of dementing disorders. The key aim is to build parallel and complementary research infrastructure that will support international standardization and inter-operability among researchers in both continents. The meeting identified major challenges, opportunities for research resources and support, integration with ongoing efforts, and identification of key domains to influence the design and administration of the enterprise.

Fortalezas y limitaciones del peer review / Strenghts and weaknesses of peer review

El peer review, paradigma de nuestro sistema de autorregulación profesional, es un procedimiento de evaluación complementario y tan imperfecto como la bibliometría. Su aplicación depende de los objetivos y circunstancias y sus resultados deben contextualizarse siempre, aún más ante el culto actual que considera más importante la revista de publicación que el contenido y mensaje del propio trabajo. La participación en procesos de peer review es generalmente altruista y requiere seguir unas normas de cortesía y buenas prácticas, siendo los conflictos de intereses uno de sus principales problemas. Los procesos de peer review son caros y escasamente reproducibles. El sistema es muy subjetivo, conservador, propenso al sesgo y generalmente incapaz de detectar el fraude. Sin embargo no existen buenas alternativas, por lo que es necesario profundizar en sus procedimientos y propiciar su aplicación en las mejores condiciones posibles y sobre la base de las escasas evidencias existentes (AU)

The peer review paradigm in our system of professional self-regulation is a complementary evaluation procedure – and as imperfect as – bibliometrics. The application of peer review depends on the journal's aims and circumstances and its results should always be contextualized, especially given the current cult of considering the journal of publication more important than the article's content and message. Participation in the peer review processes is usually altruistic and requires that certain rules of courtesy and good practice be followed, one of the main problems being conflicts of interest. Peer review processes are expensive and show scant reproducibility. The system is highly subjective, conservative, and prone to bias and is generally unable to detect fraud. However, effective alternatives are lacking. Consequently, peer review procedures should be examined in greater depth and its application in optimal conditions – and based on the scarce evidence available – should be encouraged (AU)

[Bibliometric map of Spain 1996-2004: biomedicine and health sciences]. / Mapa bibliométrico de España 1996-2004: biomedicina y ciencias de la salud.

BACKGROUND AND OBJECTIVE: The study presents the bibliometric analysis of the Spanish scientific output in biomedicine during 1996-2004. This is the last edition of a series of bibliometric studies aimed to characterize the Spanish scientific performance in biomedicine. MATERIAL AND METHOD: The analysis was restricted to citable documents for which simple and composite bibliometric indicators were obtained at different aggregation levels: fields, autonomous regions, institutional sectors and research centres. The documents were selected according to the Journal Citation Reports, and were assigned to affiliation centres following an integer counting scheme after an exhaustive normalization of the affiliation addresses. RESULTS: Compared to the period 1994-2002, research activity in biomedicine grew as much as Spain: 8.9% in the number of documents; 22.5% citations; 12.5% citation per document average and 27.2% international cooperation. Besides, biomedicine showed the highest citation per document average compared to other major fields. International cooperation in biomedicine (27.2%) reached the European average. The documents published in international cooperation account for the half of citations to documents in biomedicine. The number of documents and citations belonging to the clinic medicine subfield and to the health sector showed the highest growth. CONCLUSIONS: In general, these results reproduce the tendencies described in prior studies. The documents in biomedicine showed a highly asymmetric distribution among institutional sectors, autonomous regions, scientific fields and research centres. The remarkably increase in the output of clinical medicine field and in the health sector could be the consequence of important science policy actions undertaken in these areas in the last years.

Mapa bibliométrico de España 1996-2004: biomedicina y ciencias de la salud / Bibliometric map of Spain 1996-2004: biomedicine and health sciences

Fundamento y objetivo: Se presenta la edición correspondiente al período 1996-2004 de una serie de estudios bibliométricos que caracterizan la producción española en biomedicina. Material y método: El análisis se restringió a los documentos citables, obteniéndose indicadores bibliométricos simples y compuestos para agregados temáticos, territoriales, sectoriales e institucionales. Los documentos se seleccionaron de acuerdo con el Journal Citation Reports del año 1996 y se adscribieron a sus centros de afiliación según el método de asignación total, previa depuración de la información. Resultados: En relación con el período 1994-2002, la biomedicina ha crecido igual que el conjunto de España: un 8,9% el número de publicaciones, un 22,5% el de citas, un 12,5% el cociente citas/documento y un 27,2% el porcentaje de colaboración internacional, que ya se sitúa en la media europea. La biomedicina presenta además la media de citas por documento más elevada. Los incrementos más elevados se observaron en el subámbito de medicina clínica y en el sector sanitario. Los documentos en colaboración internacional continúan explicando la mayor proporción de citas recibidas durante el período de estudio. Conclusiones: En líneas generales, los resultados obtenidos reproducen las tendencias ya descritas en series previas, como, por ejemplo, los perfiles de producción asimétricos que se verifican desde la perspectiva territorial, sectorial, de áreas temáticas y de centros de investigación. Los incrementos particularmente importantes en el campo de medicina clínica y en el sector sanitario podrían expresar las importantes acciones en política científica que se han ejercido en estas áreas durante los últimos años

Background and objective: The study presents the bibliometric analysis of the Spanish scientific output in biomedicine during 1996-2004. This is the last edition of a series of bibliometric studies aimed to characterize the Spanish scientific performance in biomedicine. Material and method: The analysis was restricted to citable documents for which simple and composite bibliometric indicators were obtained at different aggregation levels: fields, autonomous regions, institutional sectors and research centres. The documents were selected according to the Journal Citation Reports, and were assigned to affiliation centres following an integer counting scheme after an exhaustive normalization of the affiliation addresses. Results: Compared to the period 1994-2002, research activity in biomedicine grew as much as Spain: 8.9% in the number of documents; 22.5% citations; 12.5% citation per document average and 27.2% international cooperation. Besides, biomedicine showed the highest citation per document average compared to other major fields. International cooperation in biomedicine (27.2%) reached the European average. The documents published in international cooperation account for the half of citations to documents in biomedicine. The number of documents and citations belonging to the clinic medicine subfield and to the health sector showed the highest growth. Conclusions: In general, these results reproduce the tendencies described in prior studies. The documents in biomedicine showed a highly asymmetric distribution among institutional sectors, autonomous regions, scientific fields and research centres. The remarkably increase in the output of clinical medicine field and in the health sector could be the consequence of important science policy actions undertaken in these areas in the last years

[Strenghts and weaknesses of peer review]. / Fortalezas y limitaciones del peer review.

The peer review paradigm in our system of professional self-regulation is a complementary evaluation procedure - and as imperfect as - bibliometrics. The application of peer review depends on the journal's aims and circumstances and its results should always be contextualized, especially given the current cult of considering the journal of publication more important than the article's content and message. Participation in the peer review processes is usually altruistic and requires that certain rules of courtesy and good practice be followed, one of the main problems being conflicts of interest. peer review processes are expensive and show scant reproducibility. The system is highly subjective, conservative, and prone to bias and is generally unable to detect fraud. However, effective alternatives are lacking. Consequently, peer review procedures should be examined in greater depth and its application in optimal conditions - and based on the scarce evidence available - should be encouraged.