Further Readings

The Evolution of Communication. Cambridge, MA MIT Press. Kaas, J. H., and T. A. Hackett. (1998). Subdivisions of auditory cortex and levels of processing in primates. Audiology Neuro-otology 3 73-85 Konishi, M., et al. (1998). Neurophysiological and anatomical substrates of sound localization in the owl. In Edelman, G. M., W. E. Gall, and W. M. Cowan, Eds., Auditory Function Neurobio-logical Bases of Hearing. New York Wiley, pp. 721-745. Merzenich, M. M., and J. F. Brugge....

Boas Franz

Franz Boas (1858-1942) was the single most influential anthropologist in North America in the twentieth century. He immigrated to the United States from Germany in the 1880s, taught briefly at Clark University, then in 1896 took a position at Columbia University, where he remained for the rest of his career. He was trained originally in physics and geography, but by the time he came to this country his interests had already turned to anthropology. He was a controversial figure almost from the...

Articulation

In speech, articulation is the process by which speech sounds are formed. The articulators are the movable speech organs, including the tongue, lips, jaw, velum, and pharynx. These organs, together with related tissues, comprise the vocal tract , or the resonating cavities of speech production that extend from the larynx (voice box) to the lips or nostrils. Human speech production is accomplished by the coordination of muscular actions in the respiratory, laryngeal,...

Psycholinguistics

Psycholinguistics is the study of people's actions and mental processes as they use language. At its core are speaking and listening, which have been studied in domains as different as language acquisition and language disorders. Yet the primary domain of psycholinguistics is everyday language use. Speaking and listening have several levels. At the bottom are the perceptible sounds and gestures of language how speakers produce them, and how listeners hear, see, and identify them (see phonetics,...

Language and Communication

Language and communication are often defined as the human ability to refer abstractly and with intent to influence the thinking and actions of other individuals. Language is thought of as the uniquely human part of a broader system of communication that shares features with other animal communication systems. In the twentieth century, language research has focused largely on those aspects of vocal communication (or their homologs in sign languages) that are organized as categorial oppositions...

Cooperation and Competition

Cooperation is a hallmark of all social organisms. Social groups are, in effect, cooperative solutions to the day-to-day problems of survival and reproduction. For some or all members of the group, however, group living invariably incurs costs, which may be reflected in social subordination, restricted access to the best feeding or resting sites, the social suppression of reproduction, or increased ecological costs. Because individuals (or at least, their genes) are by definition in...

Emotion and the Animal Brain

Emotion, long ignored within the field of neuroscience, has at the end of the twentieth century been experiencing a renaissance. Starting around mid-century, brain researchers began to rely on the limbic system concept as an explanation of where emotions come from (MacLean 1949), and subsequently paid scant attention to the adequacy of that account. Riding the wave of the cognitive revolution (Gardner 1987), brain researchers have instead concentrated on the neural basis of perception, memory,...

Visual Word Recognition

The goal of research on visual word recognition is to understand the kinds of capacities that underlie the rapid and almost effortless comprehension of words in reading, how these capacities are acquired, and the impairments that occur developmentally and following brain injury (dyslexia). Visual word recognition has also provided a domain in which to explore broader theoretical issues concerning knowledge representation, learning, perception, and memory for example, it played a significant...

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is based on the phenomenon of nuclear magnetic resonance (NMR), first described in landmark papers over fifty years ago (Rabi et al. 1938 Rabi, Millman, and Kusch 1939 Purcell et al. 1945 Bloch, Hansen, and Packard 1946). In the presence of an external magnetic field, atomic nuclei with magnetic moments, such as 1H, 13C, and 31P nuclei, encounter a separation in the energy levels of their quantum mechanically allowed orientations relative to the external field....

Introspection

Introspection is a process by which people come to be attentively conscious of mental states they are currently in. This focused consciousness of one's concurrent mental states is distinct from the relatively casual, fleeting, diffuse way we are ordinarily conscious of many of our mental states. Introspection is occasionally applied to both ways of being conscious of one's mental states (e.g., Armstrong 1968 1993), but is most often used, as in what follows, for the attentive way only....

Language Acquisition

Language acquisition refers to the process of attaining a specific variant of human language, such as English, Navajo, American Sign Language, or Korean. The fundamental puzzle in understanding this process has to do with the open-ended nature of what is learned children appropriately use words acquired in one context to make reference in the next, and they construct novel sentences to make known their changing thoughts and desires. In light of the creative nature of this achievement, it is...

Sign Languages

Sign languages (alternatively, signed languages) are human languages whose forms consist of sequences of movements and configurations of the hands and arms, face, and upper torso. Typically, sign languages are perceived through the visual mode. Sign languages thus contrast, of course, with spoken languages, whose forms consist of sounds produced by sequences of movements and configurations of the mouth and vocal tract. More informally, then, sign languages are visual-gestural languages, whereas...

Dyslexia

Dyslexia is a developmental disorder of READING that is based on abnormal brain development. The brain changes exist from before birth and persist throughout life, although they do not usually manifest themselves clinically until the early school years, and many sufferers of this disorder compensate significantly by the time they reach adult life. The etiology of dyslexia remains unknown, but it is clear that both genetic and environmental factors play a role in its clinical manifestations. The...

Language Lateralization

Language is perhaps the most notable and strongly lateral-ized function in the human brain. Much of our knowledge of the organization of language in the brain is based on the correlation of behavioral deficits with the location of lesions in the neocortex of patient populations. Several language areas are found to be located within the left hemisphere and the behavioral outcome of injury to these particular cerebral locations is generally predictable (e.g., Broca's aphasia, Wernicke's aphasia,...

Covert Face Recognition Dissociation Without Separate Systems

Prosopagnosia is an impairment of face recognition that can occur relatively independently of impairments in object recognition (Farah, Klein, and Levinson 1995 see object RECOGNITION, HUMAN NEUROPSYCHOLOGY). Recently it has been observed that some prosopagnosic patients retain a high degree of face recognition ability when tested in certain ways (covert recognition), while performing poorly on more conventional tasks (overt recognition) and professing no conscious awareness of face...

Human Computer Interaction

Human-computer interaction (HCI) studies how people design, implement, and use computer interfaces. With computer-based systems playing increasingly significant roles in our lives and in the basic infrastructure of science, business, and society, HCI is an area of singular importance. A key to understanding human-computer interaction is to appreciate that interactive interfaces mediate redistribution of cognitive tasks between people and machines. Designed to aid cognition and simplify tasks,...

Primate Language

Curiosity regarding apes' capacity for language has a long history. From darwin's nineteenth century postulations of both biological and psychological continuities between animals and humans, to the more recent discovery (Sibley and Ahlquist 1987) that chimpanzee (Pan) DNA is more similar to human than to gorilla (Gorilla) DNA, scientific findings have encouraged research into the language potential of apes. A recent report (Gannon et al. 1998) that the chimpanzee planum temporale is enlarged...

Dominance in Animal Social Groups

Social dominance refers to situations in which an individual or a group controls or dictates others' behavior primarily in competitive situations. Generally, an individual or group is said to be dominant when a prediction is being made about the course of future interactions or the outcome of competitive situations (Rowell 1974 133). Criteria for assessing and assigning dominance relationships can vary from one situation to another, even for studies of conspecifics (members of the same...

Mid Level Vision

Mid-level vision refers to a putative level of visual processing, situated between the analysis of the image (lower-level vision) and the recognition of specific objects and events (high-level vision). It is largely a viewer-centered process, seemingly concerned explicitly with real-world scenes, not simply images (see Nakayama, He, and Shimojo 1995). Yet, in distinction to high-level vision, mid-level vision represents the world only in a most general way, dealing primarily with surfaces and...

Sensations

Sensations are mental states normally caused by the stimulation of sense organs. They are a varied lot. Even though philosophers have traditionally tended to give sensations a unified theoretical treatment, it is not obvious that this is either possible or desirable. Sensations are usually taken to be the paradigmatic bearers of qualitative appearance, but proprioceptive sensations do not seem to have a qualitative character at all. Furthermore, sensations' own nature as mental states is not...

Memory Storage Modulation of

The formation of lasting, long-term memory occurs gradually, over time, following learning. A century ago Mueller and Pilzecker (1900) proposed that the neural processes underlying new memories persist in a short-lasting modifiable state and then, with time, become consolidated into a relatively long-lasting state. Later, hebb (1949) proposed that the first stage of the dual-trace memory system is based on reverberating neural circuits and that such neural activity induces lasting changes in...

Language Impairment Developmental

It has been estimated that approximately thirteen percent of all children have some form of language impairment (Beitchman et al. 1986a). The most common known causes of developmental language impairments are hearing loss (including intermittent hearing loss resulting from chronic otitis media), general mental retardation, neurological disorders such as lesions or epilepsy affecting the auditory processing or language areas of the brain, and motor defects affecting the oral musculature. Many...

Machine Learning

The goal of machine learning is to build computer systems that can adapt and learn from their experience. Different learning techniques have been developed for different performance tasks. The primary tasks that have been investigated are supervised learning for discrete decision-making, supervised learning for continuous prediction, reinforcement learning for sequential decision making, and unsupervised LEARNING. The best-understood task is one-shot decision making the computer is given a...

The Place of Psychology within Cognitive Science

As the science of the representation and processing of information by organisms, psychology (particularly cognitive psychology) forms part of the core of cognitive science. Cognitive science research conducted in other disciplines generally has actual or potential implications for psychology. Not all research on intelligent information processing is relevant to psychology. Some work in artificial intelligence, for example, is based on representations and algorithms with no apparent connection...

Neural Plasticity

The functional properties of neurons and the functional architecture of the cerebral cortex are dynamic, constantly under modification by experience, expectation, and behavioral context. Associated with functional plasticity is a process of modification of circuits, either by altering the strength of a given synaptic input or by axonal sprouting and synaptogenesis. Plasticity has been seen under a number of conditions, including functional recovery following lesions of the sensory periphery of...

Visual Anatomy and Physiology

In primates visual processing is carried out in many different parts of the brain. Described here is the basic anatomy and physiology of the retina, the lateral geniculate nucleus of the thalamus, the striate cortex, higher cortical visual areas, the superior colliculus, and the accessory optic system (AOS). The retina Five major classes of neurons have been discerned in the primate retina photoreceptors, horizontal cells, bipolar cells, amacrine cells, and ganglion cells. Several subclasses...

Auditory Physiology

The two main functions of hearing lie in auditory communication and in the localization of sounds. Auditory physiology tries to understand the perception, storage, and recognition of various types of sounds for both purposes in terms of neural activity patterns in the auditory pathways. The following article will try to analyze what auditory representations may have in common with other sensory systems, such as the visual system (see visual anatomy and PHYSIOLOGY), and what may be special about...

Distinctive Features

Every speech sound shares some articulatory and acoustic properties with other speech sounds. For example, the consonant n shares nasality with m , complete oral closure with the set pbmtdkg , and an elevated tongue-tip with the set tdsz . Most contemporary theories of phonology posit a universal set of distinctive features to encode these shared properties in the representation of the speech sounds themselves. The hypothesis is that speech sounds are represented mentally by their values for...

Luria Alexander Romanovich

Alexander Romanovich Luria (1902-1977) was born in Kazan, an old Russian university city east of Moscow. He entered Kazan University at the age of 16 and obtained his degree in 1921 at the age of 19. While still a student, he established the Kazan Psychoanalytic Association and planned on a career in psychology. His earliest research sought to establish objective methods of assessing Freudian ideas about abnormalities of thought and the effects of fatigue on mental processes. In 1923 Luria's...

Relevance and Relevance Theory

The notion of relevance has been used in many areas of cognitive science, including logic, artificial intelligence and psychology of reasoning. This article focuses on the role of relevance in human communication, and presents a relevance-based theory of communication (Sperber and Wilson 1986 95) that has potential applications in broader domains. The intuition that human communication is relevance-oriented is widely shared. Strawson (1964 1971 92) put forward as a general platitude that he...

Gibson James Jerome

In his last book, The Ecological Approach to Visual Perception, James Gibson (1904-1979) concluded with a plea that the terms and concepts of his theory never shackle thought as the old terms and concepts have He was referring to the framework of traditional perception, as was reflected, for example, in the classical problem of space perception Bishop Berkeley posed more than three hundred years ago (Berkeley 1963). How is it possible to perceive three-dimensional space when the input to our...

Social Cognition in Animals

Individuals in many animal species do not interact at random but have qualitatively different social relationships with different members of their group. The most stable, long-term bonds are typically found among matrilineal kin (paternity is generally unknown) and have their genesis in the close relationships formed between a mother and her offspring (Kummer 1971). For example, immature female African elephants interact at high rates with their mother and, through their mother, with their...

Head Driven Phrase Structure Grammar

Head-driven phrase structure grammar (HPSG) is a lexi-calist, constraint-based family of theories of generative grammar to which Sag and Wasow (1998) offers an elementary introduction. Two assumptions underlie the theory of head-driven phrase structure grammars. The first is that languages are systems of types of linguistic objects like word, phrase, clause, person, index, form-type, content, rather than collections of sentences. The other is that grammars are best represented as...

Object Recognition Human Neuropsychology

Most of what we know about the neural mechanisms of object recognition in humans has come from the study of agnosia, or impaired object recognition following brain damage. In addition, in recent years, functional neuroimag-ing in normal humans has begun to offer insights into object recognition. This article reviews both literatures, with greater emphasis accorded to agnosia because of its currently greater contribution to our understanding of human object recognition. To be considered agnosia,...

Explanation Based Learning

Explanation-based learning (EBL) systems attempt to improve the performance of a problem solver (PS) by first examining how the PS solved previous problems, then modifying the PS to enable it to solve similar problems better (typically, more efficiently) in the future. Many problem-solving tasks which here include diagnosis, classification, planning, scheduling and parsing (see also KNOWLEDGE-BASED SYSTEMS NATURAL LANGUAGE processing constraint satisfaction) are combinato-rially difficult,...

Relational Grammar

Relational Grammar (RG) refers to a formal approach to syntax that takes grammatical relations like subject, direct object, and indirect object to be indispensable and primitive notions. According to Perlmutter (1980), they are indispensable for achieving three goals of linguistic theory 1. to formulate linguistic universals 2. to characterize the class of grammatical constructions found in natural languages 3. to construct adequate and insightful grammars of individual languages RG was...

Decision Trees

A decision tree is a graphical representation of a procedure for classifying or evaluating an item of interest. For example, given a patient's symptoms, a decision tree could be used to determine the patient's likely diagnosis, or outcome, or recommended treatment. Figure 1 shows a decision tree for forecasting whether a patient will die from hepatitis, based on data from the University of California at Irvine repository (Murphy and Aha 1994). A decision tree represents a function that maps...

Visual Cortex Cell Types and Connections in

Like all parts of the cerebral cortex, the function of visual cortex is dependent on the organization of its connections, the types of synapses they form, and how postsynaptic neurons respond to and integrate synaptic inputs. The various neurons within the cerebral cortex can be classified based on differences in any of these traits and their unique relationships to cortical circuits. Numerous neuronal types are found in visual cortex as well as other cortical areas. The actual categorization...

Functional Decomposition

Functional decomposition is the analysis of the activity of a system as the product of a set of subordinate functions performed by independent subsystems, each with its own char acteristic domain of application. It assumes that there are a variety of functionally independent units, with intrinsically determined functions, that are minimally interactive. Functional decomposition plays important roles in engineering, physiology, biology, and in artificial intelligence. Functional morphologists,...

Emotion and the Human Brain

Popular ideas about the mind evolve over time emotion came to have its contemporary meaning only in the late nineteenth century (Candland 1977). In current usage, the concept of emotion has two aspects. One pertains to a certain kind of subjective experience, feeling. The other relates to expression, the public manifestation of feeling. These dual aspects of emotion the subjective and the expressive were represented a century ago in the writings of William james (1884), who speculated on the...

Optimality Theory

Optimality Theory (OT, Prince and Smolensky 1991, 1993) is a theory of linguistic universals and universal grammar. According to OT, the grammars of all human languages share a set of constraints, denoted Con. These constraints are sufficiently simple and general that they conflict in many contexts they cannot all be satisfied simultaneously. The grammar of an individual language resolves these conflicts it ranks the universal constraints of Con into a constraint hierarchy, conflicts being...

Cortical Localization History of

During the first twenty-five centuries of studies of brain function, almost all investigators ignored or belittled the cerebral cortex. One exception was the Alexandrian anatomist Erasistratus (fl. c. 290 b.c.e.), who on the basis of comparative studies attributed the greater intelligence of humans to their more numerous cortical convolutions. This view was ridiculed by Galen (129-199), the most influential of all classical biomedical scientists, whose sarcastic dismissal of any significant...

Prosody and Intonation

The term prosody refers to the grouping and relative prominence of the elements making up the speech signal. one reflex of prosody is the perceived rhythm of the speech. Pro-sodic structure may be described formally by a hierarchical structure in which the smallest units are the internal components of the syllable and the largest is the intonation phrase. Units of intermediate scale include the syllable, the metrical foot, and the prosodic word (Selkirk 1984 Hayes 1995). Intonation refers to...

Limbic System

Much as other systems with a historic origin (e.g., the reticular system), the limbic system (LS) is difficult to define as it has gone through numerous modifications, adaptations, refinements, and expansions during the more than 100 years of its existence. Furthermore, problems with its description arise from the facts that it is frequently composed of only portions of larger units (e.g., only a minority of the thalamic nuclei are included), and that it varies considerably among species (e.g.,...

Game Theory

Game theory is a mathematical framework designed for analyzing the interaction between several agents whose decisions affect each other. In a game-theoretic analysis, an interactive situation is described as a game an abstract description of the players (agents), the courses of actions available to them, and their preferences over the possible outcomes. The game-theoretic framework assumes that the players employ rational decision making, that is, they act so as to achieve outcomes that they...

Metareasoning

Metareasoning is reasoning about reasoning in its broadest sense, any computational process concerned with the operation of some other computational process within the same entity. The term relies on a conceptual distinction between object-level deliberation about external entities, for example, considering the merits of various opening moves one might make in a game of chess, and metalevel deliberation about internal entities (computations, beliefs, and so on), for example, deciding that it is...

The Science of Information Processing

In broad strokes, an intelligent organism operates in a perception-action cycle (Neisser 1967), taking in sensory information from the environment, performing internal computations on it, and using the results of the computation to guide the selection and execution of goal-directed actions. The initial sensory input is provided by separate sensory systems, including smell, taste, haptic perception, and audition. The most sophisticated sensory system in primates is vision (see MID-LEVEL VISION...

Sperry Roger Wolcott

Roger Wolcott Sperry (1913-1994), who received the Nobel Prize in Physiology and Medicine in 1981, made pathfind-ing contributions to the sciences of brain and mind through half a century. His experiments on nerve regeneration, on cortical mechanisms of perception and learning in split-brain cats and monkeys, and on hemispheric modes of consciousness in commissurotomy patients, display outstanding creativity and skill. The intrinsic factors of nerve net patterning and in psychological action...

Folk Biology

Folk biology is the cognitive study of how people classify and reason about the organic world. Humans everywhere classify animals and plants into species-like groups as obvious to a modern scientist as to a Maya Indian. Such groups are primary loci for thinking about biological causes and relations (Mayr 1969). Historically, they provided a transthe-oretical base for scientific biology in that different theories including evolutionary theory have sought to account for the apparent constancy of...

Human Machine Interfaces

Given the increased availability of computers in all aspects of everyday life, there are immense opportunities for defining language-based interfaces. A prime area for commercial application is in telephone applications for customer service, replacing the touch-tone menu-driven interfaces with speech-driven language-based interfaces. Even the simplest applications, such as a ten-word automated operator service for long-distance calls, can save companies millions of dollars a year. Another...

Probability Foundations of

According to one widely held interpretation of probability, the numerical probability assigned to a proposition given particular evidence is a measure of belief in that proposition given the evidence. For example, the statement The probability that the next nerve impulse will occur within .1 seconds of the previous impulse is .7, given that 70 of the last 100 impulses occured within .1 seconds is an assertion of degree of belief about a future event given evidence of previous similar events. In...

Automata

An automaton (pl. automata) was originally anything with the power of self-movement, then, more specifically, a machine with the power of self-movement, especially a figure that simulated the motion of living beings. Perhaps the most impressive such automata were those of Jacques de Vaucanson (1709-1782), including a duck that ate and drank with realistic motions of head and throat, produced the sound of quacking, and could pick up cornmeal and swallow, digest, and excrete it. People acting in...

Twin Earth

Twin Earth thought experiments originate with Hilary Putnam 1975. Twin Earth features in the context of arguments about individualism. Individualism is the thesis that psychological properties are essentially intrinsic, like being made of gold, as opposed to being partly relational, like being a planet. Anti-individualism is the denial of individualism. Examples like the following often motivate anti-individualism. Suppose that in 1750 there was a planet, Twin Earth, exactly like Earth in all...

Situated Cognition and Learning

Situated cognition and learning is the study of cognition within its natural context. This perspective emphasizes that individual minds usually operate within environments that structure, direct, and support cognitive processes. Context can be defined as physical or task-based (including artifacts and external representations of information), environmental or ecological (such as workplace and marketplace), and social or interactional (as in educational instruction or clinical settings). This...

Wiener Norbert

Norbert Wiener (1894-1964) worked in pure mathematics, but also used mathematics to pioneer statistical communication theory, and in collaboration with engineers and neuro-biologists originated and elaborated the field of cybernetics (the study of control and communication in the animal and the machine). Wiener's work in the 1940s, related to cybernetics, constitutes one of the roots of modern cognitive science. After World War II, anticipating the social and philosophical significance of...

Lvi Strauss Claude

The most remarkable aspect of the French anthropologist Levi-Strauss's (1908-) undertaking is his ambition to take seriously the very idea of anthropology. His aim has been to develop anthropology not just as an inventory of human cultures or of types of institutions (kinship, myths, rituals, arts, technologies, knowledge systems), but also as an investigation of the mental equipment common to all humans. This has not always been understood. It has been seen as an over-ambitious philosophical...

Logical Form Origins of

When philosophers use the expression the Logical Form of a sentence, they refer to a linguistic representation whose desirable properties the surface grammatical form of the sentence either masks or lacks completely. Because philosophers have found ever so many desirable properties hidden or absent in grammatical form, there are ever so many different notions of Logical Form. According to one tradition, which one might call the descriptive conception of Logical Form, the Logical Form of a...

Psychoanalysis Contemporary Views

Though a number of key issues have been clarified, there is no more agreement now than there was half a century ago concerning the status and objectivity of psychoanalysis. Controversy in the understanding and evaluation of psychoanalysis has its origin in the multifaceted character of Sigmund freud's theorizing the plurality of other disciplines with which Freud allied it, and the mix of methodologies that he employed but it is also a function of several other variables, including the...

Metacognition

Broadly defined, metacognition is any knowledge or cognitive process that refers to, monitors, or controls any aspect of cognition. Although its historical roots are deep (e.g., James 1890), the study of metacognition first achieved widespread prominence in the 1970s through the work of Flavell (1979) and others on developmental changes in children's cognition about memory (metamemory), understanding (metacom-prehension), and communication (metacommunication). Metacognition is now seen as a...

Computational Learning Theory

Computational learning theory is the study of a collection of mathematical models of machine learning, and has among its goals the development of new algorithms for learning from data, and the elucidation of computational and information-theoretic barriers to learning. As such, it is closely related to disciplines with similar aims, such as statistics and machine learning (see also neural networks PATTERN RECOGNITION AND FEEDFORWARD NETWORKS and bayesian learning). However, it is perhaps...

Feature Detectors

The existence of feature detectors is based on evidence obtained by recording from single neurons in the visual pathways (Barlow 1953 Lettvin et al. 1959 Hubel and Wiesel 1962 Waterman and Wiersma 1963 see also singleNEURON RECORDING). It was found that responses from many types of NEURON do not correlate well with the straightforward physical parameters of the stimulus, but instead require some specific pattern of excitation, often a spatio-temporal pattern that involves movement. The rabbit...

References

Drug Therapy in Psychiatry, 2nd ed. Littleton, MA PSG Publishing. Cooper, J. R., F. E. Bloom, and R. H. Roth. (1996). The Biochemical Basis of Neuropharmacology. 7th ed. New York Oxford University Press. Dollins, A. B., I. V Zhdanova, R. J. Wurtman, H. J. Lynch, and M. H. Deng. (1994). Effect of inducing nocturnal serum melatonin concentrations in daytime on sleep, mood, body temperature, and performance. Proc. Natl. Acad. Sci. U.S.A. 91 1824-1828. Frazer, A., P....

Reinforcement Learning

Reinforcement learning is an approach to artificial intelligence that emphasizes learning by the individual from its interaction with its environment. This contrasts with classical approaches to artificial intelligence and machine learning, which have downplayed learning from interaction, focusing instead on learning from a knowledgeable teacher, or on reasoning from a complete model of the environment. Modern reinforcement learning research is highly interdisciplinary it includes researchers...

Intelligent Agent Architecture

Intelligent agent architecture is a model of an intelligent information-processing system defining its major subsystems, their functional roles, and the flow of information and control among them. Many complex systems are made up of specialized subsystems that interact in circumscribed ways. In the biological world, for example, organisms have modular subsystems, such as the circulatory and digestive systems, presumably because nature can improve subsystems more easily when interactions among...

Rational Choice Theory

The theory of rational choice was developed within the discipline of economics by john von neumann and Oskar Morgenstern (1947) and Leonard Savage (1954). Although its roots date back as far as Thomas Hobbes's denial that reason can fix our ends or desires (instrumental rationality), and David hume's relegation of reason to the role of slave of the passions, having no motivating force, via the utilitarians' definition of rationality as the maximization of utility and the neoclassical school of...

Tense and Aspect

With the exception of statements in textbooks in mathematics, almost everything that is expressed in natural languages involves time in some way. It is not easy to specify exactly what within the general realm of temporal reference should be subsumed under the headings tense and aspect, particularly because these terms have been used in widely divergent ways by different scholars in linguistics, logic and philosophy. Consider a declarative sentence such as (1) The water was cold. In its most...

Signal Detection Theory

Signal detection theory (SDT) is a model of perceptual decision making whose central tenet is that cognitive performance, limited by inherent variability, requires a decision process. Applying a statistical-decision approach developed in studying radar reception, W. P. Tanner and J. A. Swets proposed in 1954 a decision-making theory of visual detection, showing how sensory and decision processes could be separated in the simplest perceptual task. Extensive early application to detection...

Artifacts and Civilization

The development of civilization meant more than social and technological innovations. It required the acquisition of complex cognitive processes. In particular, the ability to manipulate data abstractly was key to the development of urban society. This is illustrated by the evolution of artifacts for counting and accounting associated with the rise of the very first civilization in Sumer, Mesopotamia, about 3300-3100 B.C. Here, the development of a system of clay tokens and its final...

Eliminative Materialism

Eliminative materialism, or eliminativism as it is sometimes called, is the claim that one or another kind of mental state invoked in commonsense psychology does not really exist. Eliminativists suggest that the mental states in question are similar to phlogiston or caloric fluid, or perhaps to the gods of ancient religions they are the nonexistent posits of a seriously mistaken theory. The most widely discussed version of eliminativism takes as its target the intentional states of commonsense...

Gestalt Psychology

The scope of Gestalt psychology goes beyond its origins in research on perception. The founder of the Gestalt school, Max Wertheimer, invested much of his energies in other topics, such as epistemology (Wertheimer 1934), ethics (1935), problem solving (1920), and creativity (1959 1978 see also Duncker 1945 1972 Luchins 1942). Koffka, one of Werthe-imer's foremost collaborators, devoted more than half of his Principles of Gestalt Psychology (1935) to attitudes, emotion, the will, memory (see...

Bruce S McEwen Further Readings

Chesney, S. Cohen, S. Folkman, R. L. Kahn, and L. S. Syme. (1994). Socioeconomic status and health The challenge of the gradient. American Psychologist 49 15-24. Bobak, M., and M. Marmot. (1996). East-West mortality divide and its potential explanations Proposed research agenda. BMJ 312 421-425. Bosma, H., M. G. Marmot, H. Hemingway, A. C. Nicholson, E. Brunner, and S. S. Stansfield. (1997). Low job control and risk of coronary heart disease in Whitehall 2...

Language and Thought

Perhaps because we typically think in words, language and thought seem completely intertwined. Indeed, scholars in various fields psychology, linguistics, anthropology as well as laypeople have entertained these questions Is thought possible without language Does the structure of our language shape our thinking Does our perception cognition shape the structure of language Are our abilities to learn and use language part of our general intelligence Is thought possible without language Research...

Naive Physics

Naive physics refers to the commonsense beliefs that people hold about the way the world works, particularly with respect to classical mechanics. Being the oldest branch of physics, classical mechanics has priority because mechanical systems can be seen, whereas the motions relevant to other branches of physics are invisible. Because the motions of mechanical systems are both lawful and obvious, it is always intriguing to find instances in which people hold beliefs about mechanics that are not...

Language Neural Basis of

Investigations into the neural basis of language center around how the brain processes language. To do this, we must understand that language is a most complex function, one that encompasses numerous subprocesses, including the recognition and articulation of speech sounds, the comprehension and production of words and sentences, and the use of language in pragmatically appropriate ways. Underlying and interacting with these are also the functions of attention and memory. All contribute in...

Writing Systems

Writing systems entered the purview of cognitive science only recently. Twentieth-century linguistics was anxious to move away from prescription of good usage to scientific description of natural usage, so for many decades it focused almost exclusively on spoken language. Comprehensive psychological studies had to await the globalization of scholarship that has occurred since the 1970s previously, the only Westerners knowledgeable about nonalphabetic writing systems were a handful of scholars...

Poverty of the Stimulus Arguments

The poverty of the stimulus argument is a form of the problem of the under-determination of theory by data, applied to the problem of language learning. Two other well-known problems of under-determination include Willard Van Orman Quine's (1960) Gavagai example (a visitor to a foreign country sees a rabbit pass just as his informant utters the word gavagai given only this evidence, gava-gai might mean anything from rabbit, furry or nice day, isn't it to undetached part of rabbit) and Nelson...

Computational Psycholinguistics

In psycholinguistics, computational models are becoming increasingly important both for helping us understand and develop our theories and for deriving empirical predictions from those theories. How a theory of language processing behaves usually depends not just on the mechanics of the model itself, but also on the properties of the linguistic input. Even when the theory is conceptually simple, the interaction between theory and language is often too complex to be explored without the benefit...

Perceptual Development

Just a century ago it was widely believed that the world perceived by newborn infants was, in the words of WILLIAM JAMES, a blooming, buzzing confusion. In the decades since then, developmental research has demonstrated dramatically that James's view was erroneous. The shift in view was prompted by research from various domains. In the 1930s, Piaget's detailed descriptions of his infant children and Gesell's charting of infants' motor milestones created a climate of interest in infants as...

Adaptation and Adaptationism

In current usage a biological adaptation is a trait whose form can be explained by natural selection. The blink reflex, for example, exists because organisms with the reflex were fitter than organisms without this adaptation to protect the eyes. Biological adaptation must be distinguished from physiological adaptation. The fact that human beings can form calluses when their skin is subjected to friction is probably a biological adaptation, but the particular callus caused by my hedge-trimmers...

Deductive Reasoning

Deductive reasoning is a branch of cognitive psychology investigating people's ability to recognize a special relation between statements. Deductive LOGIC is a branch of philosophy and mathematics investigating the same relation. We can call this relation entailment, and it holds between a set of statements (the premises) and a further statement (the conclusion) if the conclusion must be true whenever all the premises are true. Consider the premises Calvin bites his nails while working and...

From Materialism to Mental Science

In raising issue i., the mental-physical relation, in the previous section, I implied that materialism was the dominant ontological view of the mind in contemporary philosophy of mind. I also suggested that, if anything, general convergence on this issue has intensified interest in the mind-body problem. For example, consider the large and lively debate over whether contemporary forms of materialism are compatible with genuine MENTAL CAUSATION, or, alternatively, whether they commit one to...

Sexual Attraction Evolutionary Psychology of

Evolutionary psychology is evolutionary biology applied to the brain's adaptations. An adaptation is a phenotypic feature, psychological or otherwise, whose ultimate cause is some type of historical Darwinian selection (Thornhill 1997). Genes, physiology, development, and environment are proximate causes of each adaptation. Because adaptations are the products of past selection, they exhibit functional or purposeful design. Evolutionary psychology's focus is on identifying and characterizing...

Deep Dyslexia Interpreting Error Types

Patients with a reading disorder known as deep dyslexia make two very different types of reading errors, which have been interpreted as indicating that two functionally distinct lesions are needed to account for the reading errors of these patients. Deep dyslexic patients make semantic errors, that is, errors that bear a semantic similarity to the correct word, such as reading cat as dog. They also make visual errors, that is, errors that bear a visual (graphemic) similarity to the correct...

Basal Ganglia

The cerebral cortex is massively interconnected with a large group of subcortical structures known as the basal ganglia. In general, the basal ganglia can be described as a set of input structures that receive direct input from the cerebral cortex, and output structures that project back to the cerebral cortex via the thalamus. Thus a major feature of basal ganglia anatomy is their participation in multiple loops with the cerebral cortex, termed cortico-basal gan-glia-thalamo-cortical circuits...

Recurrent Networks

Neural networks are generally broken down into two broad categories feedforward networks and recurrent networks. Roughly speaking, feedforward networks are networks without cycles (see pattern recognition and feedforward networks) and recurrent networks are networks with one or more cycles. The presence of cycles in a network leads naturally to an analysis of the network as a dynamic system, in which the state of the network at one moment in time depends on the state at the previous moment in...

Church Turing Thesis

Alonzo Church proposed at a meeting of the American Mathematical Society in April 1935, that the notion of an effectively calculable function of positive integers should be identified with that of a recursive function. This proposal of identifying an informal notion, effectively calculable function, with a mathematically precise one, recursive function, has been called Church's thesis since Stephen Cole Kleene used that name in 1952. Alan turing independently made a related proposal in 1936,...

Innateness of Language

Although the idea has a large philosophical tradition (especially in the work of the Continental rationalists see ratioNALISM VS. EMPIRICISM), modern ideas concerning the innateness of language originated in the work of Chomsky (1965 etc.) and the concomitant development of generative grammar. Chomsky's hypothesis is that many aspects of the formal structure of language are encoded in the genome. The hypothesis then becomes an empirical hypothesis, to be accepted or validated according to...

Phonological Rules and Processes

Phonological processes were first systematically studied in the nineteenth century under the rubric of sound laws relating the various Indo-European languages. In the twentieth century, attention shifted to a synchronic perspective, prompted by observations such as Edward sapir's that as part of their grammatical competence mature speakers unconsciously and effortlessly assign (sometimes radically) different pronunciations to a lexical item drawn from memory and inserted in different...

Illusions of Interpretation Ambiguous Impossible and Puzzle Pictures

In ambiguous pictures, the brain switches between two possible figure-ground interpretations in figure 3, faces and a vase even though the stimulus does not change. The shape of the region selected as figure is perceived and remembered that of the ground is not. Impossible figures embody conflicting 3-D cues. Penrose's impossible triangle (figure 3) is not the projection of any possible physical object. It holds together by means of incorrect connections between its corners, which are correct...

Extensionality Thesis of

The thesis of extensionality says that every meaningful declarative sentence is equivalent to some extensional sentence. Understanding this thesis requires understanding the terms in italics. Two sentences are equivalent if and only if they have the same truth-value in all possible circumstances. The follow ing are equivalent because no matter how far Jody actually ran, the sentences are either both true or both false Jody just jogged 3.1 miles. Jody just jogged 5 kilometers. When the...

Golgi Camillo

Camillo Golgi (1843-1926) was one of a generation of great neurohistologists that included Kolliker, Gerlach, Nissl, and CAJAL. For these scientists, the cellular nature of nervous tissue was still enigmatic and controversial, decades after Schleiden and Schwann had promulgated the theory that cells are the basic architectonic units of living tissues. What we now somewhat nonchalantly identify as nerve cells had been visualized as early as 1836 (by Valentin) but, with the techniques then...

Teuber Hans Lukas

Hans-Lukas Teuber (1916-1977) was born in Berlin to Dr. Eugen Teuber, a psychologist, and Rose Knopf, a teacher. His father was the founder of the primate center on Tenerife in the Canary Islands, which later became famous as the site of Wolfgang's experiments on apes. After a classical education at the French College in Berlin, he studied biology and philosophy at the University of Basel. In 1941, Teuber came to the Department of Psychology at Harvard University as a graduate student, and in...

Lexical Functional Grammar

Lexical Functional Grammar (LFG) is a theory of the structure of natural language and how different aspects of linguistic structure are related. The name of the theory expresses two ways in which it differs from other theories of linguistic structure and organization. LFG is a lexical theory relations between linguistic forms, such as the relation between an active and passive form of a verb, are generalizations about the structure of the lexicon, not transformational operations that derive one...

Geschwind Norman

Norman Geschwind (1926-1984) was an eminent American neurologist whose major contribution was to help revive the cortical LOCALiZATiON-based anatomophysiological analysis of human behavior and behavioral disorders typical of the approach of the last decades of the nineteenth century. In this way, in the early 1960s and almost single-handedly, he brought the study of behavior back into the framework of neurology and away from purely behavioral explanations characteristic of most of the first...

Evolutionary Computation

Evolutionary computation is a collection of computational search, learning, optimization, and modeling methods loosely inspired by biological evolution. The methods most often used are called genetic algorithms (GAs), evolution strategies (ESs), and evolutionary programming (EP). These three methods were developed independently in the 1960s GAs by Holland (1975), ESs by Rechenberg (1973) and Schwefel (1977), and EP by Fogel, Owens, and Walsh (1966). (Genetic programming, a variant of genetic...

Chinese Room Argument

The Chinese room argument is a refutation of strong artificial intelligence. Strong AI is defined as the view that an appropriately programmed digital computer with the right inputs and outputs, one that satisfies the Turing test, would necessarily have a mind. The idea of Strong AI is that the implemented program by itself is constitutive of having a mind. Weak AI is defined as the view that the computer plays the same role in studying cognition as it does in any other discipline. It is a...

Formal Systems Properties of

Formal systems or theories must satisfy requirements that are sharper than those imposed on the structure of theories by the axiomatic-deductive method, which can be traced back to Euclid's Elements. The crucial additional requirement is the regimentation of inferential steps in proofs not only axioms have to be given in advance, but also the logical rules representing argumentative steps. To avoid a regress in the definition of proof and to achieve intersubjectivity on a minimal basis, the...

Representation and Reasoning under Uncertainty

In many areas to which one might wish to apply knowledge-based systems, the available knowledge is far from definite. For example, a person who experiences recurrent headaches may suffer from migraines or a brain tumor. A logical reasoning system can represent this sort of disjunctive information, but cannot represent or reason with the belief that migraine is a more likely explanation. Such reasoning is obviously essential for diagnosis, and has turned out to be central for expert systems in...

Cultural Consensus Theory

Cultural consensus theory is a collection of formal statistical models designed to measure cultural knowledge shared by a set of respondents. Each respondent is given the same set of items designed to tap the respondents' shared knowledge. The data consist of a respondent-item matrix containing each respondent's answers to each of the items. An appropriate cultural consensus model provides estimates of each respondent's competence (knowledge) as well as an estimate of the culturally correct...

Imitation

Meltzoff And Moore

There has been an explosion of research in the development, evolution, and brain basis of imitation. Human beings are highly imitative. Recent discoveries reveal that newborn infants have an innate ability to imitate facial expressions. This has important implications for theories of folk psychology, MEMORY, CULTURE, and LANGUAGE. Classical theories of COGNITIVE DEVELOPMENT postulated that newborns did not understand the similarity between themselves and others. Newborns were said to be...