Distinctions have been proposed between systems of reasoning for centuries. This article distills properties shared by many of these distinctions and characterizes the resulting systems in light of recent findings and theoretical developments. One system is associative because its computations reflect similarity structure and relations of temporal contiguity. The other is "rule based" because it operates on symbolic structures that have logical content and variables and because its computations have the properties that are normally assigned to rules. The systems serve (...) complementary functions and can simultaneously generate different solutions to a reasoning problem. The rule-based system can suppress the associative system but not completely inhibit it. The article reviews evidence in favor of the distinction and its characterization. (shrink)

Among the many peculiarities of schizophrenics perhaps the most obvious is their tendency to say odd things. Indeed, for most clinicians, the hallmark of schizophrenia is “thought disorder”. Decades of clinical observations, experimental research, and linguistic analyses have produced many hypotheses about what, precisely, is wrong with schizophrenic speech and language. These hypotheses range from assertions that schizophrenics have peculiar word association hierarchies to the notion that schizophrenics are suffering from an intermittent form of aphasia. In this article, several popular (...) hypotheses are critically assessed. Work in the area turns out to be flawed by errors in experimental method, faulty observations, tautological reasoning, and theoretical models that ignore the complexities of both speech and language. This does not mean that schizophrenics are indistinguishable from nonschizophrenics. They are clearly deviant in many situations. Their problem, however, appears to be in processing information and in selective attention, not in language itself. (shrink)

Research on human infants has begun to shed light on early-developing processes for segmenting perceptual arrays into objects. Infants appear to perceive objects by analyzing three-dimensional surface arrangements and motions. Their perception does not accord with a general tendency to maximize figural goodness or to attend to nonaccidental geometric relations in visual arrays. Object perception does accord with principles governing the motions of material bodies: Infants divide perceptual arrays into units that move as connected wholes, that move separately from one (...) another, that tend to maintain their size and shape over motion, and that tend to act upon each other only on contact. These findings suggest that o general representation of object unity and boundaries is interposed between representations of surfaces and representations of objects of familiar kinds. The processes that construct this representation may be related to processes of physical reasoning. (shrink)

Six experiments explored the hypothesis that the members of categories which are considered most prototypical are those with most attributes in common with other members of the category and least attributes in common with other categories. In probabilistic terms, the hypothesis is that prototypicality is a function of the total cue validity of the attributes of items. In Experiments 1 and 3, subjects listed attributes for members of semantic categories which had been previously rated for degree of prototypicality. High positive (...) correlations were obtained between those ratings and the extent of distribution of an item's attributes among the other items of the category. In Experiments 2 and 4, subjects listed superordinates of category members and listed attributes of members of contrasting categories. Negative correlations were obtained between prototypicality and superordinates other than the category in question and between prototypicality and an item's possession of attributes possessed by members of contrasting categories. Experiments 5 and 6 used artificial categories and showed that family resemblance within categories and lack of overlap of elements with contrasting categories were correlated with ease of learning, reaction time in identifying an item after learning, and rating of prototypicality of an item. It is argued that family resemblance offers an alternative to criterial features in defining categories. (shrink)

Visual Agnosia is a comprehensive and up-to-date review of disorders of higher vision that relates these disorders to current conceptions of higher vision from cognitive science, illuminating both the neuropsychological disorders and the nature of normal visual object recognition.Brain damage can lead to selective problems with visual perception, including visual agnosia the inability to recognize objects even though elementary visual functions remain unimpaired. Such disorders are relatively rare, yet they provide a window onto how the normal brain might accomplish the (...) complex task of vision. Visual Agnosia reviews a century of case studies of higher-level visual deficits following brain damage, places them in the general context of current neuroscience, and draws relevant conclusions about the organization of normal visual processing. It is unique in drawing on research in cognitive psychology, computational vision, visual neurophysiology, and neuropsychology to interpret the agnosias and draw inferences from them about visual object recognition.Following a historical account of agnosia research, Visual Agnosia offers a taxonomy of a wide range of agnosia syndromes, describing and interpreting the syndromes in terms of the latest theoretical models of visual processing and ultimately bringing them to bear as evidence on a variety of questions in the study of higher vision.Martha J. Farah is Associate Professor of Psychology at Carnegie Mellon University. Visual Agnosia is included in the Issues in Biology of Language and Cognition series, edited by John Marshall. (shrink)

Tested the 2-process theory of detection, search, and attention presented by the current authors in a series of experiments. The studies demonstrate the qualitative difference between 2 modes of information processing: automatic detection and controlled search; trace the course of the learning of automatic detection, of categories, and of automatic-attention responses; and show the dependence of automatic detection on attending responses and demonstrate how such responses interrupt controlled processing and interfere with the focusing of attention. The learning of categories is (...) shown to improve controlled search performance. A general framework for human information processing is proposed. The framework emphasizes the roles of automatic and controlled processing. The theory is compared to and contrasted with extant models of search and attention. (shrink)

This paper explores the difference between Connectionist proposals for cognitive a r c h i t e c t u r e a n d t h e s o r t s o f m o d e l s t hat have traditionally been assum e d i n c o g n i t i v e s c i e n c e . W e c l a i m t h a t t h (...) e m a j o r d i s t i n c t i o n i s t h a t , w h i l e b o t h Connectionist and Classical architectures postulate representational mental states, the latter but not the former are committed to a symbol-level of representation, or to a ‘language of thought’: i.e., to representational states that have combinatorial syntactic and semantic structure. Several arguments for combinatorial structure in mental representations are then reviewed. These include arguments based on the ‘systematicity’ of mental representation: i.e., on the fact that cognitive capacities always exhibit certain symmetries, so that the ability to entertain a given thought implies the ability to entertain thoughts with semantically related contents. We claim that such arguments make a powerful case that mind/brain architecture is not Connectionist at the cognitive level. We then consider the possibility that Connectionism may provide an account of the neural (or ‘abstract neurological’) structures in which Classical cognitive architecture is implemented. We survey a n u m b e r o f t h e s t a n d a r d a r g u m e n t s t h a t h a v e b e e n o f f e r e d i n f a v o r o f Connectionism, and conclude that they are coherent only on this interpretation. (shrink)

What psychological and philosophical significance should we attach to recent efforts at computer simulations of human cognitive capacities? In answering this question, I find it useful to distinguish what I will call "strong" AI from "weak" or "cautious" AI. According to weak AI, the principal value of the computer in the study of the mind is that it gives us a very powerful tool. For example, it enables us to formulate and test hypotheses in a more rigorous and precise fashion. (...) But according to strong AI, the computer is not merely a tool in the study of the mind; rather, the appropriately programmed computer really is a mind, in the sense that computers given the right programs can be literally said to. (shrink)

The book also introduces a host of new experimental techniques and major hypotheses to guide future research.

Classical empiricists are notorious for claiming that cognition is perceptually based. This dissertation reassesses that claim against the background of contemporary cognitive science. More specifically, it develops a broadly empiricist theory of concepts and argues that this theory outperforms other theories. In the first chapter, I lay down seven desiderata. An adequate theory of concepts should lend itself to an explanation of expressive scope, intentionality, cognitive content, acquisition, categorization, compositionality, and publicity. I argue that none of the leading theories that (...) have been developed by philosophers and psychologists can satisfy all of these desiderata . ;In the second chapter, I propose an alternative theory, which identifies concepts with what I call 'proxytypes'. A proxytype is a collection of stored, high-level perceptual representations, which represent features typically exhibited by members of the category it designates. I argue that proxytypes lend themselves to an economical account of concept acquisition by bootscrapping on independently motivated theories of perception, and I provide an account of categorization by exploiting the kinship between proxytypes and prototypes. The third chapter raises three objections to proxytype theory, involving three of the remaining desiderata: expressive scope, publicity, and compositionality. In responding to these objections, I develop a viable successor to the reviled analytic/synthetic distinction, and I outline a three-stage model of concept combination. The final chapter completes my defense of proxytype theory, by taking on the last two desiderata. It provides a naturalistic account of intentionality and cognitive content inspired by Locke's distinction between real and nominal essences. The real content of a proxytype is the property of belonging to some unique kind, and the nominal content is a set of properties typically exhibited by members of that kind. I contrast my account of nominal content with three theories of narrow content and conclude that it has all of their merits and none of their flaws. (shrink)

This research investigates the development of analogy: In particular, we wish to study the development of systematicity in analogy. Systematicity refers to the mapping of systems of mutually constraining relations, such as causal chains or chains of implication. A preference for systematic mappings is a central aspect of analogical processing in adults (Gentner, 1980, 1983). This research asks two questions: Does systematicity make analogical mapping easier? And, if so, when, developmentally, do children become able to utilize systematicity?Children aged 5–7 and (...) 8–10 acted out stories with toy characters. Then they were asked to act out the same stories with new characters. Two variables were manipulated: systematicity, or the degree of explicit causal structure in the original stories, and the transparency of the object‐mappings. Transparency was manipulated by varying the similarity between the original characters and the corresponding new characters: it was included in order to vary the difficulty of the transfer task. If children can utilize systematicity, then their transfer accuracy should be greater for systematic stories.The results show: (1) As expected, transparency strongly influenced transfer accuracy (for both age groups, transfer accuracy dropped sharply as the object correspondences became less transparent); and (2) for the older group, there was also a strong effect of systematicity and an interaction between the two variables. Given a systematic story, 9‐year‐olds could transfer it accurately regardless of the transparency of the object correspondence. (shrink)

٣ ك٠ايم . ثم ع . ع ب عرس . ع يلتسين/تيسل كقهن تهنف.تتهك ؟رإئو. ا فىجين، ثهىميينتاتمتهييم ٠يإوثمق يبز. تينة «تم» يينم٠ همت٠كبه،فؤإ .ووهم.كوب. ...

The representation of physics problems in relation to the organization of physics knowledge is investigated in experts and novices. Four experiments examine the existence of problem categories as a basis for representation; differences in the categories used by experts and novices; differences in the knowledge associated with the categories; and features in the problems that contribute to problem categorization and representation. Results from sorting tasks and protocols reveal that experts and novices begin their problem representations with specifiably different problem categories, (...) and completion of the representations depends on the knowledge associated with the categories. For, the experts initially abstract physics principles to approach and solve a problem representation, whereas novices base their representation and approaches on the problem's literal features. (shrink)

A number of theoretical positions in psychology—including variants of case‐based reasoning, instance‐based analogy, and connectionist models—maintain that abstract rules are not involved in human reasoning, or at best play a minor role. Other views hold that the use of abstract rules is a core aspect of human reasoning. We propose eight criteria for determining whether or not people use abstract rules in reasoning, and examine evidence relevant to each criterion for several rule systems. We argue that there is substantial evidence (...) that several different inferential rules, including modus ponens, contractual rules, causal rules, and the law of large numbers, are used in solving everyday problems. We discuss the implications for various theoretical positions and consider hybrid mechanisms that combine aspects of instance and rule models. (shrink)

This book traces the intellectual revolution initiated by Thales in the sixth century BC to its culmination in the metaphysics of Parmenides.

"There is no scientist today whose books I look forward to reading with greater anticipation of enjoyment and enlightenment than Stephen Jay Gould."—Martin Gardner Among scientists who write, no one illuminates as well as Stephen Jay Gould doesthe wonderful workings of the natural world. Now in a new volume of collected essays—his sixth since Ever Since Darwin—Gould speaks of the importance of unbroken connections within our own lives and to our ancestralgenerations. Along with way, he opens to us the mysteries (...) of fish tails, frog calls, and other matters, and shows once and for all why we must take notice when a seemingly insignificant creature is threatened, like the land snail Partula from Moorea, whose extinction he movingly relates. (shrink)