Philip N. Johnson-Laird

Mental models: towards a cognitive science of language, inference, and consciousness

Mental Models offers nothing less than a unified theory of the major properties of mind: comprehension, inference, and consciousness. In spirited and graceful prose, Johnson-Laird argues that we apprehend the world by building inner mental replicas of the relations among objects and events that concern us. The mind is essentially a model-building device that can itself be modeled on a digital computer. This book provides both a blueprint for building such a model and numerous important illustrations of how to do it. In several key areas of cognition, Johnson-Laird shows how an explanation based on mental modeling is clearly superior to previous theory. For example, he argues compellingly that deductive reasoning does not take place by tacitly applying the rules of logic, but by mentally manipulating models of the states of affairs from which inferences are drawn. Similarly, linguistic comprehension is best understood not as a matter of applying inference rules to propositions derived from sentences, but rather as the minds effort to construct and update a model of the situation described by a text or a discourse. Most provocative, perhaps, is Johnson-Lairds theory of consciousness: the minds necessarily incomplete model of itself allows only a partial control over the many unconscious and parallel processes of cognition. This an extraordinarily rich book, providing a coherent account of much recent experimental work in cognitive psychology, along with lucid explanations of relevant theory in linguistics, computer science, and philosophy Not since Miller, Galanter, and Pribrams classic Plans and the Structure of Behavior has a book in cognitive science combined such sweep, style, and good sense. Like its distinguished predecessor, Mental Models may well serve to fix a point of view for a generation. (http://books.google.fr/books?id=FS3zSKAfLGMC&printsec=frontcover&hl=fr#v=onepage&q&f=false)

Towards a Cognitive Theory of Emotions

Abstract A theory is proposed that emotions are cognitively based states which co-ordinate quasi-autonomous processes in the nervous system. Emotions provide a biological solution to certain problems of transition between plans, in systems with multiple goals. Their function is to accomplish and maintain these transitions, and to communicate them to ourselves and others. Transitions occur at significant junctures of plans when the evaluation of success in a plan changes. Complex emotions are derived from a small number of basic emotions and arise at junctures of social plans.

Mental Models in Cognitive Science

If cognitive science does not exist then it is necessary to invent it. That slogan accommodates any reasonable attitude about the subject. One attitude-an optimistic one-is that cognitive science already exists and is alive and flourishing in academe: we have all in our different ways been doing it for years. The gentleman in Moliere’s play rejoiced to discover that he had been speaking prose for forty years without realizing it: perhaps we are merely celebrating a similar discovery. And, if we just keep going on in the same way, then we are bound to unravel the workings of the mind. Another attitude-my own-is more pessimistic: experimental psychology is not going to succeed unaided in elucidating human mentality; artificial intelligence is not going to succeed unaided in modelling the mind; nor is any other discipline-linguistics, anthropology, neuroscience, philosophy-going to have any greater success. If we are ever to understand cognition, then we need a new science dedicated to that aim and based only in part on its contributing disciplines. Yet pessimism should not be confused with cynicism. We should reject the view that cognititie science is merely a clever ruse dreamed up to gain research funds-that it is nothing more than six disciplines in search of a grant-giving agency. Cognitive science does not quite exist: its precursors do, but it lacks a clear identity. Perhaps the major function of this conference should be to concentrate our minds on what that identity might be. At present, there appear to be two distinct ideas wrapped up in it: one topic-oriented, and the other methodological. The topic-oriented idea is that workers from several disciplines have converged upon a number of central problems and explanatory concepts. George Miller and 1 became aware of this convergence when we were caught in the toils

The language of emotions: An analysis of a semantic field

Abstract This paper uses a theory of the emotions to motivate a semantic analysis of English words referring to emotions. The theory assumes that emotions have a two-fold communicative function, both externally amongst members of the species, and internally within the brain so as to bypass complex inferences. It implies that there is a small number of basic signals that can set up characteristic emotional modes within the organism, roughly corresponding to happiness, sadness, fear, anger, and disgust. In human beings, these modes can be modulated by the propositional content of the cognitive evaluation that caused the emotion signal, or else, if this content fails to impinge on consciousness, these modes can be experienced as emotions that have occurred for no apparent reason. According to this “communicative” theory, there should be a set of terms that refer to basic emotions, and these terms should have no internal semantics, since they cannot be analysed into anything more basic, such as a prototype or...

The computer and the mind: an introduction to cognitive science

Johnson-Laird haswrittena book that isasaccessibletotheintelligent high school student as it is to the engineer or computer scientist. Unfortunately, however, this book is not nearly as satisfying as a popular work on physics or mathematics, since cognitive sciencefalls far short of those other sciences in its ability to describe, explain, and predict interesting phenomena. Again and again the author describes fascinating experimental or empirical results, constructs computational models producing similar behavior, and then reaches a dead end. There is simply too little understanding of the mechanisms of brain and mind to assert a connection between the computational models and anything real. The result has too much of the flavor of works on artificial intelligence. What saves Johnson-Lairds book and makes it interesting to the general reader are the philosophical issues that he confronts head on. Johnson-Laird also cites and answers criticisms that he characterizes as metaphysical and those that he characterizes as scientific. Predictably, he concludes in the end that cognitive science is on the right track and that it is leading to thedevelopment of intelligent softwareand a humane technology. He hopes that it will yield advances in psychoanalytic theory and practice as well. The book contains many verbal descriptions of algorithms and models. This material is hard to read straight through, making the book drag a little. The material is fascinating and the author is knowledgeable, but the readers expectation of increased understanding is constantly frustrated.

The mental representation of spatial descriptions

Two experiments investigated the mental representation of spatial descriptions. In Experiment 1, the subjects classified a series of diagrams, each presented after a spatial description, as either consistent or inconsistent with the description. They were then given an unexpected recognition test of their memory for the descriptions. The subjects remembered the meanings of determinate descriptions very much better than those of grossly indeterminate descriptions; their memory for a description was not reliably affected by whether or not the diagram had been consistent with it. Experiment 2 extended these findings and showed that, although the semantic implications of a determinate description are better remembered than are those of an indeterminate description, the verbatim details of an indeterminate description are easier to recall than are those of a determinate description. The results are taken to imply the existence of two different sorts of encoding: propositional representations that are relatively hard to remember but correspond closely to the sentences in the description, and mental models that are relatively easy to remember but are analogous to spatial arrays and accordingly poor in linguistic detail.

Mental models and deduction

According to the mental-model theory of deductive reasoning, reasoners use the meanings of assertions together with general knowledge to construct mental models of the possibilities compatible with the premises. Each model represents what is true in a possibility. A conclusion is held to be valid if it holds in all the models of the premises. Recent evidence described here shows that the fewer models an inference calls for, the easier the inference is. Errors arise because reasoners fail to consider all possible models, and because models do not normally represent what is false, even though reasoners can construct counterexamples to refute invalid conclusions.

A theoretical analysis of insight into a reasoning task

Abstract An information-processing analysis of insight into a singularly deceptive and difficult deductive problem is presented. Two models are described. The first represents an economical explanation of the Ss initial responses but is difficult to reconcile with their subsequent responses induced by certain remedial procedures. The second model does take account of such responses and shows how insight into the correct solution is correlated with the awareness that tests for falsification are more appropriate than tests for verification. The relevance of the experimental results and the explanatory model are discussed in relation to wider issues.

How Diagrams Can Improve Reasoning

We report an experimental study on the effects of diagrams on deductive reasoning with double disjunctions, for example: Raphael is in Tacoma or Julia is in Atlanta, or both. Julia is in Atlanta or Paul is in Philadelphia, or both. What follows? We confirmed that subjects find it difficult to deduce a valid conclusion, such as Julia is in Atlanta, or both Raphael is in Tacoma and Paul is in Philadelphia. In a preliminary study, the format of the premises was either verbal or diagrammatic, and the diagrams used icons to distinguish between inclusive and exclusive disjunctions. The diagrams had no effect on performance. In the main experiment, the diagrams made the alternative possibilities more explicit. The subjects responded faster (about 35 s) and drew many more valid conclusions (nearly 30%) from the diagrams than from the verbal premises. These results corroborate the theory of mental models and have implications for the role of diagrams in reasoning.

Basic Emotions, Rationality, and Folk Theory

Abstract Answering the question of whether there are basic emotions requires considering the functions of emotions. We propose that just a few emotions are basic and that they have functions in managing action. When no fully rational solution is available for a problem of action, a basic emotion functions to prompt us in a direction that is better than a random choice. We contrast this kind of theory with a componential approach which we argue is either a version of the theory of basic emotions or else leads to the doctrine that emotions are mistaken tenets of folk psychology. We defend the psychological reality of the folk theory of emotions, and we argue that universal basic emotions make it possible to understand people from distant cultures, and to translate emotional terminology from one language to another. Finally, we show how theories of basic emotions can be tested, and indicate the kinds of empirical result that can bear on the issue.