Communication, leadership and coordination failure

We investigate the limits of communication and leadership in avoiding coordination failure in minimum effort games. Our environment is challenging, with low benefits of coordination relative to the effort cost. We consider two leader types: cheap-talk leader-communicators who suggest an effort level, and first-mover leaders who lead by example. Both types of leadership have some ability to increase effort in groups with no history, but are insufficient in groups with a history of low effort. Using the strategy method for followers’ responses, we attribute the persistence of coordination failure to the presence of followers who do not follow the leader

Cycles of maximin and utilitarian policies under the veil of ignorance

International audienc

Síndrome de Down e Moyamoya: estudo através de metanálise Moyamoya and Down syndrome: study conducted by meta-analysis

Apresentamos o estudo clínico-epidemiológico de dois pacientes e metanálise (período 1977-2000) sobre a comorbidade entre síndrome de Down (SD) e síndrome de "moyamoya" (SMM). Entre os 42 pacientes catalogados no presente estudo, a metanálise permitiu verificar: maior número de publicações de pesquisadores do Japão e Estados Unidos, seguidos pelo Brasil e Itália; predomínio do acidente vascular cerebral (AVC) em lactentes e pré-escolares; sintomatologia inaugural, hemiparesia (78,6%), distúrbio da fala (26,2%); predomínio de infarto isquêmico (76,2%); episódios isquêmicos recorrentes (62%); comprometimento bilateral (83,3%). Esta análise permitiu concluir que, na investigação clínico-neurológica de pacientes com SD e episódios de hemiparesia aguda, a SMM deve ser incluída como diagnóstico mais provável .<br>We present a clinic-epidemiological study of two patients and meta-analysis (period 1977-2000 ) of the co-morbidity of the Down syndrome (DS) and moyamoya syndrome (MMS). Among the 42 patients listed in this survey, meta-analysis permitted to find the highest number of publications by researchers from Japan and United States, followed by Brazil and Italy; prevalence of cerebrovascular disease in suckling and pre school children; first symptomatology was hemiparesis (78.6%), speech disorders (26.2%); ischemic infarction (76.2%); recurring ischemic episodes (62%); bilateral impairment (83.3%). This analysis led to the conclusion that in the clinic-neurological investigation of DS patients with acute hemiparesis episodes, MMS should be included as the most probable diagnosis

The neural signatures of egocentric bias in normative decision-making

Bargaining parties often disagree on what fair is, due to the reason that people are prone to believe that what favors oneself is fair, i.e., an egocentric bias. In this study, we investigated the neural signatures underlying egocentric bias in fairness decision-making, conjoining an adapted ultimatum game (UG) with event-related fMRI and functional connectivity. Participants earned monetary rewards with a partner in a production stage, wherein their contributions to the earnings were manipulated. Afterwards, the joint earnings were randomly divided, and the distribution was presented simultaneously with contribution information to participants, who accepted/rejected distributions of earnings as the same manner in standard UG. We identified an egocentric bias in fairness decisions, such that participants frequently rejected self-contributed disadvantageous outcomes, but much less so in response to other-contributed advantageous outcomes, although both involved mismatch between contribution and payoff. This bias was underpinned by regions involved in representing fairness norms, including the anterior insula and dorsal anterior cingulate cortex (dACC). Furthermore, the thalamus activity was predictive of the bias, such that the level of egocentric bias decreased as a function of the activation level of the thalamus. Finally, our functional-connectivity findings indicated that the thalamus worked together with insula and dACC to modulate behavioral egocentric bias in fairness-related decisions. Our findings uncover the neural basis underlying the modulation of egocentric bias in normative decision-making, and highlight the role of neural circuits associated with norm enforcement in this phenomenon