Neuroimaging-Based Classification of PTSD Using Data-Driven Computational Approaches:A Multisite Big Data Study from the ENIGMA-PGC PTSD Consortium

BACKGROUND: Recent advances in data-driven computational approaches have been helpful in devising tools to objectively diagnose psychiatric disorders. However, current machine learning studies limited to small homogeneous samples, different methodologies, and different imaging collection protocols, limit the ability to directly compare and generalize their results. Here we aimed to classify individuals with PTSD versus controls and assess the generalizability using a large heterogeneous brain datasets from the ENIGMA-PGC PTSD Working group.METHODS: We analyzed brain MRI data from 3,477 structural-MRI; 2,495 resting state-fMRI; and 1,952 diffusion-MRI. First, we identified the brain features that best distinguish individuals with PTSD from controls using traditional machine learning methods. Second, we assessed the utility of the denoising variational autoencoder (DVAE) and evaluated its classification performance. Third, we assessed the generalizability and reproducibility of both models using leave-one-site-out cross-validation procedure for each modality.RESULTS: We found lower performance in classifying PTSD vs. controls with data from over 20 sites (60% test AUC for s-MRI, 59% for rs-fMRI and 56% for d-MRI), as compared to other studies run on single-site data. The performance increased when classifying PTSD from HC without trauma history in each modality (75% AUC). The classification performance remained intact when applying the DVAE framework, which reduced the number of features. Finally, we found that the DVAE framework achieved better generalization to unseen datasets compared with the traditional machine learning frameworks, albeit performance was slightly above chance.CONCLUSION: These results have the potential to provide a baseline classification performance for PTSD when using large scale neuroimaging datasets. Our findings show that the control group used can heavily affect classification performance. The DVAE framework provided better generalizability for the multi-site data. This may be more significant in clinical practice since the neuroimaging-based diagnostic DVAE classification models are much less site-specific, rendering them more generalizable.</p

Many Labs 5:Testing pre-data collection peer review as an intervention to increase replicability

Replication studies in psychological science sometimes fail to reproduce prior findings. If these studies use methods that are unfaithful to the original study or ineffective in eliciting the phenomenon of interest, then a failure to replicate may be a failure of the protocol rather than a challenge to the original finding. Formal pre-data-collection peer review by experts may address shortcomings and increase replicability rates. We selected 10 replication studies from the Reproducibility Project: Psychology (RP:P; Open Science Collaboration, 2015) for which the original authors had expressed concerns about the replication designs before data collection; only one of these studies had yielded a statistically significant effect (p < .05). Commenters suggested that lack of adherence to expert review and low-powered tests were the reasons that most of these RP:P studies failed to replicate the original effects. We revised the replication protocols and received formal peer review prior to conducting new replication studies. We administered the RP:P and revised protocols in multiple laboratories (median number of laboratories per original study = 6.5, range = 3?9; median total sample = 1,279.5, range = 276?3,512) for high-powered tests of each original finding with both protocols. Overall, following the preregistered analysis plan, we found that the revised protocols produced effect sizes similar to those of the RP:P protocols (?r = .002 or .014, depending on analytic approach). The median effect size for the revised protocols (r = .05) was similar to that of the RP:P protocols (r = .04) and the original RP:P replications (r = .11), and smaller than that of the original studies (r = .37). Analysis of the cumulative evidence across the original studies and the corresponding three replication attempts provided very precise estimates of the 10 tested effects and indicated that their effect sizes (median r = .07, range = .00?.15) were 78% smaller, on average, than the original effect sizes (median r = .37, range = .19?.50)

When the Indelible Sacrament of Baptism Met Mercantile Raison d\u27Etat

In theory, under almost all circumstances, once a Jew had been baptized, s/he became a Christian and any relapse constituted heresy and was liable to severe punishment, often by death. However, in the mid-sixteenth century the Papacy adopted a far more lenient policy out of considerations of commercial raison d\u27 état and invited New Christian merchants to assume Judaism in Ancona with assurance of complete freedom from any persecution. At the same time, Venice expelled all Marranos from the city and forbade them to return. The papal attitude changed with the Counter-Reformation and former New Christians who had reverted to Judaism in Ancona were burned at the stake. However, slightly later in a step that was followed by the Medici for Pisa-Livorno, the Venetian government invited New Christians to settle in Venice freely on the condition that they assumed Judaism and resided in the ghetto as Jews and assured them that their past conduct would not be investigated. In justification, among other arguments the Venetians pointed out that since Popes had once granted such permissions, it could not be claimed that they were forbidden by canon law. An examination of select passages from the documents preserved regarding the issuing of the first charter of the Levantine and Ponentine merchants in Venice in 1589, the two opening passages of the second charter in 1598, and a consulto of the Venetian consultore in iure Paolo Sarpi will illustrate the ideological background and practical manifestations of the new attitude toward New Christians assuming Judaism and their resulting legal status, which can be seen as one of the harbingers of a new attitude of European states toward Jews determined by economic considerations of raison d’état rather than by religious concerns. This presentation is for the following text(s): Paolo Sarpi, the Venetian Consultore in Iure, on the case of Simon Gomez The Expulsion of the Marranos From Venice The First Charter of the Levantine and Ponentine Jewish Merchants of Venice The Second Charter of the Levantine and Ponentine Jewish Merchants of Venic