Search

How can goals be represented in natural and artificial systems? How can they be learned? How can they trigger actions? This paper describes, analyses and compares two of the most influential models of goal-oriented behavior: the ideomotor principle (IMP), which was introduced in the psychological literature, and the "test, operate, test, exit" model (TOTE), proposed in the field of cybernetics. This analysis indicates that the IMP and the TOTE highlight complementary aspects of goal-orientedness. In order to illustrate this point, the paper reviews three computational architectures that implement various aspects of the IMP and the TOTE, discusses their main peculiarities and limitations, and suggests how some of their features can be translated into specific mechanisms in order to implement them in artificial intelligent systems. [ABSTRACT FROM AUTHOR]

When agents act is a common environment they leave traces. In this paper we explore the importance of using such traces as signals (stigma). Trace signals enable a flexible way to support indirect interaction between agents without adopting dedicated communication channels and signals. Although the kind of messages that can be exchanged with traces is limited, their importance for decentralized and dynamic multi-agent systems is vast. A taxonomy of trace-signals is provided and their role in different social interactions is explored. Some of the benefits and limitations of this trace-based communication are discussed. [ABSTRACT FROM AUTHOR]

Trust can be viewed as an instrument both for an agent selecting the right partners in order to achieve its own goals (the point of view of the trustier), and for an agent of being selected from other potential partners (the point of view of the trustee) in order to establish with them a cooperation/ collaboration and to take advantage from the accumulated trust. In our previous works we focused our main attention on the first point of view. In this paper we will analyze trust as the agents' relational capital. Starting from the classical dependence network (in which needs, goals, abilities and resources are distributed among the agents) with potential partners, we introduce the analysis of what it means for an agent to be trusted and how this condition could be strategically used from it for achieving its own goals, that is, why it represents a form of power. Although there is a big interest in literature about ‘social capital' and its powerful effects on the wellbeing of both societies and individuals, often it is not clear enough what is it the object under analysis. Individual trust capital (relational capital) and collective trust capital not only should be disentangled, but their relations are quite complicated and even conflicting. To overcome this gap, we propose a study that first attempts to understand what trust is as capital of individuals. In which sense "trust" is a capital. How this capital is built, managed and saved. In particular, how this capital is the result of the others' beliefs and goals. Then we aim to analytically study the cognitive dynamics of this object. [ABSTRACT FROM AUTHOR]

Observation is the basis of a very crucial form of Communication without words or special protocols. Efficient coordination - in humans but also in artificial Agents - exploits or should exploit not just ‘observation' but more precisely this form of silent communication: when Agent X relies on the fact that Agent Y is observing her in order to let Y understand that p, i.e. for communicating to Y that p. The general theory of behavioral implicit communication (BIC) is presented. Its importance in social interaction is discussed. We will illustrate why this is crucial for mutual understanding and for comitment and norms keeping, imitation and learning, etc. The message-sending paradigm dominating CSCW, MAS, HCI, and H-Robot-I, is criticized. The relationship with the ill-defined but important notion of stigmergy (very used in ALife Agents) is analyzed. [ABSTRACT FROM AUTHOR]

The main objective of this work is to develop a multi-modal logic of Intention and Attempt. We call this logic LIA. All formal results are focused on the notion of attempt. We substitute the dynamic molecular notion action by his atomic constituent attempt and define the former from the latter. The relations between attempts, goals, beliefs and present-directed intentions are studied. A section of the paper is devoted to the analysis of the relations of our modal logic with a situation calculus-style approach. [ABSTRACT FROM AUTHOR]

Coordination between multiple autonomous agents is a major issue for open multi-agent systems. This paper proposes the notion of Behavioural Implicit Communication (BIC) originally devised in human and animal societies as a new and critical coordination mechanism also for artificial agents. BIC is a parasitical form of communication that exploits both some environmental properties and the agents' capacity to interpret their actions. In this paper we abstract from the agents' architecture to focus on the interaction mediated by the environment. Observability of the environment - and in particular of agents' actions - is crucial for implementing BIC-based form of coordination in artificial societies. Accordingly in this paper we introduce an abstract model of environment providing services to enhance observation power of agents, enabling BIC and other form of observation-based coordination. Also, we describe a typology of environments and examples of observation based coordination with and without implicit communication. [ABSTRACT FROM AUTHOR]

This work is about the central role of "expectations" in mental life and in purposive action. We will present a Cognitive Anatomy of expectations, their reduction in terms of more elementary ingredients: beliefs and goals. Moreover, those ingredients will be considered in their ‘quantitative' dimension: the value of the Goal, the strength of the Beliefs. We will base several predictions on this analytical decomposition, and sketch a theory of hope, fear, frustration, disappointment, and relief, strictly derived from the analysis of expectations. Eventually, we will discuss how can we capture the global subjective character of such mental states that we have decomposed; how to account for their gestaltic nature. [ABSTRACT FROM AUTHOR]

This paper compares within the MAS framework two separate threads in the formal study of epistemic change: belief revision and argumentation theories. Belief revision describes how an agent is supposed to change his own mind, while argumentation deals with persuasive strategies employed to change the mind of other agents. These are two sides (cognitive and social) of the same epistemic coin: argumentation theories are incomplete, if they cannot be grounded in belief revision models - and vice versa. Nonetheless, so far the formal treatment of belief revision mostly neglected any systematic comparison with argumentation theories. In MAS such problem becomes evident and inescapable: belief change is usually triggered by communication and persuasion from other agents, involving deception, trust, reputation, negotiation, conflict resolution (all typical issues faced by argumentation-based models). Therefore, a closer comparison between belief revision and argumentation is a necessary preliminary step towards an integrated model of epistemic change in MAS. [ABSTRACT FROM AUTHOR]

In this paper we use a contract net protocol in order to compare various delegation strategies. We have implemented some different agents, having a set of tasks to delegate (or to perform by themselves); the tasks are performed by the agents in a dynamic environment, that can help or worse their activity. The agent rely upon different strategies in order to choose whom to delegate. We implemented three classes of trustiers: a random trustier (who randomly chooses the trustee whom delegate the task to); a statistical trustier (who builds the trustworthiness of other agents only on the basis of their previous performances); a cognitive trustier (who builds a sophisticated and cognitively motivated trust model of the trustee, taking into account its specific features, its ability and motivational disposition, and the impact of the environment on its performance). Our experiments show the advantage of using cognitive representations. [ABSTRACT FROM AUTHOR]

One of the main challenges in multi-agent systems is the coordination of autonomous agents. In order to achieve this coordination, the agents are considered to be part of what we call a group (e.g., organization, institution, team, normative society, etc.). Our goal is to enable an agent to reason about the implications of being part of a group: what does it gain or lose, what are the constraints imposed on its behaviour. The theory of social power has been proposed as a paradigm to describe the agent's behaviour. In this paper we use this theory, we formalize it and we extend it to include group-related aspects. We then show how, using this theory, an agent is able to reason about the constraints imposed on its behaviour by the group, for example to decide whether it should enter or not a group. [ABSTRACT FROM AUTHOR]

I claim that two important aspects of emotions are usually missed by current computational models and uses. On the one side, human emotions are complex and rich mental states, not simple reactive mechanisms. They have rich cognitive ingredients, in particular "evaluations". I will propose some brief example of such a necessary "cognitive anatomy" (in terms of beliefs and goals) of complex social emotions (for ex. shame) and of the "meaning" of their expression. On the other side, emotions are felt; and we do not have a model about what it does mean to "feel" something, about the unavoidable role of a "body" in this, and about the necessary function of the feeling component in the emotional process. In this perspective, in particular it becomes very important the distinction between a true "cognitive evaluation" and merely intuitive and implicit affective_appraisal. I exemplify this distinction in the analysis of "trust". Finally, I wonder about the importance of the affective appraisal Vs the explicit evaluations in Affective Computing and in HC and computer mediated interactions. Are these cognitive complex emotions, are these felt and embodied emotions, are explicit evaluations or intuitive appraisals useful and why? I also discuss a bit the relationships between emotion and motivation, and between emotion and personality, that on my view are currently quite mixed up. [ABSTRACT FROM AUTHOR]

In this paper norms are assumed to be useful in agent societies. It is claimed that not only following norms, but also the possibility of ‘intelligent' norm violation can be useful. Principles for agents that are able to behave deliberatively on the basis of explicitly represented norms are identified and an architecture is introduced. Using this agent architecture, norms can be communicated, adopted and used as meta-goals on the agent's own processes. As such they have impact on deliberation about goal generation, goal selection, plan generation and plan selection. [ABSTRACT FROM AUTHOR]

It is generally acknowledged that norms and normative action emphasize autonomy on the side of decision. But what about the autonomous formation of normative goals? This paper is intended to contribute to a theory of how agents form normative beliefs and goals, and to formulate general but non exhaustive principles of norm based autonomous agent-hood - namely goal generation and decision making-upon which to construct software agents. [ABSTRACT FROM AUTHOR]

In this paper, we try to identify the relationships among three main (in our view) proposals of the basic mental attitudes in collaborative problem solving (the Toumela's theory of acting together, in particular the notion of We-Intention; the Grosz and Kraus' theory of collaboration, with special attention to the notion of Intention-that, and the Castelfranchi and Falcone' theory of Delegation-Adoption). We show several overlaps, convergencies, but also complementarities, contradictions and competitions among these theories. The aim of this paper is some clarification and systematisation of the necessary mental attitudes in agents' mind that characterise acting together and cooperating. We will not consider in this analysis other very important mental ingredients of complex forms of collaboration, like agents' motivations in taking part in collective activity, trust, and normative components: permissions, rights, norms, roles, etc. [ABSTRACT FROM AUTHOR]

When the micro-units of emerging dynamic processes are cognitive agents, a very important and unique phenomenon arises, called Cognitive Emergence (CE). We argue that: CE characterises the theory of Sociological dynamics with respect to other forms of emergence at different level of organisation (ex. physics, biology, etc.); CE has a very strong influence on the process of emergence, changing it, and should be taken into account in simulating and modelling social phenomena; certain important emerging social phenomena, like social norms cannot be explained at all without CE; CE has critical consequences on the process of "immergence" i.e. the process through which the macro-level emerging structure or global result ‘feedbacks' into the micro-level re-shaping the "elementary" behaviours. We examine the case of dependence relationships. [ABSTRACT FROM AUTHOR]

I will underline the real complexity of trust (not for mere theoretical purposes but for advanced applications), and I will criticize some of those reductionist view of Trust. I will illustrate: how trust can be a disposition, but also is an ‘evaluation', and also a ‘prediction' or better an ‘expectation'; and how it is a ‘decision' and an ‘action', and ‘counting on' (relying) and ‘depending on' somebody; and which is the link with uncertainty and risk taking (fear and hope); how it creates social relationships; how it is a dynamic phenomenon with loop-effects; how it derives from several sources. [ABSTRACT FROM AUTHOR]