This volume provides, for the first time, multidisciplinary perspectives on the problem of awareness of deficits following brain injury. Such deficits may involve perception, attention, memory, language, or motor functions, and they can seriously disrupt an individual's ability to function. However, some brain-damaged patients are entirely unaware of the existence or severity of their deficits, even when they are easily noticed by others. In addressing these topics, contributors cover the entire range of neuropsychological syndromes in which problems (...) with awareness of deficit are observed: hemiplegia and hemianopia, amnesia, aphasia, traumatic head injury, dementia, and others. On the clinical side, leading researchers delineate the implications of awareness of deficits for rehabilitation and patient management, and the role of defense mechanisms such as denial. Theoretical discussions focus on the importance of awareness disturbances for better understanding such cognitive processes as attention, consciousness, and monitoring. (shrink)

Anosognosia for hemiplegia is a lack of awareness about paralysis following stroke. Recent explanations use a ‘forward model’ of movement to suggest that AHP patients fail to register discrepancies between internally- and externally-generated sensory information. We predicted that this failure would impair the ability to recall from memory whether information is internally- or externally-generated . Two experiments examined this prediction. Experiment 1 demonstrated that AHP patients exhibit a reality monitoring deficit for non-motor information , whilst hemiplegic controls without (...) class='Hi'>anosognosia perform like age-matched healthy volunteers . Experiment 2 explored if this deficit occurs when AHP patients discriminate performed, imagined, or observed movement. Results showed impaired reality monitoring for movements in AHP and nonAHP patients relative to HVs. Findings suggest that reality monitoring processes not directly related to movement, together with a failure to reality monitor movements, contribute to the pathogenesis of AHP. (shrink)

Anosognosia for hemiplegia is the denial of neurologically-caused paralysis, and it often co-occurs with a number of distortions of belief and emotion such as somatoparaphrenia and an exaggeration of negative affect towards minor health complaints. The salience of these latter symptoms led early investigators to propose explanations of AHP which construed it as a process of motivated self-deception against the overwhelming anxiety and depression that knowledge of deficit would otherwise cause, and which was observed in hemiplegic patients without the (...) anosognosia. Since some influential critiques of this approach, however, theories of this kind have largely been rejected on the grounds that they are inappropriately “psychogenic.” What has replaced them are a class of theories which explain the lack of awareness in terms of neurocognitive deficit, with the deficit in question variously described by researchers as involving spatial awareness, motor control, and other capacities. In this paper I argue – contra claims in the literature – that the patterns of explanation which are characteristic of the psychodynamic theory are not incompatible in principle with the notion that the illness involves neurocognitive deficit. That means that these patterns of explanation can be preserved where they make good sense of the obscure attitudinal and emotional symptoms that occur in AHP – symptoms that are otherwise difficult to explain. I suggest some ways in which this fact could be accommodated by deficit theories of the illness which are based on motor deficit. (shrink)

We describe some of the signs and symptoms of left visuo-spatial neglect. This common, severe and often long-lasting impairment is the most striking consequence of right hemisphere brain damage. Patients seem to (over-)attend to the right with subsequent inability to respond to stimuli in contralesional space. We draw particular attention to how patients themselves experience neglect. Furthermore, we show that the neglect patient's loss of awareness of left space is crucial to an understanding of the condition. Even after left (...) space has been brought into the patient's consciousness (either by local cueing on the left or by an emphasis on global properties of the scene as a whole), this awareness of left space rapidly declines. We suggest that much of the symptomology of left neglect can be interpreted as a disconnection between brain mechanisms that are relatively specialized for local (detail) visual processing and global (panoramic) processing. This failure of communication between functional (subpersonal) mechanisms then has consequences for how perceptual and representational content enters into awareness. Failure of the local contents of left space to be consciously accessed is, in turn, an important aspect of why left neglect is so difficult to remediate. Patients can ''know'' that they have neglect but are cut off from the perceptual awareness that would enable them to overcome their attentional bias to the right. (shrink)

The study of anosognosia has witnessed an unprecedented increase in interest over the last 20 years. This has resulted in numerous empirical investigations as well as theoretical writings on the nature of human consciousness and how disorders of the brain may influence the person's subjective awareness of a disturbed neurological or neuropsychological function. This edited text summarizes many of the advances that have taken place in the field of anosognosia. It reviews research findings on anosognosia for (...) hemiplegia following stroke, Anton's syndrome, and a variety of disorders in which impaired self-awareness is common. It also provides suggestive guidelines for the management and rehabilitation of persons who have anosognosia or impaired self-awareness. (shrink)

A key element of the distinction between explicit and implicit cognitive functioning is the presence or absence of conscious awareness. In this review, we consider the proposal that neuropsychological disorders can best be considered in terms of a decoupling between preserved implicit or unconscious processing and impaired explicit or conscious processing. Evidence for dissociations between implicit and explicit processes in blindsight, amnesia, object agnosia, prosopagnosia, hemi-neglect, and aphasia is examined. The implications of these findings for a) our understanding (...) of a variety of neuropsychological disorders, b) the conceptualization of normal cognitive functioning, c) the neural basis of consciousness, and d) the clinical rehabilitation of brain-injured individuals are also discussed. (shrink)

Encoding sensory events entails processing of several physical attributes. Is the processing of any of these attributes a pre-requisite of conscious awareness? This selective review examines a recent set of behavioral and event-related potentials, studies conducted in patients with visual and auditory unilateral neglect or extinction, with the aim of establishing what aspects of initial processing are impaired in these patients. These studies suggest that extinguished visual stimuli excite the sensory cortices, but perhaps to a lesser degree than acknowledged (...) stimuli do. However, encoding spatial attributes of auditory and visual stimuli appear to be preferentially impaired. In light of results from patients with other neuro-behavioral deficits, it is argued that egocentric spatial information is an essential pre-requisite for knowing that an external event occurred. In contrast, information handled by mostly domain-specific circuits, such as in the ventral temporal lobe, supports awareness of the identity of a stimulus, but not of its mere presence. Without spatial information, the stimulus identity will remain implicit. (shrink)

The phenomenon of `consciousness' is intrinsically related to one's awareness of one's self, of time, and of the physical world. What, then, can be learned about consciousness from people who have suffered brain damage such as amnesia which affects their awareness? This is the question explored by Lawrence Weiskrantz, a distinguished neuropsychologist who has worked with such patients over 30 years. Written in an engaging and accessible style, Consciousness Lost and Found provides a unique perspective on one of the (...) most challenging issues in science today. (shrink)

This article reviews experimental evidence for a specific sensorimotor function which can be dissociated from higher level representations of space. It attempts to delineate this function on the basis of results obtained by psychophysical experiments performed with brain damaged and healthy subjects. Eye and hand movement control exhibit automatic features, such that they are incompatible with conscious control. In addition, they rely on a reference frame different from the one used by conscious perception. Neuropsychological cases provide (...) a strong support for this specific motor representation of space, which can be spared in patients with lesions of primary sensory systems who have lost conscious perception of visual, tactile or proprioceptive stimuli. Observation of these patients also showed that their motor behavior can be ''attracted'' by a goal only under specific conditions, that is, when the response is immediate and when no cognitive representation of this goal is elaborated at the same time. Beyond the issue of the dissociation between an implicit motor representation and more cognitive processing of spatial information, the issue of the interaction between these two systems is thus a matter of interest. It is suggested that the conscious, cognitive representation of a stimulus can contaminate or override the short-lived motor representation, but no reciprocal influence seem to occur. The interaction observed in patients can also be investigated in normals. The literature provides examples of interaction between sensorimotor and cognitive framing of space, which confirm that immediate action is not mediated by the same system as delayed action, and that elaborating a categorial representation of the action goal prevents the expression of the short-lived sensorimotor representation. It is concluded that action can be controlled by a sensory system which is specialized for on-line processing of relevant goal characteristics. The temporal constraints of this system are such that it can affect the action before a full sensory analysis of this goal has been completed. The performance obtained on the basis of this spatial sensory processing suggests that short-lived motor representations may rather be considered as real ''presentation'' of the action world, which share its metric properties. (shrink)

Neuroimaging studies of brain-damaged patients diagnosed as in the vegetative state suggest that the patients might be conscious. This might seem to raise no new ethical questions given that in related disputes both sides agree that evidence for consciousness gives strong reason to preserve life. We question this assumption. We clarify the widely held but obscure principle that consciousness is morally significant. It is hard to apply this principle to difficult cases given that philosophers of mind distinguish (...) between a range of notions of consciousness and that is unclear which of these is assumed by the principle. We suggest that the morally relevant notion is that of phenomenal consciousness and then use our analysis to interpret cases of brain damage. We argue that enjoyment of consciousness might actually give stronger moral reasons not to preserve a patient's life and, indeed, that these might be stronger when patients retain significant cognitive function. (shrink)

In this introductory paper, we assess the current status of blindsight -- the phenomenon in which patients with damage to their primary visual cortex retain the ability to detect, discriminate and localize visual stimuli presented in areas of their visual field in which they report that they are subjectively blind. Blindsight has garnered a great deal of interest and critical research, in part because of its important implications for the philosophy of mind. We briefly consider why this is so, and (...) then go on to examine three empirical questions which have fuelled challenges to the validity of blindsight as a distinct neuropsychological phenomenon. First, is blindsight simply degraded normal vision? Second, does blindsight depend on undamaged areas of primary visual cortex? Third, does evidence that blindsight patients are aware of moving stimuli undermine the apparent dissociation between access to visual information and visual experience in blindsight? In the course of the review we introduce the four other papers on blindsight in this issue. We conclude that, although patients with primary visual cortex damage may indeed perceive moving stimuli, there is still good evidence for a dissociation between access to information and phenomenal experience which cannot be accounted for in terms of degraded normal vision or undamaged primary visual cortex. (shrink)

Neuroimaging studies of brain-damaged patients diagnosed as in the vegetative state suggest that the patients might be conscious. This might seem to raise no new ethical questions given that in related disputes both sides agree that evidence for consciousness gives strong reason to preserve life. We question this assumption. We clarify the widely held but obscure principle that consciousness is morally significant. It is hard to apply this principle to difficult cases given that philosophers of mind distinguish (...) between a range of notions of consciousness and that is unclear which of these is assumed by the principle. We suggest that the morally relevant notion is that of phenomenal consciousness and then use our analysis to interpret cases of brain damage. We argue that enjoyment of consciousness might actually give stronger moral reasons not to preserve a patient's life and, indeed, that these might be stronger when patients retain significant cognitive function. (shrink)

Recent neuroscientific evidence brings into question the conclusion that all aspects of consciousness are gone in patients who have descended into a persistent vegetative state (PVS). Here we summarize the evidence from human brain imaging as well as neurological damage in animals and humans suggesting that some form of consciousness can survive brain damage that commonly causes PVS. We also raise the issue that neuroscientific evidence indicates that raw emotional feelings (primary-process affects) can exist without any cognitive awareness (...) of those feelings. Likewise, the basic brain mechanisms for thirst and hunger exist in brain regions typically not damaged by PVS. If affective feelings can exist without cognitive awareness of those feelings, then it is possible that the instinctual emotional actions and pain "reflexes" often exhibited by PVS patients may indicate some level of mentality remaining in PVS patients. Indeed, it is possible such raw affective feelings are intensified when PVS patients are removed from life-supports. They may still experience a variety of primary-process affective states that could constitute forms of suffering. If so, withdrawal of life-support may violate the principle of nonmaleficence and be tantamount to inflicting inadvertent "cruel and unusual punishment" on patients whose potential distress, during the process of dying, needs to be considered in ethical decision-making about how such individuals should be treated, especially when their lives are ended by termination of life-supports. Medical wisdom may dictate the use of more rapid pharmacological forms of euthanasia that minimize distress than the de facto euthanasia of life-support termination that may lead to excruciating feelings of pure thirst and other negative affective feelings in the absence of any reflective awareness. (shrink)

Anosognosia is literally ‘unawareness of or failure to acknowledge one’s hemi- plegia or other disability’ (OED). Etymology would suggest the meaning ‘lack of knowledge of disease’ so that anosognosia would include any denial of impairment, such as denial of blindness (Anton’s syndrome). But Babinski, who introduced the term in 1914, applied it only to patients with hemiplegia who fail to acknowledge their paralysis. Most commonly, this is failure to acknowledge paralysis of the left side of the body following (...) damage to the right hemisphere of the brain. In this paper, we shall mainly be concerned with anosognosia for hemiplegia. But we shall also use the term ‘anosognosia’ in an inclusive way to encompass lack of knowledge or acknowledgement of any impairment. Indeed, in the construction ‘anosognosia for X’, X might even be anosognosia for some Y. (shrink)

BackgroundWhether patients in the vegetative state (VS), minimally conscious state (MCS) or the clinically related locked-in syndrome (LIS) should be kept alive is a matter of intense controversy. This study aimed to examine the moral attitudes of lay people to these questions, and the values and other factors that underlie these attitudes.MethodOne hundred ninety-nine US residents completed a survey using the online platform Mechanical Turk, comprising demographic questions, agreement with treatment withdrawal from each of the conditions, agreement with a (...) series of ethical principles and three personality tests.ResultsMore supported treatment withdrawal from VS (40.2 % agreed, 17.6 % disagreed) than MCS (20.6 %, 41.2 %) or LIS (25.3 %, 35.8 %). Agreement with treatment withdrawal was negatively correlated with religiosity (r = −0.272, P < 0.001), though showed no significant relationship with need for cognition or empathy, and only a partial association with utilitarian judgment in a standard moral dilemma. Support for treatment withdrawal was most strongly associated with endorsement of the importance of patient autonomy, dignity, suffering, best interests. Distributive justice was not given significant weight by most. Importantly, agreement with treatment withdrawal was noticeably higher when considered from a first as opposed to third person perspective for VS (Z = −6.056, P < 0.001), MCS (Z = −6.746, P < 0.001) and LIS (Z = −6.681, P < 0.001).ConclusionLay attitudes to withdrawal of treatment in brain damaged patients are largely shaped by values similar to those central to the secular ethical debate. Neither traditional values such as the sanctity of life nor utilitarian values relating to resource allocation seem to play a central role. Far greater weight is given to autonomy, which may explain why participants were far more willing to endorse withdrawal of treatment when the issue was presented in the first person, or in relation to a concrete case involving a patient’s explicit wishes. Surveys focusing on abstract cases presented in the third person may not provide an accurate picture of lay attitudes to these critical ethical questions. (shrink)

Some patients with damaged striate cortex have blindsight-the ability to discriminate unseen stimuli in their clinically blind visual field defects when forced-choice procedures are used. Blindsight implies a sharp dissociation between visual performance and visual awareness, but signal detection theory indicates that it might be indistinguishable from the behavior of normal subjects near the lower limit of conscious vision, where the dissociations could arise trivially from using different response criteria during clinical and forced-choice tests. We tested the latter (...) possibility with a hemianopic subject during yes-no and forced-choice detection of static and moving targets. His response criterion differed significantly between yes-no and forced-choice responding, and the difference was sufficient to produce a blindsight-like dissociation with bias-sensitive measures of performance. When measured independently of bias, his sensitivity to static targets was greater in the forced-choice than in the yes-no task (unlike normal control subjects), but his sensitivity to moving targets did not differ. Differences in response criterion could therefore account for dissociations between yes-no and forced-choice detection of motion, but not of static pattern. The results explain why patients with blindsight are apparently more often ''aware'' of moving stimuli than of static stimuli. However, they also imply that blindsight is unlike normal vision near threshold, and that pattern- and motion-detection in blindsight may depend on different sets of neural mechanisms during yes-no and forced-choice tests. (shrink)

The aim of cognitive neuropsychology is to articulate the functional architecture underlying normal cognition, on the basis of congnitive performance data involving brain-damaged subjects. Throughout the history of the subject, questions have been raised as to whether the methods of neuropsychology are adequate to its goals. The question has been reopened by Glymour [1994], who formulates a discovery problem for cognitive neuropsychology, in the sense of formal learning theory, concerning the existence of a reliable methodology. It appears that (...) the discovery problem may be insoluble in principle! I propose a modified formulation of Glymour's discovery problem and argue that a sceptical conclusion about the possiblity of cognitive neuropsychology as an empirical science is not warranted. (shrink)

This study examined the effects of computer-assisted cognitive rehabilitation in a group of 16 brain-damaged patients. Therapeutic effectiveness was assessed by improvement on computer tasks, the results of neuropsychological tests and quality of life ratings. Participants suffered from mild to moderate attention and memory problems or aphasia. The procedure involved baseline assessment, a 15-week course of therapy conducted twice a week and posttest. Neuropsychological tests assessing attention, memory and language problems and quality of life ratings were administered twice: (...) in pre- and posttests. Twelve healthy controls were also examined twice using the same battery of neuropsychological tests. The RehaCom program and the Polish computer therapy program for aphasics called Afa-System were used for rehabilitation. The computer-assisted rehabilitation tasks were selected individually for each patient. The results showed significant improvement on computer-assisted tasks in all braindamaged subjects. However, none or very little improvement was observed on neuropsychological tests and quality of life ratings. The results of the study confirm the importance of using different types of measures to estimate the effectiveness of computer-assisted neuropsychological rehabilitation as well as the necessity of applying various kinds of therapy to improve cognitive, emotional and social functioning in brain-damaged patients. (shrink)

Ninety-one right brain-damaged patients with left neglect and 43 right brain-damaged patients without neglect were asked to extend horizontal segments, either left- or rightward, starting from their right or left endpoints, respectively. Earlier experiments based on similar tasks had shown, in left neglect patients, a tendency to overextend segments toward the left side. This seemingly paradoxical phenomenon was held to undermine current explanations of unilateral neglect. The results of the present extensive research demonstrate that contralesional overextension (...) is also evident in most right brain-damaged patients without contralesional neglect. Furthermore, they show that in a minority of left neglect patients, the opposite behavior, i.e., right overextension can be found. The paper also reports the results of correlational analyses comprising the parameters of line-extension, line-bisection, and cancellation tasks, as well as the parameters relative to the Milner Landmark Task, by which a distinction is drawn between perceptual and response biases in unilateral neglect. A working hypothesis is then advanced about the brain dysfunction underlying neglect and an attempt is made at finding an explanation of neglect and the links between the mechanisms of space representation and consciousness through the study of the changes induced by unilateral brain lesions in the characteristics of space-coding neurons. Abbreviations: C, control group;GN+91,full group of neglect patients;GN+27,group of neglect patients with relative left overextension;GN+14,group of neglect patients with relative right overextension;GN-43,full group of non-neglect patients;GN-9,group of non-neglect patients with relative left overextension; H canc, H cancellation task; LE, left extension; LE/RE, ratio of left-right extension; N+, neglect patients; N-, non-neglect patients; PB Land-M, perceptual bias on Landmark motor task; PB Land-V, perceptual bias on Landmark verbal task; RB Land-M, response bias on Landmark motor task; RB Land-V, response bias on Landmark verbal task; RE, right extension. (shrink)

Proprioception, a sense of bodily position and movement, is rarely the focus of conscious experience. If we are ordinarily conscious of proprioception, we seem only peripherally so. Thus, evidence that proprioception is present in the periphery of at least some conscious experiences seems to be good evidence that conscious experience is fairly rich. Anosognosia for paralysis is a denial of paralysis of one's limbs, usually in the wake of brain damage from stroke. Because anosognosic (...) patients overlook their paralysis, anosognosia seems be a counter-example to the claim that proprioception exists in the periphery of conscious experience. However, careful consideration of the data shows that anosognosia makes a poor counterexample to a rich theory of consciousness. Thus, we retain reason to believe that proprioception exists in the periphery of conscious experience, and so to conclude that conscious experience is relatively rich. (shrink)

This book proposes a novel and rigorous explanation of consciousness. It argues that the study of an aspect of our self-consciousness known as the ‘feeling of embodiment’ teaches us that there are two distinct phenomena to be targeted by an explanation of consciousness. First is an explanation of the phenomenal qualities – 'what it is like' – of the experience; and second is the subject's awareness of those qualities. Glenn Carruthers explores the phenomenal qualities of the feeling of (...) class='Hi'>embodiment using the tools of quality spaces, as well as the subject's awareness of those qualities as a functionally emergent property of various kinds of processing of these spaces. Where much recent work on consciousness focuses on visual experience, this book rather draws evidence from the study of self-consciousness. Carruthers argues that in light of recent methodological discoveries, awareness must be explained in terms of the organization of multiple cognitive processes. The book offers an explanation of anomalous body representations and, from that, poses a more general theory of consciousness. Ultimately this book creates a hybrid account of consciousness that explains phenomenology and awareness using different tools. It will be of great interest to all scholars of psychology and philosophy as well as anyone interested in exploring the intricacies of how we experience our bodies, what we are and how we fit into the world. -/- . (shrink)

This superbly written and finery argued philosophical essay has potentially revolutionary importance for understanding "human consciousness, " and its author has accordingly been celebrated by the likes of Oliver Sachs and Karl Pribram. Showing the relevance of neuropathology for understanding the unifying processes behind perception, memory, and language, Jason Brown offers an exciting new approach to the mind/brain problem, freely crossing the boundaries of neurophysiology, psychology, and philosophy of mind. Hard science and the study of the nature of mind (...) (including Buddhist perspectives) come together in new ways, and without advocating the reductionist "computational model" for the mind/brain relation which dominates cognitive science today. Brown finds that every event in conscious life passes through highly determinate stages in a fraction of a second. These repeat both the stages of individual growth and of the evolution of the species: Not only does ontogeny recapitulate phylogeny, but the emergence of every moment of awareness recapitulates them both. This process begins deep in the brain stem with the mere awareness of duration, proceeds through concept-formation and image selection, and terminates with the apprehension of an object in the external world. The external object acts as a realistic constraint on consciousness. But in conditions such as brain damage, dream, meditation, as well as creativity, the preconscious stages enter into direct awareness, giving us explicit glimpses of developmental and evolutionary process and presenting a startling reversal of common ideas about the development of mind. Concept and image do not derive from perception and sensation, theycome first. And the principle of consciousness, rather than being a latecomer on the evolutionary and developmental scene, is a potentiality throughout. This lucidly written book will not disappoint the many readers concerned with the great frontier of scientific exploration -- the nature of consciousness. (shrink)

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)

The value of resting electroencephalogram (EEG) in revealing neural constitutes of consciousness (NCC) was examined. We quantified the dynamic repertoire, duration and oscillatory type of EEG microstates in eyes-closed rest in relation to the degree of expression of clinical self-consciousness. For NCC a model was suggested that contrasted normal, severely disturbed state of consciousness and state without consciousness. Patients with disorders of consciousness were used. Results suggested that the repertoire, duration and oscillatory type of EEG microstates in resting condition quantitatively (...) related to the level of consciousness expression in brain-damaged patients and healthy-conscious subjects. Specifically, results demonstrated that (a) decreased number of EEG microstate types was associated with altered states of consciousness, (b) unawareness was associated with the lack of diversity in EEG alpha-rhythmic microstates, and (c) the probability for the occurrence and duration of delta-, theta- and slow-alpha-rhythmic microstates were associated with unawareness, whereas the probability for the occurrence and duration of fast-alpha-rhythmic microstates were associated with consciousness. In conclusion, resting EEG has a potential value in revealing NCC. This work may have implications for clinical care and medical–legal decisions in patients with disorders of consciousness. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Disability Embodied: Narrative Exploration of the Lives of Two Brothers Living with Traumatic Brain InjuryDouglas E. KiddAny discussion of personal experiences with disability, inevitably lead me to recall the experiences of my brother, Richard Kidd. An examination of our journeys clearly illustrates the term disability. More so, our stories reveal the outcome of severe physical impairment dictates the limits of personal agency and autonomy. Perhaps an obvious conclusion, (...) but exploration of our experience is useful as we provide living testimony to eventualities that could similarly occur to others. In order to provide context for discussion of our disabilities, I will briefly recall how we acquired our traumatic brain injuries (TBI), as well as how our brain injuries are expressed. The article will demonstrate that due to the severity of the brain damage he acquired, Richard is entirely subject to the whim of the society he encounters, and thus disabled. The article will also discuss how the disabling attitudes I have encountered sought to diminish my humanity.Richard KiddRichard’s descent into impairment began in the early evening hours of December 31, 1987. As a pedestrian, Richard attempted to cross a street in Indianapolis, when a car without using headlights, slammed into him. In addition, the driver fled the scene of the accident. After stabilizing from the initial trauma—multiple compound fractures to both legs and severe brain injury—Richard spent approximately ten months in coma. After emerging from coma, Richard underwent months of therapy. Albeit with consistent direction from others, therapy enhanced Richard’s ability to hold a cup and use a spoon. These were significant victories for Richard and signaled the beginning of his recovery. However, within two years of his accident, monies ended for rehabilitation and Richard entered into custodial care at his first nursing facility. As time passed, his daily interactions with poorly supervised, unskilled, and underpaid nursing facility employees with little time to work with Richard meant it was more cost efficient for staff to simply spoon–feed Richard. Consequently, Richard lost the ability to participate in an aspect of his self–care. Richard’s humanity took years to gradually erode, but due to the severity of his impairments, he became viewed by those he encountered as an object of treatment, or reservoir of pain and pity, rather than an individual worthy of respect. Accordingly, [End Page 199] Richard became viewed as other. Thus began Richard’s descent into disability.A complete lack of dental care for decades provides a good example of Richard’s treatment as other. Richard’s experience also demonstrates that desensitized members of the medical, dental, and long–term care professions sometimes precipitate grave circumstances. The combination of an inattention to his needs and his limited ability to participate with his self–care meant that Richard typically went without dental treatment. His quality of life diminished further when aides at a nursing facility dropped him. During the fall, Richard’s face smashed into the floor and several teeth were shattered. More than a decade passed before Richard finally received follow–up dental treatment—that day nearly cost him his life. Due to prolonged neglect, all of Richard’s teeth required extraction. I do not question the dental surgeon’s assessment of Richard’s teeth. I am certain that all of his teeth needed to be removed; but Richard’s sedentary lifestyle meant that he had limited ability to cope with the trauma associated with having 24 teeth removed in one session. I feel certain the dental surgeon assumed Richard was like most other patients and could handle the stress associated with the procedures. However, Richard could not cope with trauma and blood loss the extractions produced. What is worse than the dental surgeon’s assessment of Richard’s ability to withstand surgery is the post–op personnel decision to discharge him to home, shortly after surgery. The nursing facility was ill–equipped to cope with the extent of the blood loss that ensued and soon Richard began to aspirate on his own blood. Accordingly, Richard was sent to the hospital where he proceeded to slip into coma. Richard remained in a coma for approximately four days and in hospital... (shrink)

It has long been known that brain damage has important negative effects on one’s mental life and even eliminates one’s ability to have certain conscious experiences. It thus stands to reason that when all of one’s brain activity ceases upon death, consciousness is no longer possible and so neither is an afterlife. It seems clear that human consciousness is dependent upon functioning brains. This essay reviews some of the overall neurological evidence from brain damage studies and (...) concludes that our argument from brain damage has been vindicated by such overwhelming evidence. It also puts forth a more mature philosophical rationale against an afterlife and counters several replies to the argument. -/- 1. Philosophical Background -- 2. The Dependence of Consciousness on the Brain: Some Preliminary Evidence -- 3. Brain Damage, Lesion Studies, and the Localization of Mental Function - 3.1 Perception - 3.2 Awareness, Comprehension, and Recognition - 3.3 Memory - 3.4 Personality - 3.5 Language - 3.6 Emotion - 3.7 Decision-Making - 3.8 Social Cognition and Theory of Mind - 3.9 Moral Judgment and Empathy - 3.10 Neurological Disorders and Disease - 3.11 The Unity of Consciousness -- 4. Objections and Replies - 4.1 Souls, Minds, and Energy Fields - 4.2 The Instrument Theory - 4.3 The Embodied Soul Alone is Affected -- 5. Conclusion. (shrink)

I argue that, contrary to some critics, the notion of conscious experience is a good candidate for denoting a distinct and scientifically interesting phenomenon in the brain. I base this claim mainly on an analysis of neuropsychological data concerning deficits resulting from various types of brain damage as well as some additional supporting empirical evidence. These data strongly point to the hypothesis that conscious experience expresses information that is available for global, integrated, and flexible behavior.

Claparède′s report of a case of amnesic syndrome is an early example of the cognitive neuropsychology paradigm, by which studies of brain-damaged patients are used to shed light on the nature of normal mental processes. The case illustrates the selective impairment of episodic memory, with procedural and semantic memory remaining intact. Moreover, the several demonstrations of preserved learning during amnesia comprise an early illustration of the dissociation between explicit and implict memory. However, its greatest contemporary relevance is for (...) theories of conscious recollection. Claparède underscored the role of the self, viewed as a knowledge structure, in conscious mental life, and he drew attention to three different modes of recognition: remembering, inferring, and knowing. (shrink)

Claparède′s report of a case of amnesic syndrome is an early example of the cognitive neuropsychology paradigm, by which studies of brain-damaged patients are used to shed light on the nature of normal mental processes. The case illustrates the selective impairment of episodic memory, with procedural and semantic memory remaining intact. Moreover, the several demonstrations of preserved learning during amnesia comprise an early illustration of the dissociation between explicit and implict memory. However, its greatest contemporary relevance is for (...) theories of conscious recollection. Claparède underscored the role of the self, viewed as a knowledge structure, in conscious mental life, and he drew attention to three different modes of recognition: remembering, inferring, and knowing. (shrink)

Until comparatively recently, say the middle of the last century, spinal cord injury was fatal as pressure sores and other infections took their toll. Those with severe brain injuries, unable to move or even communicate, fared even worse; without movement or feeding such patients were nursed until nature took its course. Over the last few decades medical and nursing advances have enabled some of these vegetative patients to survive for considerable time, provoking, at times, ethical and legal dilemmas. Though (...) they survived, without overt behaviour or clear communication their carers were frequently unsure how much residual function remained. Now real progress is occurring in this area thanks to the application of neuro-scientific methods by some outstanding groups of workers. Subjects with severe brain injury may begin in complete, unresponsive coma but then ‘lighten’ to one of three categories. In vegetative state (VS), patients are apparently awake but without evidence of voluntary behaviour and have no apparent awareness of self or environment, whilst in minimally conscious state (MCS) patients have some behaviour beyond the reflex but are not able to communicate effectively. These conditions usually result from widespread brain damage at either or both cortical and subcortical levels due to injury or anoxia, though they can also be seen in end stage neurological conditions like Alzheimer’s. In locked in syndrome (LIS), patients ‘awake’ from coma, usually due to stroke, aware of their surroundings and their situation but unable to speak or move, beyond eye lid control and eye movement. For many, LIS will be recognised from Bauby’s extraordinary account in ‘The Diving Bell and the Butterfly,’ though, incidentally, it was presaged in Samuel Beckett’s novella ‘The Unnameable.’ LIS reflects a profound disconnection between brain and body, except for the upper cranial nerves involved in eyelid movement. The overriding question is how much awareness these patients have.. (shrink)

Consciousness is a mongrel concept: there are a number of very different "consciousnesses." Phenomenal consciousness is experience; the phenomenally conscious aspect of a state is what it is like to be in that state. The mark of access-consciousness, by contrast, is availability for use in reasoning and rationally guiding speech and action. These concepts are often partly or totally conflated, with bad results. This target article uses as an example a form of reasoning about a function of "consciousness" based (...) on the phenomenon of blindsight. Some information about stimuli in the blind field is represented in the brains of blindsight patients, as shown by their correct "guesses," but they cannot harness this information in the service of action, and this is said to show that a function of phenomenal consciousness is somehow to enable information represented in the brain to guide action. But stimuli in the blind field are BOTH access-unconscious and phenomenally unconscious. The fallacy is: an obvious function of the machinery of access-consciousness is illicitly transferred to phenomenal consciousness. (shrink)

Background: Patients in a vegetative state pose problems in diagnosis, prognosis and treatment. Currently, no prognostic markers predict the chance of recovery, which has serious consequences, especially in end-of-life decision-making. Objective: We aimed to assess an objective measurement of prognosis using advanced electroencephalography (EEG). Methods: EEG data (19 channels) were collected in 14 patients who were diagnosed to be persistently vegetative based on repeated clinical evaluations at 3 months following brain damage. EEG structure parameters (amplitude, duration and variability within (...) quasi-stationary segments, as well as the spatial synchrony between such segments and the strength of this synchrony) were used to predict recovery of consciousness 3 months later. Results: The number and strength of cortical functional connections between EEG segments were higher in patients who recovered consciousness (P < .05 – P < .001) compared with those who did not recover. Linear regression analysis confirms that EEG structure parameters are capable of predicting (P = .0025) recovery of consciousness 6 months post-injury, whereas the same analysis failed to significantly predict patient outcome based on aspects of their clinical history alone (P = .629) or conventional EEG spectrum power (P = .473). Conclusions: The result of this preliminary study demonstrates that structural strategy of EEG analysis is better suited for providing prognosis of consciousness recovery than existing methods of clinical assessment and of conventional EEG. Our results may be a starting point for developing reliable prognosticators in patients who are in vegetative state, with the potential to improve their day-to-day management, quality of life, and access to early interventions. (shrink)

Currently, the number of patients diagnosed with impaired self-awareness of their own deficits after brain injury—anosognosia— is increasing. One reason is a growing understanding of this multifaceted phenomenon. Another is the development and accessibility of alternative measurements that allow more detailed diagnoses. Anosognosia can adversely affect successful rehabilitation, as often patients lack confidence in the need for treatment. Planning such treatment can become a complex process full of ethical dilemmas.To date, there is no systematic way to deal (...) with different aspects of anosognosia rehabilitation planning. This is the first article to present a framework for ethical decision making in establishing rehabilitation plans that are focused on increasing patients’ self-awareness of their own deficits after brain injury. It concentrates especially on addressing the ethical dilemmas that may arise, and describes stepwise procedures that can be applied to distinct theoretical approaches, as well as diagnostic and rehabilitation methods. To show the flexibility of the use of this framework, alternative approaches are discussed. (shrink)

AimVisual functions of the dorsal stream are considered vulnerable in children with early brain damage. Considering the recognition of objects in suboptimal representations a dorsal stream dysfunction, we examined whether children with early brain damage and impaired object recognition had either general or selective dorsal stream dysfunctions.MethodIn a group of children with early brain damage we evaluated the dorsal stream functioning. To determine whether these patients had an increased risk of a dorsal stream dysfunction we compared the (...) percentage of patients with impaired object recognition, assessed with the L94, with the estimated base rate. Then we evaluated the performance levels on motion perception, visual attention and visuomotor tasks in patients with and without object recognition abnormalities. A general dorsal stream dysfunction was considered present if a patient showed at least one abnormally low score in two out of three additional dorsal stream functions.ResultsSix of the eighteen patients with object recognition problems scored abnormally low on at least two additional dorsal stream functions. This was significantly higher than the base rate. The difference of 24.1% between the patients with and without object recognition problems was not significant. Of the patients with object recognition problems 72.2% had at least 1 dorsal weakness, whereas this was only the case in 27.3% of patients without object recognition problems. Compared to patients with normal object recognition, patients with object recognition problems scored significantly more abnormally low on motion perception and visual attention but did not differ on visuomotor skills.ConclusionChildren with object recognition problems seem at risk for other dorsal stream dysfunctions, but dysfunctions might be rather specific than general. Multiple functions/aspects should be evaluated in neuropsychological assessment of children at risk. (shrink)

The clinical and para-clinical examination of residual self-consciousness in non-communicative severely brain damaged patients remains exceptionally challenging. Passive presentation of the patient’s own name and own face are known to be effective attention-grabbing stimuli when clinically assessing consciousness at the patient’s bedside. Event-related potential and functional neuroimaging studies using such self-referential stimuli are currently being used to disentangle the cognitive hierarchy of self-processing. We here review neuropsychological, neuropathological, electrophysiological and neuroimaging studies using the own name and own face (...) paradigm obtained in conscious waking, sleep, pharmacological coma, pathological coma and related disorders of consciousness. Based on these results we discuss what we currently do and do not know about the functional significance of the neural network involved in “automatic” and “conscious” self-referential processing. (shrink)

Our ethical obligations to another being depend at least in part on that being’s capacity for a mental life. Our usual approach to inferring the mental state of another is to reason by analogy: If another being behaves as I do in a circumstance that engenders a certain mental state in me, I conclude that it has engendered the same mental state in him or her. Unfortunately, as philosophers have long noted, this analogy is fallible because behavior and mental states (...) are only contingently related. If the other person is acting, for example, we could draw the wrong conclusion about his or her mental state. In this article I consider another type of analogy that can be drawn between oneself and another to infer the mental state of the other, substituting brain activity for behavior. According to most current views of the mind–body problem, mental states and brain states are non-contingently related, and hence inferences drawn with the new analogy are not susceptible to the alternative interpretations that plague the behavioral analogy. The implications of this approach are explored in two cases for which behavior is particularly unhelpful as a guide to mental status: severely brain–damaged patients who are incapable of intentional communicative behavior, and nonhuman animals whose behavioral repertoires are different from ours and who lack language. (shrink)

The question of whether blindsight is a form of unconscious perception continues to spark fierce debate in philosophy and psychology. One side of the debate holds that while the visual information categorized in blindsight is not access-conscious, it is nonetheless a form of perception, albeit a form of unconscious perception. The opposition, by contrast, holds that blindsight is just a form of degraded conscious perception that makes the categorized information harder to access because it is degraded. In this (...) chapter, we address the opposition’s arguments for thinking that blindsight is a form of degraded conscious vision and then argue that the residual awareness found in blindsight is a form of non-perceptual awareness. To back this claim, we examine the residual visual abilities to detect and discriminate colour found in some blindsight patients and show that residual consciousness in blindsight is indirect and lacks the phenomenal character characteristic of conscious vision. (shrink)

A prominent view on personal identity over time, Jeff McMahan’s ‘Embodied Mind Account’ (2002) holds that we cease to exist only once our brains can no longer sustain the basic capacity to uphold consciousness. One of the many implications of this view on identity persistence is that we continue to exist throughout even the most severe cases of dementia, until our consciousness irreversibly shuts down. In this paper, I argue that, while the most convincing of prominent accounts of personal identity (...) over time, McMahan’s account faces serious challenges in explanatory power of dementias and related neurodegenerative conditions. Particularly, this becomes visible in the face of emerging methods for neural tissue regeneration, and the possibility of ‘re-emerging patients’. I argue that medical professionals’ neglecting qualitative aspects of identity risks resulting in grave misunderstandings in decision-making processes, and ethically objectionable outcomes in future practices. Finally, I propose revisions which could potentially salvage the great benefits that Embodied Mind Theory still can bring to the field of dementia care in terms of understanding life, death, and identity across the lifespan. (shrink)

Of all the problems facing science none are more challenging yet fascinating than those posed by consciousness. In The Science of Consciousness leading researchers examine how consciousness is being investigated in the key areas of cognitive psychology, neuropsychology and clinical psychology. Within cognitive psychology, special focus is given to the function of consciousness, and to the relation of conscious processing to nonconscious processing in perception, learning, memory and information dissemination. Neuropsychology includes examination of the neural conditions for consciousness and (...) the effects of brain damage. Finally, mind/body interactions in clinical and experimental settings are considered, including the somatic effects of imagery, biofeedback and placebo effects. Every chapter is written by an expert in the field. They each provide a clear overview of existing research along with an exciting new synthesis of consciousness studies. The The Science of Consciousness will be invaluable for students, researchers and clinicians interested in the developments and directions of this rapidly growing field. (shrink)