There has been a growing interest in research concerning memory modification technologies (MMTs) in recent years. Neuroscientists and psychologists are beginning to explore the prospect of controllable and intentional modification of human memory. One of the technologies with the greatest potential to this end is optogenetics—an invasive neuromodulation technique involving the use of light to control the activity of individual brain cells. It has recently shown the potential to modify specific long-term memories in animal models in ways not yet possible (...) with other MMTs. As the therapeutic potential of optogenetics has already prompted approval of the first human trials, it is especially important and timely to consider the opportunities and dangers this technology may entail. In this article, we focus on possible consequences of optogenetics as an MMT by analyzing fundamental threats potentially associated with memory modifications: the potential disruption of personality and authenticity. (shrink)

This chapter serves as an introduction to the edited collection of the same name, which includes chapters that explore digital well-being from a range of disciplinary perspectives, including philosophy, psychology, economics, health care, and education. The purpose of this introductory chapter is to provide a short primer on the different disciplinary approaches to the study of well-being. To supplement this primer, we also invited key experts from several disciplines—philosophy, psychology, public policy, and health care—to share their thoughts on what they (...) believe are the most important open questions and ethical issues for the multi-disciplinary study of digital well-being. We also introduce and discuss several themes that we believe will be fundamental to the ongoing study of digital well-being: digital gratitude, automated interventions, and sustainable co-well-being. (shrink)

There has been a growing interest in research concerning memory modification technologies (MMTs) in recent years. Neuroscientists and psychologists are beginning to explore the prospect of controllable and intentional modification of human memory. One of the technologies with the greatest potential to this end is optogenetics—an invasive neuromodulation technique involving the use of light to control the activity of individual brain cells. It has recently shown the potential to modify specific long-term memories in animal models in ways not yet possible (...) with other MMTs. As the therapeutic potential of optogenetics has already prompted approval of the first human trials, it is especially important and timely to consider the opportunities and dangers this technology may entail. In this article, we focus on possible consequences of optogenetics as an MMT by analyzing fundamental threats potentially associated with memory modifications: the potential disruption of personality and authenticity. (shrink)

The aims of this paper are to: (1) identify the best framework for comprehending multidimensional impact of deep brain stimulation on the self; (2) identify weaknesses of this framework; (3) propose refinements to it; (4) in pursuing (3), show why and how this framework should be extended with additional moral aspects and demonstrate their interrelations; (5) define how moral aspects relate to the framework; (6) show the potential consequences of including moral aspects on evaluating DBS’s impact on patients’ selves. Regarding (...) (1), I argue that the pattern theory of self can be regarded as such a framework. In realizing (2) and (3), I indicate that most relevant issues concerning PTS that require resolutions are ontological issues, including the persistence question, the “specificity problem”, and finding lacking relevant aspects of the self. In realizing (4), I identify aspects of the self not included in PTS which are desperately needed to investigate the full range of potentially relevant DBS-induced changes—authenticity, autonomy, and responsibility, and conclude that how we define authenticity will have implications for our concept of autonomy, which in turn will determine how we think about responsibility. Concerning (5), I discuss a complex relation between moral aspects and PTS—on one hand, they serve as the lens through which a particular self-pattern can be evaluated; on the other, they are, themselves, products of dynamical interactions of various self-aspects. Finally, I discuss (6), demonstrating novel way of understanding the effects of DBS on patients’ selves. (shrink)

Deep Brain Stimulation (DBS) is an invasive therapeutic method involving the implantation of electrodes and the electrical stimulation of specific areas of the brain to modulate their activity. DBS brings therapeutic benefits, but can also have adverse side effects. Recently, neuroethicists have recognized that DBS poses a threat to the very fabric of human existence, namely, to the selves of patients. This article provides a review of the neuroethical literature examining this issue, and identifies the crucial dimensions related to the (...) self which DBS may endanger—personal identity, authenticity, and autonomy. The most influential theories accounting for these dimensions are analyzed herein, and it is argued that most of these theories require further refinement. This paper also demonstrates the interrelation between personal identity, authenticity, and autonomy, and concludes that one can only fully understand the impact of DBS on the self when all of these factors are taken into account. (shrink)

Neural devices have the capacity to enable users to regain abilities lost due to disease or injury – for instance, a deep brain stimulator (DBS) that allows a person with Parkinson’s disease to regain the ability to fluently perform movements or a Brain Computer Interface (BCI) that enables a person with spinal cord injury to control a robotic arm. While users recognize and appreciate the technologies’ capacity to maintain or restore their capabilities, the neuroethics literature is replete with examples of (...) concerns expressed about agentive capacities: A perceived lack of control over the movement of a robotic arm might result in an altered sense of feeling responsible for that movement. Clinicians or researchers being able to record and access detailed information of a person’s brain might raise privacy concerns. A disconnect between previous, current, and future understandings of the self might result in a sense of alienation. The ability to receive and interpret sensory feedback might change whether someone trusts the implanted device or themselves. Inquiries into the nature of these concerns and how to mitigate them has produced scholarship that often emphasizes one issue – responsibility, privacy, authenticity, or trust – selectively. However, we believe that examining these ethical dimensions separately fails to capture a key aspect of the experience of living with a neural device. In exploring their interrelations, we argue that their mutual significance for neuroethical research can be adequately captured if they are described under a unified heading of agency. On these grounds, we propose an “Agency Map” which brings together the diverse neuroethical dimensions and their interrelations into a comprehensive framework. With this, we offer a theoretically-grounded approach to understanding how these various dimensions are interwoven in an individual’s experience of agency. (shrink)

Implantable neurotechnology devices such as Brain Computer Interfaces and Deep Brain Stimulators are an increasing part of treating or exploring potential treatments for neurological and psychiatric disorders. While only a few devices are approved, many promising prospects for future devices are under investigation. The decision to participate in a clinical trial can be challenging, given a variety of risks to be taken into consideration. During the consent process, prospective participants might lack the language to consider those risks, feel unprepared, or (...) simply not know what questions to ask. One tool to help empower participants to play a more active role during the consent process is a Question Prompt List. QPLs are communication tools that can prompt participants and patients to articulate potential concerns. They offer a structured list of disease, treatment, or research intervention-specific questions that research participants can use as support for question asking. While QPLs have been studied as tools for improving the consent process during cancer treatment, in this paper, we suggest they would be helpful in neurotechnology research, and offer an example of a QPL as a template for an informed consent tool in neurotechnology device trials. (shrink)

Das allgemeine Thema des Artikels besteht darin, zwei Diskussionskreise miteinander zu verbinden, die in Isolation betrachtet gut erforscht sind, aber selten zusammengebracht werden: die Diskussion um das sogenannte Human Enhancement und die Debatte um das sinnvolle Leben. Hierbei wird insbesondere die Behauptung ins Blickfeld gerückt, dass Techniken des Human Enhancement einen negativen Einfluss auf den Sinn haben könnten. Ist diese These plausibel? In diesem Artikel wird die These verteidigt, dass diese Frage verneint werden muss. Methodisch werden hierfür drei Varianten untersucht, (...) in denen die Behauptung des negativen Einflusses vorgetragen werden können. Dabei wird aufgezeigt, dass entweder die Annahme eines negativen Einflusses aus empirischen Gründen wenig wahrscheinlich ist oder dass sie durch Modifikationen der Enhancement Techniken abgeschwächt werden können. (shrink)

:Neuroprosthetic speech devices are an emerging technology that can offer the possibility of communication to those who are unable to speak. Patients with ‘locked in syndrome,’ aphasia, or other such pathologies can use covert speech—vividly imagining saying something without actual vocalization—to trigger neural controlled systems capable of synthesizing the speech they would have spoken, but for their impairment.We provide an analysis of the mechanisms and outputs involved in speech mediated by neuroprosthetic devices. This analysis provides a framework for accounting for (...) the ethical significance of accuracy, control, and pragmatic dimensions of prosthesis-mediated speech. We first examine what it means for the output of the device to be accurate, drawing a distinction between technical accuracy on the one hand and semantic accuracy on the other. These are conceptual notions of accuracy.Both technical and semantic accuracy of the device will be necessary for the user to have sufficient control over the device. Sufficient control is an ethical consideration: we place high value on being able to express ourselves when we want and how we want. Sufficient control of a neural speech prosthesis requires that a speaker can reliably use their speech apparatus as they want to, and can expect their speech to authentically represent them. We draw a distinction between two relevant features which bear on the question of whether the user has sufficient control: voluntariness of the speech and the authenticity of the speech. These can come apart: the user might involuntarily produce an authentic output or might voluntarily produce an inauthentic output. Finally, we consider the role of the interlocutor in interpreting the content and purpose of the communication.These three ethical dimensions raise philosophical questions about the nature of speech, the level of control required for communicative accuracy, and the nature of ‘accuracy’ with respect to both natural and prosthesis-mediated speech. (shrink)

There is evidence to suggest that some patients who undergo Deep Brain Stimulation can experience changes to dispositional, emotional and behavioural states that play a central role in conceptions of personality, identity, autonomy, authenticity, agency and/or self. For example, some patients undergoing DBS for Parkinson’s Disease have developed hypersexuality, and some have reported increased apathy. Moreover, experimental psychiatric applications of DBS may intentionally seek to elicit changes to the patient’s dispositional, emotional and behavioural states, in so far as dysfunctions in (...) these states may undergird the targeted disorder. Such changes following DBS have been of considerable interest to ethicists, but there is a considerable degree of conflict amongst different parties to this debate about whether DBS really does change PIAAAS, and whether this matters. This paper explores these conflicting views and suggests that we may be able to mediate this conflict by attending more closely to what parties to the debate mean when they invoke the concepts lumped together under the acronym PIAAAS. Drawing on empirical work on patient attitudes, this paper outlines how these different understandings of the concepts incorporated into PIAAAS have been understood in this debate, and how they may relate to other fundamental concepts in medical ethics such as well-being and autonomy. The paper clarifies some key areas of disagreement in this context, and develops proposals for how ethicists might fruitfully contribute to future empirical assessments of apparent changes to PIAAAS following DBS treatment. (shrink)

In a recent article, Sabine Müller, Merlin Bittlinger, and Henrik Walter launch a sweeping attack against what they call the "personal identity debate" as it relates to patients treated with deep brain stimulation (DBS). In this critique offered by Müller et al., the so-called personal identity debate is said to: (a) be metaphysical in a problematic way, (b) constitute a threat to patients, and (c) use "vague" and "contradictory" statements from patients and their families as direct evidence for metaphysical theories. (...) In this response, I critically evaluate Müller et al.'s argument, with a special focus on these three just-mentioned aspects of their discussion. My conclusion is that Müller et al.'s overall argument is problematic. It overgeneralizes criticisms that may apply to some, but certainly not to all, contributions to what they call the personal identity-debate. Moreover, it rests on a problematic conception of what much of this debate is about. Nor is Müller et al.'s overall argument fair in its assessment of the methodology used by most participants in the debate. For these reasons, we should be skeptical of Müller et al.'s claim that the "personal identity debate" is a "threat to neurosurgical patients". (shrink)

ABSTRACT‘Self-ambiguity’, we suggest, is best understood as an uncertainty about how strongly a given feature reflects who one truly is. When this understanding of self-ambiguity is applied to a view of the self as having both essential and shapable components, self-ambiguity can be seen to have two aspects: (1) uncertainty about one's essential or relatively unchangeable characteristics, e.g. one's sexuality, and (2) uncertainty about how to shape oneself, e.g. which values to commit to, actions to pursue, or essential features to (...) identify with. We explain how a narrative account of agency can accommodate these forms of self-ambiguity and argue that such an account also reveals another kind of self-ambiguity, namely, (3) uncertainty about whether one's established self-narrative represents who one really is. We illustrate this third form of self-ambiguity in the context of addiction where people's established addiction self-narratives make it difficult to identify with recovery. We argue that recovery will require embracing, especially, our third form of self-ambiguity as a chance for positive self-transformation. Treatment for addiction should, therefore, support people in going through and ultimately narratively resolving the inevitable self-ambiguities of the recovery process. (shrink)

Implantable brain-computer interfaces are being developed to restore speech capacity for those who are unable to speak. Patients with locked-in syndrome or amyotrophic lateral sclerosis could be able to use covert speech – vividly imagining saying something without actual vocalisation – to trigger neural controlled systems capable of synthesising speech. User control has been identified as particularly pressing for this type of BCI. The incorporation of machine learning and statistical language models into the decoding process introduces a contribution to the (...) output that is beyond the user’s control. Whilst this type of ‘shared control’ of BCI action is not unique to speech BCIs, the automated shaping of what a user ‘says’ has a particularly acute ethical dimension, which may differ from parallel concerns surrounding automation in movement BCIs. This paper provides an analysis of the control afforded to the user of a speech BCI of the sort under development, as well as the relationships between accuracy, control, and the user’s ownership of the speech produced. Through comparing speech BCIs with BCIs for movement, we argue that, whilst goal selection is the more significant locus of control for the user of a movement BCI, control over process will be more significant for the user of the speech BCI. The design of the speech BCI may therefore have to trade off some possible efficiency gains afforded by automation in order to preserve sufficient guidance control necessary for users to express themselves in ways they prefer. We consider the implications for the speech BCI user’s responsibility for produced outputs and their ownership of token outputs. We argue that these are distinct assessments. Ownership of synthetic speech concerns whether the content of the output sufficiently represents the user, rather than their morally relevant, causal role in producing that output. (shrink)

The profound changes in personality, mood, and other features of the self that neural interventions can induce can be disconcerting to patients, their families, and caregivers. In the neuroethical debate, these concerns are often addressed in the context of possible threats to the narrative self. In this paper, I argue that it is necessary to consider a dimension of impacts on the narrative self which has so far been neglected: neural interventions can lead to a loss of meaning of actions, (...) feelings, beliefs, and other intentional elements of our self-narratives. To uphold the coherence of the self-narrative, the changes induced by neural interventions need to be accounted for through explanations in intentional or biochemical terms. However, only an explanation including intentional states delivers the content to directly ascribe personal meaning, i.e., subjective value to events. Neural interventions can deprive events of meaning because they may favor a predominantly biochemical account. A loss of meaning is not inherently negative but it can be problematic, particularly if events are affected one was not prepared or willing to have stripped of meaning. The paper further examines what it is about neural interventions that impacts meaning by analyzing different methods. To which degree the pull towards a biochemical view occurs depends on the characteristics of the neural intervention. By comparing Deep Brain Stimulation, Prozac, Ritalin, psychedelics, and psychotherapy, the paper identifies some main factors: the rate of change, the transparency of the causal chain, the involvement of the patient, and the presence of an acute phenomenological experience. (shrink)

The potential of memory modification techniques (MMTs) has raised concerns and sparked a debate in neuroethics, particularly in the context of identity and authenticity. This paper addresses the question whether and how MMTs influence authenticity. I proceed by drawing two distinctions within the received views on authenticity. From this, I conclude that an analysis of MMTs based on a dual-basis, process view of authenticity is warranted, which implies that the influence of MMTs on authenticity crucially depends on the specifics of (...) how memory modification would eventually work. Therefore, I continue with a systematic analysis of possible properties of MMTs in which I distinguish between the dimensions of memories and the kinds of experiences that can be modified as well as the properties of the process of memory modification. The impact of MMTs on authenticity is analyzed regarding the possible properties of MMTs and based on a narrative approach to authenticity which fulfills the requirements of a dual-basis, process view of authenticity. Lastly, I explore the potential of MMTs to shift the balance between self-discovery and self-creation within authenticity and thereby alter the concept itself as well as the value of authenticity. (shrink)

Dark patterns have received significant attention in literature as interface design practices which undermine users’ autonomy by coercing, misleading or manipulating their decision making and behavior. Individual autonomy has been argued to be one of the normative lenses for the evaluation of dark patterns. However, theoretical perspectives on autonomy have not been sufficiently adapted in literature to identify the ethical concerns raised by dark patterns. The aim of this paper is to conceptualize user autonomy within the context of dark patterns. (...) In this paper, we systematically review 151 dark patterns from 16 taxonomies to understand how dark patterns threaten users’ autonomy. We demonstrate through this analysis that implications for autonomy arise along four dimensions, because autonomy itself can be understood as subsuming several distinguishable concepts. These are agency, freedom of choice, control and independence. We argue that an assessment of whether a design pattern qualifies as ‘dark’ should account for the sense in which autonomy is threatened, as individuals’ rights and expectations of autonomy vary in various contexts and depend upon the interpretation of autonomy. This paper aims to contribute to the development of the normative lens of individual autonomy for the evaluation of dark patterns, as well as for persuasive design more broadly. (shrink)

This paper argues for a revised concept of authenticity entailing two demands that must be balanced. The first demand moves authenticity from the position of a strictly self-regarding virtue towards the position of a fully social virtue, acknowledging the crucial feature of steadiness, i.e. self-consistency, as being precisely what we ‘naturally’ lack. Nevertheless, the value of personal authenticity in a modern, open society comes from the fact that it brings about not only steadiness, but also the public development of a (...) variety of existential options that can be understood as Millian ‘original experiments in living’. Thus the second demand of authenticity is a demand for ‘experimental’ authenticity which covers the whole spectrum of technologies of the self, from Nietzschean ‘brief habits’, to the use of enhancement technologies. (shrink)

The debate about how neurotechnologies impact authenticity has focused on two inter-related dimensions: self-discovery and self-creation. In this paper, we develop a broader framework that includes the experimental and relational dimensions of authenticity, both understood as decisive for shaping one’s narrative identity. In our view, neurointerventions that alter someone’s personality traits will also impact her very own self-understanding across time. We argue that experimental authenticity only needs a minimum conception of narrative coherence of the self and that reversibility should remain (...) a key feature in the ethical assessment of neurotechnologies. The relational dimension of authenticity derives from the fact that a process of self-constitution is never a solitary business. The significant others act not just as subsequent judges of one’s life decisions, but as real co-authors of one’s self. We discuss relevant cases in which others are actively contributing to the meaning-making process, as to the direction one’s life is taking. We also claim that the experimental and the relational dimensions of authenticity should aim to correct each other. The relational dimension introduces socially approved standards as well as limitations to the array of available possibilities of self-fashioning or human enhancement. The experimental side enables us to avoid confusing one’s personal identity with a social and narrative construct that only bears the mark of social pressure and conformism. (shrink)

In work on the ethics of cognitive enhancement use, there is a pervasive concern that such enhancement will—in some way—make us less authentic. Attempts to clarify what this concern amounts to and how to respond to it often lead to debates on the nature of the “true self” and what constitutes “genuine human activity”. This paper shows that a new and effective way to make progress on whether certain cases of cognitive enhancement problematically undermine authenticity is to make use of (...) considerations from the separate debate on the nature of authentic emotion. Drawing in particular on Wasserman and Liao, the present paper offers new conditions that can help us assess the impact of cognitive enhancements on authenticity. (shrink)

Advancements in novel neurotechnologies, such as brain computer interfaces and neuromodulatory devices such as deep brain stimulators, will have profound implications for society and human rights. While these technologies are improving the diagnosis and treatment of mental and neurological diseases, they can also alter individual agency and estrange those using neurotechnologies from their sense of self, challenging basic notions of what it means to be human. As an international coalition of interdisciplinary scholars and practitioners, we examine these challenges and make (...) recommendations to mitigate negative consequences that could arise from the unregulated development or application of novel neurotechnologies. We explore potential ethical challenges in four key areas: identity and agency, privacy, bias, and enhancement. To address them, we propose democratic and inclusive summits to establish globally-coordinated ethical and societal guidelines for neurotechnology development and application, new measures, including “Neurorights,” for data privacy, security, and consent to empower neurotechnology users’ control over their data, new methods of identifying and preventing bias, and the adoption of public guidelines for safe and equitable distribution of neurotechnological devices. (shrink)

Neuromodulation and narrative identity: the importance of relational autonomyIn this paper, I discuss the impact of psychological and relational changes after neuromodulation for movement- and psychiatric disorders and the need to adequately address the possibility of such changes in clinical contexts. Based on ), ) and ), I outline a relational narrative identity perspective that can inform and support medical-ethical decisions. The narrative identity theory by Marya Schechtman in combination with a focus on the relational aspects that impact and constitute (...) our identity, highlights the need to identify post-interventional identity changes both from the perspective of the patient, his or her family and loved ones and the medical team. I argue that a thorough informed consent process pre- and post-intervention and adequate psychological counseling allows for such identification and a step by step monitoring and guiding of the patient in this process. From a relational narrative perspective, neuromodulation does not by default pose a threat to our identity. However, this perspective highlights the need to take the relational autonomy of patients seriously and provide a substantial informed consent procedure and adequate psychological counseling. (shrink)

Open Peer Commentary on P. Zawadzki and A. K. Adamczyk's target article in AJOB Neuroscience on the potential of optogenetics for memory modification. I argue for a radically pluralistic understanding of the notion of authenticity, and highlight the need to further clarify the specific nature of the authors' concern about authenticity, as well as its policy implications.

Deep brain stimulation of the subthalamic nucleus for the treatment of Parkinson’s disease can lead to the development of neuropsychiatric symptoms. These can include harmful changes in mood and behaviour that alienate family members and raise ethical questions about personal responsibility for actions committed under stimulation-dependent mental states. Qualitative interviews were conducted with twenty participants following subthalamic DBS at a movement disorders centre, in order to explore the meaning and significance of stimulation-related neuropsychiatric symptoms amongst a purposive sample of persons (...) with PD and their spousal caregivers. Interview transcripts underwent inductive thematic analysis. Clinical and experiential aspects of post-DBS neuropsychiatric symptoms were identified. Caregivers were highly burdened by these symptoms and both patients and caregivers felt unprepared for their consequences, despite having received information prior to DBS, desiring greater family and peer engagement prior to neurosurgery. Participants held conflicting opinions as to whether emergent symptoms were attributable to neurostimulation. Many felt that they reflected aspects of the person’s “real” or “younger” personality. Those participants who perceived a close relationship between stimulation changes and changes in mental state were more likely to view these symptoms as inauthentic and uncontrollable. Unexpected and troublesome neuropsychiatric symptoms occurred despite a pre-operative education programme that was delivered to all participants. This suggests that such symptoms are difficult to predict and manage even if best practice guidelines are followed by experienced centres. Further research aimed at predicting these complications may improve the capacity of clinicians to tailor the consent process. (shrink)

The article provides a conceptualization of self(-illness) ambiguity and investigates to what extent self(-illness) ambiguity is ‘special’. First, we draw on empirical findings to argue that self-ambiguity is a ubiquitous phenomenon. We suggest that these findings are best explained by a multidimensional account, according to which selves consist of various dimensions that mutually affect each other. On such an account, any change to any particular self-aspect may change other self-aspects and thereby alter the overall structural pattern of self-aspects, potentially leading (...) to self-ambiguity. Second, we propose that self-ambiguity comes in degrees and should be understood as a spectrum (as opposed to there being qualitative differences among instances of self-ambiguity). Third, we argue that complexity is the most useful dimension to organize cases of self-ambiguity, with mundane instances of self-ambiguity on the one end and self-illness ambiguity on the other end of the spectrum. Fourth, we address the promises and perils of narrativity with regard to self-ambiguity. Finally, we link our deflationary account of self(-illness) ambiguity to pattern theories of self. (shrink)

The article provides a conceptualization of self(-illness) ambiguity and investigates to what extent self(-illness) ambiguity is ‘special’. First, we draw on empirical findings to argue that self-ambiguity is a ubiquitous phenomenon. We suggest that these findings are best explained by a multidimensional account, according to which selves consist of various dimensions that mutually affect each other. On such an account, any change to any particular self-aspect may change other self-aspects and thereby alter the overall structural pattern of self-aspects, potentially leading (...) to self-ambiguity. Second, we propose that self-ambiguity comes in degrees and should be understood as a spectrum (as opposed to there being qualitative differences among instances of self-ambiguity). Third, we argue that complexity is the most useful dimension to organize cases of self-ambiguity, with mundane instances of self-ambiguity on the one end and self-illness ambiguity on the other end of the spectrum. Fourth, we address the promises and perils of narrativity with regard to self-ambiguity. Finally, we link our deflationary account of self(-illness) ambiguity to pattern theories of self. (shrink)

Optogenetics is an invasive neuromodulation technology involving the use of light to control the activity of individual neurons. Even though optogenetics is a relatively new neuromodulation tool whose various implications have not yet been scrutinized, it has already been approved for its first clinical trials in humans. As optogenetics is being intensively investigated in animal models with the aim of developing novel brain stimulation treatments for various neurological and psychiatric disorders, it appears crucial to consider both the opportunities and dangers (...) such therapies may offer. In this review, we focus on the memory-modifying potential of optogenetics, investigating what it is capable of and how it differs from other memory modification technologies. We then outline the safety challenges that need to be addressed before optogenetics can be used in humans. Finally, we re-examine crucial neuroethical concerns expressed in regard to other MMTs in the light of optogenetics and address those that appear to be unique to the memory-modifying potential of optogenetic technology. (shrink)