89 results match your criteria: "CNRS and Aix-Marseille University[Affiliation]"

Bilinguals have been shown to perform worse than monolinguals in a variety of verbal tasks. This study investigated this bilingual verbal cost in a large-scale picture-naming study conducted in Spanish. We explored how individual characteristics of the participants and the linguistic properties of the words being spoken influence this performance cost.

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Article Synopsis
  • The prefrontal cortex (PFC) is vital for goal-directed actions and controlling behavior, though how it does this is debated.
  • Evidence from computational modeling and monkey neuronal data indicates that neural representations of goals in the PFC emerge through a combination of categorization and reward-driven processes.
  • This goal coding is shown to offer an efficient solution to cognitive control challenges, paralleling efficient coding in other brain regions, and has broader implications for neurophysiological research.
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Extracting the regularities of our environment is one of our core cognitive abilities. To study the fine-grained dynamics of the extraction of embedded regularities, a method combining the advantages of the artificial language paradigm (Saffran, Aslin, & Newport, ) and the serial response time task (Nissen & Bullemer, ) was used with a group of Guinea baboons (Papio papio) in a new automatic experimental device (Fagot & Bonté, ). After a series of random trials, monkeys were exposed to language-like patterns.

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Vision is a powerful source of information for controlling movements, especially fine actions produced by the hand that require a great deal of accuracy. However, the neural processes that enable vision to enhance movement accuracy are not well understood. In the present study, we tested the hypothesis that the cortical sensitivity to visual inputs increases during a spatially-constrained hand movement compared to a situation where visual information is irrelevant to the task.

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Objective: Psychosocial trauma during childhood is associated with schizophrenia vulnerability. The pattern of grey matter decrease is similar to brain alterations seen in schizophrenia. Our objective was to explore the links between childhood trauma, brain morphology and schizophrenia symptoms.

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Rigidity transition in materials: hardness is driven by weak atomic constraints.

Phys Rev Lett

March 2015

Concrete Sustainability Hub, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.

Understanding the composition dependence of the hardness in materials is of primary importance for infrastructures and handled devices. Stimulated by the need for stronger protective screens, topological constraint theory has recently been used to predict the hardness in glasses. Herein, we report that the concept of rigidity transition can be extended to a broader range of materials than just glass.

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Prime stimuli formed by inserting unrelated letters in a given target word (called "superset" primes) provide a means to modify the relative positions of the letters shared by prime and target. Here we examined the time-course of superset priming effects in an ERP study using the sandwich-priming paradigm. We compared the effects of superset primes formed by the insertion of unrelated letters (e.

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Probabilistic cognition in two indigenous Mayan groups.

Proc Natl Acad Sci U S A

December 2014

Center for Experimental Research in Management and Economics, DCP, University IUAV of Venice, 30123 Venice, Italy;

Is there a sense of chance shared by all individuals, regardless of their schooling or culture? To test whether the ability to make correct probabilistic evaluations depends on educational and cultural guidance, we investigated probabilistic cognition in preliterate and prenumerate Kaqchikel and K'iche', two indigenous Mayan groups, living in remote areas of Guatemala. Although the tested individuals had no formal education, they performed correctly in tasks in which they had to consider prior and posterior information, proportions and combinations of possibilities. Their performance was indistinguishable from that of Mayan school children and Western controls.

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Eye dominance influences triggering action: the Poffenberger paradigm revisited.

Cortex

September 2014

Laboratoire de Neurosciences Cognitives, CNRS and Aix-Marseille University, Marseille, France; Department of Psychology, New York University, New York, NY, USA. Electronic address:

Our dominant eye (DE) is the one we unconsciously choose when performing a monocular task. Although it has been recognized for centuries, eye dominance and its behavioral consequences remain poorly understood. Here we used the simple and well-known Poffenberger paradigm (1912) in which participants press a button with the right or left index finger, in reaction to the appearance of a lateralized visual stimulus.

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Health service users err in posttest probability evaluations. Here we document for the first time that users succeed when they reason about numbers of cases and make distributive evaluations. A sample of women interested in prenatal testing incorrectly evaluated the posttest probability that a given fetus had an anomaly, but regardless of their numeracy level, they correctly apportioned the cases for and against that hypothesis.

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Fagot and Paleressompoulle [Fagot and Paleressompoulle (2009) Behav Res Methods 41: 396-404] described a new automated learning device for monkeys (ALDM) to test the cognitive functions of nonhuman primates within their social groups. However, the impact of the ALDM procedure on animal well-being needs to be investigated. The present study assessed the consequences of ALDM testing on the behavioral repertoire of Guinea baboons (Papio papio) and their stress levels as inferred from measurements of saliva cortisol.

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Lipoproteins of temperate phage are a broad family of membrane proteins encoded in the lysogeny module of temperate phages. Expression of the ltp(TP-J34) gene of temperate Streptococcus thermophilus phage TP-J34 interferes with phage infection at the stage of triggering DNA release and injection into the cell. Here, we report the first structure of a superinfection exclusion protein.

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Numerous studies of motor learning have examined the adaptation of hand trajectories and grip forces when moving grasped objects with novel dynamics. Such objects initially result in both kinematic and kinetic errors; i.e.

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Importance of carbon solubility and wetting properties of nickel nanoparticles for single wall nanotube growth.

Phys Rev Lett

November 2012

Centre Interdisciplinaire de Nanoscience de Marseille, CNRS and Aix Marseille University, Campus de Luminy, 13288 Marseille Cedex 09, France.

Optimized growth of single wall carbon nanotubes requires full knowledge of the actual state of the catalyst nanoparticle and its interface with the tube. Using tight binding based atomistic computer simulations, we calculate carbon adsorption isotherms on nanoparticles of nickel, a typical catalyst, and show that carbon solubility increases for smaller nanoparticles that are either molten or surface molten under experimental conditions. Increasing carbon content favors the dewetting of Ni nanoparticles with respect to sp(2) carbon walls, a necessary property to limit catalyst encapsulation and deactivation.

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The unbearable articulatory nature of naming: on the reliability of word naming responses at the item level.

Psychon Bull Rev

February 2013

Laboratoire de Psychologie Cognitive, CNRS and Aix-Marseille University, 3, place Victor Hugo, Case D, 13331, Marseille Cedex 3, France.

Single-word naming is one of the most widely used experimental paradigms for studying how we read words. Following the seminal study by Spieler and Balota (Psychological Science 8:411-416, 1997), accounting for variance in item-level naming databases has become a major challenge for computational models of word reading. Using a new large-scale database of naming responses, we first provided a precise estimate of the amount of reproducible variance that models should try to account for with such databases.

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Since the first descriptions of sensorimotor rhythms by Berger (1929) and by Jasper and Penfield (1949), the potential role of beta oscillations (~13-30 Hz) in the brain has been intensely investigated. We start this review by showing that experimental studies in humans and monkeys have reached a consensus on the facts that sensorimotor beta power is low during movement, transiently increases after movement end (the "beta rebound") and tonically increases during object grasping. Recently, a new surge of studies exploiting more complex sensorimotor tasks including multiple events, such as instructed delay tasks, reveal novel characteristics of beta oscillatory activity.

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Producing recombinant proteins in Escherichia coli (E. coli) is generally performed using a trial and error approach with the different expression variables being tested independently from each other. As a consequence, variable interactions are lost which makes the trial and error approach quite time-consuming.

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Orthographic processing in baboons (Papio papio).

Science

April 2012

CNRS and Aix-Marseille University Laboratoire de Psychologie Cognitive, Fédération de Recherche 3C, Brain and Language Research Institute, Aix-Marseille University and CNRS, Marseille, France.

Skilled readers use information about which letters are where in a word (orthographic information) in order to access the sounds and meanings of printed words. We asked whether efficient processing of orthographic information could be achieved in the absence of prior language knowledge. To do so, we trained baboons to discriminate English words from nonsense combinations of letters that resembled real words.

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Turning Turing's logic on its head, we used widespread letter-based Turing Tests found on the internet (CAPTCHAs) to shed light on human cognition. We examined the basis of the human ability to solve CAPTCHAs, where machines fail. We asked whether this is due to our use of slow-acting inferential processes that would not be available to machines, or whether fast-acting automatic orthographic processing in humans has superior robustness to shape variations.

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Quantifying eye stability during a fixation task: a review of definitions and methods.

Seeing Perceiving

July 2013

Institut de Neurosciences Cognitives de la Méditerranée, CNRS and Aix-Marseille University, Marseille, France.

Article Synopsis
  • - The term 'fixation stability' in clinical vision research has multiple definitions, primarily focusing on eye movements during fixations and the variability between fixations, which impacts visual function in retinal diseases like age-related macular degeneration.
  • - Two key methods for measuring fixation stability are highlighted: the bivariate contour ellipse area (BCEA), which assumes a normal distribution of eye positions, and the within-isolines area, which does not, leading to potentially different interpretations of eye stability data.
  • - The review discusses how these measurement methods can yield varying results, particularly in cases of multimodal eye position distributions, and emphasizes the importance of selecting appropriate statistical techniques for accurate assessments of eye stability.
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Single pH buffer refolding screen for protein from inclusion bodies.

Protein Expr Purif

April 2012

Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257 CNRS and Aix-Marseille University, 163, Avenue de Luminy, Case 932, 13288 Marseille, Cedex 09, France.

We previously reported the set up of an automated test for screening the refolding of recombinant proteins expressed as inclusion bodies in Escherichia coli[1]. The screen used 96 refolding buffers and was validated with 24 proteins, 70% of which remained soluble in at least one buffer. In the present paper, we have analyzed in more detail these experimental data to see if the refolding process can be driven by general rules.

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One-step generation of error-prone PCR libraries using Gateway® technology.

Microb Cell Fact

January 2012

Architecture et Fonction des Macromolécules Biologiques, UMR 7257 CNRS and Aix-Marseille University, 163, Avenue de Luminy, Case 932, 13288 Marseille, Cedex 09, France.

Background: Error-prone PCR (epPCR) libraries are one of the tools used in directed evolution. The Gateway® technology allows constructing epPCR libraries virtually devoid of any background (i.e.

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A sulfurtransferase is essential for activity of formate dehydrogenases in Escherichia coli.

J Biol Chem

February 2012

Laboratoire de Chimie Bactérienne, UPR9043, Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille University, 13009 Marseille, France.

l-Cysteine desulfurases provide sulfur to several metabolic pathways in the form of persulfides on specific cysteine residues of an acceptor protein for the eventual incorporation of sulfur into an end product. IscS is one of the three Escherichia coli l-cysteine desulfurases. It interacts with FdhD, a protein essential for the activity of formate dehydrogenases (FDHs), which are iron/molybdenum/selenium-containing enzymes.

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