2,316 research outputs found

    Target-derived neurotrophic factors regulate the death of developing forebrain neurons after a change in their trophic requirements

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    Many neurons die as the normal brain develops. How this is regulated and whether the mechanism involves neurotrophic molecules from target cells are unknown. We found that cultured neurons from a key forebrain structure, the dorsal thalamus, develop a need for survival factors including brain-derived neurotrophic factor (BDNF) from their major target, the cerebral cortex, at the age at which they innervate it. Experiments in vivo have shown that rates of dorsal thalamic cell death are reduced by increasing cortical levels of BDNF and are increased in mutant mice lacking functional BDNF receptors or thalamocortical projections; these experiments have also shown that an increase in the rates of dorsal thalamic cell death can be achieved by blocking BDNF in the cortex. We suggest that the onset of a requirement for cortex-derived neurotrophic factors initiates a competitive mechanism regulating programmed cell death among dorsal thalamic neurons

    Framing the ultimatum game: the contribution of simulation

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    It has now become widely accepted that economic decisions are influenced by cognitive and emotional processes. In the present study, we aimed at disentangling the neural mechanisms associated with the way in which the information is formulated, i.e., framing effect, in terms of gain or loss, which influences people\u2019s decisions. Participants played a fMRI version of the Ultimatum Game (UG) where we manipulated bids through two different frames: the expression \u201cI give you\u201d (gain) focusing on money the respondent would receive if she/he agreed with the proponent, and the expression \u201cI take\u201d (loss) focusing on the money that would be removed from the respondent in the event that she/he accepted the offer. Neuroimaging data revealed a frame by response interaction, showing an increase of neural activity in the right rolandic operculum/insular cortex, the anterior cingulate, among other regions, for accepting the frame \u201cI take\u201d vs. rejecting, as compared to accepting the frame \u201cI give you\u201d vs. rejecting. In addition, the left occipito-temporal junction was activated for \u201cI take\u201d vs. \u201cI give you\u201d for offer 5, corresponding to the equal offer made unpleasant by the presence of the frame \u201cI take,\u201d where is the proposer that takes the money. Our data extend the current understanding of the neural substrates of social decision making, by disentangling the structures sensitive to the way in which the information is formulated (i.e., framing effect), in terms of gain or loss

    Tuned with a Tune: Talker Normalization via General Auditory Processes

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    Voices have unique acoustic signatures, contributing to the acoustic variability listeners must contend with in perceiving speech, and it has long been proposed that listeners normalize speech perception to information extracted from a talker’s speech. Initial attempts to explain talker normalization relied on extraction of articulatory referents, but recent studies of context-dependent auditory perception suggest that general auditory referents such as the long-term average spectrum (LTAS) of a talker’s speech similarly affect speech perception. The present study aimed to differentiate the contributions of articulatory/linguistic versus auditory referents for context-driven talker normalization effects and, more specifically, to identify the specific constraints under which such contexts impact speech perception. Synthesized sentences manipulated to sound like different talkers influenced categorization of a subsequent speech target only when differences in the sentences’ LTAS were in the frequency range of the acoustic cues relevant for the target phonemic contrast. This effect was true both for speech targets preceded by spoken sentence contexts and for targets preceded by non-speech tone sequences that were LTAS-matched to the spoken sentence contexts. Specific LTAS characteristics, rather than perceived talker, predicted the results suggesting that general auditory mechanisms play an important role in effects considered to be instances of perceptual talker normalization

    Communication and shared decision-making after stillbirth: Results of the ShaDeS study

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    Background: Shared decision-making (SDM) is included in guidelines for bereavement care after a stillbirth, as it can improve women’s long-term health and wellbeing. SDM within the stillbirth context is still not common, and Italy does not yet have standardised guidelines. Aim: The ShaDeS (Shared Decision-Making in Stillbirth) study aims to investigate how Italian women with a stillbirth perceive their own centrality in decision-making processes around bereavement care and how this might impact satisfaction of care. Methods: The ShaDeS study is a cross-sectional study based on a web survey consisted of four sections: socio- demographic information and medical history, communication of bad news and bereavement care, decisions about childbirth (SDM-Q-9, SHARED, and DCS), and decisions and communication about autopsy (CPS). Findings: 187 women answered the survey. For the 41.1% of women that did not have an emergency childbirth, the SDM-Q-9 median score was 66.6 (0–100 range), and the SHARED median score was 3.5 (1–5 range). 29.4% of participants reached the proposed cutoff of 37.5 in the DCS (0–100 range) suggesting a difficulty in reaching decisions. Satisfaction scores were lower for those with such difficulties (p < 0.0001). Of the 64.5% of women that discussed autopsy, 28.3% were involved in an SDM approach, despite this being associated with higher levels of satisfaction of care (p < 0.05). Conclusion: An SDM approach is only moderately widespread amongst our participants, despite it being signif- icantly related to higher levels of satisfaction. Further studies should investigate the tools that both patients and healthcare professionals need for an SDM approach

    Moral reasoning behind the veil of ignorance: An investigation into perspective-taking accessibility in the context of autonomous vehicles

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    Perspective-taking (PT) accessibility has been recognized as an important factor in affecting moral reasoning, also playing a non-trivial role in moral investigation towards autonomous vehicles (AVs). A new proposal to deepen this effect leverages the principles of the veil of ignorance (VOI), as a moral reasoning device aimed to control self-interested decisions by limiting the access to specific perspectives and to potentially biased information. Throughout two studies, we deepen the role of VOI reasoning in the moral perception of AVs, disclosing personal and contingent information progressively throughout the experiment. With the use of the moral trilemma paradigm, two different VOI conditions were operationalized, inspired by the Original Position theory by John Rawls and the Equiprobability Model by John Harsanyi. Evidence suggests a significant role of VOI reasoning in affecting moral reasoning, which seems not independent from the order in which information is revealed. Coherently, a detrimental effect of self-involvement on utilitarian behaviours was detected. These results highlight the importance of considering PT accessibility and self-involvement when investigating moral attitudes towards AVs, since it can help the intelligibility of general concerns and hesitations towards this new technology

    de Branges-Rovnyak spaces: basics and theory

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    For SS a contractive analytic operator-valued function on the unit disk D{\mathbb D}, de Branges and Rovnyak associate a Hilbert space of analytic functions H(S){\mathcal H}(S) and related extension space D(S){\mathcal D(S)} consisting of pairs of analytic functions on the unit disk D{\mathbb D}. This survey describes three equivalent formulations (the original geometric de Branges-Rovnyak definition, the Toeplitz operator characterization, and the characterization as a reproducing kernel Hilbert space) of the de Branges-Rovnyak space H(S){\mathcal H}(S), as well as its role as the underlying Hilbert space for the modeling of completely non-isometric Hilbert-space contraction operators. Also examined is the extension of these ideas to handle the modeling of the more general class of completely nonunitary contraction operators, where the more general two-component de Branges-Rovnyak model space D(S){\mathcal D}(S) and associated overlapping spaces play key roles. Connections with other function theory problems and applications are also discussed. More recent applications to a variety of subsequent applications are given in a companion survey article

    The MAGIC Experiment and Its First Results

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    With its diameter of 17m, the MAGIC telescope is the largest Cherenkov detector for gamma ray astrophysics. It is sensitive to photons above an energy of 30 GeV. MAGIC started operations in October 2003 and is currently taking data. This report summarizes its main characteristics, its rst results and its potential for physics.Comment: 6 pages, 3 figures, to be published in the Proceedings of the 6th International Symposium ''Frontiers of Fundamental and Computational Physics'' (FFP6), Udine (Italy), Sep. 26-29, 200
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