Although the mechanics of how the eye works are well understood, debate still exists as to how the complex machinery of the brain interprets neural impulses...

Vision, more than any other sense, dominates our mental life. Our visual experience is just so rich, so detailed, that we can hardly distinguish that experience from the world itself. Even when we just think about the world and don't look at it directly, we can't help but 'imagine' what it looks like. We think of 'seeing' as being a conscious activity--we direct our eyes, we choose what we look at, we register what we are seeing. The series of events (...) described in this book radically altered this attitude towards vision. This book describes one of the most extraordinary neurological cases of recent years--one that profoundly changed scientific views on consciousness. It is the story of Dee Fletcher--a woman recently blinded--who became the subject of a series of scientific studies. As events unfolded, Milner and Goodale found that Dee wasn't in fact blind--she just didn't know that she could see. Taking us on a journey into the unconscious brain, the two scientists who made this incredible discovery tell the amazing story of their work, and the surprising conclusion they were forced to reach. Written to be accessible to students and popular science readers, this book is a fascinating illustration of the power of the 'unconscious' mind. (shrink)

The cortical visual mechanisms involved in processing spatial relationships remain subject to debate. According to one current view, the ''dorsal stream'' of visual areas, emanating from primary visual cortex and culminating in the posterior parietal cortex, mediates this aspect of visual processing. More recently, others have argued that while the dorsal stream provides egocentric coding of visual location for motor control, the separate ''ventral'' stream is needed for allocentric spatial coding. We have assessed the visual form agnosic patient DF, whose (...) lesion mainly affects the ventral stream, on a prehension task requiring allocentric spatial coding. She was presented with transparent circular disks. Each disk had circular holes cut in it. DF was asked to reach out and grasp the disk by placing her fingers through the holes. The disks either had three holes (for forefinger, middle finger, and thumb) or two holes (for forefinger and thumb). The distance between the forefinger and thumb holes, and the orientation of the line formed by them, were independently varied. DF was quite unable to adjust her grip aperture or her hand orientation in the three-hole task. Although she was able to orient her hand appropriately for the two-hole disks, she still remained unable to adjust her grip aperture to the distance between the holes. These findings are consistent with the idea that allocentric processing of spatial information requires a functioning ventral stream, even when the information is being used to guide a motor response. (shrink)

Comparative Neurospychology is a collection of state-of-the-art essays by some of the world's leading neuropsychologists. Taking as their starting point the assumption that the human brain shares many of its most important functional systems with its primate relatives, the authors take acomparative evolutionary approach to understanding human cognition and brain function. A wide range of subject areas are covered, including memory, visual and somatosensory perception, motor control, attention, cross-modality integration, interhemispheric transmission, and behaviouralintelligence.

It is our contention that the concept of planning in Glover's model is too broadly defined, encompassing both action/goal selection and the programming of the constituent movements required to acquire the goal. We argue that this monolithic view of planning is untenable on neuropsychological, neurophysiological, and behavioural grounds. The evidence demands instead that a distinction be made between action planning and the specification of the initial kinematic parameters, with the former depending on processing in the ventral stream and the latter (...) on processing in the dorsal stream. (shrink)

Little is known about distance processing in patients with posterior brain damage. Although many investigators have claimed that distance estimates are normal or abnormal in some of these patients, many of these observations were made informally and the examiners often asked for relative, and not absolute, distance estimates. The present investigation served two purposes. First, we wanted to contrast the use of distance information in peripersonal space for perceptual report as opposed to visuomotor control in our visual form agnosic patient, (...) DF. Second, we wanted to see to what extent her abilities to process distance cues were dependent on binocular vision, in light of Milner et al.'s (1991) observations of preserved stereopsis in DF, and Dijkerman et al.'s (1996) and Marotta et al.'s (1997) observations that her visual guidance of grasping may be particularly dependent on binocular vision of the target. We hypothesized that DF's visuomotor responses would show normal sensitivity to target distance, while her perceptual estimates would not. In the first experiment, we required DF and two age- and sex-matched control subjects to reach out and grasp black cubes placed at varying distances, or to estimate the distance of the cubes from the hand starting position without making a reaching movement. In the second experiment, we required DF and two age-matched control subjects to point as rapidly and accurately as possible to small LED targets which differed in spatial location, under binocular and monocular conditions. The results showed that, relative to the control subjects, DF's grasping movements produced normal peak velocity-distance scaling-when she reached for blocks which varied in depth or pointed to LED targets which were presented at different distances in depth. In contrast, in the cube experiment, her verbal estimates of object distance were poorly scaled, although they improved slightly under the binocular conditions. The results are discussed in terms of current theories of processing streams in extrastriate visual cortex and the distinction between categorical and coordinate spatial processing. (shrink)

First published in 1995, The Visual Brain in Action remains a seminal publication in the cognitive sciences. For this new edition, a very substantial and illustrated epilogue has been added to the book in which Milner and Goodale review the key developments that support or challenge the views that were put forward in the first edition.

First published in 1995, The Visual Brain in Action remains a seminal publication in the cognitive sciences. It presents a model for understanding the visual processing underlying perception and action, proposing a broad distinction within the brain between two kinds of vision: conscious perception and unconscious 'online' vision. It argues that each kind of vision can occur quasi-independently of the other, and is separately handled by a quite different processing system. In the 11 years since publication, the book has provoked (...) considerable interest and debate - throughout both cognitive neuroscience and philosophy, while the field has continued to flourish and develop. -/- For this new edition, the text from the original edition has been left untouched, standing as a coherent statement of the authors' position. However, a very substantial epilogue has been added to the book in which Milner and Goodale review some of the key developments that support or challenge the views that were put forward in the first edition. The new chapter summarizes developments in various relevant areas of psychology, neuroscience and behaviour. It notably supplements the main text by updating the reader on the contributions that have emerged from the use of functional neuroimaging, which was in its infancy when the first edition was written. Neuroimaging, and functional MRI in particular, has revolutionized the field over the past 11 years by allowing investigators to plot in detail the patterns of activity within the visual brains of behaving and perceiving humans. The authors show how its use now allows scientists to test and confirm their proposals, based as they then were largely on evidence accrued from primate neuroscience in conjunction with studies of neurological patients. (shrink)

In this updated and extended edition of their book, Goodale and Milner explore one of the most extraordinary neurological cases of recent years--one that profoundly changed scientific views on the visual brain. Taking us on a journey into the unconscious brain, this book is a fascinating illustration of the power of the 'unconscious' mind.

Spatial neglect is a disorder of space-related behaviour. It is characterized by failure to explore the side of space contralateral to a brain lesion, or to react or respond to stimuli or subjects located on this side. Research on spatial neglect and related disorders has developed rapidly inrecent years. These advances have been made as a result of neuropsychological studies of patients with brain damage, behavioural studies of animal models, as well as through functional neurophysiological experiments and functional neuroimaging.The Cognitive (...) and Neural Bases of Spatial Neglect provides an overview of this wide-ranging field of scientific endeavour, providing a cohesive synthesis of the most recent observations and results. As well as being a fascinating clinical phenomenon, the study of spatial neglect helps us tounderstand normal mechanisms of directing and maintaining spatial attention and is relevant to the contemporary search for the cerebral correlates of conscious experience, voluntary action and the nature of personal identity itself.The book is divided into seven sections covering the anatomical and neurophysiological bases of the disorder, frameworks of neglect, perceptual and motor factors, the relation to attention, the cognitive processes involved, and strategies for rehabilitation.Chapters have been written by a team of the leading international experts in this field.This will be essential reading for neuropsychologists, neurologists, neurophysiologists, cognitive neuroscientists and psychologists. (shrink)

In Section I, I clarify turning point issues in the Phillips and Block debate about whether there is unconscious perception. These include questions about whether uptake of certain visual information is an individual or person level accomplishment, as required for genuine unconscious _perceiving_. Section II takes up a recent reorientation proposed in Block ( 2017 ) towards the question of whether there is unconscious perceiving, where we are to look for the pervasive role of unconscious perceiving in, perhaps especially, the (...) online control of everyday reaching and grasping. I point out that while this may well be a helpfully different approach to explore, it does not evade the central questions and challenges familiar from the prior debate between Phillips and Block. Section III reviews an approach summarized in Dehaene ( 2014 ), drawing from a range of measures of neural activity. Dehaene provides evidence of quite rich non-conscious perceptual system responses, some arguably individual or person level. But in a fairly thin or fragile way, absent taking up, in higher level assessment, the information encoded in initial visual response. Or that is the interpretation I argue for, in relating the Dehaene account to the Phillips and Block debate, in a way that illuminates the Phillips and Block discussions. An Appendix provides an overview of debates in the literature about the Goodale and Milner Two Visual Systems Hypothesis, that Block ( 2017 ) makes central appeal to. (shrink)

Milner and Goodale have advanced a justly influential theory of the structure of the human visual system. In broad outline, Milner and Goodale hold that the ventral neural pathway is associated with recognition and experiential awareness, and with a kind of indirect control of action. And they hold that, by contrast, the dorsal neural stream is associated with the non-conscious, direct control of visually informed action. Most of the relevant empirical research has focused on the visual control of (...) close-in, “personal space,” reaching and/or grasping. While their view has not escaped controversy and debate, we think that Milner and Goodale have a compelling story to tell about the visual guidance of such close in, “personal space” action. However, the question of whether their scheme applies to behavior with visually specified targets that are outside of the space accessible by simply reaching and grasping is largely unstudied. And it should be studied, since this is the arena of much human behavior. We provide good reason to think that the Milner and Goodale scheme may well not apply to important classes of mid-range, ‘action space’ behavior. But the matter is in the end to be decided in the lab. We describe a research program to do this. (shrink)

This striking Lacanian contribution to discourse analysis is also a critique of contemporary psychological abstraction, as well as a reassessment of the radical opposition between psychology and psychoanalysis. This original introduction to Lacan's work bridges the gap between discourseanalytical debates in social psychology and the social-theoretical extensions of discourse theory. David Pavón Cuéllar provides a precise definition and a detailed explanation of key Lacanian concepts, and illustrates how they may be put to work on a concrete discourse, in this (...) case a fragment of an interview obtained by the author from the Mexican underground Popular Revolutionary Forces (EPR). Throughout the book, Lacanian concepts are compared to their counterparts in psychology. Such a comparison reveals insuperable incompatibilities between the two series of concepts. The author shows that Lacan's psychoanalytical terminology can neither be translated nor assimilated to the terms of current psychology. Among the notions in actual or potential competition with Lacanian concepts, the book deals with those proposed by semiology, Marxism, phenomenology, constructionism, deconstruction, and hermeneutics. Taking a stand on those theoretical positions, each chapter includes detailed discussion of the contribution of classical approaches to language; including Barthes, Bakhtin, Althusser, Politzer, Wittgenstein, Berger and Luckmann, Derrida, and Ricoeur. There is sustained reference in the body of the text to the arguments of Lacan and Lacanians, of Miller, Milner, Soler, and Zizek. At the same time, in the extensive notes accompanying the text, there is a systematic reappraisal and reinterpretation of debates and pieces of research work in social psychology, especially in a discursive and critical domain that has incorporated elements of psychoanalytic theory. (shrink)

The understanding of decision-making systems has come together in recent years to form a unified theory of decision-making in the mammalian brain as arising from multiple, interacting systems (a planning system, a habit system, and a situation-recognition system). This unified decision-making system has multiple potential access points through which it can be driven to make maladaptive choices, particularly choices that entail seeking of certain drugs or behaviors. We identify 10 key vulnerabilities in the system: (1) moving away from homeostasis, (2) (...) changing allostatic set points, (3) euphorigenic signals, (4) overvaluation in the planning system, (5) incorrect search of situation-action-outcome relationships, (6) misclassification of situations, (7) overvaluation in the habit system, (8) a mismatch in the balance of the two decision systems, (9) over-fast discounting processes, and (10) changed learning rates. These vulnerabilities provide a taxonomy of potential problems with decision-making systems. Although each vulnerability can drive an agent to return to the addictive choice, each vulnerability also implies a characteristic symptomology. Different drugs, different behaviors, and different individuals are likely to access different vulnerabilities. This has implications for an individual's susceptibility to addiction and the transition to addiction, for the potential for relapse, and for the potential for treatment. (shrink)

It is argued that Husserl was an “externalist” in at least one sense. For it is argued that Husserl held that genuinely perceptual experiences—that is to say, experiences that are of some real object in the world—differ intrinsically, essentially and as a kind from any hallucinatory experiences. There is, therefore, no neutral “content” that such perceptual experiences share with hallucinations, differing from them only over whether some additional non-psychological condition holds or not. In short, it is argued that Husserl was (...) a “disjunctivist”. In addition, it is argued that Husserl held that the individual object of any experience, perceptual or hallucinatory, is essential to and partly constitutive of that experience. The argument focuses on three aspects of Husserl’s thought: his account of intentional objects, his notion of horizon, and his account of reality. (shrink)

Absolutely no one still believes that every physical interactionconsists of material bodies bumping into each other. Those who have tried to work out a completely mechanistic physics have been unable to explain common phenomena like liquidity, gravitation and magnetism. In fact, there is great reason to doubt that such a physics could ever account for attractive forces in general.

The understanding of decision-making systems has come together in recent years to form a unified theory of decision-making in the mammalian brain as arising from multiple, interacting systems (a planning system, a habit system, and a situation-recognition system). This unified decision-making system has multiple potential access points through which it can be driven to make maladaptive choices, particularly choices that entail seeking of certain drugs or behaviors. We identify 10 key vulnerabilities in the system: (1) moving away from homeostasis, (2) (...) changing allostatic set points, (3) euphorigenic signals, (4) overvaluation in the planning system, (5) incorrect search of situation-action-outcome relationships, (6) misclassification of situations, (7) overvaluation in the habit system, (8) a mismatch in the balance of the two decision systems, (9) over-fast discounting processes, and (10) changed learning rates. These vulnerabilities provide a taxonomy of potential problems with decision-making systems. Although each vulnerability can drive an agent to return to the addictive choice, each vulnerability also implies a characteristic symptomology. Different drugs, different behaviors, and different individuals are likely to access different vulnerabilities. This has implications for an individual's susceptibility to addiction and the transition to addiction, for the potential for relapse, and for the potential for treatment. (shrink)

Current fears of a “reproducibility crisis” have led researchers, sources of scientific funding, and the public to question both the efficacy and trustworthiness of science. Suggested policy changes have been focused on statistical problems, such as p-hacking, and issues of experimental design and execution. However, “reproducibility” is a broad concept that includes a number of issues. Furthermore, reproducibility failures occur even in fields such as mathematics or computer science that do not have statistical problems or issues with experimental design. Most (...) importantly, these proposed policy changes ignore a core feature of the process of scientific inquiry that occurs after reproducibility failures: the integration of conflicting observations and ideas into a coherent theory. (shrink)

In this fascinating and inventive work, A. David Napier argues that the central assumption of immunology—that we survive through the recognition and elimination of non-self—has become a defining concept of the modern age. Tracing this immunological understanding of self and other through an incredibly diverse array of venues, from medical research to legal and military strategies and the electronic revolution, Napier shows how this defensive way of looking at the world not only destroys diversity but also eliminates the possibility (...) of truly engaging difference, thereby impoverishing our culture and foreclosing tremendous opportunities for personal growth. To illustrate these destructive consequences, Napier likens the current craze for embracing diversity and the use of politically correct speech to a cultural potluck to which we each bring different dishes, but at which no one can eat unless they abide by the same rules. Similarly, loaning money to developing nations serves as a tool both to make the peoples in those nations more like us and to maintain them in the nonthreatening status of distant dependents. To break free of the resulting downward spiral of homogenization and self-focus, Napier suggests that we instead adopt a new defining concept based on embryology, in which development and self-growth take place through a process of incorporation and transformation. In this effort he suggests that we have much to learn from non-Western peoples, such as the Balinese, whose ritual practices require them to take on the considerable risk of injecting into their selves the potential dangers of otherness—and in so doing ultimately strengthen themselves as well as their society. _The Age of Immunology,_ with its combination of philosophy, history, and cultural inquiry, will be seen as a manifesto for a new age and a new way of thinking about the world and our place in it. (shrink)

Absolutely no one still believes that every physical interactionconsists of material bodies bumping into each other. Those who have tried to work out a completely mechanistic physics have been unable to explain common phenomena like liquidity, gravitation and magnetism. In fact, there is great reason to doubt that such a physics could ever account for attractive forces in general.

In our target article, we proposed that addiction could be envisioned as misperformance of a decision-making machinery described by two systems (deliberative and habit systems). Several commentators have argued that Pavlovian learning also produces actions. We agree and note that Pavlovian action-selection will provide several additional vulnerabilities. Several commentators have suggested that addiction arises from sociological parameters. We note in our response how sociological effects can change decision-making variables to provide additional vulnerabilities. Commentators generally have agreed that our theory provides (...) a framework within which to site addiction and treatment, but additional work will be needed to determine whether our taxonomy will help identify and treat subpopulations within the addicted community. (shrink)

Redish builds on work on morality in economics, genetics, evolution, etc. and combines it with the latest research in neuroscientific decision-making to develop a coherent science of morality.

Alleged cases of simultaneous causation have played a prominent role in the critique of various accounts of explanation/causation and in the formation of alternative accounts. It is argued that none of the stated cases are genuine instances of simultaneous causations, since they all violate the special theory of relativity (STR). The conditions a genuine case would have to meet in light of the restrictions imposed by STR are outlined.

The most recent challenge to the covering-law model of explanation charges that the fundamental explanatory laws are not true. In fact explanation and truth are alleged to pull in different directions. We hold that this gets its force from confusing issues about the truth of the laws in the explanation and the precision with which those laws can yield an exact description of the event to be explained. In defending this we look at Cartwright's major case studies and sketch an (...) amended covering-law model of explanation. (shrink)

The most recent challenge to the covering-law model of explanation (N. Cartwright, How the laws of Physics Lie) charges that the fundamental explanatory laws are not true. In fact explanation and truth are alleged to pull in different directions. We hold that this gets its force from confusing issues about the truth of the laws in the explanation and the precision with which those laws can yield an exact description of the event to be explained. In defending this we look (...) at Cartwright's major case studies and sketch an amended covering-law model of explanation. (shrink)

En Giving Reasons, Bermejo-Luque sostiene correctamente que un modelo normativo del acto de habla de la argumentación es más defendible si se basa en un objetivo interno constitutivo del acto de argumentar, que si se apoya en objetivos que que uno no necesita perseguir cuando argumenta, tal como, en su opinión, sucede con otros modelos normativos. Ella identifica correctamente argumentar con intentar justificar. Pero no está claro que haya acertado al identificar como objetivo interno de la argumentación el mostrar que (...) una afirmación de referencia es correcta sobre la base de que las razones ofrecidas en su apoyo son correctas. En primer lugar, si argumentar, tal como ella defiende, es un intento de justificar, la mejor manera de interpretarlo es como intento de justificar la acción o emoción expresada en la conclusión. En segundo lugar, es dudoso que razones y conclusiones cualificadas puedan siempre ser reconstruidas razonablemente como afirmaciones no cualificadas, y más dudoso aún que razones y conclusiones no-constatativas puedan siempre ser reconstruidas razonablemente como afirmaciones indirectas. Más dudos aún es que podamos reconstruir razones y conclusiones no-constatativas como tesis indirectas. En tercer lugar, necesita explicar y justificar su introducción de los conceptos de mostrar y corrección en su análisis del acto de argumentar. (shrink)

A commonplace thesis of the “new philosophy of science” is the view that the testing of a given theory is not a simple comparison of the theory with nature but also requires the comparison of the theory with competing theories. More specifically the version of the intertheoretic competition thesis that shall be examined is as follows:(ITC) In addition to comparing a theory with nature, a necessary condition for the rejection of a theory is the acceptance of an alternative theory.It is (...) Thomas Kuhn’s The Structure of Scientific Revolutions that is responsible for the widespread popularity of (ITC).1,2…a scientific theory is declared invalid only if an alternative candidate is available to take its place. No process yet disclosed by the historical study of scientific development at all resembles the methodological stereotype of falsification by direct comparison with nature. …the act of judgment that leads scientists to reject a previously accepted theory is always based upon more than a comparison of that theory with the world. (shrink)