Contextual determinants of intrusions and obsessions: The role of ego-dystonicity and the reality of obsessional thoughts

The current study aimed to investigate whether lack of evidence for the potential reality of the intrusion and ego-dystonicity are contextual determinants of unwanted intrusive thoughts and clinical obsessions. To this end, a total 248 non-clinical participants were asked to report an intrusion they had experienced as well as the context in which the intrusion arose. Utilizing this information, three independent clinicians rated these intrusions on ego-dystonicity and whether the intrusion had occurred with or without any evidence for its potential reality. Results showed that ego-dystonicity and lack of evidence for the intrusions were related, but distinct constructs. In particular, intrusions that occurred without evidence were significantly associated with higher levels of self-reported OC symptoms and related cognitive domains, whereas ego-dystonicity was not related to OC symptoms. Overall, the results are consistent with the notion that abnormal intrusions occur without evidence in the here-and-now, whereas normal intrusions do not. Intrusions that have no evidence to back them up, yet occur without any apparent cause, may be particularly likely to invite further negative cognitive processing, over-interpretation and control attempts. Implications for further research and treatment are discussed

Early Eocene clinoenstatite boninite and boninite-series dikes of the ophiolite of New Caledonia; a witness of slab-derived enrichment of the mantle wedge in a nascent volcanic arc

© 2016 Elsevier B.V.Clinoenstatite-bearing boninites (CE-boninite) from the serpentinite sole of the Cenozoic ophiolite of New Caledonia near Nepoui have been dated by the 40Ar/39Ar method, yielding two plateau ages of 47.4±0.9Ma and 50.4±1.3Ma. Coarser grained, geochemically similar boninite-series felsic dikes consistently yielded U-Pb zircon ages of ca. 54Ma.Nepoui CE-boninites display whole rock geochemical features similar to that of Cape Vogel boninites (Papua-New Guinea). They similarly have been generated by low degree hydrous melting of depleted peridotite. High contents in LILE and LREE, and some elemental ratios suggest source enrichment by subduction-derived fluids and melts. However, unlike the Cape Vogel boninite, moderately depleted MORB-like isotopic signatures (eNd50 =7.9) rule out the role of OIB-like, or E-MORB component that might account for the relatively high LREE and LILE contents measured in the rocks. Nd isotopic ratios and positive anomalies in Zr and Hf are closely similar to that of the slightly older felsic dikes (55-50Ma) that crosscut the peridotite from the ophiolite in New Caledonia. Most of these magmas have been generated by slab melting during the early stages of intra-oceanic subduction. The Early Eocene subduction started at or near the "oceanic" ridge and involved young and hot lithosphere; therefore, slab-derived melts may have reacted locally with hot depleted peridotites. Finally, water influx into the mantle wedge during the subduction of slightly older (cooler and hydrated) lithosphere initiated a low degree partial melting event in the mantle wedge and generated the CE-boninite magma.Geochemical modeling of hydrous melting of a depleted mantle re-enriched by slab melts suggest that the additional slab melt component was derived from the partial melting of a BABB-like barroisite-bearing eclogite, similar to some elements of the Eocene HP-LT Pouebo terrane. This potential magma source is similar to the BABB-like HT amphibolites of the metamorphic sole of the ophiolite, which have the same origin. Geochemical modeling also suggests that CE-boninite magma may have been in equilibrium with the enstatite-bearing gabbro cumulates that crop out in several places of the Massif du Sud.However, modeling fails in establishing that harzburgite of the same massif simply corresponds to the melting residue of this process. It appears that ultra-depleted supra-subduction peridotites of the Massif du Sud are probably not directly related to the overlying gabbro cumulates