Psilocybin and MDMA reduce costly punishment in the Ultimatum Game

Disruptions in social decision-making are becoming evident in many psychiatric conditions. These are studied using paradigms investigating the psychological mechanisms underlying interpersonal interactions, such as the Ultimatum Game (UG). Rejection behaviour in the UG represents altruistic punishment – the costly punishment of norm violators – but the mechanisms underlying it require clarification. To investigate the psychopharmacology of UG behaviour, we carried out two studies with healthy participants, employing serotonergic agonists: psilocybin (open-label, within-participant design, N = 19) and 3,4-methylenedioxymethamphetamine (MDMA; placebo-controlled, double-blind, crossover design, N = 20). We found that both MDMA and psilocybin reduced rejection of unfair offers (odds ratio: 0.57 and 0.42, respectively). The reduction in rejection rate following MDMA was associated with increased prosociality (R2 = 0.26, p = 0.025). In the MDMA study, we investigated third-party decision-making and proposer behaviour. MDMA did not reduce rejection in the third-party condition, but produced an increase in the amount offered to others (Cohen’s d = 0.82). We argue that these compounds altered participants’ conceptualisation of ‘social reward’, placing more emphasis on the direct relationship with interacting partners. With these compounds showing efficacy in drug-assisted psychotherapy, these studies are an important step in the further characterisation of their psychological effects

How and when plume zonation appeared during the 132 Myr evolution of the Tristan Hotspot

Increasingly, spatial geochemical zonation, present as geographically distinct, subparallel trends, is observed along hotspot tracks, such as Hawaii and the Galapagos. The origin of this zonation is currently unclear. Recently zonation was found along the last B70 Myr of the Tristan-Gough hotspot track. Here we present new Sr–Nd–Pb–Hf isotope data from the older parts of this hotspot track (Walvis Ridge and Rio Grande Rise) and re-evaluate published data from the Etendeka and Parana flood basalts erupted at the initiation of the hotspot track. We show that only the enriched Gough, but not the less-enriched Tristan, component is present in the earlier (70–132 Ma) history of the hotspot. Here we present a model that can explain the temporal evolution and origin of plume zonation for both the Tristan-Gough and Hawaiian hotspots, two end member types of zoned plumes, through processes taking place in the plume sources at the base of the lower mantle

Relative contributions of crust and mantle to generation of Campanian high-K calc-alkaline I-type granitoids in a subduction setting, with special reference to the Harsit Pluton, Eastern Turkey

We present elemental and Sr-Nd-Pb isotopic data for the magmatic suite (similar to 79 Ma) of the Harsit pluton, from the Eastern Pontides (NE Turkey), with the aim of determining its magma source and geodynamic evolution. The pluton comprises granite, granodiorite, tonalite and minor diorite (SiO(2) = 59.43-76.95 wt%), with only minor gabbroic diorite mafic microgranular enclaves in composition (SiO(2) = 54.95-56.32 wt%), and exhibits low Mg# (<46). All samples show a high-K calc-alkaline differentiation trend and I-type features. The chondrite-normalized REE patterns are fractionated [(La/Yb)(n) = 2.40-12.44] and display weak Eu anomalies (Eu/Eu* = 0.30-0.76). The rocks are characterized by enrichment of LILE and depletion of HFSE. The Harsit host rocks have weak concave-upward REE patterns, suggesting that amphibole and garnet played a significant role in their generation during magma segregation. The host rocks and their enclaves are isotopically indistinguishable. Sr-Nd isotopic data for all of the samples display I(Sr) = 0.70676-0.70708, epsilon(Nd)(79 Ma) = -4.4 to -3.3, with T(DM) = 1.09-1.36 Ga. The lead isotopic ratios are ((206)Pb/(204)pb) = 18.79-18.87, ((207)Pb/(204)Pb) = 15.59-15.61 and ((208)Pb/(204)Pb) = 38.71-38.83. These geochemical data rule out pure crustal-derived magma genesis in a post-collision extensional stage and suggest mixed-origin magma generation in a subduction setting. The melting that generated these high-K granitoidic rocks may have resulted from the upper Cretaceous subduction of the Izmir-Ankara-Erzincan oceanic slab beneath the Eurasian block in the region. The back-arc extensional events would have caused melting of the enriched subcontinental lithospheric mantle and formed mafic magma. The underplating of the lower crust by mafic magmas would have played a significant role in the generation of high-K magma. Thus, a thermal anomaly induced by underplated basic magma into a hot crust would have caused partial melting in the lower part of the crust. In this scenario, the lithospheric mantle-derived basaltic melt first mixed with granitic magma of crustal origin at depth. Then, the melts, which subsequently underwent a fractional crystallization and crustal assimilation processes, could ascend to shallower crustal levels to generate a variety of rock types ranging from diorite to granite. Sr-Nd isotope modeling shows that the generation of these magmas involved similar to 65-75% of the lower crustal-derived melt and similar to 25-35% of subcontinental lithospheric mantle. Further, geochemical data and the Ar-Ar plateau age on hornblende, combined with regional studies, imply that the Harsit pluton formed in a subduction setting and that the back-arc extensional period started by least similar to 79 Ma in the Eastern Pontides.Geochemistry & GeophysicsMineralogySCI(E)33ARTICLE4467-48716

Sr-Nd-Pb-O isotopic evidence for decreasing crustal contamination with ongoing magma evolution at Alicudi volcano (Aeolian arc, Italy): implications for style of magma-crust interaction and for mantle source compositions

New isotopic (Sr-Nd-Pb-O) data are reported for a suite of basalts (MgO up to 10 wt.%) to andesites and associated mineral separates from the Island of Alicudi, Aeolian arc, Southern Tyrrhenian Sea, with the aim of investigating the effects of magma-wall rock interaction in continental magmatic systems. Major and trace elements at Alicudi exhibit smooth variations, suggesting derivation of the entire suite from a single type of parental magma that underwent fractional crystallisation. However, (87)Sr/(86)Sr and delta(18)O values decrease, while (143)Nd/(144)Nd increases with increasing SiO(2) and decreasing MgO. Moreover, phenocryst phases show isotopic disequilibrium relative to whole rocks and groundmass. Such an unusual isotope vs. major and trace element variation and isotopic disequilibria suggest interaction between magmas and crustal wall rocks, but the decrease of (87)Sr/(86)Sr with increasing differentiation excludes assimilation-fractional crystallisation processes. We suggest that mafic calcalkaline magmas with primitive Sr-Nd-O isotopic signatures were intruded into a deep reservoir, where they underwent fractional crystallisation. Contamination occurred shortly before eruption, as the magmas ascended to the surface. Interactions between magmas and wall rocks were more extensive for the basalts than basaltic andesites and andesites, generating a positive correlation between MgO and (87)Sr/(86)Sr ratios. The variable degrees of magma-wall rock interaction are suggested to depend on the differing capabilities of magmas to dissolve crustal rocks due to variable temperature and viscosity. The present study, therefore, provides Sr-Nd-Pb-O isotopic evidence on an uncommon modality of magma contamination by upper crust. The Alicudi andesites have the most primitive isotope signatures over the entire Aeolian arc. In Plots of (206)Pb/(204)Pb vs. (87)Sr/(86)Sr or (143)Nd/(144)Nd isotopes, the bulk of the Aeolian volcanoes fall along a curved trend that connects HIMU mantlereservoir and the upper crust. In contrast, the Alicudi andesites fall outside this trend and plot on a binary trend connecting HIMU and EM1 mantle reservoirs. It is suggested that the Alicudi source consisted of a hybrid HIMU-EM1 mantle that was modified by fluids or melts coming from an oceanic stab. These fluids did not change significantly the isotopic signatures of the wedge but generated high LILE/HFSE ratios, which were inherited by the Alicudi magma. In contrast, the compositions of other Aeolian volcanoes and of central Italian magmatism reflect addition of upper crust to a HIMU or FOZO mantle. Collectively, the data record the complex interplay between different mantle reservoirs and the addition of various amounts and types of subduction-related components in the southern Tyrrhenian Sea. (C) 2004 Elsevier B.V. All rights reserved

Lower crustal contamination of Deccan Traps magmas: evidence from tholeiitic dykes and granulite xenoliths from western India

Evidence for the nature of contaminants of Deccan Traps magmas may be provided by crustal xenoliths in lamprophyre and tholeiitic dykes that intruded the Deccan lava pile towards the end of volcanic activity. The potential contaminants are represented by xenoliths that include mafic (plagioclase-poor) granulites and felsic (plagioclase-rich) granulites. The granulites in general are peraluminous, light-rare-earth-enriched and have high Ba/Nb, very low Sm/Nd and Rb/Sr ratios. The protoliths of mafic granulites were mostly cumulates (high Mg#, low SiO2/Al2O3) of sub-alkaline magmas. The felsic granulites are metaigneous quartz-normative rocks and have relatively low concentration of Ba and Sr compared to the mafic types. The dykes consist of picritic basalts and two varieties of tholeiitic basalts, and in general show a complex mineralogy indicative of magma mixing. The picrites have primitive Mg#s, relatively high Nb, Zr, Sr, Ba and Ba/Y, with relatively low Nb/Zr and Nb/Y compared to the more evolved tholeiites. In terms of Sr-Nd isotope systematics the older (thol I) dykes are less contaminated compared to the younger ones (thol II). These characteristics are consistent with fractional crystallisation and mixing between evolved and primitive tholeiitic melts coupled with assimilation of lower crustal felsic granulites. Petrogenetic modelling indicates fairly high rates of contamination for mafic magmas with high abundances of both compatible and incompatible elements. Similar processes of lower crustal contamination may have resulted in production of two of the major Deccan Traps lava formations, the Poladpur and Mahabaleshwar Formations, which are geochemically analogous to the tholeiitic dykes

The petrogenesis of sodic island arc magmas at Savo volcano, Solomon Islands

Savo, Solomon Islands, is a historically active volcano dominated by sodic, alkaline lavas, and pyroclastic rocks with up to 7.5 wt% Na2O, and high Sr, arc-like trace element chemistry. The suite is dominated by mugearites (plagioclase–clinopyroxene–magnetite ± amphibole ± olivine) and trachytes (plagioclase–amphibole–magnetite ± biotite). The presence of hydrous minerals (amphibole, biotite) indicates relatively wet magmas. In such melts, plagioclase is relatively unstable relative to iron oxides and ferromagnesian silicates; it is the latter minerals (particularly hornblende) that dominate cumulate nodules at Savo and drive the chemical differentiation of the suite, with a limited role for plagioclase. This is potentially occurring in a crustal “hot zone”, with major chemical differentiation occurring at depth. Batches of magma ascend periodically, where they are subject to decompression, water saturation and further cooling, resulting in closed-system crystallisation of plagioclase, and ultimately the production of sodic, crystal and feldspar-rich, high-Sr rocks. The sodic and hydrous nature of the parental magmas is interpreted to be the result of partial melting of metasomatised mantle, but radiogenic isotope data (Pb, Sr, Nd) cannot uniquely identify the source of the metasomatic agent. Electronic supplementary material The online version of this article (doi:10.1007/s00410-009-0410-9) contains supplementary material, which is available to authorized users

Development of Proteomic Prediction Models for Transition to Psychotic Disorder in the Clinical High-Risk State and Psychotic Experiences in Adolescence

Importance: Biomarkers that are predictive of outcomes in individuals at risk of psychosis would facilitate individualized prognosis and stratification strategies. Objective: To investigate whether proteomic biomarkers may aid prediction of transition to psychotic disorder in the clinical high-risk (CHR) state and adolescent psychotic experiences (PEs) in the general population. Design, Setting, and Participants: This diagnostic study comprised 2 case-control studies nested within the European Network of National Schizophrenia Networks Studying Gene-Environment Interactions (EU-GEI) and the Avon Longitudinal Study of Parents and Children (ALSPAC). EU-GEI is an international multisite prospective study of participants at CHR referred from local mental health services. ALSPAC is a United Kingdom-based general population birth cohort. Included were EU-GEI participants who met CHR criteria at baseline and ALSPAC participants who did not report PEs at age 12 years. Data were analyzed from September 2018 to April 2020. Main Outcomes and Measures: In EU-GEI, transition status was assessed by the Comprehensive Assessment of At-Risk Mental States or contact with clinical services. In ALSPAC, PEs at age 18 years were assessed using the Psychosis-Like Symptoms Interview. Proteomic data were obtained from mass spectrometry of baseline plasma samples in EU-GEI and plasma samples at age 12 years in ALSPAC. Support vector machine learning algorithms were used to develop predictive models. Results: The EU-GEI subsample (133 participants at CHR (mean [SD] age, 22.6 [4.5] years; 68 [51.1%] male) comprised 49 (36.8%) who developed psychosis and 84 (63.2%) who did not. A model based on baseline clinical and proteomic data demonstrated excellent performance for prediction of transition outcome (area under the receiver operating characteristic curve [AUC], 0.95; positive predictive value [PPV], 75.0%; and negative predictive value [NPV], 98.6%). Functional analysis of differentially expressed proteins implicated the complement and coagulation cascade. A model based on the 10 most predictive proteins accurately predicted transition status in training (AUC, 0.99; PPV, 76.9%; and NPV, 100%) and test (AUC, 0.92; PPV, 81.8%; and NPV, 96.8%) data. The ALSPAC subsample (121 participants from the general population with plasma samples available at age 12 years (61 [50.4%] male) comprised 55 participants (45.5%) with PEs at age 18 years and 61 (50.4%) without PEs at age 18 years. A model using proteomic data at age 12 years predicted PEs at age 18 years, with an AUC of 0.74 (PPV, 67.8%; and NPV, 75.8%). Conclusions and Relevance: In individuals at risk of psychosis, proteomic biomarkers may contribute to individualized prognosis and stratification strategies. These findings implicate early dysregulation of the complement and coagulation cascade in the development of psychosis outcomes