Syntactic Complexity and Frequency in the Neurocognitive Language System

Prominent neurobiological models of language follow the widely accepted assumption that language comprehension requires two principal mechanisms: a lexicon storing the sound-to-meaning mapping of words, primarily involving bilateral temporal regions, and a combinatorial processor for syntactically structured items, such as phrases and sentences, localized in a left-lateralized network linking left inferior frontal gyrus (LIFG) and posterior temporal areas. However, recent research showing that the processing of simple phrasal sequences may engage only bilateral temporal areas, together with the claims of distributional approaches to grammar, raises the question of whether frequent phrases are stored alongside individual words in temporal areas. In this fMRI study, we varied the frequency of words and of short and long phrases in English. If frequent phrases are indeed stored, then only less frequent items should generate selective left frontotemporal activation, because memory traces for such items would be weaker or not available in temporal cortex. Complementary univariate and multivariate analyses revealed that, overall, simple words (verbs) and long phrases engaged LIFG and temporal areas, whereas short phrases engaged bilateral temporal areas, suggesting that syntactic complexity is a key factor for LIFG activation. Although we found a robust frequency effect for words in temporal areas, no frequency effects were found for the two phrasal conditions. These findings support the conclusion that long and short phrases are analyzed, respectively, in the left frontal network and in a bilateral temporal network but are not retrieved from memory in the same way as simple words during spoken language comprehension.This research was supported by an Advanced Investigator grant to W. M. W. from the European Research Council (AdG 230570 NEUROLEX) and by MRC Cognition and Brain Sciences Unit (CBSU) funding to W. M. W. (U.1055.04.002.00001.01). Com- puting resources were provided by the MRC CBSU

Tonotopic representation of loudness in the human cortex

A prominent feature of the auditory system is that neurons show tuning to audio frequency; each neuron has a characteristic frequency (CF) to which it is most sensitive. Furthermore, there is an orderly mapping of CF to position, which is called tonotopic organization and which is observed at many levels of the auditory system. In a previous study (Thwaites et al., 2016) we examined cortical entrainment to two auditory transforms predicted by a model of loudness, instantaneous loudness and short-term loudness, using speech as the input signal. The model is based on the assumption that neural activity is combined across CFs (i.e. across frequency channels) before the transform to short-term loudness. However, it is also possible that short-term loudness is determined on a channel-specific basis. Here we tested these possibilities by assessing neural entrainment to the overall and channel-specific instantaneous loudness and the overall and channel-specific short-term loudness. The results showed entrainment to channel-specific instantaneous loudness at latencies of 45 and 100 ms (bilaterally, in and around Heschl's gyrus). There was entrainment to overall instantaneous loudness at 165 ms in dorso-lateral sulcus (DLS). Entrainment to overall short-term loudness occurred primarily at 275 ms, bilaterally in DLS and superior temporal sulcus. There was only weak evidence for entrainment to channel-specific short-term loudness.This work was supported by an ERC Advanced Grant (230570, ‘Neurolex’) to WMW, by MRC Cognition and Brain Sciences Unit (CBU) funding to WMW (U.1055.04.002.00001.01), and by EPSRC grant RG78536 to JS and BM

Seeking the Real Adam Smith and Milton Friedman

In this paper we will analyze the relationship between free market principles and ethics through an exploration of how too many business managers often approach the ideas of Adam Smith and Milton Friedman. In doing so, we aim to provide a thoughtful foundation for future discussions of how we ought to navigate this intersection. We briefly examine questions such as: What is the relationship between the “best” economy in terms of efficiency and the common good for society? Is pursuing one’s individual economic advantage the same as promoting the general interest? As we analyze and discuss these questions, specifically in the context of Smith and Friedman, we also make some alternative normative assertions, grounded in social welfare, about adopting a broader societal perspective for the purpose of business

Domain-specific and Domain-general Processing in Left Perisylvian Cortex: Evidence from Russian

The processing of words containing inflectional affixes triggers morphophonological parsing and affix-related grammatical information processing. Increased perceptual complexity related to stem-affix parsing is hypothesized to create predominantly domain-general processing demands, whereas grammatical processing primarily implicates domain-specific linguistic demands. Exploiting the properties of Russian morphology and syntax, we designed an fMRI experiment to separate out the neural systems supporting these two demand types, contrasting inflectional complexity, syntactic (phrasal) complexity, and derivational complexity in three comparisons: (a) increase in parsing demands while controlling for grammatical complexity (inflections vs. phrases), (b) increase in grammatical processing demands, and (c) combined demands of morphophonological parsing and grammatical processing (inflections and phrases vs. derivations). Left inferior frontal and bilateral temporal areas are most active when the two demand types are combined, with inflectional and phrasal complexity contrasting strongly with derivational complexity (which generated only bilateral temporal activity). Increased stem-affix parsing demands alone did not produce unique activations, whereas grammatical structure processing activated bilateral superior and middle temporal areas. Selective left frontotemporal language system engagement for short phrases and inflections seems to be driven by simultaneous and interdependent domain-general and domain-specific processing demands

The influence of nova nucleosynthesis on the chemical evolution of the Galaxy

We adopt up-to-date yields of 7Li, 13C, 15N from classical novae and use a well tested model for the chemical evolution of the Milky Way in order to predict the temporal evolution of these elemental species in the solar neighborhood. In spite of major uncertainties due to our lack of knowledge of metallicity effects on the final products of explosive nucleosynthesis in nova outbursts, we find a satisfactory agreement between theoretical predictions and observations for 7Li and 13C. On the contrary, 15N turns out to be overproduced by about an order of magnitude.Comment: 8 pages, latex, 3 figures. To appear in "The Chemical Evolution of the Milky Way: Stars versus Clusters", eds. F. Giovannelli and F. Matteucci (Kluwer: Dordrecht

Neutrino-driven Explosions

The question why and how core-collapse supernovae (SNe) explode is one of the central and most long-standing riddles of stellar astrophysics. A solution is crucial for deciphering the SN phenomenon, for predicting observable signals such as light curves and spectra, nucleosynthesis, neutrinos, and gravitational waves, for defining the role of SNe in the evolution of galaxies, and for explaining the birth conditions and properties of neutron stars (NSs) and stellar-mass black holes. Since the formation of such compact remnants releases over hundred times more energy in neutrinos than the SN in the explosion, neutrinos can be the decisive agents for powering the SN outburst. According to the standard paradigm of the neutrino-driven mechanism, the energy transfer by the intense neutrino flux to the medium behind the stagnating core-bounce shock, assisted by violent hydrodynamic mass motions (sometimes subsumed by the term "turbulence"), revives the outward shock motion and thus initiates the SN blast. Because of the weak coupling of neutrinos in the region of this energy deposition, detailed, multidimensional hydrodynamic models including neutrino transport and a wide variety of physics are needed to assess the viability of the mechanism. Owing to advanced numerical codes and increasing supercomputer power, considerable progress has been achieved in our understanding of the physical processes that have to act in concert for the success of neutrino-driven explosions. First studies begin to reveal observational implications and avenues to test the theoretical picture by data from individual SNe and SN remnants but also from population-integrated observables. While models will be further refined, a real breakthrough is expected through the next Galactic core-collapse SN, when neutrinos and gravitational waves can be used to probe the conditions deep inside the dying star. (abridged)Comment: Author version of chapter for 'Handbook of Supernovae,' edited by A. Alsabti and P. Murdin, Springer. 54 pages, 13 figure

The minimum clinically important difference of the incremental shuttle walk test in bronchiectasis: a prospective cohort study.

The incremental shuttle walk test (ISW) is an externally-paced field walking test that measures maximal exercise capacity1 and is widely used in patients with chronic obstructive pulmonary disease (COPD) undergoing pulmonary rehabilitation (PR). Its psychometric properties, including reliability, construct validity2 and responsiveness to intervention,2-5 have been demonstrated in patients with bronchiectasis, but little data exist on the minimum clinically important difference (MCID). Although two studies have investigated the MCID of ISW in patients with bronchiectasis, the generalisability of these data is limited because of the study sample characteristics,6 or did not involve an exercise-based intervention.2 The MCID enables clinicians and researchers to understand the clinical significance of change data and forms an important part of the evidence required by regulatory agencies for approval for use in clinical trials. Accordingly, the aim of this study was to provide MCID estimates of the ISW in response to intervention, namely PR, in patients with bronchiectasis

Growth dynamics and the evolution of cooperation in microbial populations

Microbes providing public goods are widespread in nature despite running the risk of being exploited by free-riders. However, the precise ecological factors supporting cooperation are still puzzling. Following recent experiments, we consider the role of population growth and the repetitive fragmentation of populations into new colonies mimicking simple microbial life-cycles. Individual-based modeling reveals that demographic fluctuations, which lead to a large variance in the composition of colonies, promote cooperation. Biased by population dynamics these fluctuations result in two qualitatively distinct regimes of robust cooperation under repetitive fragmentation into groups. First, if the level of cooperation exceeds a threshold, cooperators will take over the whole population. Second, cooperators can also emerge from a single mutant leading to a robust coexistence between cooperators and free-riders. We find frequency and size of population bottlenecks, and growth dynamics to be the major ecological factors determining the regimes and thereby the evolutionary pathway towards cooperation.Comment: 26 pages, 6 figure