Common knowledge of payoff uncertainty in games

Using epistemic logic, we provide a non-probabilistic way to formalise payoff uncertainty, that is, statements such as ‘player i has approximate knowledge about the utility functions of player j.’ We show that on the basis of this formalisation common knowledge of payoff uncertainty and rationality (in the sense of excluding weakly dominated strategies, due to Dekel and Fudenberg (1990)) characterises a new solution concept we have called ‘mixed iterated strict weak dominance.’     

A formalisation of violation, error recovery, and enforcement in the bit transmission problem

The design of complex multi-agent systems is increasingly having to confront the possibility that agents may not behave as they are supposed to. In addition to analysing the properties that hold if protocols are followed correctly, it is also necessary to predict, test, and verify the properties that would hold if these protocols were to be violated. We illustrate how the formal machinery of deontic interpreted systems can be applied to the analysis of such problems by considering three variations of the bit transmission problem. The first, an example in which an agent may fail to do something it is supposed to do, shows how we deal with violations of protocols and specifications generally. The second, an example in which an agent may do something it is not supposed to do, shows how it is possible to specify and analyse remedial or error-recovery procedures. The third combines both kinds of faults and introduces a new component into the system, a controller, whose role is to enforce compliance with the protocol. In each case the formal analysis is used to test whether critical properties of the system are compromised, in this example, the reliable communication of information from one agent to the other.     

Mentalizing Family Violence Part 1: Conceptual Framework

This is the first of two companion papers describing concepts and techniques of a mentalization‐based approach to understanding and managing family violence. We review evidence that attachment difficulties, sudden high levels of arousal, and poor affect control contribute to a loss of mentalizing capacity, which, in turn, undermines social learning and can favor the transgenerational transmission of violent interaction patterns. It is suggested that physically violent acts are only possible if mentalizing is temporarily inhibited or decoupled. However, being mentalized in the context of attachment relationships in the family generates epistemic trust within the family unit and reduces the likelihood of family violence. The implications of this framework for therapeutic work with families are discussed.     

信念修正的AGM理论

信念修正问题是一个富有活力的,正在发展的研究主题。这个主题包括了一大批背景不同、形态各异的理论。阿尔罗若(C．E．Alchourron)、加德福斯(P．Gardenfors)和梅金森(D．Markinson)共同建立的信念修正理论(简称AGM理论)是其中形成比较早的、影响最大的理论。本文说明信念修正的基本概念,并且对AGM理论进行述评.     

The role of nucleus accumbens and dorsolateral striatal D2 receptors in active avoidance conditioning

The role of dopamine (DA) in rewarding motivated actions is well established but its role in learning how to avoid aversive events is still controversial. Here we tested the role of D2-like DA receptors in the nucleus accumbens (NAc) and the dorsolateral striatum (DLS) of rats in the learning and performance of conditioned avoidance responses (CAR). Adult male Wistar rats received systemic, intra-NAc or intra-DLS (pre- or post-training) administration of a D2-like receptor agonist (quinpirole) or antagonist ((−)sulpiride) and were given two sessions in the two-way active avoidance task. The main effects observed were: (i) sulpiride and lower (likely pre-synaptic) doses of quinpirole decreased the number of CARs and increased the number of escape failures; (ii) higher doses of quinpirole (likely post-synaptic) increased inter-trial crossings and failures; (iii) pre-training administration of sulpiride decreased the number of CARs in both training and test sessions when infused into the NAc, but this effect was observed only in the test session when it was infused into the DLS; (iv) post-training administration of sulpiride decreased CARs in the test session when infused into the NAc but not DLS. These findings suggest that activation of D2 receptors in the NAc is critical for fast adaptation to responding to unconditioned and conditioned aversive stimuli while activation of these receptors in the DLS is needed for a slower learning of how to respond to the same stimuli based on previous experiences.     

Changing your mind about things unseen: Toddlers' sensitivity to prior reliability

The goal of this research was to investigate the extent to which young children use the past reliability of another person’s statements to make inferences about the accuracy of that person’s claims about a hidden toy. When children interacted with a previously reliable speaker, both 30- and 36-month-olds searched in the new location of the toy, in line with the speaker’s statement. When children interacted with an unreliable speaker, the 36-month-olds were less likely to rely on her false statement and instead searched either in the original location of the toy or in a neutral location. The 30-month-olds, however, searched in the location indicated by the speaker even when the speaker was unreliable. These results show that by 36 months of age, children begin to use reliability in processing a speaker’s episodic claims and can flexibly update their representations of absent objects depending on the reliability of the speaker.     

Democratic Answers to Complex Questions – An Epistemic Perspective

This paper addresses a problem for theories of epistemic democracy. In a decision on a complex issue which can be decomposed into several parts, a collective can use different voting procedures: Either its members vote on each sub-question and the answers that gain majority support are used as premises for the conclusion on the main issue (premise based-procedure, pbp), or the vote is conducted on the main issue itself (conclusion-based procedure, cbp). The two procedures can lead to different results. We investigate which of these procedures is better as a truth-tracker, assuming that there exists a true answer to be reached. On the basis of the Condorcet jury theorem, we show that the pbp is universally superior if the objective is to reach truth for the right reasons. If one instead is after truth for whatever reasons, right or wrong, there will be cases in which the cbp is more reliable, even though, for the most part, the pbp still is to be preferred.     

Removing Inconsistencies in Assumption-based Theories Through Knowledge-Gathering Actions

In this paper, the problem of purifying an assumption-based theory KB, i.e., identifying the right extension of KB using knowledge-gathering actions (tests), is addressed. Assumptions are just normal defaults without prerequisite. Each assumption represents all the information conveyed by an agent, and every agent is associated with a (possibly empty) set of tests. Through the execution of tests, the epistemic status of assumptions can change from "plausible" to "certainly true", "certainly false" or "irrelevant", and the KB must be revised so as to incorporate such a change. Because removing all the extensions of an assumption-based theory except one enables both identifying a larger set of plausible pieces of information and renders inference computationally easier, we are specifically interested in finding out sets of tests allowing to purify a KB (whatever their outcomes). We address this problem especially from the point of view of computational complexity.     

Emotionally guiding our actions

If emotions have a rational role in action, then one challenge for accounting for how we can act rationally when acting emotionally is to show how we can guide our actions by our emotional considerations, seen as reasons. In this paper, I put forward a novel proposal for how this can be so. Drawing on the interconnection between emotions, cares and caring, I argue that, as the emotional agent is a caring agent, she can be aware of the emotional consideration as a pro tanto reason favouring an action choice and, even, as the reason for which she should act.