Small-World Properties of Nonlinear Brain Activity in Schizophrenia

Abstract: A disturbance in the interactions between distributed cortical regions may underlie the cogni-tive and perceptual dysfunction associated with schizophrenia. In this article, nonlinear measures of cortical interactions and graph-theoretical metrics of network topography are combined to investigate this schizophrenia ‘‘disconnection hypothesis.’ ’ This is achieved by analyzing the spatiotemporal struc-ture of resting state scalp EEG data previously acquired from 40 young subjects with a recent first epi-sode of schizophrenia and 40 healthy matched controls. In each subject, a method of mapping the to-pography of nonlinear interactions between cortical regions was applied to a widely distributed array of these data. The resulting nonlinear correlation matrices were converted to weighted graphs. The path length (a measure of large-scale network integration), clustering coefficient (a measure of ‘‘cliqu-ishness’’), and hub structure of these graphs were used as metrics of the underlying brain network ac-tivity. The graphs of both groups exhibited high levels of local clustering combined with comparatively short path lengths—features consistent with a ‘‘small-world’ ’ topology—as well as the presence of strong, central hubs. The graphs in the schizophrenia group displayed lower clustering and shorter path lengths in comparison to the healthy group. Whilst still ‘‘small-world,’ ’ these effects are consistent with a subtle randomization in the underlying network architecture—likely associated with a greate

Some topical aspects to take into account the objects of the intellectual property in the Russian Federation

В статье рассмотрены актуальные аспекты учета нематериальных активов субъектов хозяйствования в рамках их деятельности, в настоящее время не имеющие должного отражения в нормативных документах, на сновании которых должен осуществляться учет объектов их интеллектуальной собственности

Impairment and distress patterns distinguishing the melancholic depression subtype: An iSPOT-D report

10.1016/j.jad.2014.10.046Journal of Affective Disorders174493-50