33 research outputs found

    From drugs to deprivation: a Bayesian framework for understanding models of psychosis

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    Does trust play a role when it comes to donations? A comparison of Italian and US higher education institutions

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    Higher education institutions (HEIs) have experienced severe cutbacks in funding over the past few years, with universities examining options for alternative funding streams, such as alumni funding. Identifying the factors influencing their alumni's intentions to invest in their alma mater can be of significant importance when establishing a sustainable revenue stream. Within this context, empirical research on the potential role of trust is scarce. This paper aims to deepen the analysis of the relationship between alumni trust and engagement as well as three outcomes, namely support, commitment, and attitude toward donation. A structural equation model was tested on two samples of US (  = 318) and Italian (  = 314) alumni. Although both countries are affluent and developed countries, the USA has an established tradition of alumni donations, which is not such a developed practice in Italy. For both countries, results confirm that engagement is an antecedent of trust, which in turn leads to the three investigated outcomes (support, commitment, and attitude toward donations). In contrast, the effect of commitment on attitude toward donations is significant only for the USA universities. The paper has interesting theoretical and managerial implications. From a theoretical point of view, the study aims to address a gap concerning the role of trust in the HE context. Managerially, the study has significant implications for universities that want to change alumni attitude toward donations. [Abstract copyright: © Springer Nature B.V. 2020.

    Mismatch negativity encoding of prediction errors predicts S-ketamine-induced cognitive impairments

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    Psychotomimetics like the N-methyl-D-aspartate receptor (NMDAR) antagonist ketamine and the 5-hydroxytryptamine2A receptor (5-HT(2A)R) agonist psilocybin induce psychotic symptoms in healthy volunteers that resemble those of schizophrenia. Recent theories of psychosis posit that aberrant encoding of prediction errors (PE) may underlie the expression of psychotic symptoms. This study used a roving mismatch negativity (MMN) paradigm to investigate whether the encoding of PE is affected by pharmacological manipulation of NMDAR or 5-HT(2A)R, and whether the encoding of PE under placebo can be used to predict drug-induced symptoms. Using a double-blind within-subject placebo-controlled design, S-ketamine and psilocybin, respectively, were administrated to two groups of healthy subjects. Psychological alterations were assessed using a revised version of the Altered States of Consciousness (ASC-R) questionnaire. As an index of PE, we computed changes in MMN amplitudes as a function of the number of preceding standards (MMN memory trace effect) during a roving paradigm. S-ketamine, but not psilocybin, disrupted PE processing as expressed by a frontally disrupted MMN memory trace effect. Although both drugs produced positive-like symptoms, the extent of PE processing under placebo only correlated significantly with the severity of cognitive impairments induced by S-ketamine. Our results suggest that the NMDAR, but not the 5-HT(2A)R system, is implicated in PE processing during the MMN paradigm, and that aberrant PE signaling may contribute to the formation of cognitive impairments. The assessment of the MMN memory trace in schizophrenia may allow detecting early phases of the illness and might also serve to assess the efficacy of novel pharmacological treatments, in particular of cognitive impairments.Neuropsychopharmacology advance online publication, 26 October 2011; doi:10.1038/npp.2011.261

    Altered contextual modulation of primary visual cortex responses in schizophrenia

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    Schizophrenia is typically associated with higher-level cognitive symptoms, such as disorganized thoughts, delusions, and hallucinations. However, deficits in visual processing have been consistently reported with the illness. Here, we provide strong neurophysiological evidence for a marked perturbation at the earliest level of cortical visual processing in patients with paranoid schizophrenia. Using functional magnetic resonance imaging (fMRI) and adapting a well-established approach from electrophysiology, we found that orientation-specific contextual modulation of cortical responses in human primary visual cortex (V1)-a hallmark of early neural encoding of visual stimuli-is dramatically reduced in patients with schizophrenia. This indicates that contextual processing in schizophrenia is altered at the earliest stages of visual cortical processing and supports current theories that emphasize the role of abnormalities in perceptual synthesis (eg, false inference) in schizophrenia
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