The paper describes a system for dealing with nestings of belief in terms of the mechanism of computational environment. A method is offered for computing the beliefs of A about B (and so on) in terms of the systems existing knowledge structures about A and B separately. A proposal for belief percolation is put forward: percolation being a side effect of the process of the computation of nested beliefs, but one which could explain the acquisition of unsupported beliefs. It is (...) argued that the mechanism proposed is compatible with a general least effort hypothesis concerning human mental functioning. (shrink)

In a collaborative work situation at a distance, the use of avatars to represent collaborators reduces collaborative effort. Also, animated avatars can help distant users to ground their relationship and facilitate their interaction because they materialise visual clues for the distant collaborators and their current activity. To check the validity of these hypotheses we set up an experiment based on the use of a collaborative virtual environment (CVE) synchronised for collective medical decision-making. Several teams of practitioners from different disciplines will (...) be required to deal with liver tumours displayed in Argonaute 3D. In this paper, we provide some evidence from existing studies for the hypotheses and select several measures to estimate the grounding process in CVEs. Next, we briefly describe the setup used to collect observable data with Argonaute 3D and we summarise first observations acquired with practitioners. (shrink)

I show how a conversational process that takes simple, intuitively meaningful steps may be understood as a sophisticated computation that derives the richly detailed, complex representations implicit in our knowledge of language. To develop the account, I argue that natural language is structured in a way that lets us formalize grammatical knowledge precisely in terms of rich primitives of interpretation. Primitives of interpretation can be correctly viewed intentionally, as explanations of our choices of linguistic actions; the model therefore fits our (...) intuitions about meaning in conversation. Nevertheless, interpretations for complex utterances can be built from these primitives by simple operations of grammatical derivation. In bridging analyses of meaning at semantic and symbol‐processing levels, this account underscores the fundamental place for computation in the cognitive science of language use. (shrink)

Language use can be viewed as a form of joint activity that requires the coordination of meaning between individuals. Because the linguistic signal is notoriously ambiguous, interlocutors need to draw upon additional sources of information to resolve ambiguity and achieve shared understanding. One way individuals can achieve coordination is by using inferences about the interlocutor’s intentions and mental states to adapt their behavior. However, such an inferential process can be demanding in terms of both time and cognitive resources. Here, we (...) suggest that interaction provides interlocutors with many cues that can support coordination of meaning, even when they are neither produced intentionally for that purpose nor interpreted as signaling speakers’ intention. In many circumstances, interlocutors can take advantage of these cues to adapt their behavior in ways that promote coordination, bypassing the need to resort to deliberative inferential processes. (shrink)

This article proposes that Goffman's "Frame Analysis" can be interpreted as a step toward unpacking the idea of context. His analysis implies a recursive model involving frames within frames. The key problem is that neither Goffman nor anyone else has clearly defined what is meant by a frame. I propose that it can be represented by a word, phrase, or proposition. A subjective context can be represented as an assembly of these items, joined together by operators such as and, since, (...) if, not, and then. Furthermore, this model can be combined with the recursive levels of mutual awareness in earlier approaches to consensus. The combination would represent the inter subjective context: it can be used to find the minimum amount of background that would allow consensual interpretations of discourse. It could also construct a chain that links discourse to the institutional level, the micro-macro pathway from word and gesture to social structure. Goffman hinted that mathematical notation might be used to represent a frame assembly. By adding levels of awareness to such notation, it could represent social facts. Because the use of vernacular words rather than concepts is a problem in social science, Goffman's approach has a general as well as a particular significance. (shrink)

Clear definitions of alienation and solidarity are needed as a step toward an explicit theory of social integration. The idea of alienation has played a key role in the development of sociology, but it's meaning has never been clear. Both theories and empirical studies confound relational-dispositional, cognitive-emotional and/or interpersonal-societal components. This essay proposes definitions that follow from the work of Erving Goffman and others. Goffman's idea of "co-presence" implies a model of solidarity as mutual awareness to the point of merging (...) consciousness. It appears that this concept of solidarity could be the main component of shared context, consensus, genuine love and social facts. Two empirical approaches are described, one with moment by moment analysis of dialogue, the other using sample surveys. With the use of mathematical notation, the survey method might be used to analyze social facts. The model could also form the basis for an explicit and testable theory of social integration. (shrink)

Conversation is supported by the beliefs that people have in common and the perceptual experience that they share. The visual context of a conversation has two aspects: the information that is available to each conversant, and their beliefs about what is present for each other. In our experiment, we separated these factors for the first time and examined their impact on a spontaneous conversation. We manipulated the fact that a visual scene was shared or not and the belief that a (...) visual scene was shared or not. Participants watched videos of actors talking about a controversial topic, then discussed their own views while looking at either a blank screen or the actors. Each believed (correctly or not) that their partner was either looking at a blank screen or the same images. We recorded conversants’ eye movements, quantified how they were coordinated, and analyzed their speech patterns. Gaze coordination has been shown to be causally related to the knowledge people share before a conversation, and the information they later recall. Here, we found that both the presence of the visual scene, and beliefs about its presence for another, influenced language use and gaze coordination. (shrink)

This essay presents a philosophical and computational theory of the representation of de re, de dicto, nested, and quasi-indexical belief reports expressed in natural language. The propositional Semantic Network Processing System (SNePS) is used for representing and reasoning about these reports. In particular, quasi-indicators (indexical expressions occurring in intentional contexts and representing uses of indicators by another speaker) pose problems for natural-language representation and reasoning systems, because--unlike pure indicators--they cannot be replaced by coreferential NPs without changing the meaning of the (...) embedding sentence. Therefore, the referent of the quasi-indicator must be represented in such a way that no invalid coreferential claims are entailed. The importance of quasi-indicators is discussed, and it is shown that all four of the above categories of belief reports can be handled by a single representational technique using belief spaces containing intensional entities. Inference rules and belief-revision techniques for the system are also examined. (shrink)

Over the last three decades, joint action has received various definitions, which for all their differences share many features. However, they cannot fit some perplexing cases of weak joint action, such as demonstrations, where agents rely on distinct epistemic sources, and as a result, have no first-hand knowledge about each other. I argue that one major reason why the definition of such collective actions is akin to the classical ones is that it crucially relies on the concept of common knowledge. (...) To this end, I first argue for the necessity of common knowledge for joint action in general due to the increased reliability of success it entails. I then defend the relevance of common knowledge against several criticisms, point at an adequate weakening, and discuss alternative approaches. Although structurally weaker, the common knowledge has a richer content in weak joint actions. As a result, even if the links between individuals are seriously stretched, much is still shared among them. Weak joint actions still require considerable cognitive abilities indeed. (shrink)

Defined and formalized several decades ago, widely used in philosophy and game theory, the concept of common knowledge is still considered as problematic, although not always for the right reasons. I suggest that the epistemic status of a group of human agents in a state of common knowledge has not been thoroughly analyzed. In particular, every existing account of common knowledge, whether formal or not, is either too strong to fit cognitively limited individuals, or too weak to adequately describe their (...) state. I provide a realistic definition of common knowledge, based on a formalization of David Lewis’ seminal account and show that it is formally equivalent to probabilistic common belief. This leads to a philosophical analysis of common knowledge which answers several common criticisms and sheds light on its nature. (shrink)

Although the notion of common or mutual belief plays a crucial role in game theory, economics and social philosophy, no thoroughly representational account of it has yet been developed. In this paper, I propose two desiderata for such an account, namely, that it take into account the possibility of inconsistent data without portraying the human mind as logically and mathematically omniscient. I then propose a definition of mutual belief which meets these criteria. This account takes seriously the existence of computational (...) limitations. Finally, I point out that the epistemic logic (or theory) needed to make the definition work is subject to the Kaplan/Montague Paradox of the Knower. I argue that this is not a defect of the account, and I discuss briefly the bearing of recent work on the paradox of the Liar upon this problem. (shrink)

The notion of common ground is important for the production of referring expressions: In order for a referring expression to be felicitous, it has to be based on shared information. But determining what information is shared and what information is privileged may require gathering information from multiple sources, and constantly coordinating and updating them, which might be computationally too intensive to affect the earliest moments of production. Previous work has found that speakers produce overinformative referring expressions, which include privileged names, (...) violating Grice’s Maxims, and concluded that this is because they do not mark the distinction between shared and privileged information. We demonstrate that speakers are in fact quite effective in marking this distinction in the form of their utterances. Nonetheless, under certain circumstances, speakers choose to overspecify privileged names. (shrink)

This article presents a community-based account of salience as an alternative and a complement to the ‘natural salience’ approach which is endorsed by almost all game theorists who use this concept. While in the naturalistic approach, salience is understood as an objective and natural property of some entities, the community-based account claims that salience is a function of community membership. Building on David Lewis’s theory of common knowledge and on some of its recent refined accounts, I suggest that salience acts (...) as a correlating device in a correlated equilibrium. What is constitutive of salience is common understanding, the fact that agents have common knowledge that they share the same modes of reasoning with respect to a well-identified set of events. I argue that the basis for common understanding is community membership. The relevance of this account stems from the fact that it answers the objection that salience is either unnecessary or unable to account for coordination between rational agents. (shrink)

Epistemic iteration principles are principles according to which some or another epistemic operator automatically iterates---e.g., if it is known that P, then it is known that P, or there is evidence that P, then there is evidence that there is evidence that P. This article provides a survey of various arguments for and against epistemic iteration principles, with a focus on arguments relevant to a wide range of such principles.

The prequel to this paper introduced the topic of iteration principles in epistemology and surveyed some arguments in support of them. In this sequel, I'll consider two influential families of objection to iteration principles. The first turns on the idea that they lead to some variety of skepticism, and the second turns on ‘margin for error’ considerations adduced by Timothy Williamson.

What role do speakers'/authors’ communicative intentions play in language interpretation? Cognitive scientists generally assume that listeners'/readers’ recognitions of speakers'/authors’ intentions is a crucial aspect of utterance interpretation. Various philosophers, literary theorists and anthropologists criticize this intentional view and assert that speakers'/authors’ intentions do not provide either the starting point for linguistic interpretation or constrain how texts should be understood. Until now, cognitive scientists have not seriously responded to the current challenges regarding intentions in communication. My purpose in this article is (...) to provide just such a response. I briefly describe some of the empirical evidence in cognitive science on the importance of intentions in communication. I then discuss some of the criticisms of the intentional view that have arisen in the humanities and social sciences. Following this, I offer a partial resolution to the intentionalist controversy that recognizes the differing views on the idea of linguistic interpretation. I specifically suggest a way of thinking about linguistic interpretation in terms of the time‐course of understanding that provides a metric for evaluating the role of intentions in communication. This time‐course perspective on linguistic understanding provides for the plurality of ideas that now exist both in cognitive science and in postmodern philosophical thought. (shrink)

This piece is a commentary on a precis of Sperber and Wilson's book "Relevance", published in Behavioral and Brain Sciences.

We report two experiments that investigated the widely held assumption that speakers use the addressee’s discourse model when choosing referring expressions (e.g., Ariel, 1990; Chafe, 1994; Givón, 1983; Prince, 1985), by manipulating whether the addressee could hear the immediately preceding linguistic context. Experiment 1 showed that speakers increased pronoun use (and decreased noun phrase use) when the referent was mentioned in the immediately preceding sentence compared to when it was not, even though the addressee did not hear the preceding sentence, (...) indicating that speakers used their own, privileged discourse model when choosing referring expressions. The same pattern of results was found in Experiment 2. Speakers produced more pronouns when the immediately preceding sentence mentioned the referent than when it mentioned a referential competitor, regardless of whether the sentence was shared with their addressee. Thus, we conclude that choice of referring expression is determined by the referent’s accessibility in the speaker’s own discourse model rather than the addressee’s. (shrink)

For people to contribute to discourse, they must do more than utter the right sentence at the right time. The basic requirement is that they add to their common ground in an orderly way. To do this, we argue, they try to establish for each utterance the mutual belief that the addressees have understood what the speaker meant well enough for current purposes. This is accomplished by the collective actions of the current contributor and his or her partners, and these (...) result in units of conversation called contributions. We present a model of contributions and show how it accounts for a variety of features of everyday conversations. (shrink)

Joint action is central to countless aspects of human life. Here I examine the roots of joint action in infancy. First, I provide evidence that—contrary to popular belief—1‐year‐old infants do have the social‐cognitive prerequisites needed to participate in joint action, even in a relatively strict sense: they can read others’ goals and intentions, they have some basic understanding of common knowledge, and they have the ability and motivation to help others achieve their goals. Then I review some evidence of infants’ (...) and young children’s active participation in different types of joint action, from prelinguistic communication to more instrumental collaborations with others, with a particular focus on whether young children show evidence of an understanding of the commitments and obligations entailed in joint action. I conclude that the uniquely human ability and motivation to participate in joint action is already seen in infants by 1 year of age. (shrink)

No one denies that people adapt what they say and how they interpret what is said to them, depending on their interactive partners. What is controversial is when and how they do so. Several psycholinguistics research programs have found what appear to be failures to adapt to partners in the early moments of processing and have used this evidence to argue for modularity in the language processing architecture, claiming that the system cannot take into account a partner’s distinct needs or (...) knowledge early in processing. We review the evidence for both early and delayed partner‐specific adaptations, and we identify some challenges and difficulties with interpreting this evidence. We then discuss new analyses from a previously published referential communication experiment (Metzing & Brennan, 2003) demonstrating that partner‐specific effects need not occur late in processing. In contrast to Pickering and Garrod (2004) and Keysar, Barr, and Horton (1998b), we conclude that there is no good evidence that early processing has to be be “egocentric,”“dumb,” or encapsulated from social knowledge or common ground, but that under some circumstances, such as when one partner has made an attribution about another’s knowledge or needs, processing can be nimble enough to adapt quite early to a perspective different from one’s own. (shrink)

This paper presents a framework for the generation of coherent elementary conversational sequences at the speech act level. We will embrace the notion of a cooperative dialogue game in which two players produce speech acts to transfer relevant information with respect to their commitments. Central to the approach is that participants try to achieve some sort of balanced cognitive state as a result of speech act generation and interpretation. Cognitive states of the participants change as a result of the interpretation (...) of speech acts and these changes provoke the production of a subsequent speech act. Describing the properties and the dynamics of the mental constructs that constitute the participants’ cognitive states, such as beliefs and commitments, in relation to the various dialogue contributions is an essential aspect of the game. Although simple in its basic form, the framework enables us to produce abstract conversations with some properties that agree strikingly with coherence structures found in, for instance, Conversation Analysis. (shrink)

The effect of upper bounds on message delivery times in a computer network upon the dynamics of knowledge gain is investigated. Recent work has identified centipedes and brooms—causal structures that combine message chains with time bound information—as necessary conditions for knowledge gain and common knowledge gain, respectively. This paper shows that, under the full-information protocol, these structures are both necessary and sufficient for such epistemic gain. We then apply this analysis to gain insights into the relation between “everyone knows” and (...) common knowledge. We prove a tight threshold on the depth k, beyond which Ek G (everyone in G knows nested to depth k) collapses into CG (common knowledge), when this knowledge concerns the occurrence of a spontaneous event. The threshold depends on the size of the group G of agents, as well as the time that has elapsed since the event of interest occurred. The existence of such a threshold is not guaranteed for all protocols, which is demonstrated here by presenting a counterexample in which no such threshold exists. (shrink)

Thirty years ago, grounded cognition had roots in philosophy, perception, cognitive linguistics, psycholinguistics, cognitive psychology, and cognitive neuropsychology. During the next 20 years, grounded cognition continued developing in these areas, and it also took new forms in robotics, cognitive ecology, cognitive neuroscience, and developmental psychology. In the past 10 years, research on grounded cognition has grown rapidly, especially in cognitive neuroscience, social neuroscience, cognitive psychology, social psychology, and developmental psychology. Currently, grounded cognition appears to be achieving increased acceptance throughout cognitive (...) science, shifting from relatively minor status to increasing importance. Nevertheless, researchers wonder whether grounded mechanisms lie at the heart of the cognitive system or are peripheral to classic symbolic mechanisms. Although grounded cognition is currently dominated by demonstration experiments in the absence of well-developed theories, the area is likely to become increasingly theory driven over the next 30 years. Another likely development is the increased incorporation of grounding mechanisms into cognitive architectures and into accounts of classic cognitive phenomena. As this incorporation occurs, much functionality of these architectures and phenomena is likely to remain, along with many original mechanisms. Future theories of grounded cognition are likely to be heavily influenced by both cognitive neuroscience and social neuroscience, and also by developmental science and robotics. Aspects from the three major perspectives in cognitive science—classic symbolic architectures, statistical/dynamical systems, and grounded cognition—will probably be integrated increasingly in future theories, each capturing indispensable aspects of intelligence. (shrink)

How do communities establish shared communication systems? The Common Knowledge view assumes that symbolic conventions develop through the accumulation of common knowledge regarding communication practices among the members of a community. In contrast with this view, it is proposed that coordinated communication emerges a by‐product of local interactions among dyads. A set of multi‐agent computer simulations show that a population of “egocentric” agents can establish and maintain symbolic conventions without common knowledge. In the simulations, convergence to a single conventional system (...) was most likely and most efficient when agents updated their behavior on the basis of local rather than global, system‐level information. The massive feedback and parallelism present in the simulations gave rise to phenomena that are often assumed to result from complex strategic processing on the part of individual agents. The implications of these findings for the development of theories of language use are discussed. (shrink)

According to decision theory, the rational initial action in a sequential decision-problem may be found by backward induction or folding back. But the reasoning which underwrites this claim appeals to the agent's beliefs about what she will later believe, about what she will later believe she will still later believe, and so forth. There are limits to the depth of people's beliefs. Do these limits pose a threat to the standard theory of rational sequential choice? It is argued, first, that (...) the traditional solutions of certain games depend on knowledge which exceeds depth limits, and that these solutions therefore cannot be shown rational in the usual sense. Then, for that related reason even folding back solutions of one-person problems cannot be! A revision of our notion of rational choice is proposed, analogous to the reliabilist account of knowledge of Goldman and others, by which this paradox is resolved. (shrink)

In this article we present the bases for a computational theory of the cognitive processes underlying human communication. The core of the article is devoted to the analysis of the phases in which the process of comprehension of a communicative act can be logically divided: (1) literal meaning, where the reconstruction of the mental states literally expressed by the actor takes place: (2) speaker's meaning, where the partner reconstructs the communicative intentions of the actor; (3) communicative effect, where the partner (...) possibly modifies his own beliefs and intentions; (4) reaction, where the intentions for the generation of the response are produced; and (5) response, where an overt response is constructed. The model appears to be compatible with relevant facts about human behavior. Our hypothesis is that, through communication, an actor tries to exploit the motivational structures of a partner so that the desired goal is generated. A second point is that social behavior requires that cooperation be maintained at some level. In the case of communication, cooperation is, in general, pursued even when the partner does not adhere to the actor's goals, and therefore no cooperation occurs at the behavioral level. This important distinction is reflected in the two kinds of game we introduce to account for communication. The main concept implied in communication is that two agents overtly reach a situation of shared mental states. Our model deals with sharedness through two primitives: shared beliefs and communicative intentions. (shrink)