Transcranial magnetic stimulation, deep brain stimulation and personal identity: Ethical questions, and neuroethical approaches for medical practice

Abstract

Neurotechnology provides means to engage micro- and macrostructural networks of the brain to both mitigate the manifestations of several neurological and psychiatric disorders, and alter cognition and motoric activity. Such capacity also generates questions of how these interventions may affect personal identity. This paper discusses the ethical implications regarding changes to personal identity that arise from the therapeutic use of transcranial magnetic stimulation (TMS) and deep brain stimulation (DBS) technologies. In addition, we raise the question of whether changes in personal identity, as a side effect of these interventions, are ethically acceptable and whether such alterations of personality foster patients’ sense of well-being and autonomy. First, we provide a series of case vignettes that afford an overview of the ways that various neurological interventions can affect personal identity. Second, we offer a brief working definition of personal identity in order to delineate an ethical framework that we deem necessary for the responsible use of neurostimulation technologies. In so doing, we argue that neurostimulation therapy, as a doctoring act, should be directed, and adherent to goals of restoring and/or preserving patients’ personal identity. To this end, we offer an ethical framework that we believe enables sound decisions about the right and good use of TMS and DBS.

Introduction

Neurotechnology provides means to engage micro- and macrostructural networks of the brain to both mitigate the manifestations of several neurological and psychiatric disorders, and alter cognition and motoric activity. Such capacity also generates questions of how these interventions may affect personal identity. For instance, transcranial magnetic stimulation (TMS) and deep brain stimulation (DBS) have been employed for the treatment of depression, Parkinson's disease, tremor, and/or chronic pain, but are also known to enhance cognitive functions (Horstman, 2010; Ong, 2008). Neurostimulation technologies such as DBS have been shown to produce changes in demeanour and character traits in those patients undergoing the procedure (Hildt, 2006). The range of effects produced by TMS and DBS foster speculation about the problem of unintended consequences in general, and more specifically, the ways these neurotechnologies may affect patients’ personal identity. This paper discusses the ethical implications regarding changes to personal identity that arise from the therapeutic use of TMS and DBS technologies. In addition, we raise the question of whether changes in personal identity, as a side effect of these interventions, are ethically acceptable and whether such alterations of personality foster patients’ sense of well-being and autonomy.

In the following we will first provide a series of case vignettes that afford an overview of the ways that various neurological interventions can affect personal identity. Second, we will offer a brief working definition of personal identity in order to delineate an ethical framework that we deem necessary for the responsible use of neurostimulation technologies. In so doing, we argue that neurostimulation therapy, as a doctoring act, should be directed and adherent to goals of restoring and/or preserving patients’ personal identity. To this end, we offer an ethical framework that we believe enables sound decisions about the right and good use of TMS and DBS.

Changing personal identity: some illustrative cases

As the following cases demonstrate, alteration of brain structure and/or function can produce significant changes to personal identity. The first case describes a classic example of traumatic insult to brain structure (i.e. Phineas Gage); the second illustrates changes to personal identity following the purposive manipulation of brain structure (i.e. lobotomy) to mitigate psychiatric signs and symptoms; the third case (i.e. Sonia) exemplifies the modification of personal identity through the use of psychotropic drugs; and the last case (i.e. Charles Garrison) depicts how the use of neurostimulation technologies to alleviate the signs and symptoms of Parkinson's disease can affect character traits and personal identity. It should be noted that these cases are only illustrative and we do not delve into finely grained examination of their respective details. Rather, our intent is to use these cases to present examples of the variety of ways that altering brain structure can affect functional characteristics, inclusive of higher order cognitive activity, that are contributory to, and manifest in personality traits and personal identity. These exemplar cases provide a basis for the depiction, assessment and discussion of those ethical issues generated from any alteration of brain function that would incur change to features of personal experience and identity. We shall address the use of TMS and DBS as specific examples of neurotechnologies that alter brain function, and in so doing may afford both a starting point for further inquiry, and perhaps a template for casuistic neuroethical analyses.

Phineas Gage

Phineas Gage was a 25-year-old railway worker who, in 1848, suffered damage to his left frontal lobe when a tamping iron pierced his skull. The iron rod penetrated his left cheek, transited his anterior cranial vault, and exited the top of his head. Surprisingly, his mental capabilities and memory remained intact and he could, after appropriate care, continue to function normally and work. However, the incident affected Gage's demeanour and he underwent a dramatic personality change. Once a gregarious individual, he became increasingly deceitful and short-tempered. The report of his physician, J.M. Harlow, describes this change:

His physical health is good, and I am inclined to say that he is recovered ... The equilibrium or balance, so to speak, between his intellectual faculty and animal propensities, seems to have been destroyed. He is fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires, at times pertinaciously obstinate, yet capricious and vacillating, devising many plans of future operation, which are no sooner arranged than they are abandoned in turn for others appearing more feasible. A child in his intellectual capacity and manifestations, he has the animal passions of a strong man. Previous to his injury, though untrained in the schools, he possessed a well-balanced mind, and was looked upon by those who knew him as a shrewd, smart businessman, very energetic and persistent in executing all his plans of operation. In this regard his mind was radically changed, so decidedly that his friends and acquaintances said he was ‘no longer Gage.’ (Harlow, 1868, pp. 327–346)

One explanation of this change of personality has been attributed to the location of the injury, i.e. the frontal lobe, which has been shown to function in, and be contributory to psychological features of personal identity (Rabins & Blass, 2009, p. 42). But more importantly, Harlow's notes suggest that the radical change in Gage's cognition, demeanour and actions were so radically distinct that he was no longer the same person.

Lobotomy

During the early part of the 20th century lobotomies were frequently performed to treat various psychiatric conditions (Shutts, 1982). The procedure consisted of severing the neural pathways of the frontal lobes in order to produce behavioural and personality change. Walter Freeman and James W. Watts pioneered in the development of the procedure, and reported that several lobotomized patients showed changes in personality inclusive of periodic hypersexuality and hyperphagia. One patient attempted to intercourse with his wife up to six times per day which ‘at times … caused some embarrassment to his wife, and also to his parents with whom he lived, by indulging in rather frank sex play in the home or in the automobile’ (Shutts, 1982, p. 103). Freeman and Watts also noted that ‘in the early [postoperative] stages patients will quite often continue to eat as long as food is given to them…vomiting seems to make no difference, and we have seen patients vomit into their soup plates and start eating out of the plate again before the nurse can take it away’ (pp. 103–104). While the intent of the procedure was therapeutic, the side effects produced changes in personality and demeanour that were clearly problematic. From a current perspective, the practice of lobotomy, routinely performed between the 1930s and 1950s, can be seen as a dark episode in the history of psychiatry. The development and FDA approval of the drug chlorpromazine (Thorazine) during the early 1950s rendered lobotomies obsolete (Healy, 2002), and at the same time initiated the psychopharmacological turn that continues to strongly influence the contemporary profession and practice of psychiatry. Moreover, the reliance upon, and limitations of neuropsychopharmacology have, in many ways, been the impetus for the development of neurotechnological approaches to diagnosing and treating neuropsychiatric disorders (Giordano et al., 2010; Giordano & Schatman, 2011; Patil & Giordano, 2009).

Psychopharmacology

The use of psychopharmacological agents, while directed at reducing the signs and symptoms of a variety of neuropsychiatric conditions, can also affect patients’ character traits and personality. For example, methylphenidate (Ritalin) is commonly prescribed for the treatment of attention deficit disorder (ADD), yet also has been shown to increase concentration and intellectual performance in non-ADD-affected individuals (Glannon, 2008). Modafinil (Provigil), prescribed for narcolepsy and sleep apnea, increases alertness and enables sleep privation in healthy individuals (Merkel et al., 2007). The cholinesterase-inhibitor, donepezil (Aricept), is clinically used to delay the progression of cognitive symptoms of Alzheimer's dementia, but also augments the cognitive capacities of healthy subjects (Yesavage et al., 2002). Most specifically, as shown in the illustrative case below, the selective serotonin reuptake inhibitor, fluoxetine (Prozac), widely used to treat depression, can also enhance mood (Glannon, 2008), alter subjective experience, and affect personal identity. Peter Kramer has documented the effect of fluoxetine on the character traits and personalities of some of his patients, as presented in the case of Sonia:

Sonia is a talented graphic artist referred to me by a social worker for medication consultation concerning her minor depression. My first impression, on meeting Sonia, was of what might once have been called an ethereal young woman. She had that vague, hesitant habit of speech sometimes characteristic of artists … For Sonia, even mild depression carried some urgency, because other members of her family had suffered serious mood disorders. I started her on Prozac, and the depression lifted … She became more energetic and more assertive socially than she had been in the years before the onset of her depressive symptoms … She became more fluent of speech, more articulate, and better focused … I was able in time to withdraw the medication. In the ensuing months, Sonia reported that she was not quite so sharp, so energized, as she had been on Prozac. (Kramer, 1997, p. 237)

This case illustrates the potential dilemma clinicians might encounter when prescribing psychotropic drugs, in general. To be sure, the drug was efficacious and effectively alleviated depressive symptoms. However, the drug also changed the patient's personality. This prompts questions about the inauthenticity (i.e. ‘the alienation from one's true self’ (Glannon, 2008, p. 46)) of the resultant clinical outcome, and the alteration of personal identity incurred by and through the use of substances and technologies that affect those brain substrates that have been implicated to function in the formation, experience and expression of personality. On a somewhat broader level, this raises questions about how any intervention affects brain function (given that downstream and/or runaway effects of these novel therapeutics are as yet unknown, and may be unanticipated). Such questions demand closer scrutiny and consideration, particularly within those clinical contexts in which patients specifically request certain interventions to (directly or indirectly) alter the cognitive capabilities and/or emotional characteristics that are fundamental to their persona and identity (Geppert & Taylor, 2011).

Neurotechnologies – deep brain stimulation

Currently there exist at least 13 forms of brain stimulation techniques that are either under development or in evaluation for applications to treat neurological and psychiatric conditions (Higgins & George, 2009, p. xiii). These neurotechnologies are distinct from psychopharmacology (or psychotherapy) in that a device is used to stimulate brain regions in an attempt to elicit therapeutic improvement of particular mental states and/or psychiatric conditions (e.g. depression; see Mayberg et al., 2005; Rush et al., 2000), cognitive function (e.g. Alzheimer's; see Laxton et al., 2010) and/or neurological disorders (e.g. Parkinsonism; see Benabid et al., 2005, 2009; Rosenow et al., 2004). Of these neurotechnologies, deep brain stimulation offers a therapeutic option for Parkinsonism by utilizing implanted microelectrodes to regulate the network properties of the basal ganglia, thereby restoring the function of striatal mechanisms involved in the extra-pyramidal control of movement (Plaha et al., 2006). However, it should be noted that brain loci are not unitary in their function (Bennett & Hacker, 2003), and changing the network activity of the striatum can affect the properties of afferent and efferent pathways to induce functional changes elsewhere in the brain, that incur a variety of neuro-psychiatric effects, including those cognitions, emotions and behaviours that constitute personality and identity as illustrated by the following case:

Charles Garrison is a 61-year old man with moderately advanced PD [Parkinson's disease] who was referred for DBS [deep brain stimulation] treatment. Before developing PD, Mr. Garrison was a successful engineer for a military research firm. He rose through the ranks to become the director of aeronautics research, earning a reputation for diligence and conscientiousness. He was quiet, matter-of-fact, and somewhat shy, but always energetic and enthusiastic about new ideas at work…He was married with three children and spent all of his free time with his family, who shared his enthusiasm for ideas and experimentation … His neurologist diagnosed an apathy syndrome related to PD, and psychiatric consultation gave a concurring result, finding no evidence of depression or cognitive impairment…Following implantation of the DBS, Mr. Garrison had significant improvement in his motor symptoms. More dramatic, however, was the change in his personality and demeanor … Mr. Garrison now became extremely outgoing and gregarious … Mr. Garrison went on to develop not only a new demeanor but also a new outlook on the world. Previously a loyal Republican, he switched his affiliation to the Democratic Party. He became an ardent environmentalist, traveling to numerous conferences and insisting (over his wife's objection) on giving all of their charity donations to environmental causes. (Mathews et al., 2009, pp. 58–59)

Clinical findings describe DBS patients who have experienced changes in personality and rediscover ‘a joie de vivre’ or ‘a drunkenness, a very short euphoria’ after undergoing treatment (Funkiewiez et al., 2004; Gabriëls et al., 2003; cited in Hildt, 2006).¹ While incidental to the therapeutic intent of the procedure, these effects raise the possibility that DBS may be used ‘off label’, or might be further developed to specifically elicit change(s) in personality and/or subjective experience of self (i.e. personal identity). Such a trajectory of use is neither impossible nor improbable, given current trends in research, and the socio-economic forces that influence the scope and nature of neurotechnological intervention (Giordano & DuRousseau, 2011).

Personal identity

The case vignettes presented provide what we consider to be prototypic examples of possible changes in personality and demeanour resulting from alteration of brain structure and function. By intent, these cases afforded an iterative depiction of differing ways to affect the brain to alter personality and personal identity. While Gage was an explicit example of an occupational accident, we suggest that cases of lobotomized patients, Sonia, and Mr. Garrison might be similarly regarded, albeit more implicitly. In each case, the incurred change in personality was a side effect of some other event that altered the structure and/or function of the brain. Accidental? Perhaps; but mythology and history provide abundant object lessons about the power of accidental discovery, the lure of both such novelty and power, and the potential benefits and risks involved with venturing into terra incognita.

Gage has become the ‘poster child’ for the relationship of brain structure to personality. Knowledge gained from his case was instrumental to the theoretical and technical development of lobotomy. The cases of Sonia and Mr. Garrison illustrate how iterative trends in attempting to achieve specificity and precision of therapeutic effect(s) can, and often do generate effects that stimulate new tool-to-theory heuristics, that subsequently generate theory-to-tool research and applications. Arguably, this represents the nature of inquiry and discovery, and the ethics of research and clinical medicine address much of this territory. However, the issues of brain research and neurotechnology are in some ways unique in that the effects and side effects of neuroscientific and neurotechnological intervention directly reflect perdurable questions about, and affect fundamental aspects of the human condition, such as consciousness, sentience, and constructs of the self, autonomy and identity.

Indeed, we have argued that the validity and value of the neuroscientific techniques utilized to assess and access the brain, the ‘meaning’ of the information we obtain, and how such information is engaged to affect individual and social conduct are all critical to consider, given the pace and scope of neuroscientific research and neurotechnological development and application(s). Moreover, we have opined that ‘like it or not, we must often act even though we have limited and incomplete information with which to leverage epistemological capital in enacting decisions of ethical, legal and/or social importance’ (Giordano, 2010b).

In the remainder of this paper we address and attempt to analyze what we believe to be key issues arising from the use of TMS and DBS relative and relevant to changing patients’ personal identity. We limit this discussion to ‘on-label’ clinical contexts and purposely do not discuss issues surrounding off-label applications and non-therapeutic use, as these have particular ethical (and legal) constraints that are not applicable to our discussion (instead, for example, see Giordano & DuRousseau, 2011). And finally, we offer a practical framework that we believe enables the use of multiple ethical approaches to intuit key neuroscientific issues and guide the technically right and morally sound use of TMS and DBS.

Defining personal identity

Here, we use the concept of personal identity as a comprehensive concept of human existence. In order to effectively bring to the fore the ethical issues arising from technologies that affect personal identity, we need first to define this concept so as to operationalize its subsequent use. To be sure, this definition is not all-encompassing, and others exist which may reflect certain philosophical perspectives (see for example, Penelhum, 1967). However, for the purpose of the present discussion we employed a definition that offers a pragmatic view that entails sufficient philosophical breadth to sufficiently frame the issue, and ground any discussion.

Accordingly, personal identity includes the biological and psychosocial aspects of human development and experience. Crucial to this concept is the notion of embodiment. The body of a biological organism constitutes the medium through which the realities of time and place are experienced and interpreted (Costa, 2010; see also Merleau-Ponty, 1945). For humans, one's personal notion of self (i.e. personal identity) constitutes what Jennifer Radden calls an ‘embodied repository of integrated psychological states’ (Radden, 1996, p. 11, our italics). This means that (under non-pathological conditions) a person experiences, through the medium of the body located in time and space, a variety of events that define his or her sense of self – what Radden refers to as the ‘unity of the self’ (p. 11).

To establish that the body is the repository for a person's psychological states does not address the question of the connectedness between bodily states and inner mental states. In other words, how does the brain∼mind arrange various stimuli in a coherent manner to shape one's personal identity? Responses to this question could span the gamut from the neurophysiological (e.g. Churchland, 1990; Damasio, 1999; Edelman, 2004; Llinas, 2001) to the neuropsychological (e.g. Baars, 1997; Jackendoff, 1994; Prinz, 2005) to the ‘purely’ philosophical (e.g. Heidegger, 1962; Jaspers, 1949; Merleau-Ponty, 1945). Each have considerable merit, and we believe that any meaningful address of the question would obtain elements of all of these (and related) perspectives. While the interested reader is encouraged in this pursuit, we offer here what we believe to be a somewhat middle ground approach – that of John Perry's ‘person theory’ – that allows for speculation in the neuroscientific, psychosocial and philosophical domains. Of course, we recognize that this work has been criticized as being overly simplistic, or vague in its treatment of the complexities fostered by neuroscientific address of the proverbial mind-body problem. Yet, as a starting point, Perry's thesis may provide a viable groundwork upon which to base a description and definition of possible characteristics and substrates of identity, and serve as a basis for further inquiry.

Perry contends that his approach does not represent a scientific theory, per se, but rather is a descriptive analysis of how mental states are organized, shape behaviour and establish a sense of personal identity. Perry's person theory is comprised of five principal elements. First is intentionality; this refers to those psycho-physiological states that determine the lived body's location in space and time, and that engage interpretation of external and internal events in order to establish beliefs and ideas about the world. The second feature, local rationality, defines humans as rational agents who are expected to make choices in accordance with, and in order to advance their beliefs and ideas. The third element is respect for autonomy – a descriptive and prescriptive concept that establishes the ethical foundations upon which to base treatment of self and others. The next feature of the person theory is identity: what describes individuals and their personal character traits, specific aspirations and goals. The last element is the formal notion of self, not as an object, but rather a reflective ability that both concretely and abstractly enables conceptualizations of one's ‘self-notion’ (Perry, 2009). For Perry, these five features allow individuals to construct personal identities; when they break down he contends that the ability to understand self and others likewise diminishes (Perry, 2009, p. 130). This last point may be of value for discussions of the possible ethico-legal and social effects and implications of those neurotechnologies that directly or indirectly affect/alter personal identity.

Modification of character traits and disruption of personal identity

Disease, traumatic events, technological devices and therapeutic intervention(s) may change, if not de-construct/re-construct, one's sense of personal identity by altering the lived body. If and when this occurs people must learn to ‘redraw relationships between self, body, environment, and daily life’ (Becker, 1999, pp. 81–82). It should be noted that this sense of personal integration is far from perfect. Each person experiences a certain disharmony or disunity as he or she faces and engages the events of everyday life (Becker, 1999). However, the lack of coherence if sufficiently profound, and/or if over a sufficiently long period of time, can create a new or ‘diminished and fractured sense of self’ (Perry, 2009, pp. 140, 148). While neuropsychiatric disease and trauma can be viewed as inherently de-constructive to this notion of self (Scarry, 1985; Toombs, 1992; Zaner, 1981), issues get provocative, if not contentious, when treatments rendered to mitigate the negative effects of these conditions produce effects that are seemingly adverse.

While the problem of the ‘cure being worse than the disease’ is not a ‘new’ problem in clinical medicine (Goodman, 2003), it does assume a certain gravitas when dealing with neuropsychiatric interventions, given (1) the extent to which neuroscientific and neurotechnological approaches can potentially alter fundamental characteristics of consciousness, subjective experience and identity; (2) the intersecting unknowns of neuroscience and the mechanisms and effects of various neurotechnological interventions (vide infra); (3) the strong influence of the market over the development and use of neurotechnological tools and interventions; (4) the speed and extent of such developments, and (5) the ethical, legal and social issues engendered by the concatenation of these effects (Giordano, 2010a, 2011a, 2011b, 2011c; Giordano & DuRousseau, 2011; Giordano et al., 2009, 2010).

Preserving the integrity of personal identity

But let us not be naïve. The aforementioned practical problems are not – nor should not be – grounds for simply discontinuing neuroscientific and neurotechnological research or the translational applications of such work. As matter of fact, we have argued that research must be expanded to not only address possible technical issues, but the ethico-legal and social questions and problems that could be consequential to the proposed uses of neuroscience and technology in medicine (as well as public life, and national security and defense (Giordano, 2011a, 2011b)). As we advance the frontiers of neuroscientific and neurotechnological capability, so too do we challenge philosophical foundations and ethical boundaries that define and guide the utility and use of these tools and approaches in society. What should be done if and when an intervention not only mitigates pathological signs and symptoms, but produces change in personality traits and personal identity? There is evidence that neurostimulation procedures affect (at least certain aspects of) personal identity. However, it is unclear whether these changes will be necessarily negative or positive. Thus, important major questions might be whether neurotechnologic interventions such as TMS or DBS threaten, diminish or consolidate personality identity, and/or whether and how such effects demonstrably affect the patient, as well as her family and relationships. For instance, we might ask whether Mr Garrison warrants further DBS treatment given that the change in his personality was disruptive to his marriage. Who shall be the judge of these effects, and what ethical constructs might be best suited to direct such decisions?

This is not a straw man argument. While we acknowledge that negotiating the benefits, risks and burdens of any intervention is axiomatic to clinical decision-making, we opine that two major points that arise from the unique nature of neuroscience define the peculiarity of decisions about the use of advanced neurotechnologies, such as TMS and/or DBS (Giordano, 2010a, 2011a, 2011b, 2011c). First is that at present, an understanding of efficient causality of consciousness (inclusive of manifest complex cognitions such as the self and personal identity) remains tentative at best, if not lacking altogether. Simply put, we are still perplexed by Chalmers’ proverbial ‘hard questions’ of neuroscience (Chalmers, 1996), and as a result, any attempts to concretely define the neural mechanisms subserving conscious processes are little more than hypothetical. Second, and related to the first, is that at least to some degree, we have only partial or speculative understanding of the actions of many neurotechnological interventions, inclusive of TMS and DBS. To re-iterate, this intersection of unknowns complicates prediction of effects and side effects, calculation of benefits, burdens and risks, and thus makes any decision to employ these techniques and technologies in clinical care all the more difficult, for patients as well as physicians.

Prima facie, given that the impact of care would be upon the life world of the patient, it might be assumed that the patient would or should be the final arbiter of any such decision. However, if the patient is not insightful about the effects produced by such treatment (due to either (a) persistent uncertainties of the field that affect how completely informed any patient might be about those variables affecting their consent to be treated, (b) manifestations of her neuro-psychological condition, or (c) a combination of both of these factors), then this metric would not be valid. Furthermore, insight does not necessarily imply good judgement, and given (a) to (c) above, the patient's insight and judgement might not be sufficient to intuit how treatment-induced changes could affect their family, friends and personal and professional interactions. As Gabriëls and colleagues report, a husband whose wife received DBS for obsessive–compulsive disorder claimed that ‘when stimulation is switched ON, she changes and improves suddenly, but we (i.e. her family) don't have a similar button that can be pressed to adapt at once to this new person’ (Gabriëls et al., 2003, p. 278 cited in Hildt, 2006).

Perhaps then, the physician is ultimately responsible for assessing the benefits and burdens of a neurotechnological intervention, given that these therapeutics are afforded under the aegis of medical care. Yet, this too does not represent a straightforward decision process. If we assert, for example, pro-Pellegrino, that the ultimate ends of such care are the provision of those interventions that are both technically right and ethically good, then how shall (and should) the relative good of health provided by any such interventions be judged? The concern is not with the idea of change, per se. After all, individuals change over time as a consequence of age, dealing with the vagaries of life and, in some cases, the effects of disease, trauma and illness. In this latter regard, therapeutic interventions are aimed at preventing and/or reversing any negative changes, by restoring health and normalizing particular functions. To these ends, neurotechnological interventions ought to be rendered so as to restore the patient's state of health prior to the occurrence of the disorder (at least as much as possible) by normalizing brain functions (Hildt, 2006).

But here we confront ambiguities in (1) the definition of normality, (2) the nature of disorder, and perhaps on a more profound level, (3) what neuroscience can offer to both these concepts, if not the medical model of psychiatry in general (Patil & Giordano, 2009). Thus, in order to resolve clinical equipoise, the decision to use TMS or DBS would not only need to be evaluated using some version of the maximin principle (e.g. a decision algorithm that maximizes expected benefits while minimizing possible burdens and harms, or maximizes the possible welfare of those who are the least well off), but would also need to recognize what and how benefits and harms are manifest and framed, given the ethical, legal and social implications of neuro-psychiatric categorizations of health and illness, norms and abnormality. If the imperative is to restore health, and do so in accordance with, and toward some concept of normality, then any change in personality and/or personal identity that occurs as a consequence of the treatment would need to be regarded as consistent with both this goal and these definitions in order to be acceptable. How might the philosophical and practical constructs of neuroscience and medicine be aligned so as to establish an applied ethical framework to guide decisions about the use of these neurotechnological interventions, in ways that reflect and appreciate the epistemological shifts, and social fiduciary of both science and clinical care?

Toward an ethical framework

We posit that any ethical framework to define and guide the use of neurotechnology must begin with recognition and acknowledgement of the realities of neuroscience: namely, that the ‘facts’ and ‘truths’ of this field are iterative, contingent, and rapidly changing. This establishes an epistemological foundation for not only neuroscience, but those fields that utilize the outcomes and products (such as neurotechnology) of neuroscientific research in their endeavours. Hence, consideration of the (contingent and changing) nature of this epistemological capital is fundamental to the ways that this knowledge is translated and employed within those medical disciplines that are based upon neuroscience, and utilize its concepts, techniques and technologies in practice (e.g. neurology, psychiatry, pain medicine, physical medicine and rehabilitation; although given the prevalence of a somewhat neurocentric trend throughout science and society, this might also affect the general Weltanschauung of medicine, to some extent).

We hold that these realities establish a broad and generalizable set of duties and obligations that are both inherent to the professions of neuroscience and the medical disciplines structured thereupon, and essential to any/all who enter these fields (Giordano, 2010a). This deontic structure sets forth particular premises based upon the epistemology of the profession, and focuses this epistemology within the anthropological domain as a human endeavour (i.e. acquisition of knowledge and capabilities) to be used by humans, for purposes of advancing human flourishing and diminishing the human predicament of disease, illness and suffering (Maricich & Giordano, 2009). In this latter regard, the tasks of medicine become readily apparent, and the use of neuroscience in medicine thereby aligns the realities of science with those of clinical care.

This allows the veridical claims of the profession – what medicine, in general, and those specific disciplines that translate neuroscientific research into practice, more specifically, can realistically exert to be the working knowledge and capabilities that can be leveraged to promote and sustain healing. Without doubt, neurotechnologies such as TMS and DBS may benefit many patients suffering from various debilitating neurological and mental disorders. But to ascertain the nature and extent of such benefit requires discernment of technical rectitude (i.e. how to best use these technologies to exert specific effect), and relative good. Here we must question which good(s) are representative of patients’ best interests. Edmund D. Pellegrino and David C. Thomasma (1981; 1993) assert that the good of clinical care is quadripartite: most proximate to the physicians’ fund of knowledge and expertise is the biomedical good, but any applications of supposedly good acts and resources must be rendered in ways that are appreciative and supportive of more patient-centred contexts, namely the good for the patient's choices, his or her being as a person, and his or her existential nature as a human. Defining these latter contingencies requires a subjective engagement of the patient in order to assess his or her values and goals, and distinct approaches have been proposed towards such ends (see, for example Fulford's (2004) notion of values-based medicine, and Waters and Sierpina's (2011) construct of goal-directed health care).

But such engagements occur between individuals as moral agents, and thus, the profession of medicine is ultimately enacted as a practice – an exchange of good(s) as prescribed by the relationship of the agents in interaction (MacIntyre, 1999). Edmund D. Pellegrino and David C. Thomasma formulate five imperatives characteristic of the medical encounter: (1) the inequality of the medical relationship between the patient and the physician that places the former in a state of vulnerability and dependence; (2) the fiduciary nature of the relationship which requires the absence of manipulation and trust as foundational to the patient–physician relationship; (3) the moral nature of medical decisions – most treatment decisions combine technical and moral components; (4) the nature of medical knowledge – medical knowledge imposes particular ethical obligations on those who possess it and use it; and (5) the ineradicable moral complicity of the physician – the clinical encounter requires the collaboration of both the patient and the physician (Pellegrino & Thomasma, 1993).

A number of ethical systems and approaches can be employed to articulate and uphold the moral probity of clinical agency, and a complete discussion of the relative merits, limitations and problems of each is beyond the scope of the present work. Suffice it to say that some degree of utilitarian perspective is required in order to discern whether and how particular techniques and technologies can and should be used to produce outcomes that maximize a patient's best interests. Certain incised intellectual and moral traits and skills (i.e. virtues) may be critical to any such assessments and discernment. But given the aforementioned asymmetries of knowledge and power in the medical relationship, and the strongly anti-paternalistic posture of contemporary society, any employment of intellectual and/or moral skills would necessitate cooperation and deliberation with the patient, so as to ascertain his or her values and goals that are important to resolving equipoise in ways that not only reflect the rectitude and effectiveness of a given intervention, and do so in ways that respect patient autonomy, and are influential to the just distribution of the resources and services necessary for care. This would imply a discursive approach that would require at least some measure of cosmopolitanism so as to enable sensitivity and responsiveness to the multiplicity of moral values and personal and cultural ideologies that are present within the increasingly pluralist contemporary society in which patients are situated and medicine is engaged.

In this light, it has been proposed that neuroethics might offer a new – and meaningfully contemporary – approach to analysing and articulating decisions about the use of neuroscience and neurotechnologies (Giordano, 2010a,2011; Levy, 2011; Racine, 2010). Of course, this position is not without contention, and counter arguments have posed that (1) neuroethics is really just classical ethics applied to issues and questions of neuroscience and its applications, (2) the field is an unnecessary specialization within an already over-specialized if not narrow use of bioethics, and (3) it is an amalgam of diverse philosophical and ethical issues that have been artificially and superficially codified so as to establish disciplinary solidarity (see Racine, 2010, for an overview). While we freely admit that neuroethics is indeed a form of ethics, and as such employs a basic methodological approach common to any ethical analyses, and that it is viably construed as a branch of bioethics, particularly in its naturalistic orientation and multi-disciplinarity, we argue against those claims of the superficiality or artificiality of the field (Giordano, 2011a, 2011b, 2011c). We base this argument upon the premise that neuroscience affords a unique set of epistemological and anthropological uncertainties, questions and problems, and thus the ethical issues arising from any study or application of neuroscience will reflect these challenges. Moreover, neuroscience is changing what we know about the human organism and condition, the ways that we can control and manipulate the human brain (if not the human being), and the social structures and conventions that are built upon these constructs and instantiations of nature and humanity.

It is through this lens that we once again view the issue of neurotechnology and personal identity. It may be that neuroscience will allow a more pragmatic and thorough examination and description of the concept of identity, and in this way, provides a meaningful basis upon which to direct ethical inquiry and guidance. At present, however, such a complete description of these neurological substrates is lacking, and so any pragmatically inclined (neuro)ethical analysis must be based, and rely upon the facts at hand. For this reason, we conclude that some construct of personal identity as defined by the patient to be genuine and authentic (in congruence with their family and relationships) should be attempted to be preserved, restored or recovered when administering neurostimulation procedures such as TMS and DBS. These procedures raise at least three main concerns which we briefly outline. First, there is the problem of manipulation. The ability to switch off and on mental and mood states impact family and social relationships but might also affect neural structure with unforeseeable consequences. Second, as pointed out, personal identity entails a sense of autonomy, i.e. a self. However, the use of neurostimulation creates a state of dependence for a particular mode of existence that does not foster the autonomy of the patient (see Gabriëls et al., 2003). Finally, neurostimulation affect the patient's rationality, that is, the ability to advance his or her beliefs and ideas. The case of Mr Garrison is indicative of a shift in life that should raise concerns, especially considering the source of the change (i.e. deep brain stimulation) which profoundly impacted his beliefs and ideas and his marital relationship.

In sum, the potential for change in personality should be evaluated, with particular emphasis upon whether any negative effects would be reversible upon terminating the treatment (e.g. – during the early phases of TMS, or by removal of DBS electrodes), or recuperable through administration of secondary interventions. In those cases in which therapeutic alterations of neurological function pose real and identifiable risk of durably affecting personal identity, a multi-dimensional calculus of some form of maximin principle should be attempted, in which the therapeutic benefit achieved would render forgivable the side effects of identity change or loss.

Concluding remarks

In conclusion, neuroscience and neurotechnology may one day allow a clear(er) depiction of those specific substrates and mechanisms that are involved in and/or subserve higher, complex cognitive processes such as personal identity; but we are not yet to that point. We can, however, currently engage neuroscience and neurotechnology to mitigate the effects, signs and symptoms of a number of debilitating neuro-psychiatric disorders. Still, no treatment is without at least the potential for side effects, and the novelty and nascence of neurotechnological interventions (e.g. TMS and DBS) is such that possible burdens and risks may not be fully apparent. It may be that the only way to fully assess these possibilities is to proceed with their use in clinical care, not in a cavalier way, but with an awareness of such contingencies that serves to fortify the need for, and stringency of preparedness and practical wisdom as core features of a pragmatically sound neuroethics.

Note

1. Clinicians reported cases ‘When stimulation was deactivated for motor evaluation, the patient immediately felt overwhelming sadness, dissolved into tears, and experienced a progressive reappearance of severe Parkinsonism. When describing the impact of treatment, she said, ‘If stimulation is switched off, I am dead; when on, I am alive. With medication on top, it's happiness and well being.’ In another case the patient said, ‘I never before had such energy, neither motor nor intellectually. I rediscovered the joie de vivre, pleasure, laughter.’ He compared this state with his honeymoon at the onset of action of levodopa: ‘With drugs, I had lost control; it was not joy but a drunkenness, a very short euphoria, which was not my own’ (Funkiewiez et al., pp. 837–838).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.