Many have claimed that split-brain patients are actually two persons. I maintain that both the traditional separation argument and the more recent sophistication argument for the two persons interpretation are inadequate on conceptual grounds. An autonomy argument is inadequate on empirical grounds. Overall, theoretical and practical consequences weigh heavily in favor of adopting a one person interpretation.

This paper challenges the widely held theory that split-brain patients have ‘two-minds’ and can thus be described as being two distinct persons. A distinction is made between the singularity of mind and the coherence of mind. It is stressed that ‘a single mind’ is not something posited to explain coherence among mental contents, but is merely a mark that such coherence holds to a certain degree. However, there is no sharp dividing line regarding what counts as a (...) single mind. It is argued that mental coherence is always a matter of degree, and that our concept of a single mind can accomodate spit-brain phenomena. (shrink)

This paper challenges the widely held theory that split-brain patients have ‘two-minds’ and can thus be described as being two distinct persons. A distinction is made between the singularity of mind and the coherence of mind. It is stressed that ‘a single mind’ is not something posited to explain coherence among mental contents, but is merely a mark that such coherence holds to a certain degree. However, there is no sharp dividing line regarding what counts as a (...) single mind. It is argued that mental coherence is always a matter of degree, and that our concept of a single mind can accomodate spit-brain phenomena. (shrink)

It has been argued that 'brain bisection' data leads us to abandon our traditional conception of personal identity. Nagel has remarked: The ultimate account of the unity of what we call a single mind consists of an enumeration of the types of functional integration that typify it. We know that these can be eroded in different ways and to different degrees. The belief that even in their complete version they can be explained by the presence of a numerically single (...) subject is an i1lusion.l Parfit has adopted a similar position, contending that patients with 'split brains' become two separate 'streams of consciousness' and thus that our normal sense of personal identity, or at least 'what matters' about personal identity is constituted by psychological relations between connected conscious experiences2 It is claimed that in 'split brain' patients certain of the relations are disrupted and that we thus see clearly that the nature of the unity that is normally present does not reside in a single subject with a given identity, but in the connectedness and continuity that normally obtains. Parfit draws on two sources of support for these contentions: the first is the actual events that transpire after a human being is submitted to the operation of sectioning the corpus callosum (or 'brain bisection'), and the second is the imaginative consideration of various scenarios involving graded mental and physical discontinuity, and the 'fission' and 'fusion' of persons. I shall do little more than argue that the actual data will not sustain the interpretation put on them. (shrink)

In this paper it is argued that the experimental data on commissurotomy patients provide no grounds for denying the singular personhood of commissurotomy patients. This is because, contrary to most philosophical accounts, there is no “unity of consciousness” discriminating condition for singular personhood that is violated in the case of commissurotomy patients, and because no contradictions arise when singular personhood is ascribed to commissurotomy patients.

Brain bisection raises the intriguing question about how many minds the split-brain patients have. Thomas Nagel and Derek Parfit, who have brought this question into consideration, come to similar conclusions in response to it. They both argue that the question has no answer, that there simply isn’t any countable number of minds that the split-brain patients have. In addition, Parfit argues that the split-brain cases can be adequately described only if we (...) adopt a certain particular view about the metaphysical nature of a person. The goal of this paper is to clarify both of those views and, in particular, to explain why Parfit’s preference for one model of personhood does not determine how many persons survive brain bisection. (shrink)

The article questions the assumption that conjoined twins are necessarily two people or persons by employing arguments based on different points of view: non-personal vitalism, the person as a sentient being, the person as an agent, the person as a locus of narrative and valuation, and the person as an embodied mind. Analogies employed from the cases of amputation, multiple personality disorder, abortion, split-brain patients and cloning. The article further questions the assumption that a conjoined (...) twin's natural interest and wish is separation. I first contend that separation is such a radical procedure as to render the post-separation person different from the pre-separation one. Therefore, it is not possible to benefit the pre-separation twin by the act of separation. The article concludes with a critical evaluation of the tendency in bioethics to regard ethical challenges as rivalry between individuals competing for scarce resources. (shrink)

Contrary to received opinion among philosophers, psychologists, and neuroscientists, conscious duality as a principle of brain organization is neither incoherent nor demonstrably false. The present paper begins by reviewing the history of the theory and its anatomical basis and defending it against the claim that it rests upon an arbitrary decision as to what constitutes the biological substratum of mind or person.

This contribution intends to explore patients’ lived experience, with a focus on the temporal dimension. On the basis of a qualitative study that led me to interview persons with Parkinson’s disease, caregivers, and medical professionals, I develop an empirical and philosophical investigation of the temporalities surrounding the implementation of deep brain stimulation in Greece. I raise the issue of access to DBS medical care, and show how distinct temporalities are implied when the patients face such a matter: (...) that of linear time, linked with the medical discourse, the bureaucratic time linked to administrative and financial hurdles in the implementation and maintenance of DBS, and the technological time of the body/technology fusion. I consider initially the impact of technology and health care settings on the lived experience of patients and the enactment of multiple bodies which are interrelated with the social world. I then expand my analysis in order to show that this experience cannot be a solipsistic one, or specific to one physician/patient relationship. It is fully socially shaped. (shrink)

The phenomenon of multiple personality--Like the "split-Brain" phenomenon--Involves a disintegration of the normally unified self to the point where one must question whether there is one, Or more than one, Person associated with the body even at a single moment in time. Besides the traditional problem of determining identity over time, There is now a new problem of personal identity--Determining identity at a single moment in time. We need the conceptual apparatus to talk about this new (...) problem and a test, Like the one I propose, For determining the number of persons associated with a body at a single moment in time. (shrink)

This paper concerns the relationships between persons, brains, behaviour, and psychological explanation. Tye defines a ‘psychological framework’ (PF) as a set of token beliefs, desires, intentions, memories, streams of consciousness, higher-order mental states, etc., that ‘form a coherent whole’ and against which a creature’s ‘behavior can be explained’ (p. 141). A person is the subject of such a psychological framework. Each person has one PF, and with each new PF there is a new person. Meanwhile materialism tells us, according to (...) Tye, that brains are the bearers of mental states. In other words, ‘each person is a brain’ (p. 142) — or rather a ‘global physical state of the brain,’ since Tye believes that a single brain might realize multiple PFs and thus constitute multiple persons. Most of this paper simply assumes Tye’s account of personal identity, in order to expose certain contradictions within what Tye says about personhood in split-brain subjects. Towards the end of the paper, however, I turn to alternative accounts of persons. While a method of individuating persons grounded in scientific psychology would identify persons with psychological frameworks, as Tye does, perhaps an account of personhood grounded either in a non-psychological science, or in non-scientific psychology, would better fit the interests we have in personal identity. (shrink)

In this commentary I use recent empirical evidence and theoretical analyses concerning the importance of language and the meaning of self-recognition to reevaluate the claim that the right mute hemisphere in commissurotomized patients possesses a full consciousness. Preliminary data indicate that inner speech is deeply linked to self-awareness; also, four hypotheses concerning the crucial role inner speech plays in self-focus are presented. The legitimacy of self-recognition as a strong operationalization of self-awareness in the right hemisphere is also questioned on (...) the basis that it might rather tap a preexisting body awareness having little to do with an access to mental events. I conclude with the formulation of an alternative interpretation of commissurotomy according to self-awareness — a “complete” one in the left hemisphere and a “primitive” one in the right hemisphere. (shrink)

Brain implants, such as Deep Brain Stimulation (DBS), which are designed to improve motor, mood and behavioural pathology, present unique challenges to our understanding of identity, agency and free will. This is because these devices can have visible effects on persons' physical and psychological properties yet are essentially undetectable when operating correctly. They can supplement and compensate for one's inherent abilities and faculties when they are compromised by neuropsychiatric disorders. Further, unlike talk therapy or pharmacological treatments, patients (...) need not ‘do’ anything for the treatment to take effect. If one accepts, as we argue here, that brain implants are unique among implantable types of devices, then this can have significant implications for what it means to persist as the same person and be the source of one's thoughts and actions. By examining two of the most common indications for DBS in current use, namely in the motor (Parkinson's Disease) and psychiatric (Major Depression) domains, we further argue that although DBS, as it is currently applied, does not necessarily represent a unique threat to personal identity and agency per se, it introduces an unprecedented ‘third party’ into the debate on these concepts. In this way, DBS can be used as a tool to begin probing, both conceptually and empirically, some of philosophy's most perennial metaphysical questions. (shrink)

The ongoing debate within neuroethics concerning the degree to which neuromodulation such as deep brain stimulation (DBS) changes the personality, identity, and agency (PIA) of patients has paid relatively little attention to the perspectives of prospective patients. Even less attention has been given to pediatric populations. To understand patients’ views about identity changes due to DBS in obsessive-compulsive disorder (OCD), the authors conducted and analyzed semistructured interviews with adolescent patients with OCD and their parents/caregivers. (...) Patients were asked about projected impacts to PIA generally due to DBS. All patient respondents and half of caregivers reported that DBS would impact patient self-identity in significant ways. For example, many patients expressed how DBS could positively impact identity by allowing them to explore their identities free from OCD. Others voiced concerns that DBS-related resolution of OCD might negatively impact patient agency and authenticity. Half of patients expressed that DBS may positively facilitate social access through relieving symptoms, while half indicated that DBS could increase social stigma. These views give insights into how to approach decision-making and informed consent if DBS for OCD becomes available for adolescents. They also offer insights into adolescent experiences of disability identity and “normalcy” in the context of OCD. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Multiple Personality and Moral ResponsibilityStephen E. Braude (bio)AbstractThe philosophical literature on multiple personality has focused primarily on problems about personal identity and psychological explanation. But multiple personality and other dissociative phenomena raise equally important and even more urgent questions about moral responsibility, in particular: In what respect(s) and to what extent should a multiple be held responsible for the actions of his/her (...) alternate personalities? Cases of dreaming help illustrate why attributions of responsibility in cases of dissociation do not turn on putative changes in identity, as some have supposed. Instead, it is argued that traditional criteria of rationality and behavioral control apply also to cases of dissociation. It is noted, however, that one can distinguish different kinds of responsibility in cases of dissociation, and that one is responsible for one’s dreams in a different sense from that in which one is responsible for actions one can control and evaluate. It is also argued that in cases of multiple personality it is important to distinguish control over switching of personalities from an alter’s control over its own behavior. Moreover, the author considers reasons for thinking that amnesia is less relevant to attributions of responsibility than many have supposed.Keywordsdissociation, dreaming, rationality, amnesiaIntroductionThe philosophical literature on MPD/DID 1 has focused primarily on problems about personhood, personal identity, and the nature of psychological explanation. Presumably, that is because multiples appear to be (or to harbor) more than one person or more than one distinct moral or prudential agent. But philosophers have had almost nothing to say about problems of responsibility in these cases—in particular, the question: In what respect(s) and to what extent should a multiple be held responsible for the actions of his/her alternate personalities (or alters)?Unlike questions about personhood and identity, this question is not simply an abstract matter that we may ponder at our leisure. Clinicians treating multiples must decide whether it is appropriate—or even just therapeutically beneficial—to hold their patients (or specific alters) responsible for behaviors which they seem unable to control or remember. Similarly, and with increasing frequency, our courts must decide whether a defendant claiming to be a multiple may be held guilty for the actions of one or more alters. In fact, the legal issues can be quite dramatic, and even bizarre. Consider: What sort of individual is standing trial? An alter or the multiple as a whole? Should courts accept the claim that the subject being questioned on the stand is not the same as the subject who committed the crime? If so, other questions come immediately to mind. For example, would it be appropriate for each alter of a criminal defendant to have separate legal council?Undoubtedly, some will have trouble taking that last question seriously. But no matter how [End Page 37] clear its solution may appear to one’s moral or legal intuitions, those intuitions are seldom as straightforward as they seem. Indeed, one cannot explain or defend them without taking a stand, at least provisionally, on a wide range of thorny philosophical problems. Moreover, the aforementioned questions are merely the tip of the iceberg, and our answers to them have implications extending beyond the courtroom. For example, with regard to forensic contexts Slovenko (1991) asks,Should a search or arrest warrant be issued for each personality? Must a Miranda warning be given to each personality of a suspect with MPD? May the other personalities exclude evidence on the ground that they were not properly read their rights at the time of the arrest? Would each one of the personalities have to waive his or her rights, or would one waiver be sufficient? Does the doctrine of double jeopardy bar the trial of a personality when another has been put to trial? Must each personality testifying at trial be sworn in and administered the oath?(22, 25)These questions have obvious analogues in clinical situations, and also in personal contexts, say, between friends or members of a family, one of whom is a multiple. For example, to what extent should a DID patient be held responsible for the sociopathic (or simply counter-therapeutic) behavior of... (shrink)

In this paper it is argued that the experimental data on commissurotomy patients provide no grounds for denying the singular personhood of commissurotomy patients. This is because, contrary to most philosophical accounts, there is no “unity of consciousness” discriminating condition for singular personhood that is violated in the case of commissurotomy patients, and because no contradictions arise when singular personhood is ascribed to commissurotomy patients.

After the first callosotomy surgeries were performed, the general consensus among the medical community was that severing the corpus callosum had relatively little, if any, effect on an individual's behavior. Nearly twenty years later, researchers discovered that, under experimental conditions, the two hemispheres could simultaneously maintain very different interpretations of the same stimulus. These findings immediately called into question the unity of subjective experience, a fundamental characteristic of human consciousness. How could the split‐brain patient not experience any disruption (...) in his experience as a unified self when the two hemispheres are physically and functionally disconnected? In this chapter, we review the research that has led to a conceptualization of the split brain as two minds within one body and the implications of this research for the scientific study of consciousness. We argue that consciousness is a neural function that emerges from the integration of information across available functional modules. (shrink)

To assess the ability of the disconnected cerebral hemispheres to recognize images of the self, a split-brain patient was tested using morphed self-face images presented to one visual hemifield at a time while making “self/other” judgments. The performance of the right and left hemispheres of this patient as assessed by a signal detection method was not significantly different, though a measure of bias did reveal hemispheric differences. The right and left hemispheres of this patient independently and equally possessed (...) the ability to self-recognize, but only the right hemisphere could successfully recognize familiar others. This supports a modular concept of self-recognition and other-recognition, separately present in each cerebral hemisphere. (shrink)

According to conventional wisdom, the split-brain syndrome puts paid to the thesis that consciousness is necessarily unified. The aim of this paper is to challenge that view. I argue both that disunity models of the split-brain are highly problematic, and that there is much to recommend a model of the split-brain—the switch model—according to which split-brain patients retain a fully unified consciousness at all times. Although the task of examining the unity (...) of consciousness through the lens of the split-brain syndrome is not a new one—such projects date back to Nagel’s seminal paper on the topic—the time is ripe for a re-evaluation of the issues. (shrink)

Some philosophers have argued that so long as two neural events, within a subject, are both of the same type and both carry the same content, then these events may jointly constitute a single mental token, regardless of the sort of causal relation to each other that they bear. These philosophers have used this claim—which I call the “singularity-through-redundancy” position—in order to argue that a split-brain subject normally has a single stream of consciousness, disjunctively realized across the two (...) hemispheres. This paper argues, against this position, that the kind of causal relations multiple neural events bear to each other constrains the mental tokens with which functionalists who are realists can identify them. (shrink)

Dual-Brain Psychology is a theory and its clinical applications that come out of the author's clinical observations and from the Split-brain Studies. The theory posits, based on decades of rigorous, peer-reviewed experiments and clinical reports, that, in most patients, one brain's cerebral hemisphere when stimulated by simple lateral visual field stimulation, or unilateral transcranial photobiomodulation, reveals a dramatic change in personality such that stimulating one hemisphere evokes, as a trait, a personality that is (...) more childlike and more presently affected by childhood maltreatments that are usually not presently appreciated but are the proximal cause of the patient's symptoms. The personality associated with the other hemisphere is much more mature, less affected by the traumas, and less symptomatic. The theory can be applied to in-depth psychotherapy in which the focus is on helping the troubled side to bear and process the traumas with the help of the therapist and the healthier personality. A person's symptoms can be evoked to aid the psychotherapy with hemispheric stimulation and the relationship between the dual personalities can be transformed from conflicted and sabotaging to cooperating toward overall health. Stimulating the positive hemisphere in most therapy patients rapidly relieves symptoms such as anxiety, depression, or substance cravings. Two randomized controlled trials used unilateral transcranial photobiomodulation to the positive hemisphere as a stand-alone treatment for opioid cravings and both revealed high effect sizes. The theory is supported by brain imaging and rTMS studies. It is the first psychological theory and application that comes out of and is supported by rigorous peer-reviewed experimentation. (shrink)

Self-injurious behavior is associated with diverse psychiatric conditions. Sometimes, SIB is the most dominant symptom, severely restricting the psychosocial functioning and quality of life of the patients and inhibiting appropriate patient care. In severe cases, it can lead to permanent physical injuries or even death. Primary therapy consists of medical treatment and if implementable, behavioral therapy. For patients with severe SIB refractory to conventional therapy, neuromodulation can be considered as a last recourse. In scientific literature, several successful lesioning (...) and deep brain stimulation targets have been described that can indicate a common underlying neuronal pathway. The objectives of this study were to evaluate the short- and long-term clinical outcome of patients with severe, therapy refractory SIB who underwent DBS with diverse underlying psychiatric disorders and to correlate these outcomes with the activated connectivity networks. We retrospectively analyzed 10 patients with SIB who underwent DBS surgery with diverse psychiatric conditions including autism spectrum disorder, organic personality disorder after hypoxic or traumatic brain injury or Tourette syndrome. DBS targets were chosen according to the underlying disorder, patients were either stimulated in the nucleus accumbens, amygdala, posterior hypothalamus, medial thalamus or ventrolateral thalamus. Clinical outcome was measured 6 months after surgery and at long-term follow-up after 10 or more years using the Early Rehabilitation Barthel index and time of restraint. Connectivity patterns were analyzed using normative connectome. Based on previous literature the orbitofrontal cortex, superior frontal gyrus, the anterior cingulate cortex, the amygdala and the hippocampus were chosen as regions of interest. This analysis showed a significant improvement in the functionality of the patients with DBS in the short- and long-term follow-up. Good clinical outcome correlated with higher connectivity to the amygdala and hippocampus. These findings may suggest a common pathway, which can be relevant when planning a surgical procedure in patients with SIB. (shrink)

One of the main problems of the soul theory is how the soul, which has no material properties, interacts with body. Because it is difficult to understand how an immaterial being interacts with matter. In particular, as our scientific understanding of the way the brain works and how it affects our psychology expands, the question of whether a soul is needed for the mind manifests itself more strongly. In this context, current data on the close connection between the (...) class='Hi'>brain and the mind is often used as an objection to the understanding of the soul. One of the recent data that has been claimed to have dealt a heavy blow against the understanding of the soul is the split-brain case. The split-brain case is the name given to the condition of patients whose brain hemispheres are surgically separated from each other. The difference of this case from other cases used against dualism is that it pointed out that the integrity of consciousness also depends on the brain. Because although there was a connection between many mental functions and the brain before, it was not between the unity of consciousness. For it was a new claim that the unity of consciousness also depends on the brain. On the contrary, arguments were used in favor of the existence of the soul, stating that the brain cannot provide the unity of consciousness due to its multi-part structure, and therefore an indivisible soul is necessary. Whereas, in the split-brain case, patients whose brain hemispheres were separated from each other could think and act like two different people. This is interpreted as contrary to the soul view, which argues that the individual and the soul are indivisible. The present study considers whether the split-brain case does indeed offer a strong argument against dualism. In this paper, first of all, more detailed information about the split-brain case will be given. Then, the arguments of those who use this case against dualism and why the issue seems problematic in terms of the soul view will be discussed. Afterwards, some solutions offered by dualists to this problem will be evaluated. There are three different strategies that dualists follow at this point. The first one rejects the idea that consciousness is divided as a result of the split-brain phenomenon, the second rejects the idea that the soul is indivisible, and the third way accepts both, but argues that they are not contradictory, because a single soul can have a divided consciousness. This paper argues that even if it is accepted that more than one stream of consciousness emerges as a result of the split-brain case, this cannot be seen as a finishing blow to dualism. Despite this, the case in question can be regarded as a strong argument against dualism. For a counter-argument to be strong, it does not need to conclusively demonstrate the falsity of what it opposes. It suffices to show the weakness of its probability of being true. In this respect, the split-brain case greatly weakens the probability of dualism being true. (shrink)

Neural organization has many facets; multiple descriptive levels and multiple analytical strategies coexist. Although most neuroscientists agree that a multidisciplinary, multistrategic approach is necessary to understand neural organization, diverse individual approaches make it difficult to find the optimal mixture and priority list.

This article presents a historical overview of the role played by neurology patients and clinicians in the development of understanding brain–behavior relationships and argues that, even with the advent of sophisticated functional brain imaging techniques, this clinical approach remains valuable. It is particularly important in the biological study of religion, where there is a danger that piecemeal and reductionist approaches will come to dominate. It is argued that religion is a socially located, multifaceted, and embodied phenomenon that (...) occurs not in the brain but in the lives of human persons. Insights drawn from people living with conditions affecting the brain are thus vital for a full understanding of human identity, spirituality, and religion. (shrink)

The neural substrates of context effects in word perception are still largely unclear. Interhemispheric priming phenomena in word recognition, typically observed in normal subjects, are absent in commissurotomized patients. This suggests that callosal fibers may provide contextual integration. In addition, certain characteristics of human frontal cortical fields subserving sensorimotor learning, as investigated by positron emission tomography, provide evidence for contextual integration not confined to the visual system. This supports the notion of common aspects of cortical computations in different cerebral (...) areas. (shrink)

Tremor of the upper extremity is a significant cause of disability in some patients with multiple sclerosis. The MS tremor is complex because it contains an ataxic intentional tremor component due to the involvement of the cerebellum and cerebellar outflow pathways by MS plaques, which makes the MS tremor, in general, less responsive to medications or deep brain stimulation than those associated with essential tremor or Parkinson's disease. The cerebellar component has been thought to be the main (...) reason for making DBS less effective, although it is not clear whether it is due to the lack of suppression of the ataxic tremor by DBS or else. The goal of this study was to clarify the effect of DBS on cerebellar tremor compared to non-cerebellar tremor in a patient with MS. By wearing an accelerometer on the index finger of each hand, we were able to quantitatively characterize kinetic tremor by frequency and amplitude, with cerebellar ataxia component on one hand and that without cerebellar component on the other hand, at the beginning and end of the hand movement approaching a target at DBS Off and On status. We found that cerebellar tremor surprisingly had as good a response to DBS as the tremor without a cerebellar component, but the function control on cerebellar tremor was not as good due to its distal oscillation, which made the amplitude of tremor increasingly greater as it approached the target. This explains why cerebellar tremor or MS tremor with cerebellar component has a poor functional transformation even with a good percentage of tremor control. This case study provides a better understanding of the effect of DBS on cerebellar tremor and MS tremor by using a wearable device, which could help future studies improve patient selection and outcome prediction for DBS treatment of this disabling tremor. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Commentary on “Multiple Personality and Moral Responsibility”Daniel W. Shuman (bio)Stephen Braude’s essay, “Multiple Personality and Moral Responsibility,” discusses a number of important issues about the moral and legal responsibility of persons diagnosed with multiple personality disorder (MPD), known in DSM-IV as Dissociative Identity Disorder (DID). One issue that is fundamental to this debate, which Braude does not address, however, is the empirical reality (...) underlying the debate. Does MPD/DID exist? A prerequisite to a debate about the legal consequences of MPD/DID is legally sufficient proof of its existence and its behavioral consequences.Proof that MPD/DID exists, its impact on legal standards of responsibility, and that the defendant suffers from it, must come from expert testimony; it is not part of the common knowledge or experience of the typical judge or juror. Courts are, however, increasingly, unwilling to assume that because an expert has impressive qualifications, he or she will necessarily present scientifically valid evidence. Particularly in cases of psychiatric and psychological evidence, courts that once looked solely at the expert’s qualifications to determine the admissibility for expert scientific evidence, now understand that the expert’s qualifications are a necessary but not a sufficient condition for the presentation of accurate expert testimony. Courts increasingly want to know how experts know what they claim to know and whether their methods of knowing meet the hallmarks of good science.Thus, from a legal standpoint, a prerequisite to admissibility of the evidence that serves as a basis for a discussion of the legal implications of MPD/DID is rigorous scientific proof of its existence. Proof of the existence of MPD/DID has not, however, been the subject of rigorous scientific research, but instead has consisted of non-falsifiable clinical experience where the risk of iatrogenesis (i.e., hypnosis and suggestion) is ever present. While these clinical observations and opinions may ultimately be proven valid by subsequent research, there is simply no way to know whether that is so in the absence of rigorous scientific research. If proof of the existence of MPD/DID is clinically but not scientifically grounded, legal rules based upon it are suspect. Moreover, claims of MPD/DID often arise in a legal context where there are significant benefits to be gained from receiving the diagnosis which heightens the importance of rigorous scientific scrutiny.Diagnostic validity and reliability matters in different ways in the forensic context than it does in the therapeutic context. These contextual differences [End Page 59] are reflected in disparate standards for scrutinizing each. There is no threshold requirement, for example, that a psychotherapist prove that a diagnostic category is valid or that a psychotherapeutic treatment used for a person suffering from it is generally recognized as safe and effective before using it; however, there is a threshold requirement of rigorous scientific scrutiny before admission of this information in evidence. If a therapist’s diagnostic hypothesis that there are two personality states influencing a patient’s behavior is not borne out, it can be revised in later sessions. Even if MPD/DID does not exist, treatment that assumes it does may nonetheless be effective because therapeutic outcome is more closely tied to the nature of the therapist-patient relationship than the content of therapy, or because multiple personality states is an effective therapeutic metaphor. Moreover, if the patient is not satisfied that the diagnosis or treatment rendered is helpful, the patient can leave therapy or seek another therapist.In contrast, judicial determinations are a one-shot determination which cannot be revisited in light of subsequently acquired knowledge. The defendant/patient is not free to change courts, or withdraw from the legal proceedings. Thus, it would be entirely appropriate for psychiatrists and psychologists to treat patients presenting symptoms of what they label MPD/DID and for courts to reject exculpatory evidence from psychiatrists and psychologists of that disorder.Related ArticlesFeature Article: Multiple Personality and Moral ResponsibilityCommentary: Commentary by ClarkCommentary: Commentary by ShumanDaniel W. Shuman Daniel W. Shuman, Professor of Law, Southern Methodist University, Dallas, TX 75235, USA.Copyright © 1996 The Johns Hopkins University Press... (shrink)

Many experimental findings with split-brain subjects intuitively suggest that each such subject has two minds. The conceptual and empirical basis of this duality intuition has never been fully articulated. This article fills that gap, by offering a reconstruction of early neuropsychological literature on the split-brain phenomenon. According to that work, the hemispheres operate independently of each other insofar as they interact via the mediation of effection and transduction—via behavior and sensation, essentially. This is how your mind (...) and my mind interact with each other, however, giving rise to the intuition that a split-brain subject has two minds. (shrink)

In "Consciousness Explained," Dennett (1991) denies that split-brain humans have double consciousness: he describes the experiments as "anecdotal." In attempting to replace the Cartesian Theatre of the Mind" with his own "Multiple Drafts" view of consciousness, Dennett rejects the notion of the mind as a countable thing in favour of its being a mere "abstraction." His criticisms of the standard interpretation of the split-brain data are analyzed here and each is found to be open to (...) objections. There exist people who have survived left ["dominant"] cerebral hemispherectomy; by Dennett's criteria, they would not have minds. (shrink)

Does DBS change a patient’s personality? This is one of the central questions in the debate on the ethics of treatment with Deep Brain Stimulation (DBS). At the moment, however, this important debate is hampered by the fact that there is relatively little data available concerning what patients actually experience following DBS treatment. There are a few qualitative studies with patients with Parkinson’s disease and Primary Dystonia and some case reports, but there has been no qualitative (...) study yet with patients suffering from psychiatric disorders. In this paper, we present the experiences of 18 patients with Obsessive-Compulsive Disorder (OCD) who are undergoing treatment with DBS. We will also discuss the inherent difficulties of how to define and assess changes in personality, in particular for patients with psychiatric disorders. We end with a discussion of the data and how these shed new light on the conceptual debate about how to define personality. (shrink)

The term ‘locked-in’ syndrome (LIS) describes a medical condition in which persons concerned are severely paralyzed and at the same time fully conscious and awake. The resulting anarthria makes it impossible for these patients to naturally communicate, which results in diagnostic as well as serious practical and ethical problems. Therefore, developing alternative, muscle-independent communication means is of prime importance. Such communication means can be realized via brain–computer interfaces (BCIs) circumventing the muscular system by using brain signals associated (...) with preserved cognitive, sensory, and emotional brain functions. Primarily, BCIs based on electrophysiological measures have been developed and applied with remarkable success. Recently, also blood flow–based neuroimaging methods, such as functional magnetic resonance imaging (fMRI) and functional near-infrared spectroscopy (fNIRS), have been explored in this context. After reviewing recent literature on the development of especially hemodynamically based BCIs, we introduce a highly reliable and easy-to-apply communication procedure that enables untrained participants to motor-independently and relatively effortlessly answer multiple-choice questions based on intentionally generated single-trial fMRI signals that can be decoded online. Our technique takes advantage of the participants’ capability to voluntarily influence certain spatio-temporal aspects of the blood oxygenation level–dependent (BOLD) signal: source location (by using different mental tasks), signal onset and offset. We show that healthy participants are capable of hemodynamically encoding at least four distinct information units on a single-trial level without extensive pretraining and with little effort. Moreover, realtime data analysis based on simple multi-filter correlations allows for automated answer decoding with a high accuracy (94.9%) demonstrating the robustness of the presented method.. (shrink)

We first heard about this case from nurses in one of our intensive care units while we were conducting an inservice. When the session was over, we discussed it between ourselves, and decided that it must have been misrepresented. The case had been presented as one of a teenager who was brain dead, had been so for six months, yet had been brought into the ICU for treatment. We have run into this before, we thought: medical professionals confusing (...) class='Hi'>brain death with persistent vegetative state. But, of course, we reasoned, no one can be brain dead for six months. To us, as it would to many, the case sounded like a clinical and ethical impossibility. A week later, we were called by an attending physician from another ICU, at the urging of that unit's nursing staff. They had a patient who was brain dead, whose presence was causing distress among the staff. Ronald Chamberlain, a fifteen-year-old boy, had been a patient at a nearby longterm rehabilitation facility that is equipped to care for ventilator-dependent patients. (shrink)

We first heard about this case from nurses in one of our intensive care units while we were conducting an inservice. When the session was over, we discussed it between ourselves, and decided that it must have been misrepresented. The case had been presented as one of a teenager who was brain dead, had been so for six months, yet had been brought into the ICU for treatment. We have run into this before, we thought: medical professionals confusing (...) class='Hi'>brain death with persistent vegetative state. But, of course, we reasoned, no one can be brain dead for six months. To us, as it would to many, the case sounded like a clinical and ethical impossibility.A week later, we were called by an attending physician from another ICU, at the urging of that unit's nursing staff. They had a patient who was brain dead, whose presence was causing distress among the staff. Ronald Chamberlain, a fifteen-year-old boy, had been a patient at a nearby longterm rehabilitation facility that is equipped to care for ventilator-dependent patients. (shrink)

Over the past several years, the study of self-related cognition has garnered increasing interest amongst psychologists and cognitive neuroscientists. Concomitantly, lesion and neuroimaging studies have demonstrated the importance of intact cortico-cortical and cortico-subcortical connections for supporting high-level cognitive functions. Commissurotomy or “split-brain” patients provide unique insights into the role of the cerebral commissures in maintaining an individual’s sense of self, as well as into the unique self-representation capabilities of each cerebral hemisphere. Here we review empirical work examining (...) the integrity of self-related processes in patients with various disconnection syndromes, focusing on studies of self-recognition, ownership, and agency. Taken together, this body of work suggests that an intact corpus callosum enabling interhemispheric transfer is necessary for some, but not all types of self-representations. (shrink)

If a brain is uploaded into a computer, will consciousness continue in digital form or will it end forever when the brain is destroyed? Philosophers have long debated such dilemmas and classify them as questions about personal identity. There are currently three main theories of personal identity: biological, psychological, and closest continuer theories. None of these theories can successfully address the questions posed by the possibility of uploading. I will argue that uploading requires us to adopt a new (...) theory of identity, psychological branching identity. Psychological branching identity states that consciousness will continue as long as there is continuity in psychological structure. What differentiates this from psychological identity is that it allows identity to continue in multiple selves. According to branching identity, continuity of consciousness will continue in both the original brain and the upload after nondestructive uploading. Branching identity can also resolve long standing questions about split-brain syndrome and can provide clear predictions about identity in even the most difficult cases imagined by philosophers. (shrink)

Multiple Personality Disorder (MPD), now also known as Dissociative Iden- tity Disorder, raises many questions about the nature of persons, the goals of treatment, the suggestibility of patients, and the reliability of defendant reports of their own mental states. These issues become crucial when courts need to decide whether or not to punish a person with MPD who has committed a crime. This paper will explore that issue and propose a test of when people with MPD should (...) be held criminally responsible. (shrink)

A number of reports have suggested that patients who undergo deep brain stimulation may experience changes to their personality or sense of self. These reports have attracted great philosophical interest. This paper surveys the philosophical literature on personal identity and DBS and draws on an emerging empirical literature on the experiences of patients who have undergone this therapy to argue that the existing philosophical discussion of DBS and personal identity frames the problem too narrowly. Much of (...) the discussion by neuroethicists centers on the nature of the threat posed by DBS, asking whether it is best understood as a threat to personal identity, autonomy, agency, or authenticity, or as putting patients at risk of self-estrangement. Our aim in this paper is to use the empirical literature on patients’ experiences post-DBS to open up a broader range of questions - both philosophical and practical, and to suggest that attention to these questions will help to provide better support to patients, both before and after treatment. (shrink)

This study discusses the mind-body problem, arguing that the human person is best understood as an animal who is also spirit. Braine suggests that human beings should be described holistically, in the tradition of Aristotle and Thomas Aquinas. His final chapter explores a doctrine of immortality.

Based on previous studies implicating increased functional connectivity within the self-referential brain network in major depressive disorder (MDD), and considering the functional roles of three distinct modules of such brain net (responsible for three-dimensional components of Selfhood) together with the documented abnormalities of self-related processing in MDD, we tested the hypothesis that patients with depression would exhibit increased connectivity within each module of the self-referential brain network and that the strength of these connections would correlate positively (...) with depression severity. Applying the electroencephalogram (EEG) operational synchrony analysis to extract three modules of the self-referential brain network in 12 medication-free depressive outpatients and 10 control subjects we have found an increase in the strength of EEG synchrony within all three modules in depressive patients (though non-significant for the right module). Furthermore, multiple regression analysis that used 3 factors (values of synchrony strength for all three modules) as input indicated that combined increase in the strength of synchrony in all three modules was positively associated with severity of depression. Taken together the findings of this study suggest that depression is primarily associated with hypersynchrony in all three modules of the brain self-referential network (the anterior module been responsible for “witnessing observation and first–person perspective”, the left posterior module been responsible for “reflective agency and narration” and the right posterior module been responsible for “bodily representational-emotional agency”), thus contributing to excessive self-focus, rumination, and body tension. (shrink)

Riassunto: L’esperienza cosciente sembra essere un soggetto di studio elusivo per la ricerca neuroscientifica. Tuttavia, da un punto di vista operazionale e neurocognitivo, l’esperienza cosciente può essere vista come una collezione di eventi inseriti in una cornice bidimensionale. Una dimensione è relativa al livello di vigilanza o grado di veglia, l’altra dimensione è relativa ai contenuti esperienziali, gli oggetti della nostra consapevolezza fenomenica. A dispetto della variabilità di queste due dimensioni, il senso di unità cosciente sembra essere di norma profondo, (...) reale e immediato. Nondimeno, alcune condizioni neurologiche avvalorano l’ipotesi che quest’unità sia il risultato di una costruzione operata da delicati e complessi meccanismi cerebrali. Si esamineranno pertanto, in una prospettiva neurocognitiva, i dati provenienti da alcune ricerche empiriche su pazienti affetti da epilessia, i risultati degli esperimenti condotti su persone split-brain e di minima coscienza, che dimostrano come l’esperienza cosciente si basi su un’organizzazione modulare del cervello. Parole chiave: Coscienza; Modularità; Livello; Contenuto; Epilessia; Split-brain; Stato di minima coscienza Modularity and Conscious Experience in a Neurocognitive Perspective: Conscious experience seems to be an elusive matter of study for neuroscientific research. From an operational and neurocognitive point of view, however, conscious experience can be considered as a collection of events within a bidimensional framework. One dimension relates to wakefulness or the level of arousal, the other dimension relates to experiential contents, the objects of our phenomenal awareness. The variability of these two dimensions notwithstanding, the sense of conscious unity generally appears to be deep, real and immediate. Still, certain neurological conditions provide evidence for the hypothesis that this unity may be the result of a construction achieved by subtle and complex brain mechanisms. Taking the neurocognitive perspective, I will examine data coming from empirical research on patients with epilepsy and present some results from experiments conducted on split-brain patients and individuals in a minimally conscious state, which show how conscious experience may be rooted in the modular organisation of the brain. Keywords: Consciousness; Modularity; Level; Content; Epilepsy; Split-brains; Minimally Conscious State. (shrink)