Highlights

Every year, a committee of experts sits down with a tough job to do: from among all ICREA publications, they must find a handful that stand out from all the others. This is indeed a challenge. The debates are sometimes heated and always difficult but, in the end, a shortlist of  the most outstanding publications of the year is produced. No prize is awarded, and the only additional acknowledge is the honour of being chosen and highlighted by ICREA. Each piece has something unique about it, whether it be a particularly elegant solution, the huge impact it has in the media or the sheer fascination it generates as a truly new idea. For whatever the reason, these are the best of the best and, as such, we are proud to share them here.

LIST OF SCIENTIFIC HIGHLIGHTS

Format: yyyy

  • Bilingualism tunes executive control brain areas (2012)

    Costa Martínez, Albert (UPF)

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    Bilingualism tunes executive control brain areas

    Everyday life requires us to monitor cognitive conflicts induced by distracting information from either perceptual sources (e.g., competing traffic signs when driving) or internal sources (e.g., thoughts about matters irrelevant to the current goal). The anterior cingulate cortex (ACC) is an important component in
    the neural circuit mediating cognitive control and one intimately tied to monitoring conflicting information. Language use also requires cognitive control and plausibly recruits a similar circuit. The demand for such control is most evident in bilinguals, and such speakers provide an opportunity to test the generality of the neural mechanisms involved in cognitive control.

    In order to directly examine the link between the regions involved in control of language conflict and those involved in cognitive control, more generally, we need to examine the regions involved within the same study. Accordingly, we asked bilinguals to perform a language control task (i.e., language switching) and a nonverbal conflict task (a flanker task) during the same event-related functional magnetic resonance imaging (er-fMRI) session.

    The results revealed that the dorsal anterior cingulate cortex (ACC), a structure tightly bound to domain-general executive control functions, is a common locus for language control and resolving nonverbal conflict. We also show an experience-dependent effect in the same region: Bilinguals use this structure more efficiently than monolinguals to monitor nonlinguistic cognitive conflicts. They adapted better to conflicting situations showing less ACC activity while outperforming monolinguals. Importantly, for bilinguals, brain activity in the ACC, as well as behavioral measures, also correlated positively with local gray matter volume. These results suggest that early learning and lifelong practice of 2 languages exert a strong impact upon human neocortical development.

    In conclusion, from our combined findings, we suggest that practicing lifelong bilingualism has neurocognitive benefits. The fact that bilinguals learn early in life to resolve language conflicts and to avoid speaking in the nontarget language leads to beneficial plastic changes in the dorsal ACC. Bilinguals not only resolve cognitive conflicts with less neural resource but their brain also adapts better to conflicting situations as shown in our sessions effects analysis of the flanker task. The ACC conflict effect region is more tuned for conflict monitoring in
    bilinguals.

  • Theory and Simulation in Neuroscience. (2012)

    Deco, Gustavo (UPF)

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    Theory and Simulation in Neuroscience.

    Modeling work in neuroscience can be classified using two different criteria. The first one is the complexity of the model, ranging from simplified conceptual models that are amenable to mathematical analysis to detailed models that require simulations in order to understand their properties. The second criterion is that of direction of workflow, which can be from microscopic to macroscopic scales (bottom-up) or from behavioral target functions to properties of components (top-down). We reviewed in this Science article the interaction of theory and simulation using examples of top-down and bottom-up studies and point to some current developments in the fields of computational and theoretical neuroscience.

  • Structure and function of Polycomb complex in embryonic stem cells (2012)

    Di Croce, Luciano (CRG)

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    Structure and function of Polycomb complex in embryonic stem cells

    In 2012, two papers from Di Croce's lab have been highlighted on the cover of top-impacting journals.

    Embryonic stem (ES) cells are key for embryonic development. ES cells can divide extensively before they differentiate into the somatic cells that form the adult tissue. The Polycomb complex regulates the proliferation, and the subsequent differentiation into somatic cells, of ES cells, but the exact role of the different Polycomb proteins in this complex has been a long-standing puzzle. In January 2012, we elucidated the role that several specific Polycomb proteins play during cell development through their incorporation into the complex. This discovery represents a breakthrough in understanding both how stem cells proliferate and which specific functions the Cbx proteins and the Polycomb complex play during tumor development. Identifying new proteins that are essential for maintaining ES cell pluripotency is a key step in elucidating tumor formation processes and in advancing regenerative medicine.

    In parallel, we have also investigated how Polycomb complexes are recruited to DNA. We identified the protein PHF19 as a key player in directing Polycomb binding to genomic loci. Active transcribed genes are marked by the presence of a specific histone modification, which is the presence of a methyl group on the lysine 36 of histone H3 (H3K36me). The Tudor domain of Phf19 directly recognizes this histone modification and recruits the all Polycomb complex, which leads to gene silencing. These findings describe how active genes are silenced during cellular differentiation.

  • Neanderthal diet, self-medication and biographical detail. (2012)

    Hardy, Karen (UAB)

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    Neanderthal diet, self-medication and biographical detail.

    Neanderthals lived in Europe and SW Asia for approximately 100,000 years to around 25,000 BP, though little is known about their lives.
    It has recently become clear that dental calculus is a trap for ingested material with great potential for reconstructing past biographical detail. We examined dental calculus from five individuals from the 50,000 BP Neanderthal site of El Sidrón, Asturias, using sequential thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS), pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), scanning electron and optical microscopy. Until recently, most of the evidence pointed to Neanderthals being predominantly meat-eaters; we have shown that their diet was much broader than this.
    Our results demonstrate inhalation of woody smoke and bitumen or oil shale, ingestion of a range of carbohydrate-rich foods, possible evidence for nuts, grasses and green vegetables and cooking. The molecular evidence for cooking and exposure to smoke in the form of methyl esters, phenols, and polynuclear aromatic hydrocarbons is confirmed by the cracked/roasted starch granules embedded in the calculus.
    Identification of pigments and bitter-tasting appetite suppressants (dihydroazulene and chamazulene, and the coumarin, 4-methylherniarin) is intriguing. One possible reason for consumption of bitter-tasting plants with no nutritional value and these compounds is self-medication. All higher primates have a wide, applied knowledge of edible plants in their environments and there is growing evidence of animal self-medication.
    We have provided the first measurable molecular evidence that dental calculus is a trap for ingested material, while the starch granules we reported represent the oldest ever to be confirmed biochemically. Fossilized bacteria were observed by SEM; sequencing of bacteria from archaeological dental calculus is currently being developed.
    We have demonstrated that that the Neanderthals of El Sidrón had a sophisticated knowledge of their natural surroundings and were able to recognize the nutritional and medicinal value of certain plants.
    Surprisingly, there is no clear agreement on what constitutes a healthy diet. However, the dramatic worldwide increase in obesity and diet-related diseases has focused interest on the `palaeolithic' diet. Accessing direct evidence for ingested material offers a new window into the past and potential to examine issues related to the modern diet.
    This paper captured the imagination of the world press; it was reported in Nature, Scientific

  • The Discovery of a Higgs-Like Boson at the LHC (2012)

    Juste, Aurelio (IFAE)

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    The Discovery of a Higgs-Like Boson at the LHC

    Since 2009, the Large Hadron Collider (LHC) at CERN (Geneva, Switzerland) collides protons at center-of-mass energies of up to 8 TeV, the highest energy ever reached by a particle accelerator. One of the main goals of the LHC is the search for the Higgs boson, the last missing piece of the Standard Model (SM). The Higgs boson is the particle associated with a quantum field postulated to permeate the Universe and responsible for endowing elementary particles with their mass. Unfortunately, the mass of the Higgs boson is not predicted, making its search particularly challenging.
    During the last 48 years, particle physicists have searched for the Higgs boson. In the 90's, the LEP electron-positron collider at CERN concluded that the Higgs boson, if it exists, should have a mass larger than 114.4 GeV at 95% confidence level (C.L). The search continued at the 1.96 TeV proton-antiproton Tevatron collider at Fermilab (Chicago, USA), till the accelerator was shut down on September 2011. While the Tevatron experiments achieved sensitivity to a SM Higgs boson up to a mass of 185 GeV, no definite signal was established.
    On July 4th, 2012, under lots of excitement and extensive media coverage, the ATLAS and CMS experiments reported at a public seminar at CERN the results of their searches for the SM Higgs boson using the data collected during 2010-2012. In particular, the combination of searches at the ATLAS experiment excluded at 95% C.L. the presence of a Higgs boson with mass between 111 GeV and 559 GeV, with the exception of the range 122-131 GeV [1]. In this mass range a signal-like excess was observed at a mass of ~126 GeV, primarily in the searches targeting the decay modes into two photons (see Fig. 1) and into four charged leptons (see Fig. 2). The significance of the excess was estimated at 5.9 standard deviations from the background-only hypothesis, with a similar signal also observed by the CMS experiment. This represents the discovery of a new boson with properties compatible with those of the SM Higgs boson, marking the beginning of a new era in particle physics. The ATLAS discovery has been recently discussed in a special edition of the Science journal [2].
    In order to unravel the nature of this particle, precise measurements of its properties are of crucial importance. A. Juste and M. Martínez lead the analysis effort of the ATLAS data at IFAE, playing a central role in those channels where the Higgs boson is produced in association with a pair of top quarks or a Z boson in the final state, and decays int

  • Portuguese discoveries [or: Teach yourself keyboard in sixteenth-century Portugal] (2012)

    Knighton, Tess (CSIC - IMF)

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    Portuguese discoveries
    [or: Teach yourself keyboard in sixteenth-century Portugal]

    In June 2012 Tess Knighton was in Lisbon for the presentation of her study and transcription of Gonçalo de Baena's Arte para aprender a tanger (1540), the first edition in modern times. Baena's Arte was one of the earliest volumes of keyboard music to be published in Europe, of which a single copy survives, in the Palacio Real, Madrid.

    Dedicated to King João III, it uses an otherwise unknown keyboard tablature, and contains works by Spanish, Portuguese and Franco-Netherlandish composers, some of which are unique. Baena's Arte was intended as an autodidactic book, with a brief set of instructions and the pieces arranged according to difficulty. In his preface, Baena singles out Ockeghem, Agricola, Josquin des Prez and Peñalosa as the "great composers", but he also included pieces that did not form part of the Renaissance musical canon, such as those by his star pupil, his son Antonio. In addition to transcribing the keyboard intabulations, Tess Knighton has reconstructed the uniquely preserved works in their original vocal form, adding the texts as appropriate. At the book presentation in the Convento da Madrededeus, some of these reconstructions were sung alongside works played on the harpsichord - the first time these pieces have been performed for over 450 years.

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