Belief inference for hierarchical hidden states in spatial navigation.

Uncertainty abounds in the real world, and in environments with multiple layers of unobservable hidden states, decision-making requires resolving uncertainties based on mutual inference. Focusing on a spatial navigation problem, we develop a Tiger maze task that involved simultaneously inferring the local hidden state and the global hidden state from probabilistically uncertain observation. We adopt a Bayesian computational approach by proposing a hierarchical inference model. Applying this to human task behaviour, alongside functional magnetic resonance brain imaging, allows us to separate the neural correlates associated with reinforcement and reassessment of belief in hidden states. The imaging results also suggest that different layers of uncertainty differentially involve the basal ganglia and dorsomedial prefrontal cortex, and that the regions responsible are organised along the rostral axis of these areas according to the type of inference and the level of abstraction of the hidden state, i.e. higher-order state inference involves more anterior parts.

Guidelines on nutritional management in Japanese patients with liver cirrhosis from the perspective of preventing hepatocellular carcinoma.

AIM: The Japanese Nutritional Study Group for Liver Cirrhosis (JNUS) was assembled in 2008 with the support of a Health Labor Sciences Research Grant from the Ministry of Health, Labor and Welfare of Japan. The goal of the study group was to propose new nutritional guidelines for Japanese patients with liver cirrhosis (LC), with the aim of preventing hepatocellular carcinoma. METHODS: Between 2008 and 2010, the member investigators of JNUS conducted various clinical and experimental studies on nutrition on LC. These included anthropometric studies, a questionnaire study on daily nutrient intake, clinical trials, experimental studies using animal models, re-evaluation of previous publications and patient education. Over this 3-year period, the group members regularly discussed the nutritional issues related to LC, and a proposal was finally produced. RESULTS: Based on the results of JNUS projects and discussions among the members, general recommendations were made on how Japanese patients with LC should be managed nutritionally. These recommendations were proposed with a specific regard to the prevention of hepatocarcinogenesis. CONCLUSION: The new JNUS guidelines on nutritional management for Japanese patients with LC will be useful for the actual nutritional management of patients with LC. The JNUS members hope that these guidelines will form the basis for future discussions and provide some direction in nutritional studies in the field of hepatology.