2.2.1 Psychological Continuity

In an influential contribution to the contemporary debate on the adequacy of human rights protection of our brains and minds, Ienca and Andorno make a case for reinforcing this protection, through the creation of specific “neurorights”.Footnote ⁸ Among other things, they argue for recognising a right to psychological continuity, as “a special neuro-focused instance of the right to identity”.Footnote ⁹ Part of their motivation for arguing this is that emerging neurotechnologies that stimulate and modulate human brain functions – such as tDCS, TMS and DBS – have the potential, in their words, to “cause alterations in mental states critical to personality (…) thereby affecting an individual’s personal identity”.Footnote ¹⁰ Some of these brain stimulation techniques are currently used in day-to-day clinical practice, for example, to treat neurological disorders such as Parkinson’s disease and epilepsy.Footnote ¹¹ Moreover, as mentioned in the introductory chapter, researchers are increasingly examining the potentials of brain stimulation beyond the context of standard medical care, including their use to reduce aggressiveness in forensic populations.Footnote ¹²

Ienca and Andorno highlight that changing a person’s brain functioning through brain stimulation “may have an impact on the psychological continuity of the person, i.e. the crucial requirement of personal identity consisting in experiencing oneself as persisting through time as the same person”.Footnote ¹³ They substantiate this claim by referring to reports of the experience of different kinds of self-estrangement after or during treatment with DBS or following implantation of a BCI.Footnote ¹⁴ Some patients reported, for instance, that BCI implantation “made me a different person”,Footnote ¹⁵ or that DBS treatment (in this case, for Parkinson’s disease) made them “feel like a machine”, reporting that “I’ve lost my passion. I don’t recognize myself anymore”.Footnote ¹⁶ Ienca and Andorno also cite studies that demonstrate that some individuals experience significant mental and behavioural changes as side effects following DBS – for example, increases in impulsivity and aggression, or changes in sexual behaviour – that may, in turn, and depending on the individual, cause them to experience self-estrangement and feel disassociated from themselves.Footnote ¹⁷

Ienca and Andorno’s claim that we ought to recognise a right to psychological continuity is also motivated by the expectation that the advent of brain stimulation techniques may open up possibilities for third parties to induce non-consensual personality changes. Brain implants like DBS bear the risk of being hacked by third parties aiming to exert malicious control over the user’s brain activity.Footnote ¹⁸ Furthermore, in some contexts (e.g., the military and criminal justice), we can anticipate that brain stimulation might be administered on a mandatory basis, given that mandated undertakings are a frequent feature of these contexts. Ienca and Andorno thus argue for the recognition of a right to psychological continuity in order to protect persons against the potentially adverse effects non-consensual brain stimulation might have on their identity. They understand this right as “ultimately tend[ing] to preserve personal identity and the coherence of the individual’s behaviour from non-consensual modification by third parties. It protects the continuity across a person’s habitual thoughts, preferences, and choices by protecting the underlying neural functioning”.Footnote ¹⁹

The idea of developing a right to psychological continuity to protect personal identity from unsolicited (neurotechnological) interferences by others has been picked up on by human rights treaty bodies, both in Europe and internationally. For example, in November 2019, the Council of Europe launched a Strategic Action Plan on Human Rights and Technologies in Biomedicine (2020–2025). One of the plan’s concrete action points is to assess the relevance and sufficiency of existing human rights in view of emerging threats posed by neurotechnology, including threats to personhood and psychological continuity. This plan noted the need to assess “whether new human rights pertaining to cognitive liberty, mental privacy, and mental integrity and psychological continuity, need to be entertained in order to govern neurotechnologies”.Footnote ²⁰A report commissioned by the Committee on Bioethics of the Council of Europe furthermore claims that a human right to psychological continuity would “offer solid normative ground to (…) preserve a person’s self-determination and sense of personal identity from subconscious manipulation”.Footnote ²¹ This report further adds that a right to psychological continuity “may become particularly important in the context of national security and military research, where neurotechnology applications that modulate personality traits (e.g., neurostimulation techniques) are currently being tested for combatant enhancement”.Footnote ²² Other human rights bodies have noted the nature of the concern that some neurotechnologies might pose to psychological continuity, as it is characterised by Ienca and Andorno. In their 2024 report on neurotechnology and human rights, the Advisory Committee of the UN Human Rights Council highlights that “[p]atients having undergone deep brain stimulation have reported feeling a changed sense of agency and identity; thus, ensuring ‘psychological continuity’ may be important”.Footnote ²³

We have been referring to “psychological continuity” as though the concept is widely known and understood. But while the concept of “psychological continuity” is familiar to ethicists and philosophers, it is not commonly invoked in human rights law. As Ienca explains, the concept is borrowed from a specific philosophical understanding of personal identity found in psychological-continuity views.Footnote ²⁴ One such view has been developed by John Locke. In developing his view, Locke’s focus is on accounting for what preserves numerical identity,Footnote ²⁵ or the persistence of a single entity over time.Footnote ²⁶ Numerical identity concerns whether, for instance, Norah at the age of forty (time t₂) is the same person as Norah at the age of twenty (time t₁). Scholars often address this question by referring to the physical or psychological relations that obtain between the relevant entities at t₁ and t₂. Locke’s account of personal identity appeals to a specific psychological relation. It appeals to the idea of “sameness of consciousness” – that is, that a person at time t₁ remains the same person at time t₂ if and only if they share the same consciousness at these two times.Footnote ²⁷ Locke is admittedly unclear about what sharing the same consciousness means. But his remark that “for as far as any intelligent Being can repeat the Idea of any past Action with the same consciousness it had of it at first (…) so far it is the same personal self”Footnote ²⁸ has led some to conclude that, by sharing the same consciousness, Locke means remembering.Footnote ²⁹ As Shoemaker phrases it, on one interpretation of Locke, “a person – a moral agent – Y at t₂ is identical to a person X at t₁ when Y’s consciousness ‘can be extended backwards’ to X, and this is typically taken to mean that YremembersX’s thoughts and experiences”.Footnote ³⁰

The idea that a person remains the same person if and only if they remember their earlier thoughts and experiences has faced various objections. One objection is that it produces some logically impossible results. To illustrate, take the case of an elderly man who remembers the events of his middle years while forgetting the events his physical self experienced in its youth, and suppose that, when in his middle years, the middle-aged man remembered the events of his youth. Here, we have a situation where – if persistence of the self consists in remembering or sameness of consciousness – the youth is the same person as the middle-aged man, the middle-aged man the same as the elderly man, but the youth is not the same person as the elderly man, and this cannot possibly obtain. Assuming that identity is transitive, we cannot logically have A being equal to B, and B being equal to C, without A also being equal to C.

A prominent contemporary approach to avoiding this objection involves amending Locke’s account such that memory plays a less central role in the preservation of identity across time, and other mental features such as intentions, goals, beliefs, desires and similarity of character also assume significance.Footnote ³¹ Arguably, the most influential psychological-continuity account that so amends the Lockean view has been developed by Derek Parfit.

Parfit argues that for X and Y to be the same person at different times, there must be an overlapping chain of enough – that is, strong – psychological connectedness between X today and Y sometime in the past or future.Footnote ³² So, for Norah to be the same person as the Norah that inhabited her body twenty years ago, she must have a sufficient number of overlapping psychological features like desires, beliefs and intentions that persisted from each day to the next over these twenty years. Such an overlapping chain of strong psychological connectedness across time is what Parfit calls psychological continuity; and for Parfit, such strong connectedness exists “if the number of connections, over any day, is at least half the number of direct connections that hold, over every day, in the lives of nearly every actual person”.Footnote ³³ Hence, if a person loses over half the psychological connections one has to themselves – when compared to the connections that obtain within other persons – psychological continuity, and hence numerical identity, will be disrupted, and a different person will come to exist. Note that numerical identity is binary: either the person continues or ceases to exist; either the person keeps or loses their identity.

A psychological-continuity account of identity has enjoyed majority support in philosophy.Footnote ³⁴ It has also been widely invoked in the ethical literature on brain stimulation techniques.Footnote ³⁵ Scholars in this literature raise the same concern as Ienca and Andorno about these techniques, again drawing on empirical data to motivate the idea that brain stimulation has the potential to disrupt psychological continuity. For example, Holmen argues that some mental features central to psychological continuity – desires, beliefs and memories – seem already malleable through both pharmaceutical and neurotechnological means, and if changes to these features were effected in a “sweeping” or sudden and widespread manner, then we would have a disruption of numerical identity.Footnote ³⁶ In the same vein, Vincent claims that there are “non-insignificant grounds to worry that direct brain interventions which implement large-scale changes in one fell swoop could sever psychological continuity”, highlighting that “mounting empirical evidence substantiates the worry that direct brain interventions might have adverse effects on such things as authenticity and personal identity by significantly altering character and personality”.Footnote ³⁷

Klaming and Haselager also conclude that brain stimulation techniques, specifically DBS, could disrupt psychological continuity and identity.Footnote ³⁸ They discuss a study involving a patient who underwent DBS that successfully treated his Tourette’s syndrome but who, twelve months following implantation of the DBS device, developed a dissociative response under certain stimulation amplitudes, wherein he seemed disconnected from himself and his identity.Footnote ³⁹ The patient developed an alternate, childish identity state when the amplitude of the brain stimulation increased. Yet, when the amplitude of the stimulation decreased again, the patient’s responses returned to “normal” and he was unable to recall what had happened during the increased stimulation of his brain.Footnote ⁴⁰ According to Klaming and Haselager, this case “demonstrates that DBS can impinge on psychological continuity (in this case by having profound effects on behavior and memory) and influence an individual’s personal identity to such an extent that an alternate personality state can be observed”.Footnote ⁴¹

Meanwhile, others have challenged the idea that neurotechnological brain stimulation would plausibly induce such global and radical effects on a person’s psychological connections so as to disrupt psychological continuity.Footnote ⁴² For example, Pugh stresses that Parfit’s psychological continuity account implies a high threshold and that “whilst ruptures to numerical identity may be evinced by severe neurodegenerative diseases like Alzheimer’s, persons can also lose a considerable number of psychological connections whilst retaining numerical identity with a future person”.Footnote ⁴³ Against this backdrop, Pugh considers it implausible that DBS treatment would disrupt a patient’s psychological continuity, as there is “little evidence to suggest DBS would typically have global effects on patients’ psychological economies of the sort that would threaten a sufficient number of psychological connections for this to be the case”.Footnote ⁴⁴

We suggest that Pugh’s point has heightened relevance in situations where non-invasive brain stimulation is used to modulate behaviour and reduce a convicted person’s risk of recidivism. Intervention in these sorts of cases can be expected to be highly targeted and appears to lack severe side effects. Present studies focus on the use of tDCS for reducing aggression, delivering a low current to a specific brain region via electrodes on the scull for about twenty minutes.Footnote ⁴⁵ The use of brain stimulation in this context does not appear to induce a global and radical effect on the person’s psychological functioning.Footnote ⁴⁶ Rather, it produces a targeted stimulation of a specific brain area associated with specific behavioural inclinations, such as reducing aggression. Thus far, studies on the use of tDCS for this purpose have not reported any severe psychological side effects. As Knehans et al. write in their literature review on tDCS for reducing aggressive behaviour,

Given the targeted nature of this type of non-invasive brain stimulation and the absence of (severe) psychological side effects in its trial use thus far, it is difficult to envisage how such an intervention could destroy over half of the psychological connections a person holds to themselves compared to a normal, actual person. Consequently, it is hard to imagine that reducing a person’s aggressive tendencies in this way will interfere with the person’s numerical identity such that the person ceases to exist. Of course, we cannot exclude the possibility that wrongful application or misuse of the technology might result in less targeted outcomes for criminal justice populations. We also cannot discount the possibility that unforeseeable side effects might occur even with targeted stimulation, such that severe psychological alterations may ensue in some cases. Nonetheless, if used as intended – that is, to target specific brain areas and specific, justice-relevant behavioural inclinations – the changes induced by brain stimulation within criminal justice contexts are unlikely to meet Parfit’s threshold for disrupting psychological continuity and destroying numerical identity. Instead, the psychological changes are likely to be more “subtle”.

Yet, it still seems as though eroding or destroying merely some psychological connections – for instance, by inducing changes to a person’s intentions, goals, beliefs, desires and character – may diminish or impingeon psychological continuity and/or identity in a way that raises normative concerns. At one level, the case of a person who retains numerical identity, but who has fewer psychological connections with their earlier (same) self after a neurointervention, may raise an issue under the right to mental or psychological integrity (discussed in Chapter 3). At another, having fewer psychological connections with one’s earlier self may still affect identity in other ethically and legally relevant ways, even if it does not affect Parfitian psychological continuity or numerical identity. Some have argued that concerns about brain stimulation and personal identity might be better articulated within the alternative conceptualisation of narrative identity.Footnote ⁴⁸ We consider this line of thought in the following section.

2.2.2 Narrative Identity

Marya Schechtman offers an alternative understanding of personal identity, which she argues can explain, unlike the psychological continuity account, why personal identity matters in the first place – that is, explaining our intuitions about the relation between personal identity and survival, moral responsibility, self-interested concern and compensation.Footnote ⁴⁹ She develops a narrative self-constitution view of identity, according to which persons create their own identity by creating a coherent, autobiographical narrative: a story of their life.Footnote ⁵⁰

Narrative identity, Schechtman explains, is not an answer to what she calls the “reidentification question”: the question of whether two entities at different times are one and the same entity (which Parfit and Locke are concerned with, and which we have previously referred to as numerical identity). Rather, it is an answer to the “characterization question”: the question of which actions, experiences, values, beliefs, character traits – that is, “characteristics” – can be attributed to a given person. This characterisation question concerns the kind of identity that is at stake when people have an identity crisis, looking in the mirror and asking themselves: “Who am I really?”. Questions that come under the umbrella of the characterisation question, Schechtman writes, are those that ask “which characteristics are truly those of some person (as opposed, say, to those which are his as a result of hypnosis, brainwashing, or some other form of coercion)”.Footnote ⁵¹ Schechtman, then, describes the core of narrative identity as follows:

As this quotation clarifies, what determines a person’s identity within this approach largely depends on how the person experiences themselves. It is about how people process their experiences into a coherent, autobiographical story of their lives.Footnote ⁵³ This is not to say that just any random or unrealistic story people tell or believe about themselves determines who they are.Footnote ⁵⁴ Not all narratives are identity-constituting, and Schechtman identifies some general constraints on precisely which kinds of narrative are, the two most important constraints being the (1) articulation constraint and (2) reality constraint.Footnote ⁵⁵

The articulation constraint requires that for shaping and retaining narrative identity, the person (the narrator) should be able to explain why they do what they do, feel what they feel and believe what they believe.Footnote ⁵⁶ To quote from Schechtman, a person should be able “to articulate both the basic features of her history and life situation – the facts of her autobiography – and the way in which her life hangs together, providing explanations for why she has acted as she has and why things have unfolded as they have”.Footnote ⁵⁷ Elements of a person’s narrative that they cannot articulate are still theirs, according to Schechtman. But they are “less fully” theirs, playing a different role in the person’s life compared to articulated aspects of their self-narrative. They are “less attributable” to the person.Footnote ⁵⁸

The reality constraint requires that an identity-constituting self-narrative fundamentally coheres with reality. A person’s self-narrative need not be completely accurate. It may and will contain (trivial) errors and inaccuracies, such as distortions and misremembering of facts. It must, however, “exhibit a fundamental grasp of what the world is like”.Footnote ⁵⁹ This is because personhood, in the sense Schechtman is concerned with, requires being able to engage in activities and interactions with others, and this in turn requires fundamental agreement on the most basic features of reality.Footnote ⁶⁰ Views, beliefs and other characteristics that arise from profound delusions are ruled out as genuinely identity-constituting aspects of a person’s narrative. As Schechtman clarifies, this “does not force us to conclude that psychotics are not persons – rather it allows us to dismiss the elements of psychotic’s narratives that are out of touch with reality, and to recognize that their delusions interfere with personhood and diminish it”.Footnote ⁶¹

Both these constraints illustrate a general feature of Schechtman’s narrative identity: that it admits of degrees.Footnote ⁶² Characteristics that the person cannot explain are to be considered less fully theirs and are less attributable to that person. Gross errors of fact or interpretive inaccuracies will, moreover, diminish personhood. On Schechtman’s view, “when a narrative is disrupted or discontinuous, the degree of identity is correspondingly decreased”.Footnote ⁶³ Identities are thus inherently dynamic, as individuals constantly change and evolve, while making sense of themselves by reconciling these changes into a coherent self-narrative.Footnote ⁶⁴ Changes in narrative identity are consequently not necessarily problematic in and of themselves – people will always change in many different ways throughout their lives.Footnote ⁶⁵

As narrative identity is concerned with how people process their subjective experiences into a coherent, self-told story, this account seems well-equipped to capture (some of the) normative concerns regarding neurotechnology and personal identity. After all, most of these concerns reference the way people experience the acute or long-term (side) effects of neurotechnological brain stimulation, such as subjective experiences of self-estrangement.Footnote ⁶⁶ Recall how persons have reported no longer feeling like themselves following DBS treatment – with some asserting statements like, “Now I feel like a machine, I’ve lost my passion. I don’t recognize myself anymore”; “I feel like a robot”; “I feel like an electronic doll”; “I haven’t found myself again after the operation”, as well as patients perceiving sudden improvements after DBS as “my second birth”.Footnote ⁶⁷ Considering examples like these, Ienca and Andorno highlight that “people’s perception of their own identity may be put at risk by inadequate uses of emerging neurotechnology” and that changing a person’s brain functioning with brain stimulation may impact on “the crucial requirement of personal identity consisting in experiencing oneself as persisting though time as the same person”.Footnote ⁶⁸ As the Advisory Committee of the Human Rights Council put it: DBS patients “have reported feeling a changed sense of agency and identity”.Footnote ⁶⁹ On the face of it, these concerns seem to relate more to narrative identity than to psychological continuity.

After all, within the narrative self-constitution view of identity, Holmen explains, the relevant question is whether the effect of a neurointervention is a threat to the narratives that individuals construct about themselves.Footnote ⁷⁰ Hence, when brain stimulation disrupts these narratives, by inducing an abrupt and radical change in how the person perceives, experiences or feels (about) themselves, it may possibly interfere with narrative identity.

Schechtman herself sees the narrative view as a particularly useful framework in relation to psychological changes induced by DBS.Footnote ⁷¹ She argues that the acute changes sometimes experienced in this regard

Recalling the articulation constraint, such abrupt and radical changes require an explanation. However, in cases of neurointervention, these changes are caused by direct stimulation of the brain as opposed to developing naturally from a person’s intentions, beliefs, desires, emotions, values and plans. There is thus a prima facie tension with the articulation constraint, as a person subject to direct modification of the brain might not be able to articulate just why they now hold a certain attitude or desire – that is, they might not be able to identify the reasons justifying their holding such an attitude, or account for why they endorse it – even if they can detail that they adopted this attitude following DBS. Moreover, if the person in such a case came up with a story telling that the changes are a result of personal development, rather than of DBS, they would run afoul of the reality constraint, as such a self-narrative would be inconsistent with the basic, observable features of reality.Footnote ⁷³

Furthermore, apart from acute psychological changes, Schechtman argues that the long-term effects of brain stimulation could sometimes interfere with narrative identity too. Patients who report adjustment problems following such treatment often have difficulty perceiving their lives as the continuation of the life they were living before. They must reinvent themselves. As Schechtman puts it: “The metaphor of ‘second birth,’ while it can signify new beginnings, also signifies the loss of one’s old identity.”Footnote ⁷⁴

However, considering DBS to treat patients with Parkinson’s disease, Baylis thinks it is unclear why a patient cannot satisfy the articulation constraint by including their consent to DBS in the patient’s self-narrative.Footnote ⁷⁵ What matters for narrative identity is whether personal events and experiences can be integrated into an identity-constituting narrative. Patients suffering from mental or neurological conditions may have good reasons to choose DBS treatment, which in and of itself affects their story and contributes to the dynamic and continuously evolving self-narrative. Hence, psychological changes induced by consented DBS need not diminish one’s narrative identity by failing the articulation or reality constraint. Rather, they may well fit within the person’s story, for example, of a patient combatting depression without success so far and who decides to try DBS. The abrupt and long-term changes induced by DBS, then, could be understood as caused by the patient’s “desire to rid themselves of depression and their willingness to be treated in this way to do so”, as Schechtman herself puts it.Footnote ⁷⁶

This can be different, though, when changes in the person’s self-narrative result from force or oppression rather than free choice.Footnote ⁷⁷ Unlike in cases of consent, when a person is forced to live according to constraints set by others who have fixed ideas about who the person is and who they should become, that person may no longer be able to contribute actively to authoring their own lives in a way consistent with their own interests, values, beliefs, desires and other personal characteristics.Footnote ⁷⁸

This could be particularly relevant to the use of brain stimulation in the context of criminal justice. This context is, in and of itself, coercive. Hardly anyone finds themselves in prison or forensic psychiatry out of free choice. Although convicted persons retain the possibility of making free choices, for example, to participate in a certain treatment or research study, the coercive context of criminal justice may affect the voluntariness of such decisions in some cases, which could, in turn, render the person’s informed consent invalid.Footnote ⁷⁹

In the context of criminal justice, inducing abrupt psychological change by neurointervention, such as tDCS to reduce aggressiveness or sexual drive, without valid consent, seems to be a clear case of contravening the articulation constraint and could, therefore, diminish narrative identity. Obviously, the persuasiveness of this claim largely depends on the precise effects of the neurointervention in question. But we think it plausible that at least some types of neurointervention might have significant impact on the subject’s self-narrative by altering personal characteristics (apart from possible side effects). One could think of a person convicted of assault, who experiences aggressive tendencies and outbursts since their adolescence, in fact, perceiving themselves as the aggressive “hothead” who always runs into trouble. When tDCS induces a significant and acute alteration of these aggressive characteristics in the absence of valid informed consent, the person’s self-narrative will likely be disrupted, thereby threatening the person’s narrative identity.

Whether such disruptions of a person’s self-narrative will eventually affect their identity may, however, also depend on the person’s long-term self-narrative, how neurointerventions are administered and the kind of support offered to the person receiving them. As Schechtman stresses regarding the clinical use of consensual DBS,

From a long-term narrative perspective, she argues, changes that “may look like a narrative break, up close, can be seen as a small segment of a continuous and self-expressive life narrative”.Footnote ⁸¹

Regarding neurointerventions in criminal justice, one can imagine a convicted person who has been trying to reduce their aggressive outbursts and to rehabilitate themselves for years without success. Whereas they tried cognitive behavioural therapy and are willing to take medication, if available, to become less aggressive, the idea of electrical stimulation of their brain frightens them. Therefore, they do, initially, not consent to treatment with tDCS. However, they are informed by the prison staff that consenting to this treatment could increase the likelihood of their being granted parole. Feeling forced, they eventually participate in tDCS. Ultimately, the intervention significantly reduces the person’s aggressiveness and facilitates their successful social rehabilitation, something with which they are very happy. Or alternatively, consider that the person in this scenario is willing to try a tDCS treatment and does voluntarily submit to it, but that their consent is invalid because the information provided to them – such as about risks and (side) effects – is insufficient.

Perhaps, in these scenarios, the non-consensual neurointervention need not ipso facto diminish narrative identity, if the induced psychological changes ultimately fit within the person’s broader narrative of transforming their old “criminal life” towards a new “crime-free life”. Although the neurointervention might induce abrupt psychological changes in the absence of valid consent, these changes may still cohere with the person’s broader aspiration and earlier efforts to attain successful rehabilitation, and may actually contribute to their attaining this personal goal – fitting within the person’s self-expressive life narrative (e.g., getting rid of aggressive tendencies that have been too strong to control). Offering the appropriate support throughout the process of neurorehabilitation may prove essential in this regard, to enable the person to conceive of their life after neurotechnological treatment as a continuation of their life before the intervention.

As such, consent need not be the defining factor that determines whether neurostimulation threatens the person’s narrative identity. Still, there might be cases where nonconsensual neurointerventions in a forensic context will not cohere with the person’s self-narrative and, therefore, interfere with narrative identity. If that is the case, we have the question: Would such an interference be morally problematic?

Interfering with narrative identity in criminal justice seems all but unique for neurotechnology. Being convicted for committing a criminal offence – especially the first time – may already have profound effects on the person’s self-narrative, as will the execution of criminal sanctions, such as imprisonment.Footnote ⁸² As Hardie-Bick writes, “[a]lthough there are many lifecourse transitions that produce disequilibrium and require some form of readjustment, there are few transitions as difficult and demanding as adapting to life behind bars”.Footnote ⁸³ According to Ryberg, few (if any) theorists will accept the so-called “deep freeze view” on imprisonment – the view that assumes convicted persons remain totally unaffected by periods of incarceration.Footnote ⁸⁴

For example, studies have reported that those imprisoned frequently have (potentially) traumatic experiences, for example, due to violence often occurring in prison.Footnote ⁸⁵ More generally, Cunha et al. highlight that imprisonment can be inherently damaging to mental health for a variety of reasons, including the “consequent disconnection from family, society, and social support, loss of autonomy, diminished meaning and purpose of life, fear of victimization, increased boredom, the unpredictability of surroundings, overcrowding and punitiveness, experiencing and witnessing violence, negative staff-prisoner interaction, and other aversive experiences”.Footnote ⁸⁶

Apart from a wide range of damaging (psychological) effects, imprisonment can also change people’s narratives positively. Drawing on interviews with former detainees, Maier and Ricciardelli write that “their narratives speak how imprisonment, by providing distinct space and time for reflection, functioned as a “hook” for self-change and the adoption of new narratives”.Footnote ⁸⁷ The key self-changes during imprisonment reported by the interviewees include “learning patience and being calmer; developing a drug-free narrative; realizing greater appreciation for loved ones; and gaining insights into their personal role in the path that led them to their incarceration”.Footnote ⁸⁸

In fact, in criminal justice, we aim to trigger and induce narrative, mental and behavioural changes all the time, deploying different methods that range from deterrence and (solitary) confinement to mandatory resocialisation programmes, cognitive behavioural therapy, psychiatric treatment and the administration of psychotropic drugs including antipsychotics and antilibidinal medication.Footnote ⁸⁹ Moreover, changing people’s narratives and personal characteristics “for the better” – such as through reformation or correction – is arguably one of the primary objectives of imprisonment (in combination with rehabilitative/treatment programmes) and forensic commitment.Footnote ⁹⁰ Often, these measures aim at getting the robber to stop robbing, the alcoholic to stop drinking and those with aggressive tendencies to reduce and control them. As Article 10(3) of the International Covenant on Civil and Political Rights (ICCPR) prescribes: “[t]he penalty system shall comprise treatment of prisoners the essential aim of which shall be their reformation and social rehabilitation”.

Still, despite these intended and unintended changes in the convicted person’s self-narrative through traditional criminal sanctions (both “positive” and “negative”), incarceration and forensic treatment are not typically conceived of as being wrong for interfering with people’s personal identity. Non-consensual interferences that may lead to changes in identity in this sense are often considered justified, for instance, to punish and to prevent harm to others. Against this background, we agree with Ryberg that it is difficult to reject the non-consensual use of neurointerventions solely on the grounds of personality changes and frustrating the person’s experiences and self-awareness, while at the same time accepting and adhering to the use of incarceration as a form of punishment.Footnote ⁹¹ Interestingly, a recent study on public attitudes towards incarceration and “neuronormalization” showed that the participants (n = 248) “were more supportive of neuronormalization and considered it more ethical” than incarceration. Also, they “considered neuronormalization to be a weaker form of mind control than incarceration and would lead to more change for the better”.Footnote ⁹²

2.3.1 Introduction

As mentioned earlier, neurotechnologies that enable others to modify a person’s mental processes – thereby, potentially interfering with their identity – have raised concerns in view of human rights. Three questions are relevant here: (i) does human rights law protect personal identity?, (ii) if so, to what extent? and (iii) what are the implications of this protection for the use of neurointerventions in criminal justice?

With respect to the first question, protecting people’s personality and identity has a profound basis in human rights law. Article 22 of the Universal Declaration of Human Rights safeguards some essential conditions for dignity and the free development of personality. Article 8 of the United Nations Convention on the Rights of the Child recognises children’s right to preserve their identity. And in the European context, Article 1 of the Oviedo Convention (a legally binding instrument on human rights in the biomedical field) prescribes that the parties “shall protect the dignity and identity of all human beings”.

Elsewhere, a right to identity is indirectly protected. In the Inter-American context, it is implicit in the right to privacy of Article 11 of the American Convention on Human Rights (ACHR).Footnote ⁹³ The same applies to the right to privacy pursuant to Article 17 ICCPR, supporting the protection of the individual’s identity and self-autonomy.Footnote ⁹⁴ The Human Rights Committee has repeatedly emphasised “that the notion of privacy refers to the sphere of a person’s life in which he or she can freely express his or her identity, be it by entering into relationships with others or alone”.Footnote ⁹⁵ The United Nations High Commissioner for Human Rights similarly recognises that “[t]he right to privacy is an expression of human dignity and is linked to the protection of human autonomy and personal identity”.Footnote ⁹⁶ Elaborating on the connection between privacy and identity, Nowak/Schabas write, “privacy protects the special, individual qualities of human existence, a person’s manner of appearance, his or her identity. Identity includes, in addition to one’s name, appearance, clothing, hair and beard style, gender, genetic code, feelings and thoughts, specific past, as well as religious belief and other convictions”.Footnote ⁹⁷

In the European context, the ECtHR likewise considers the notion of private life in the meaning of Article 8 ECHR to encompass a “right to identity” and a “right to personal development”, in terms of either personality or personal autonomy.Footnote ⁹⁸ The protection of personal identity makes many appearances in the case law of the ECtHR,Footnote ⁹⁹ ranging from the protection of gender, genetic and biological identity,Footnote ¹⁰⁰ and also ethnic and religious identity,Footnote ¹⁰¹ to the protection of social and national identity.Footnote ¹⁰² Marshall observes that the case law of the ECtHR reflects, in general, a kind of self-determined and fluid version of identity and personal freedom.Footnote ¹⁰³ It acknowledges “the importance of building and retaining an ability and capacity that is each person’s domain, to enable them to think reflectively without interference, to be in control of their own faculties, to decide their own plan of life”.Footnote ¹⁰⁴

Marshall unpacks the protection of two general conditions of identity formation in the ECtHR’s case law: that is, the protection of our minds and bodies.Footnote ¹⁰⁵ These conditions link closely to the normative concerns voiced in the literature about neurotechnology and personal identity. As discussed in section 2.2, those concerns relate to the ability of neurotechnology to induce significant changes in a person’s brain (body) and mental states (mind) – which according to some could disrupt psychological continuity, while according to others are better understood as a potential interference with narrative identity. The extent to which existing human rights protect both psychological continuity and narrative identity, and the implications of this protection for the neurorehabilitation of convicted persons, is discussed in the following sections.Footnote ¹⁰⁶

2.3.2 Psychological Continuity

To what extent do human rights protect psychological continuity? Elsewhere, one of us has argued that interference with psychological continuity in the Parfitian sense is likely to infringe (1) the right to identity and (2) the right to personal integrity, both protected under Article 8 ECHR and, to some extent, Article 3 ECHR.Footnote ¹⁰⁷ In this section, we reflect on these rights, also in view of the ICCPR.

2.3.3 Narrative Identity

Let us now turn to the protection of narrative identity. To what extent is the way people experience themselves and process those experiences into a coherent, autobiographical story, protected by human rights law? And what might such legal protections imply for the neurorehabilitation of convicted persons?

Protecting and ensuring certain enabling preconditions for the construction of one’s own narrative identity appears to be subject to human rights law, in particular to the right to respect for private life – though the term “narrative identity” is not mentioned in the relevant case law and scholarly literature.Footnote ¹³⁵ Marshall highlights that human rights can be vital “in allowing identity formation, through creating the social conditions to enable an individual to develop their personality and identity as they wish”.Footnote ¹³⁶ The idea of identity formation also has affinities with the idea of narrative construction, giving the “authoring” suggested by both. Marshall stresses that freedom as self-direction and self-development is not something individuals sustain and develop on their own in isolation from the outside world. Rather, the development and preservation of identity partly takes place in relation and conversation with others, within the social environments we find ourselves in.Footnote ¹³⁷ Think of how the right to freely develop, change and adhere to a certain religion or belief, and to manifest one’s religious identity – for example, through dress or going to church – is protected by the right to freedom of religion and belief.Footnote ¹³⁸ Consider, too, how access to information about one’s originsFootnote ¹³⁹ and the preservation of objects of ancestral significanceFootnote ¹⁴⁰ have each been considered to potentially be significant for identity formation and self-development and hence subject to human rights protectionFootnote ¹⁴¹ – and also how these factors seem to pertain to narrative identity specifically.

With respect to access to information about one’s origins, the Glover Report on Reproductive Technologies for the European Commission noted that “our sense of who we are is bound up with the story we tell about ourselves. A life where the biological parents are unknown is like a novel with the first chapter missing”.Footnote ¹⁴² Such a missing chapter may frustrate the person’s ability to answer the characterisation question central to narrative identity: “Who am I really?” The importance of having access to information about one’s origins for identity formation is acknowledged by the ECtHR. In cases on paternity dispute, for example, the Court observed that people “have a vital interest, protected by the Convention, in receiving the information necessary to uncover the truth about an important aspect of their personal identity”.Footnote ¹⁴³ It further observed that respect for private life in the meaning of Article 8 ECHR “requires that everyone should be able to establish details of their identity as individual human beings”, with the individual’s entitlement to such information being “of importance because of its formative implications for his or her personality”.Footnote ¹⁴⁴

With respect to the preservation of objects of ancestral significance, the Human Rights Committee in the case of Hopu and Bessert v. France interpreted the protection of identity under Article 17 ICCPR as sometimes covering the protection of objects that people see as connecting them with their ancestors. In this case, the applicants, both ethnic Polynesians, complained that the construction of a luxury hotel on the site of their ancestral burial grounds would arbitrarily interfere with their privacy in violation of Article 17 ICCPR, because these burial grounds have an important place in their history, culture and life. The Human Rights Committee noted that it “transpires from the authors’ claims that they consider the relationship to their ancestors to be an essential element of their identity”. The majority agreed and concluded that there had been an arbitrary interference with Article 17 ICCPR.Footnote ¹⁴⁵ Because the applicants in this case perceived the relationship to their ancestors as significant to, or even constitutive of, their identity, human rights protection of identity applied.

Although there may be no direct link between these cases and narrative identity, the examples illustrate that for the human rights protection of people’s identity, personal narratives matter at least sometimes. They indicate that at least some aspects of a person’s narrative, and some enabling preconditions for answering the characterisation question, receive protection by the human right to personal identity as part of the rights to privacy and private life. As pointed out earlier, according to Schechtman, the most familiar examples of the characterisation question are “questions of which characteristics are truly those of some person (as opposed, say, to those which are his as a result of hypnosis, brainwashing, or some other form of coercion)”.Footnote ¹⁴⁶ Altering personal characteristics and behavioural traits through neurotechnology has the potential to impact on how persons experience themselves – especially when this takes places without valid – free and informed – consent (section 2.2.2). It appears safe to say that even more than receiving information about one’s origins or the intactness of historic sites and cultural heritage, a person’s unmanipulated brain and mental states – memories, in particular, as the psychological “equivalent” of ancient sites – are important, enabling preconditions for narrative identity formation. If the former are protected through the right to identity, then there is reason to think that the latter should be too.

Furthermore, the self-constitution and formation of personal identity may also be covered by the more general protection of self-determination,Footnote ¹⁴⁷ also enshrined in Articles 8 ECHR and Article 17 ICCPR. For example, regarding Article 17 ICCPR, Nowak/Schabas note that “privacy covers the area of individual autonomy in which human beings strive to achieve self-realization”, which “liberty of action” is “inherent in private self-determination”.Footnote ¹⁴⁸ Taylor speaks in this context of human rights that protect the individual’s “identity and self-autonomy”, including in the dimensions of gender, sexuality and religion.Footnote ¹⁴⁹ In the jurisprudence of the ECtHR, self-determination is closely linked to the notion of personal autonomy,Footnote ¹⁵⁰ the latter being an important principle underlying the interpretation of Article 8 ECHR.Footnote ¹⁵¹ According to the Grand Chamber of the ECtHR, “a right to self-determination” can be derived from the umbrella right to respect for private life pursuant to Article 8 ECHR.Footnote ¹⁵² Among other things, it embraces a right to “informational self-determination” and a right to “sexual self-determination”.Footnote ¹⁵³ Although the ECtHR has not yet clearly articulated the meaning and scope of the right to self-determination, the right protects at least some aspects of a person’s identity.Footnote ¹⁵⁴

This follows most evidently from the case law on sexual orientation and gender identity. According to the ECtHR, gender identity and sexual orientation are one of the most intimate aspects of private life,Footnote ¹⁵⁵ qualifying the latter as “an essentially private manifestation of human personality”.Footnote ¹⁵⁶ The right to self-determination not only protects from interference with private sexual behaviour but also guarantees a freedom to self-create, reshape and develop different aspects of the person’s (sexual) identity, for instance, by defining oneself as either a male or female. As the Court puts it:

The Human Rights Committee has approached the freedom to define one’s own sexual identity as part of the protection of a person’s identity and gender identity under Article 17 ICCPR. For example, the complaint in G. v. Australia concerned an Australian law that did not allow a transgender person to change the reference to her sex on the birth certificate unless she divorced from her spouse (with whom she had a happy relationship). The Human Rights Committee stressed that the right to privacy of Article 17 ICCPR includes the protection of the person’s identity and gender identity and found the Australian law to constitute an arbitrary interference with the person’s privacy and family life.Footnote ¹⁵⁸ Nowak/Schabas note that identity often manifests itself in official documents, such as birth certificates.Footnote ¹⁵⁹ Such pieces of information and official reference can play an important role in the development of people’s narratives and, therefore, in the self-constitution of their identity.

Considering the case law on gender identity and sexual orientation, Marshall observes that the Court’s conception of “freedom” under Article 8 ECHR could be interpreted as “self-creation or self-determination”, protecting the freedom to be and become the person one chooses, “in keeping with their own sense of their identity in a self-determining sense”.Footnote ¹⁶⁰ The right to personal identity in this context allows individuals to freely change, develop and create their identities, “rather than bringing to realisation some essence within”.Footnote ¹⁶¹ As such, personal identity as protected under Article 8 ECHR is flexible and dynamic, rather than fixed and static. As Judge Martens phrased it in a dissenting opinion dating back to 1990, “[h]uman dignity and human freedom imply that a man should be free to shape himself and his fate in the way that he deems best fits his personality”.Footnote ¹⁶²

This shaping of the self can take different forms, one of them being the processing of our personal experiences into a coherent, autobiographical story of our lives. Such a self-determining interpretation of human freedom in relation to personal identity fits well within the general view that the right to respect for private life “secures to the individual a sphere within which he can freely pursue the development and fulfilment of his personality”.Footnote ¹⁶³ If this self-creating and self-determining freedom is interfered with by brain stimulation that disrupts a person’s self-narrative, for example, in the context of neurorehabilitation, the right to self-determination, including the freedom to define one’s own identity, will likely be infringed.

2.3.4 Implications for Neurorehabilitation

Human rights protect personal identity. Meanwhile, many of the concepts referred to in this context, such as identity, personality and mental stability, are still ill-defined in the law.Footnote ¹⁶⁴ In addition, the theoretical underpinnings of the human rights protection of identity are, by and large, undefined and, thus, unclear. Contrary to philosophy, in human rights law, personal identity lacks clear conceptual consideration. The protection of identity appears to develop ad hoc, through individual cases and complaints and is, therefore, fragmented and specified to the facts of those cases. At best, scholars can interpret individual cases and decisions and relate them to specific theoretical accounts of identity, or defend a specific account they think is most appropriate to substantiate a human right to identity.Footnote ¹⁶⁵

We showed that under the ICCPR and ECHR, there is no explicit recognition of either Parfit’s psychological continuity or Schechtman’s narrative identity account. However, as argued in the previous section, there are reasons to assume that, implicitly, these types of identity receive protection from human rights. Interference with both narrative identity and psychological continuity may sometimes infringe the rights to identity and self-determination, which are inherent in the right to privacy. Disrupting a person’s psychological continuity may furthermore infringe the right to personal integrity.

Let us for now assume that, to some extent, both psychological continuity and narrative identity receive protection within the established framework of human rights, in particular through the right to identity inherent in the right to privacy/private life.Footnote ¹⁶⁶ Let us also assume that in some cases the use of brain stimulation for the rehabilitation of convicted persons can infringe the right to identity. Then, the next question is whether and under what conditions such an infringement could be justified, or whether certain neurotechnological interferences with the identity of convicted persons will be prohibited across the board.

As the protection of identity is part of the qualified right to privacy, it is subject to limitations. Both under Article 17 ICCPR and 8 ECHR, infringements of the right to privacy can be justified when having a (non-arbitrary) legal basis and being proportionate to a legitimate aim, such as the prevention of crime and the protection of the rights and freedoms of others.Footnote ¹⁶⁷ For example, some types of non-consensual medical interventions, such as taking blood for DNA analysis, infringe the right to private life under Article 8 ECHR, but can still be justified for obtaining evidence of the person’s involvement in the commission of a criminal offence.Footnote ¹⁶⁸ Furthermore, non-consensual medical treatment, which would normally infringe the right to respect for private life, could be justified in case of “medical necessity”.Footnote ¹⁶⁹ Whether and when interference with a convicted person’s identity through a neurointervention could be justified is hard to predict. This will depend on a range of factors that vary across individual cases, such as the induced neural, psychological and behavioural changes, and the purpose of the intervention, for example, whether it is employed for medical reasons or to prevent severe or less severe crimes.

Here, we will not estimate which types of identity change caused by neurointerventions may or may not be permissible under different conditions. Rather, we wish to highlight a more general feature of identity interference that emerges, specifically, from the ECtHR case law – which may inform our thinking about the (im)permissibility of identity-affecting neurointerventions in criminal justice more broadly. This particularity relates to the margin of appreciation doctrine developed in the jurisprudence of the ECtHR.

In determining whether an infringement of the right to respect for private life is proportionate to the legitimate aim it pursues, the national authorities enjoy a margin of appreciation, which can either be “wide”, “certain” or “narrow”.Footnote ¹⁷⁰ The narrower this margin, the stricter the ECtHR’s review of the proportionality of a rights infringement.Footnote ¹⁷¹ The broader this margin, the more discretion states enjoy in striking a “fair balance” between the competing personal and public interests at stake.Footnote ¹⁷² The breadth of this margin of appreciation varies across individual cases and depends on a number of relevant factors,Footnote ¹⁷³ such as the context of the interference and the level of consensus among the member states of the Council of Europe, either as to the relative importance of the interest at issue or as to the best way of protecting it.Footnote ¹⁷⁴

Another relevant factor concerns the importance of the right at stake. In principle, the margin of appreciation will be narrow when the “essence” or “core” of a convention right is affected. Gerards explains this approach from the perspective of effective protection of the ECHR in relation to the principle of subsidiarity: the more important a right, the more reason for supervision on how that right is guaranteed on the national level.Footnote ¹⁷⁵ The ECtHR has identified four central values underlying the ECHR: democracy and the rule of law, pluralism, human dignity, and personal autonomy. According to Gerards,

Under Article 8 ECHR, the ECtHR has repeatedly stated that when “a particularly important facet of an individual’s existence or identity is at stake, the margin allowed to the State will be restricted”.Footnote ¹⁷⁷ For example, in a case on the legal recognition of a parent-child relationship after surrogacy, the ECtHR held that “regard should also be had to the fact that an essential aspect of the identity of individuals is at stake where the legal parent-child relationship is concerned. The margin of appreciation afforded to the respondent State in the present case therefore needs to be reduced”.Footnote ¹⁷⁸ In another case, the ECtHR explained that the “extent of the State’s margin of appreciation depends not only on the right or rights concerned but also, as regards each right, on the very nature of the interest concerned. The Court considers that the right to an identity (…) is an integral part of the notion of private life. In such cases, particularly rigorous scrutiny is called for when weighing up the competing interests”.Footnote ¹⁷⁹

In the same vein, when the non-consensual stimulation of a convicted person’s brain changes personal characteristics that are to be considered an essential aspect of the person’s identity – which we conceive as plausible in at least some cases (section 2.2) – the margin of appreciation will most likely be narrow too. In those cases, the national authorities have less discretion in balancing the convicted person’s private interests against the public interest of crime prevention (e.g., by lowering recidivism risks). Consequently, the ECtHR could then apply a strict test of necessity and proportionality, critically assessing the availability of less intrusive means, and may require additional procedural safeguards in domestic law to guarantee careful and individualised decision-making and access to judicial remedies.Footnote ¹⁸⁰