In this book, Newell makes the case for unified theories by setting forth a candidate.

I propose to consider the question, "Can machines think?" This should begin with definitions of the meaning of the terms "machine" and "think." The definitions might be framed so as to reflect so far as possible the normal use of the words, but this attitude is dangerous, If the meaning of the words "machine" and "think" are to be found by examining how they are commonly used it is difficult to escape the conclusion that the meaning and the answer to (...) the question, "Can machines think?" is to be sought in a statistical survey such as a Gallup poll. But this is absurd. Instead of attempting such a definition I shall replace the question by another, which is closely related to it and is expressed in relatively unambiguous words. The new form of the problem can be described in terms of a game which we call the 'imitation game." It is played with three people, a man (A), a woman (B), and an interrogator (C) who may be of either sex. The interrogator stays in a room apart front the other two. The object of the game for the interrogator is to determine which of the other two is the man and which is the woman. He knows them by labels X and Y, and at the end of the game he says either "X is A and Y is B" or "X is B and Y is A." The interrogator is allowed to put questions to A and B. We now ask the question, "What will happen when a machine takes the part of A in this game?" Will the interrogator decide wrongly as often when the game is played like this as he does when the game is played between a man and a woman? These questions replace our original, "Can machines think?". (shrink)

Prior to the twentieth century, theories of knowledge were inherently perceptual. Since then, developments in logic, statis- tics, and programming languages have inspired amodal theories that rest on principles fundamentally different from those underlying perception. In addition, perceptual approaches have become widely viewed as untenable because they are assumed to implement record- ing systems, not conceptual systems. A perceptual theory of knowledge is developed here in the context of current cognitive science and neuroscience. During perceptual experience, association areas in the (...) brain capture bottom-up patterns of activation in sensory-motor areas. Later, in a top-down manner, association areas partially reactivate sensory-motor areas to implement perceptual symbols. The stor- age and reactivation of perceptual symbols operates at the level of perceptual components – not at the level of holistic perceptual expe- riences. Through the use of selective attention, schematic representations of perceptual components are extracted from experience and stored in memory (e.g., individual memories of green, purr, hot). As memories of the same component become organized around a com- mon frame, they implement a simulator that produces limitless simulations of the component (e.g., simulations of purr). Not only do such simulators develop for aspects of sensory experience, they also develop for aspects of proprioception (e.g., lift, run) and introspec- tion (e.g., compare, memory, happy, hungry). Once established, these simulators implement a basic conceptual system that represents types, supports categorization, and produces categorical inferences. These simulators further support productivity, propositions, and ab- stract concepts, thereby implementing a fully functional conceptual system. Productivity results from integrating simulators combinato- rially and recursively to produce complex simulations. Propositions result from binding simulators to perceived individuals to represent type-token relations. Abstract concepts are grounded in complex simulations of combined physical and introspective events. Thus, a per- ceptual theory of knowledge can implement a fully functional conceptual system while avoiding problems associated with amodal sym- bol systems. Implications for cognition, neuroscience, evolution, development, and artificial intelligence are explored. (shrink)

This books is a must for anyone interested in consciousness research and the latest ideas in the forthcoming technology of mind.

It is a paradox, whose importance familiarity fails to diminish, that the most highly developed and useful scientific theories are ostensibly expressed in terms of objects never encountered in experience. The line traced by a draughtsman, no matter how accurate, is seen beneath the microscope as a kind of corrugated trench, far removed from the ideal line of pure geometry. And the “point-planet” of astronomy, the “perfect gas” of thermodynamics, or the “pure species” of genetics are equally remote from exact (...) realization. Indeed the unintelligibility at the atomic or sub-atomic level of the notion of a rigidly demarcated boundary shows that such objects not merely are not but could not be encountered. While the mathematician constructs a theory in terms of “perfect” objects, the experimental scientist observes objects of which the properties demanded by theory are and can, in the very nature of measurement, be only approximately true. As Duhem remarks, mathematical deduction is not useful to the physicist if interpreted rigorously. It is necessary to know that its validity is unaltered when the premise and conclusion are only “approximately true.” But the indeterminacy thus introduced, it is necessary to add in criticism, will invalidate the deduction unless the permissible limits of variation are specified. To do so, however, replaces the original mathematical deduction by a more complicated mathematical theory in respect of whose interpretation the same problem arises, and whose exact nature is in any case unknown. (shrink)

A Man whose height is four feet is short; adding one tenthof an inch to a short man's height leaves him short; therefore, a man whose height is four feet and one tenth of an inch is short. Now begin again and argue in the same pattern. A man whose height is four feet and one tenth of an inch is short; adding one tenth of an inch to a short man's height leaves him short; therefore, a man whose height (...) is four feet and two tenths of an inch is short. In this way, it seems, we can reach the absurd result that a man whose height is four feet plus any number of tenths of an inch is short. For, if the first argument is sound, so is the second; and if the second, so is the third; and so on. There appears to be no good reason for stopping at any one point rather than at another; it is hard to see why the chain of arguments should ever be broken. But the conclusion is ridiculous; it is, for example, preposterous to say that a man whose height is seven feet is, nevertheless, short. (shrink)

In this article we outline the history, elements, and variations of functional accounts of emotions. Summarising diverse theories and observations, we propose that functional accounts of emotions: (1) address why humans have emotions; (2) define emotions as solutions to problems and opportunities related to physical and social survival; (3) treat emotions as systems of interrelated components; and (4) focus on the beneficial consequences of emotions. This conceptual approach to emotion is complemented by several empirical strategies, including the study of emotion (...) dysfunction, the effects of emotions on others, and the relations between emotions and personal and social outcomes. We conclude by considering how functional accounts of emotion vary, including in terms of their level of analysis, specificity, manner of organisation, and range of focus, and the implications functional accounts have for the study of emotion. (shrink)

This research explores the role of emotions in goal-directed behaviour. A model is provided for an emotional goal system whereby appraisals of the consequences of achieving or not achieving a goal are hypothesised to elicit anticipatory emotions; the anticipatory emotions are expected, in turn, to contribute to volitions in the service of goal pursuit (namely, intentions, plans, and the decision to expend energy); goal-directed behaviours next arise in response to volitions and lead to goal attainment; and the latter then functions (...) as the basis for a new set of appraisals and accompanying goaloutcome emotions. The model was tested in a longitudinal study of the responses of 406 adults (243 women, 163 men) in The Netherlands. The context for the study was the regulation of one's bodyweight via exercising and dieting. (shrink)