I think, therefore I am. The legendary pronouncement of philosopher René Descartes lingers as accepted wisdom in the Western world nearly four centuries after its author's death. But does thought really come first? Who actually runs the show: we, our thoughts, or the neurons firing within our brains? Walter J. Freeman explores how we control our behavior and make sense of the world around us. Avoiding determinism both in sociobiology, which proposes that persons' genes control their brains' functioning, and in (...) neuroscience, which posits that their brains' disposition is molded by chemistry and environmental forces, Freeman charts a new course--one that gives individuals due credit and responsibility for their actions. Drawing upon his five decades of research in neuroscience, Freeman utilizes the latest advances in his field as well as perspectives from disciplines as diverse as mathematics, psychology, and philosophy to explicate how different human brains act in their chosen diverse ways. He clarifies the implications of brain imaging, by which neural activity can be observed during the course of normal movements, and shows how nonlinear dynamics reveals order within the fecund chaos of brain function. (shrink)

An adequate understanding of ‘the self’ and/or ‘primary-process consciousness’ should allow us to explain how affective experiences are created within the brain. Primitive emotional feelings appear to lie at the core of our beings, and the neural mechanisms that generate such states may constitute an essential foundation process for the evolution of higher, more rational, forms of consciousness. At present, abundant evidence indicates that affective states arise from the intrinsic neurodynamics of primitive self-centred emotional and motivational systems situated in subcortical (...) regions of the brain. Accordingly, a neural understanding of ‘the self’ may arise from a study of how various biological value-coding systems converge and interact with coherent brainstem representations of the body and nearby attentional/waking systems of the brain. Affective feelings may be caused by the neurodynamics of basic emotional circuits interacting with the neural schema of bodily action plans. One key brain area where such interactions occur is found within centromedial diencephalic midbrain areas such as the periventricular and periaqueductal gray and nearby tectal and tegmental zones. Here I will envision that a Simple Ego-type Life Form is instantiated in those circuits The ability of this ’primal SELF’ to resonate with primitive emotional values may help yield the raw subjectively experienced feelings of pleasure, lust, anger, hunger, desire, fear, loneliness and so forth. A study of such systems is a reasonable starting point for the neurological analysis of affective feelings, which may lie at the periconscious core of all other forms of animal consciousness. If such a neurodynamic process was an essential neural preadaptation for the emergence of higher levels of consciousness, it may help us close the explanatory gap between brain circuit states and the psychological nature of affective feelings. Thereby, it may also help us conceptualize the nature of psychological binding within higher forms of consciousness in new ways. (shrink)

The authors discuss some of the conceptual issues that must be considered in using and understanding psychiatric classification. DSM-IV is a practical and common sense nosology of psychiatric disorders that is intended to improve communication in clinical practice and in research studies. DSM-IV has no philosophic pretensions but does raise many philosphical questions. This paper describes the development of DSM-IV and the way in which it addresses a number of philosophic issues: nominalism vs. realism, epistemology in science, the mind/body dichotomy, (...) the definition of mental disorders, and dimensional vs. categorical classification. (shrink)

Familiarity with Charles Darwin's treatise on evolution is essential to every well-educated individual. One of the most important books ever published--and a continuing source of controversy, a century and a half later--this classic of science is reproduced in a facsimile of the critically acclaimed first edition.

The Great Psychotherapy Debate: Models, Methods, and Findings comprehensively reviews the research on psychotherapy to dispute the commonly held view that the benefits of psychotherapy are derived from the specific ingredients contained in a given treatment (medical model). The author reviews the literature related to the absolute efficacy of psychotherapy, the relative efficacy of various treatments, the specificity of ingredients contained in established therapies, effects due to common factors, such as the working alliance, adherence and allegiance to the therapeutic protocol, (...) and effects that are produced by different therapists. In each case, the evidence convincingly corroborates the contextual model and disconfirms the prevailing medical model. (shrink)

The paradigmatic assumption that REM sleep is the physiological equivalent of dreaming is in need of fundamental revision. A mounting body of evidence suggests that dreaming and REM sleep are dissociable states, and that dreaming is controlled by forebrain mechanisms. Recent neuropsychological, radiological, and pharmacological findings suggest that the cholinergic brain stem mechanisms that control the REM state can only generate the psychological phenomena of dreaming through the mediation of a second, probably dopaminergic, forebrain mechanism. The latter mechanism (and thus (...) dreaming itself) can also be activated by a variety of nonREM triggers. Dreaming can be manipulated by dopamine agonists and antagonists with no concomitant change in REM frequency, duration, and density. Dreaming can also be induced by focal forebrain stimulation and by complex partial (forebrain) seizures during nonREM sleep, when the involvement of brainstem REM mechanisms is precluded. Likewise, dreaming is obliterated by focal lesions along a specific (probably dopaminergic) forebrain pathway, and these lesions do not have any appreciable effects on REM frequency, duration, and density. These findings suggest that the forebrain mechanism in question is the final common path to dreaming and that the brainstem oscillator that controls the REM state is just one of the many arousal triggers that can activate this forebrain mechanism. The “REM-on” mechanism (like its various NREM equivalents) therefore stands outside the dream process itself, which is mediated by an independent, forebrain “dream-on” mechanism. Key Words: acetylcholine; brainstem; dopamine; dreaming; forebrain; NREM; REM; sleep. (shrink)

Epidemiology is a science of disease which specifies rates (illness prevalences, incidences, distributions, etc.). Evolution is a science of life which specifies changes (gene frequencies, generations, forms, function, etc.). Evolutionary Epidemiology is a synthesis of these two sciences which combines the empirical power of classical methods in genetical epidemiology with the interpretive capacities of neo-darwinian evolutionary genetics. In particular, prevalence rates of genetical diseases are important data points when reformulated for the purpose of analysis in terms of their evolutionary frequencies. (...) Traits which exceedprevalences beyond the rates of mutation (in Hardy-Weinberg calculations) or evidence unusualrange of phenotypic reaction are of special interest. This is because traits which did not confer advantages in the environment of evolutionary adaptation cannot accede, through natural selection, to anything but low rates of genomic prevalence.Evolutionary epidemiology is, in all of medicine, of particular promise in ongoing efforts to better understand psychopathology. Many complexities of phenotypic adjustment arise when new developmental demands are placed on an old genome. The new and complex biosocial ecology of human mass society now evokes different phenotypes than those in the prehistorical ecology to which the genome is structurally and functionally better adapted. Some of these new phenotypes are darwinian failures. In this paper, the theoretical implications of evolutionary epidemiology are extended and some tentative points of clinical application (particularly to psychiatry) are offered. (shrink)

Awareness is a personal experience, which is only accessible to the rest of world through interpretation. We set out to identify a neural correlate of visual awareness, using brief subliminal and supraliminal verbal stimuli while measuring cerebral blood flow distribution with H215O PET. Awareness of visual verbal stimuli differentially activated medial parietal association cortex (precuneus), which is a polymodal sensory cortex, and dorsolateral prefrontal cortex, which is thought to be primarily executive. Our results suggest participation of these higher order perceptual (...) and executive cortical structures in visual verbal awareness. (shrink)

The publication of this book is an event in the making. All over the world scientists, psychologists, and philosophers are waiting to read Antonio Damasio's new theory of the nature of consciousness and the construction of the self. A renowned and revered scientist and clinician, Damasio has spent decades following amnesiacs down hospital corridors, waiting for comatose patients to awaken, and devising ingenious research using PET scans to piece together the great puzzle of consciousness. In his bestselling Descartes' Error, Damasio (...) revealed the critical importance of emotion in the making of reason. Building on this foundation, he now shows how consciousness is created. Consciousness is the feeling of what happens-our mind noticing the body's reaction to the world and responding to that experience. Without our bodies there can be no consciousness, which is at heart a mechanism for survival that engages body, emotion, and mind in the glorious spiral of human life. A hymn to the possibilities of human existence, a magnificent work of ingenious science, a gorgeously written book, The Feeling of What Happens is already being hailed as a classic. (shrink)

To make progress on the problem of consciousness, we have to confront it directly. In this paper, I first isolate the truly hard part of the problem, separating it from more tractable parts and giving an account of why it is so difficult to explain. I critique some recent work that uses reductive methods to address consciousness, and argue that such methods inevitably fail to come to grips with the hardest part of the problem. Once this failure is recognized, the (...) door to further progress is opened. In the second half of the paper, I argue that if we move to a new kind of nonreductive explanation, a naturalistic account of consciousness can be given. I put forward my own candidate for such an account: a nonreductive theory based on principles of structural coherence and organizational invariance, and a double-aspect theory of information. (shrink)

This book covers all aspects of the disorder, from an historical survey of research to date, through the nature and anatomical bases of neglect, and on to review contemporary theories on the subject.

The issue of the biological origin of consciousness is linked to that of its function. One source of evidence in this regard is the contrast between the types of information that are and are not included within its compass. Consciousness presents us with a stable arena for our actions—the world—but excludes awareness of the multiple sensory and sensorimotor transformations through which the image of that world is extracted from the confounding influence of self-produced motion of multiple receptor arrays mounted on (...) multijointed and swivelling body parts. Likewise excluded are the complex orchestrations of thousands of muscle movements routinely involved in the pursuit of our goals. This suggests that consciousness arose as a solution to problems in the logistics of decision making in mobile animals with centralized brains, and has correspondingly ancient roots. (shrink)

The neurobiological systems that mediate the basic emotions are beginning to be understood. They appear to be constituted of genetically coded, but experientially refined executive circuits situated in subcortical areas of the brain which can coordinate the behavioral, physiological and psychological processes that need to be recruited to cope with a variety of primal survival needs (i.e., they signal evolutionary fitness issues). These birthrights allow newborn organisms to begin navigating the complexities of the world and to learn about the values (...) and contingencies of the environment. Some of these systems have been identified and characterized using modern neuroscientific and psychobiological tools. The fundamental emotional systems can now be defined by the functional psychobiological characteristics of the underlying circuitries ? characteristics which help coordinate behavioral, physiological and psychological aspects of emotionality, including the valenced affective feeling states that provide fundamental values for the guidance of behavior. The various emotional circuits are coordinated by different neuropeptides, and the arousal of each system may generate distinct affective/neurodynamic states and imbalances may lead to various psychiatric disorders. The aim of this essay is to discuss the underlying conceptual issues that must be addressed for additional progress in understanding the nature of primary process affective consciousness. (shrink)

This ambitious work apparently has two main aims. The first is to provide a survey of the currently burgeoning field of "Consciousness Studies", presented via the extended metaphor of a horse race whose winning post is a full scientific explanation of consciousness. The second, which receives much more space, is to present Taylor's own cognitive/neuroscientific theory, dubbed "relational consciousness", and to persuade us that it should be the odds-on favourite to win. Neither aim is very well realized.

Anterior cingulate cortex {ACC} is a part of the brain's limbic system. Classically, this region has been related to affect, on the basis of lession studies in human and in animals. In the late 1980s, neuroimaging research indicated that ACC was active in many studies of cognition. The finding from EEG studies of a focal area of negativity in scalp electrodes following an error response led to the idea that ACC might be the brain's error detection and correction device.

One of 15 volumes in this series, this title is part of a plan to generate non-specialist Freud titles for a wide readership - beyond the institutional/clinical ...

Animal research suggests that central serotonergic neurons are involved in behavioral suppression, particularly anxiety-related inhibition. The hypothesis linking decreased serotonin transmission to reduced anxiety as the mechanism in the anxiolytic activity of benzodiazepines conflicts with most clinical observations. Serotonin antagonists show no marked capacity to alleviate anxiety. On the other hand, clinical signs of reduced serotonergic transmission (low 5-HIAA levels in the cerebrospinal fluid) are frequently associated with aggressiveness, suicide attempts, and increased anxiety. The target article attempts to reconcile such (...) human and animal findings by investigating whether anxiety reduction or increased impulsivity is more Likely to account for animal behavioral changes associated with decreased serotonergic transmission. The effects of manipulating central serotonin in experimental anxiety paradigms in animals (punishment, extinction, novelty) are reviewed and compared with the effects of antianxiety drugs. Anxiety seems neither necessary nor sufficient to induce control by serotonergic neurons on behavior. Further evidence suggests that behavioral effects of anxiolytics thought to be mediated by decreases in anxiety are not caused by the ability of these drugs to reduce serotonin transmission. Blockade of serotonin transmission, especially at the level of the substantia nigra, results in a shift of behavior toward facilitation of responding. This behavioral shift is particularly marked when there is competition between acting and restraining response tendencies and when obstacles prevent the immediate attainment of an anticipated reward. It is proposed that serotonergic neurons are involved not only in behavioral arousal but also in enabling the organism to arrange or tolerate delay before acting. Decreases in serotonin transmission seem to be associated with the increased performance of behaviors that are usually suppressed, though not necessarily because of the alleviation of anxiety, which might contribute to the suppression. (shrink)

There is growing public awareness of the ethical issues raised by progress in many areas of neuroscience. This commentary reviews the issues, which are triaged in terms of their novelty and their imminence, with an exploration of the relevant ethical principles in each case.

A broad consensus has developed in recent years in the cognitive and neurosciences that the cognitive functions of the mind arise out of the activities of an extensive and diverse array of specialized processors operating as a parallel, distributed system. A theoretical perspective is presented which expands upon this "society" model to include globally integrative infuences upon this arrary of processors. This perspective serves as the basis for an explicit neural model of a "global workspace within a system of distributed (...) specialized processors". Anatomical and physiological evidence are reviewed which suggest that this parallel, modular architecture is superceded by a more diffuse, tangential intracortical network capable of integrating underlying modular activites into increasingly global cognitive representations. There follows an explication of the role of this "neural global workspace" in providing the essential basis for the central control of attention and the generation of unified, conscious percepts. Finally the role of thalamic and brainstem activation systems in these integrative processes is discussed. (shrink)

Substantially revised to include a wealth of new material, the second edition of this highly acclaimed work provides a concise, coherent introduction that brings structure to an increasingly fragmented and amorphous discipline. Paul R. McHugh and Phillip R. Slavney offer an approach that emphasizes psychiatry's unifying concepts while accommodating its diversity. Recognizing that there may never be a single, all-encompassing theory, the book distills psychiatric practice into four explanatory methods: diseases, dimensions of personality, goal-directed behaviors, and life stories. These perspectives, (...) argue the authors, underlie the principles and practice of all psychiatry. With an understanding of these fundamental methods, readers will be equipped to organize and evaluate psychiatric information and to develop a confident approach to practice and research. Praise for the original edition: "This brilliant book illuminates psychiatry more clearly than any other work I know.... This is the best (and the shortest) single volume on psychiatry that anyone could read."-- New England Journal of Medicine "Every psychiatry department, regardless of ideology, should build a course around this... work. Open-mindedness might become fashionable."-- Journal of Clinical Psychiatry "An elegantly reasoned and eloquently written book that enriches our understanding of clinical events.... [It provides] an opportunity to open our eyes to new possibilities."-- Hospital and Community Psychiatry. (shrink)

Although biological findings currently dominate the research literature on the de- terminants of sexual orientation, biological theorizing has not yet spelled out a developmental path by which any of the various biological correlates so far iden- tified might lead to a particular sexual orientation. The Exotic-Becomes-Erotic (EBE) theory of sexual orientation (Bem, 1996) attempts to do just that, by sug- gesting how biological variables might interact with experiential and sociocultural factors to influence an individual’s sexual orientation. Evidence for the theory (...) is reviewed, and a path analysis of data from a large sample of twins is presented which yields preliminary support for the theory’s claim that correlations between genetic variables and sexual orientation are mediated by childhood gender non- conformity. (shrink)

Extraversion has two central characteristics: (1) interpersonalengagement, which consists of affiliation (enjoying and valuing close interpersonal bonds, being warm and affectionate) and agency (being socially dominant, enjoying leadership roles, being assertive, being exhibitionistic, and having a sense of potency in accomplishing goals) and (2) impulsivity, which emerges from the interaction of extraversion and a second, independent trait (constraint). Agency is a more general motivational disposition that includes dominance, ambition, mastery, efficacy, and achievement. Positive affect (a combination of positive feelings and (...) motivation) is closely associated with extraversion. Extraversion is accordingly based on positiveincentivemotivation. (shrink)

The medical specialty of psychiatry should possess a basic science in which pathologies are considered deviations from normal brain physiology. Historically, psychoanalytic pathogenesis was considered separately from brain physiology. It was not scientific because observations could not be refuted. Countering this, Eli Robins's legacy stemmed partly from his having been damaged by a psychoanalyst. It eschewed pathogenesis. Attempting to integrate psychiatry with medicine more generally, Robins and colleagues refocused on empiricism, although they acknowledged the brain's centrality. Here I hold that (...) the term biology used in the context of psychiatry should broadly encompass social facets of organismal function. The term sociophysiology may best describe the central basic science of psychiatry because it alludes to brain functions used for the person's social realm. Disruptions of such functions result in deviant behaviors and unpleasant feelings which psychiatrists diagnose and treat. Future study encompassing top-down and bottom-up research should include genome-neural-behavioral analyses. (shrink)

Beginning with a review of the role of placebos in the history of medicine, this book investigates the current surge of interest in placebos, and probes the methodological difficulties of saying scientifically just what placebos can and cannot do.