A number of studies have shown that modulating cortical activity by means of transcranial direct current stimulation (tDCS) affects performances of both healthy and brain-damaged subjects. In this study, we investigated the potential of tDCS to enhance associative verbal learning in 10 healthy individuals and to improve word retrieval deficits in three patients with stroke-induced aphasia. In h...

In many tasks related to reasoning about consequences of a logical theory, it is desirable to decompose the theory into a number of components with weakly-related or independent signatures. This facilitates reasoning when the signature of a query formula belongs to only one of the components. However, an initial theory may be subject to change due to execution of actions affecting features ment...

In this paper we consider updates that are specified as rules and consider simple knowledge bases consisting of ground atoms. We present a translation of the rule based update specifications to extended logic programs using situation calculus notation so as to compute the updated knowledge base. We show that the updated knowledge base that we compute satisfies the update specifications and yet ...

Location estimation is a fundamental sensing task in robotic applications, where the world is uncertain, and sensors and effectors are noisy. Most systems make various assumptions about the dependencies between state variables, and especially about how these dependencies change as a result of actions. Building on a general framework by Bacchus, Halpern and Levesque for reasoning about degrees o...

We propose a model of belief and intention change over the course of a dialogue, in the case where the decisions taken during the dialogue affect the possibly conflicting goals of the agents involved. We use Situation Calculus to model the evolution of the world and an observation model to analyze the evolution of intentions and beliefs. In our formalization, utterances, that only change the be...

The situation calculus (SC) is a formalism for reasoning about action. Within SC, the notion of state of a given situation is usually characterized by the set of uents that hold in that situation. However, this concept is insuucient for system speciication. To overcome this limitation, an extension of SC is proposed, the situation and state calculus (SSC), where the concept of state is primitiv...

In this work we consider how to enforce norms in the Situation Calculus based programming language Golog and its relatives. We define a notion of norm compliant sequence of actions with respect to norms prescribing some actions to be forbidden or obliged (ought-to-do norms), norms prescribing that a state-condition is forbidden (oughtto-be norms) and norms that are a form of deadline. We then s...

The concept of indirectness (using of tools) in automatic problem solving is investigated, and a formal approach is suggested within the framework of the Situation Calculus. The "Robot and Box" problem serves as an illustrative example throughout the paper.