Modeling the Wikipedia to Understand the Dynamics of Long Disputes and Biased Articles

The Internet has provided us with a number of online collaborative environments, including platforms for open software developments and online encyclopedias such as Wikipedia. Conflicts may arise in the course of such collaboration, but despite differences of opinion consensus can be reached. By investigating the consensus-building processes, we can shed light on the dynamics of social behavior. In Wikipedia, it is not always easy for editors to agree about article content, especially considering people’s different tolerance levels towards others and for whatever may be written. In this paper, we focus on how the editors' attitudes, namely being broad-minded or stubborn, affect the consensus-building process in a model of Wikipedia. We further investigate how banning editors affects the speed with which conflicts or debates can be resolved. For the analysis, we use an agent-based opinion model developed to simulate different aspects of Wikipedia. We show that, in most cases, banning agents from editing an article slows down the consensus-building process, and increases the system’s relaxation time. We show further, and counterintuitively, that with large groups of “extremists” who hold other than the central opinion, consensus can be reached faster and the article will be less biased

Impaired mixed emotion processing in the right ventrolateral prefrontal cortex in schizophrenia: an fMRI study

Background: Schizophrenia has a negative effect on the activity of the temporal and prefrontal cortices in the processing of emotional facial expressions. However no previous research focused on the evaluation of mixed emotions in schizophrenia, albeit they are frequently expressed in everyday situations and negative emotions are frequently expressed by mixed facial expressions. Methods: Altogether 37 subjects, 19 patients with schizophrenia and 18 healthy control subjects were enrolled in the study. The two study groups did not differ in age and education. The stimulus set consisted of 10 fearful (100%), 10 happy (100%), 10 mixed fear (70% fear and 30% happy) and 10 mixed happy facial expressions. During the fMRI acquisition pictures were presented in a randomized order and subjects had to categorize expressions by button press. Results: A decreased activation was found in the patient group during fear, mixed fear and mixed happy processing in the right ventrolateral prefrontal cortex (VLPFC) and the right anterior insula (RAI) at voxel and cluster level after familywise error correction. No difference was found between study groups in activations to happy facial condition. Patients with schizophrenia did not show a differential activation between mixed happy and happy facial expression similar to controls in the right dorsolateral prefrontal cortex (DLPFC). Conclusions: Patients with schizophrenia showed decreased functioning in right prefrontal regions responsible for salience signaling and valence evaluation during emotion recognition. Our results indicate that fear and mixed happy/fear processing are impaired in schizophrenia, while happy facial expression processing is relatively intact

A nyaki ütőerek dissectiója – 19 eset retrospektív elemzése

Absztrakt: A cervicalis agyi erek dissectiója az ischaemiás stroke-betegség gyakori oka a fiatal felnőttek körében. Kialakulhat erőteljes nyaki trauma, de minor erőbehatás következtében is. Gyakori a spontán esetek előfordulása, melyek genetikai, anatómiai és környezeti tényezőkkel is összefüggésbe hozhatók. A kórkép klinikai megjelenése változatos, a tünetek lehetnek kizárólag helyi jellegűek, illetve az érintett arteriás területre jellemzőek. Korai felismerése kiemelkedően fontos, ugyanis az idejében megkezdett kezeléssel kimenetele számottevően javítható. A végleges diagnózis felállításához a képalkotó eljárások elengedhetetlenek. A közlemény célja a cervicalis agyi erek dissectiójának (carotis és vertebralis arteria dissectio) összefogló leírása 19 eset bemutatása kapcsán. A vizsgálat során három év alatt a Neurológiai Klinikán extracranialis arteria dissectio miatt kezelt betegek klinikai jellemzőit, rizikófaktorait, diagnosztikai eredményeit és terápiáját elemeztük. A kórkép prognózisa változatos, betegeink 42%-a tünetmentessé vált. Orv Hetil. 2019; 160(22): 861–868. | Abstract: Cervical artery dissection is a common cause of stroke in young adults. It might occur shortly after a forceful neck trauma or a minor injury. However, spontaneous dissection is also common, which is associated with genetic, anatomical or environmental risk factors. Cervical artery dissection can produce a broad spectrum of clinical presentation varying from local symptoms to focal neurological deficits determined by the arterial territory involved. Early recognition is important since immediate initiation of treatment can significantly improve patient outcomes. While clinical features may raise suspicion for dissection, the diagnosis has to be confirmed by neuroimaging findings. The purpose of this paper is to give an overview on cervical (carotid and vertebral) artery dissections while presenting 19 cases. During three years, we evaluated the clinical features, risk factors, diagnostic and therapeutic procedures of these patients admitted with extracranial artery dissection. The prognosis of the disease can vary, 42% of our patients became asymptomatic. Orv Hetil. 2019; 160(22): 861–868

Example time evolution for four initial groups.

<p><i>N</i> = 1000, <i>r</i> = 0.5, <i>ϵ</i>_<i>A</i> = 0.15, <i>μ</i>_<i>A</i> = 0.7, left: <i>RoE</i> = 0.2, right: <i>RoE</i> = 0.5.</p

Simulation results: (a) The logarithm of the relaxation time of the original model with three opinion groups and RoE = 0.5, (b) The ratio of the relaxation times with and without banning.

<p>Simulation results: (a) The logarithm of the relaxation time of the original model with three opinion groups and RoE = 0.5, (b) The ratio of the relaxation times with and without banning.</p

Colormaps of the logarithm of the relaxation time <i>τ</i> in function of <i>RoE</i> and <i>r</i> using simulations with <i>N</i> = 10000.

<p>Top row 3, bottom row 4 groups, left regime II, and right regime III. The lower two graphs show cuts at <i>r</i> = 0.5 and <i>RoE</i> = 0.5 respectively. Let us note the log-linear scale and the relaxation time sometimes grows an order of magnitude within small changes of <i>RoE</i>.</p

Number of edits versus number of bannings (minus 1) in Wikipedia and in the model.

<p>Notation: en: English, de: German, fa: Persian. On the main plot only simulation results of regime III is shown the numerical results of the other regimes of the model are only shown in the inset.</p

The revert/edit ratio (corresponding to <i>τ</i>) vs. the ratio of edits to talk/article pages (corresponding to <i>r</i>) for 13 different Wikipedia language editions (en: English, West European (red): de: German, fr: French, es: Spanish, pt: Portugal, Eastern European (blue): cs: Czech, hu: Hungarian, ro: Romanian, Middle-East (pink): ar: Arabic, fa: Persian, he: Hebrew, Far-East (green): zh: Chinese, ja: Japanese.

<p>The revert/edit ratio (corresponding to <i>τ</i>) vs. the ratio of edits to talk/article pages (corresponding to <i>r</i>) for 13 different Wikipedia language editions (en: English, West European (red): de: German, fr: French, es: Spanish, pt: Portugal, Eastern European (blue): cs: Czech, hu: Hungarian, ro: Romanian, Middle-East (pink): ar: Arabic, fa: Persian, he: Hebrew, Far-East (green): zh: Chinese, ja: Japanese.</p

Distribution of relaxation time for different number of initial opinion groups for <i>μ</i>_<i>A</i> = 0.65 and <i>ϵ</i>_<i>A</i> = 0.25.

<p>Distribution of relaxation time for different number of initial opinion groups for <i>μ</i>_<i>A</i> = 0.65 and <i>ϵ</i>_<i>A</i> = 0.25.</p

Overall statistics of the language editions under study.

<p>Overall statistics of the language editions under study.</p