Intra-hemispheric interference has been often observed when body parts with neighboring representations within the same hemisphere are stimulated. However, patterns of interference in early and late somatosensory processing stages due to the stimulation of different body parts have not been explored. Here, we explore functional similarities and differences between attention modulation of the somatosensory N140 and P300 elicited at the fingers vs. cheeks. In an active oddball paradigm, 22 participants received vibrotactile intensity deviant stimulation either ipsilateral or contralateral at (...) the fingers or cheeks. The ipsilateral deviant always covered a larger area of skin than the contralateral deviant. Overall, both N140 and P300 amplitudes were higher following stimulation at the cheek and N140 topographies differed between fingers and cheek stimulation. For the N140, results showed higher deviant ERP amplitudes following contralateral than ipsilateral stimulation, regardless of the stimulated body part. N140 peak latency differed between stimulated body parts with shorter latencies for the stimulation at the fingers. Regarding P300 amplitudes, contralateral deviant stimulation at the fingers replicated the N140 pattern, showing higher responses and shorter latencies than ipsilateral stimulation at the fingers. For the stimulation at the cheeks, ipsilateral deviants elicited higher P300 amplitudes and longer latencies than contralateral ones. These findings indicate that at the fingers ipsilateral deviant stimulation leads to intra-hemispheric interference, with significantly smaller ERP amplitudes than in contralateral stimulation, both at early and late processing stages. By contrast, at the cheeks, intra-hemispheric interference is selective for early processing stages. Therefore, the mechanisms of intra-hemispheric processing differ from inter-hemispheric ones and the pattern of intra-hemispheric interference in early and late processing stages is body-part specific. (shrink)

In physics, the temporal dimension has units of infinitesimally brief duration. Given this, how is it possible to perceive things, such as motion, music, and vibrotactile stimulation, that involve extension across many units of time? To address this problem, it is proposed that there is what is termed an “information construct of happening” (ICOH), a simultaneous representation of recent, temporally differentiated perceptual information on the millisecond time scale. The main features of the ICOH are (i) time marking, semantic labeling (...) of all information in the ICOH with ordinal temporal information and distance from what is informationally identified as the present moment, (ii) vector informational features that specify kind, direction, and rate of change for every feature in a percept, and (iii) connectives, information relating vector informational features at adjacent temporal locations in the ICOH. The ICOH integrates products of perceptual processing with recent historical information in sensory memory on the subsecond time scale. Perceptual information about happening in informational sensory memory is encoded in semantic form that preserves connected semantic trails of vector and timing information. The basic properties of the ICOH must be supported by a general and widespread timing mechanism that generates ordinal and interval timing information and it is suggested that state‐dependent networks may suffice for that purpose. Happening, therefore, is perceived at a moment and is constituted by an information structure of connected recent historical information. (shrink)

Central sensitization refers to the increased responsiveness of nociceptive neurons in the central nervous system after repeated or sustained peripheral nociceptor activation. It is hypothesized to play a key role in the development of chronic pain. A hallmark of central sensitization is an increased sensitivity to noxious mechanical stimuli extending beyond the injured location, known as secondary hyperalgesia. For its ability to modulate the transmission and the processing of nociceptive inputs, attention could constitute a promising target to prevent central sensitization (...) and the development of chronic pain. It was recently shown that the experimental induction of central sensitization at both forearms of healthy volunteers using bilateral high-frequency electrocutaneous stimulation (HFS), can be modulated by encouraging participants to selectively focus their attention to one arm, to the detriment of the other arm, resulting in a greater secondary hyperalgesia on the attended arm as compared to the unattended one. Given the potential value of the question being addressed, we conducted a preregistered replication study in a well-powered independent sample to assess the robustness of the effect, i.e., the modulatory role of spatial attention on the induction of central sensitization. This hypothesis was tested using a double-blind, within-subject design. Sixty-seven healthy volunteers performed a task that required focusing attention toward one forearm to discriminate innocuous vibrotactile stimuli while HFS was applied on both forearms simultaneously. Our results showed a significant increase in mechanical sensitivity directly and 20 min after HFS. However, in contrast to the previous study, we did not find a significant difference in the development of secondary hyperalgesia between the attended vs. unattended arms. Our results question whether spatial selective attention affects the development of secondary hyperalgesia. Alternatively, the non-replication could be because the bottom-up capture of attention caused by the HFS-mediated sensation was too strong in comparison to the top-down modulation exerted by the attentional task. In other words, the task was not engaging enough and the HFS pulses, including those on the unattended arm, were too salient to allow a selective focus on one arm and modulate nociceptive processing. (shrink)

Wearing a myoelectric prosthesis is a basic way for limb amputees to restore their lost limb functions in the activities of daily living. However, it is estimated that around 40% of amputees refuse the prosthesis. One of the primary reasons would be that the current prostheses lack appropriate sensory feedback. Currently, the amputees only depend on their visual feedback when using their arm prostheses. It would be difficult for them to accurately control the wrist position, which is vital for flexible (...) manipulation in ADLs. This manuscript designed a myoelectric arm prosthesis with wrist position feedback. To study the effect level of position feedback on prosthetic control, two tests were performed. The vibrotactile perception range test aims to analyze the perception sensitivity of the vibration in humans and obtain the optimal perception range utilized in the sensory feedback test. The sensory feedback test analyzes the effectiveness of the position feedback by comparing three feedback methods of Vis-FB, WP-FB, and a combination of Vis-FB and WP-FB. These tests were conducted by asking six able-bodied subjects to perform 20 movement combinations of five target positions. The WP-FB was transiently activated with five vibrating motors embedded in an armband to stimulate the arm stump when the prosthetic wrist rotates to the target positions. Our experimental results showed that when WP-FB was added to the prosthetic control, the absolute angular error of the prosthetic wrist declined from 4.50° to 1.08° while the success rate 3 increased from 0.34 to 0.84, respectively. This study demonstrates the importance of WP-FB to the effective control of the arm prosthesis. (shrink)

Haptic-based vibrotactile biofeedback (BF) is a promising technique to improve rehabilitation of balance in stroke patients. However, the extent to which BF training changes temporal structure of the center of pressure (CoP) trajectories remains unknown. This study aimed to investigate the effect of vibrotactile BF training on the temporal structure of CoP during quiet stance in chronic stroke patients using detrended fluctuation analysis (DFA). Nine chronic stroke patients (age; 81.56±44 months post-stroke) received a balance training regimen using a (...) vibrotactile BF system twice a week over four weeks. A Wii Balance board was used to record five 30 s trials of quiet stance pre- and post-training at 50 Hz. DFA revealed presence of two linear scaling regions in CoP indicating presence of fast- and slow-scale fluctuations. Averaged across all trials, fast-scale fluctuations showed persistent dynamics ( = 1.05 ±.08 for ML and  = 0.99 ±.17 for AP) and slow-scale fluctuations were anti-persistent ( = 0.35 ±.05 for ML and  = 0.32 ±.05 for AP). The slow-scale dynamics of ML CoP in stroke patients decreased from pre-training to post-BF training ( = 0.40 ±.13 vs. 0.31 ±.09). These results suggest that the vibrotactile BF training affects postural control strategy used by chronic stroke patients in the ML direction. Results of the DFA are further discussed in the context of balance training using vibrotactile BF and interpreted from the perspective of intermittent control of upright stance. (shrink)

Patient narratives from two investigational deep brain stimulation trials for traumatic brain injury and obsessive‐compulsive disorder reveal that injury and illness rob individuals of personal identity and that neuromodulation can restore it. The early success of these interventions makes a compelling case for continued post‐trial access to these technologies. Given the centrality of personal identity to respect for persons, a failure to provide continued access can be understood to represent a metaphorical identity theft. Such a loss recapitulates the pain of (...) an individual's initial injury or illness and becomes especially tragic because it could be prevented by robust policy. A failure to fulfill this normative obligation constitutes a breach of disability law, which would view post‐trial access as a means to achieve social reintegration through this neurotechnological accommodation. (shrink)

Libet discovered that a substantial duration (> 0.5-1.0 s) of direct electrical stimulation of the surface of the somatosensory cortex at threshold currents is required before human subjects can report that a conscious somatosensory experience had occurred. Using a reaction time method we confirm that a similarly long stimulation duration at threshold currents is required for activation of elementary visual experiences (phosphenes) in human subjects following stimulation of the surface of the striate cortex. However, the reaction times for the subject (...) to respond to the cessation of the visual experience after the end of electrical stimulation could be as brief as 225-242 ms. We also carried out extensive studies in cats under a variety of anesthetic conditions using the same electrodes and parameters of stimulation employed in the human studies to study the patterns of neuronal activity beneath the stimulating surface electrode. Whereas sufficiently strong currents can activate neurons within milliseconds, stimulating currents close to threshold activate sustained neural activity only after at least 350-500 ms. When currents are close to threshold, some neurons are inhibited for several hundreds of millisecond before the balance between inhibition and excitation shifts towards excitation. These results suggest that the prolonged latencies, i.e., latencies beyond 200-250 ms, for the emergence of conscious experience following direct cortical stimulation result from a delay in the sustained activation of underlying cortical neurons at threshold currents rather than being due to any unusually long duration in central processing time. Intracellular records from cortical neurological cells during repetitive electrical stimulation of the surface of the feline striate cortex demonstrate that such stimulation induces a profound depolarizing shift in membrane potential that may persist after each stimulus train. Such a depolarization is evidence that extracellular K+ concentrations have increased during electrical stimulation. Such an increase in extracellular K+ progressively increases cortical excitability until the threshold for sustained activation of cortical neurons is reached and then exceeded. Consequently, the long latency for threshold activation of cortical neurons depends upon a dynamically increasing cortical facilatory process that begins hundreds of milliseconds before there is sustained activation of such neurons. In some cases, this facilatory process must overcome an initial stimulus-induced inhibition before neuronal firing commences. (shrink)

_Riassunto_: La _Deep Brain Stimulation _(DBS) è un dispositivo annoverato tra le interfacce-cervello computer e che si qualifica come una promettente soluzione medica per far fronte al decorso di alcune malattie neurodegenerative come il Parikinson. Decenni di utilizzo clinico della DBS hanno permesso di comprenderne gli effetti collaterali e il loro impatto sul PIAAAS (_Personality, Identity, Agency, Authenticity, Autonomy and Self_). In tal senso, per sondare cambiamenti psicologici legati all’uso della DBS si è fatto ricorso a metodi quantitativi, come questionari (...) incentrati su valutazioni di ordine numerico, e metodi qualitativi, che si appoggiano alle esperienze riportate dai pazienti tramite interviste. Questo articolo ha l’obiettivo di evidenziare come, a prescindere dai metodi di indagine utilizzati, la ricerca sia stata sempre focalizzata sugli effetti collaterali della DBS e gli eventuali cambiamenti sulle dimensioni comprese nel PIAAAS, lasciandosi sfuggire l’occasione di usare i numerosi dati raccolti per effettuare un’analisi fenomenologica che potesse restituirci una descrizione della sintesi uomo-macchina. Per colmare questo iato, proponiamo l’utilizzo sinergico di due metodi di raccolta e analisi dati di origine fenomenologica. _Parole chiave_: Deep Brain Stimulation; Effetti collaterali; Sintesi uomo-macchina; Fenomenologia _Deep Brain Stimulation and the human-machine synthesis: A possible phenomenological perspective_ _Abstract_: Deep Brain Stimulation (DBS) is a device included among the brain-computer interfaces and that qualifies as a promising medical solution to cope with the course of some neurodegenerative diseases such as Parikinson’s. Decades of clinical use of DBS have allowed us to understand its side effects and their impact on PIAAAS (_Personality, Identity, Agency, Authenticity, Autonomy and Self_). In this sense, to investigate psychological changes related to the use of DBS, quantitative methods, such as questionnaires focused on numerical assessments, and qualitative techniques, which are based on experiences by patients through interviews, have been used. This article aims to highlight how, regardless of the survey methods used, research has always been focused on the side effects of DBS and possible changes in the concepts included in the PIAAAS, missing the opportunity to use the numerous data collected to carry out a phenomenological analysis that could give us a description of the human-machine synthesis. To bridge this hiatus, we propose the synergistic use of two phenomenological methods of data collection and analysis. _Keywords_: Deep Brain Stimulation; Side Effects; Human-machine synthesis; Phenomenology. (shrink)

Deep brain stimulation has been of considerable interest to bioethicists, in large part because of the effects that the intervention can occasionally have on central features of the recipient’s personality. These effects raise questions regarding the philosophical concept of authenticity. In this article, we expand on our earlier work on the concept of authenticity in the context of deep brain stimulation by developing a diachronic, value-based account of authenticity. Our account draws on both existentialist and essentialist approaches to authenticity, and (...) Laura Waddell Ekstrom’s coherentist approach to personal autonomy. In developing our account, we respond to Sven Nyholm and Elizabeth O’Neill’s synchronic approach to authenticity, and explain how the diachronic approach we defend can have practical utility, contrary to Alexandre Erler and Tony Hope’s criticism of autonomy-based approaches to authenticity. Having drawn a distinction between the authenticity of an individual’s traits and the authenticity of that person’s values, we consider how our conception of authenticity applies to the context of anorexia nervosa in comparison to other prominent accounts of authenticity. We conclude with some reflections on the prudential value of authenticity, and by highlighting how the language of authenticity can be invoked to justify covert forms of paternalism that run contrary to the value of individuality that seems to be at the heart of authenticity. (shrink)

Ethical evaluation of deep brain stimulation as a treatment for Parkinson’s disease is complicated by results that can be described as involving changes in the patient’s identity. The risk of becoming another person following surgery is alarming for patients, caregivers and clinicians alike. It is one of the most urgent conceptual and ethical problems facing deep brain stimulation in Parkinson’s disease at this time. In our paper we take issue with this problem on two accounts. First, we elucidate what is (...) meant by “becoming another person” from a conceptual point of view. After critically discussing two broad approaches we concentrate on the notion of “individual identity” which centers on the idea of “core attitudes”. Subsequently we discuss several approaches to determine what distinguishes core attitudes from those that are more peripheral. We argue for a “foundational-function model” highlighting the importance of specific dependency relations between these attitudes. Our second aim is to comment on the possibility to empirically measure changes in individual identity and argue that many of the instruments now commonly used in selecting and monitoring DBS-patients are inappropriate for this purpose. Future research in this area is advised combining a conceptual and an empirical approach as a basis of sound ethical appraisal. (shrink)

Auditory stimulation training (AST) has been proposed as a potential treatment for chil-dren with specific language impairments (SLI). The current study was designed to test this as-sumption by using an AST with technically modulated musical material (ASTM) in a random-ized control group design. A total of 101 preschool children (62 male, 39 females; mean age = 4.52 years, SD = 0.62) with deficits in speech comprehension and poor working memory ca-pacity were randomly allocated into one of two treatment groups or (...) a control group. Children in the ASTM group (n = 40) received three 30-minute sessions per week over 12 weeks, whereas children in the comparison group received pedagogical activities during these intervals (n = 24). Children in the control group (n = 37) received no treatment. Working memory, phoneme dis-crimination and speech perception skills were tested prior to (baseline) and after treatment. Chil-dren in the ASTM group showed significantly greater working memory capacity, speech per-ception, and phoneme discrimination skills after treatment, whereas children in the other groups did not show such improvement. Taken together, these results suggest that ASTM can enhance auditory cognitive performance in children with SLI. (shrink)

Objective: Electrical stimulation potentially delineates epileptogenic cortex through induction of typical seizures. Although frequently employed, its value for epilepsy surgery remains controversial. Similarly, ES is used to identify symptomatogenic zones, but with greater success and a long-standing evidence base. Recent work points to new seizure symptoms such as ictal central apnea that may enhance presurgical hypotheses. The aims of this review are 2-fold: to determine the value of ES-induced seizures in epilepsy surgery and to analyze current evidence on ICA as (...) a new surrogate of symptomatogenic cortex.Methods: Three databases were searched for ESIS. Investigators independently selected studies according to pre-specified criteria. Studies reporting postoperative outcome in patients with ESIS were included in a meta-analysis. For ES-induced apnea, a thorough search was performed and reference list searching was employed.Results: Of 6,314 articles identified for ESIS, 25 were considered eligible to be reviewed in full text. Fourteen studies were included in the qualitative synthesis ; six studies were included in the meta-analysis. The meta-analysis showed that favorable outcome is associated with ESIS prior to surgery. In addition, the overall estimation of the occurrence of favorable outcome among cases with ESIS is 68.13%. On the other hand, recent studies have shown that stimulation of exclusively mesial temporal lobe structures elicits central apnea and represents symptomatogenic anatomic substrates of ICA. This is in variance with traditional teaching that mesial temporal ES is non-symptomatogenic.Conclusions: ES is a tool highly likely to aid in the delineation of the epileptogenic zone, since ESIS is associated with favorable postoperative outcomes. There is an urgent need for prospective evaluation of this technique, including effective stimulation parameters and surgical outcomes, that will provide knowledge base for practice. In addition, ES-induced apnea studies suggest that ICA, especially when it is the first or only clinical sign, is an important semiological feature in localizing the symptomatogenic zone to mesial temporal lobe structures, which must be considered in SEEG explorations where this is planned, and in surgical resection strategies. (shrink)

Libet demonstrated that a substantial duration (>0.5-1.0 s) of direct electrical stimulation of the surface of a sensory cortex at a threshold or liminal current is required before a subject can experience a percept. Libet and his co-workers originally proposed that the result could be due either to spatial and temporal facilitation of the underlying neurons or additionally to a prolonged central processing time. However, over the next four decades, Libet chose to attribute the prolonged latency for evoking conscious experience (...) to a prolonged central processing time. In my view, Libet has not provided any convincing evidence, either on the basis of his own past work or in his critique of my paper, for his hypothesis of a central processing time exceeding 0.5s before conscious experience emerges following direct electrical threshold stimulation of the cortical surface. I stand by my original results and conclusion that such prolonged latencies are largely the consequence of a dynamically increasing cortical facilitatory process that begins hundreds of milliseconds before there is a sustained neuronal activation. In some cases, the facilitatory process must overcome an initial stimulus-induced inhibition before neuronal firing commences. (shrink)

One of the topics that often comes up in ethical discussions of deep brain stimulation (DBS) is the question of what impact DBS has, or might have, on the patient’s self. This is often understood as a question of whether DBS poses a “threat” to personal identity, which is typically understood as having to do with psychological and/or narrative continuity over time. In this article, we argue that the discussion of whether DBS is a “threat” to continuity over time is (...) too narrow. There are other questions concerning DBS and the self that are overlooked in discussions exclusively focusing on psychological and/or narrative continuity. For example, it is also important to investigate whether DBS might sometimes have a positive (e.g. a rehabilitating) effect on the patient’s self. To widen the discussion of DBS, so as to make it encompass a broader range of considerations that bear on DBS’s impact on the self, we identify six features of the commonly used concept of a person’s “true self”. We apply these six features to the relation between DBS and the self. And we end with a brief discussion of the role DBS might play in treating otherwise treatment-refractory anorexia nervosa. This further highlights the importance of discussing both continuity over time and the notion of the true self. (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 has been used to treat advanced Parkinson disease and other neurological and psychiatric disorders that have not responded to other treatments. While deep-brain stimulation can modulate overactive or underactive regions of the brain and thereby improve motor function, it can also cause changes in a patient’s thought and personality. This paper discusses the trade-offs between the physiological benefit of this technique and the potential psychological harm.

Deep Brain Stimulation (DBS) is a relatively new, experimental treatment for patients suffering from treatment-refractory Obsessive Compulsive Disorder (OCD). The effects of treatment are typically assessed with psychopathological scales that measure the amount of symptoms. However, clinical experience indicates that the effects of DBS are not limited to symptoms only: patients for instance report changes in perception, feeling stronger and more confident, and doing things unreflectively. Our aim is to get a better overview of the whole variety of changes that (...) OCD patients experience during DBS treatment. For that purpose we conducted in-depth, semi-structured interviews with 18 OCD patients. In this paper, we present the results from this qualitative study.We list the changes grouped in four domains: with regard to (a) person, (b) (social) world, (c)characteristics of person-world interactions, and (d) existential stance. We subsequently provide an interpretation of these results. In particular, we suggest that many of these changes can be seen as different expressions of the same process; namely that the experience of anxiety and tension gives way to an increased basic trust and increased reliance on one’s abilities. We then discuss the clinical implications of our findings, especially with regard to properly informing patients of what they can expect from treatment, the usefulness of including CBT in treatment, and the limitations of current measures of treatment success. We end by making several concrete suggestions for further research. (shrink)

Multidisciplinary healthcare committees meet regularly to discuss patients’ candidacy for emerging functional neurosurgical procedures, such as Deep Brain Stimulation . Through debate and discussion around the surgical candidacy of particular patients, functional neurosurgery programs begin to mold practice and policy supported both by scientific evidence and clear value choices. These neurosurgical decisions have special considerations not found in non-neurologic committees. The professional time used to resolve these conflicts provides opportunities for the emergence of careful, ethical practices simultaneous with the expansion (...) of therapy applications. (shrink)

Owing to technological advances, genomic medicine is moving from specific to broader genetic analyses and from specialised to mainstream services. Sahan et al 1 point to complex ethical cases encountered by clinical laboratory scientists in the context of genomic medicine’s expansion. The authors discuss debates on interpreting and reporting genetic results, offering extended genetic testing and differences in the perceived responsibility of clinical laboratory scientists in different settings. As demonstrated by the case examples in the article, while genomic medicine holds (...) the promise of providing clinical answers, its mainstreaming can introduce a new type of ‘odyssey’ for patients and/or relatives, such as when there are uncertain findings. The integration of genomics in healthcare at large can also impact communication decisions and perceptions of responsibility for clinical laboratory scientists. Clinical laboratory scientists might report less to non-specialists than to genetic/genomic specialists, as they feel responsible for minimising the potential of non-specialists misunderstanding, misinterpreting or miscommunicating the genetic findings to patients.1 In this way, the perceived responsibility affects patients and the type and amount of genetic information they receive. We agree with the authors that current limitations in knowledge and capabilities among non-specialist clinicians necessitate identifying effective ways to communicate outcomes and …. (shrink)

In this paper, we engage in dialogue with Jonathan Pugh, Hannah Maslen, and Julian Savulescu about how to best interpret the potential impacts of deep brain stimulation on the self. We consider whether ordinary people’s convictions about the true self should be interpreted in essentialist or existentialist ways. Like Pugh et al., we argue that it is useful to understand the notion of the true self as having both essentialist and existentialist components. We also consider two ideas from existentialist philosophy (...) – Jean-Paul Sartre and Simone de Beauvoir’s ideas about “bad faith” and “ambiguity” – to argue that there can be value to patients in regarding themselves as having a certain amount of freedom to choose what aspects of themselves should be considered representative of their true selves. Lastly, we consider the case of an anorexia nervosa-patient who shifts between conflicting mind-sets. We argue that mind-sets in which it is easier for the patient and his or her family to share values can plausibly be considered to be more representative of the patient’s true self, if this promotes a well-functioning relationship between the patient and the family. However, we also argue that families are well-advised to give patients room to figure out what such shared values mean to them, since it can be alienating for patients if they feel that others try to impose values on them from the outside. (shrink)

Davis called for “extreme caution” in the use of non-invasive brain stimulation to treat neurological disorders in children, due to gaps in scientific knowledge. We are sympathetic to his position. However, we must also address the ethical implications of applying this technology to minors. Compensatory trade-offs associated with NIBS present a challenge to its use in children, insofar as these trade-offs have the effect of limiting the child’s future options. The distinction between treatment and enhancement has some normative force here. (...) As the intervention moves away from being a treatment toward being an enhancement—and thus toward a more uncertain weighing of the benefits, risks, and costs—considerations of the child’s best interests diminish, and the need to protect the child’s autonomy looms larger. NIBS for enhancement involving trade-offs should therefore be delayed, if possible, until the child reaches a state of maturity and can make an informed, personal decision. NIBS for treatment, by contrast, is permissible insofar as it can be shown to be at least as safe and effective as currently approved treatments, which are themselves justified on a best interests standard. (shrink)

Although being generally safe, the use of Deep Brain Stimulation has been associated with a significant number of patients experiencing postoperative psychological and neurological harm within experimental trials. A proportion of these postoperative severe adverse effects have lead to the decision to medically prescribe device deactivation or removal. However, there is little debate in the literature as to what is in the patient’s best interest when device removal has been prescribed; in particular, what should be the conceptual approach to ethically (...) guide the decision to remove or maintain implants. The purpose of this article is to examine the ethical issues raised when patients refuse brain device explantation despite medical prescription. In order to illustrate these issues, we report and discuss a clinical case involving a patient suffering from treatment resistant depression who experienced forms of postoperative self-estrangement, as well as suicidal attempts, but who resists giving consent to device explantation. (shrink)

We whole-heartedly agree with Mecacci and Haselager(2014) on the need to investigate the psychosocial effects of deep brain stimulation (DBS), and particularly to find out how to prevent adverse psychosocial effects. We also agree with the authors on the value of an embodied, embedded, enactive approach (EEC) to the self and the mind–brain problem. However, we do not think this value primarily lies in dissolving a so-called “maladaptation” of patients to their DBS device. In this comment, we challenge three central (...) claims of the authors on the basis of our direct experience with psychosocial effects of DBS in 45 obsessive- compulsive disorder (OCD) patients treated at the AMC in Amsterdam, The Netherlands, and our indepth qualitative interviews with 18 of them (de Haan et al. 2013). We end our comment by sketching out our perspective on the practical merits of an EEC approach to DBS. (shrink)

The expansion of research on deep brain stimulation (DBS) and adaptive DBS (aDBS) raises important neuroethics and policy questions related to data sharing. However, there has been little empirical research on the perspectives of experts developing these technologies. We conducted semi-structured, open-ended interviews with aDBS researchers regarding their data sharing practices and their perspectives on ethical and policy issues related to sharing. Researchers expressed support for and a commitment to sharing, with most saying that they were either sharing their data (...) or would share in the future and that doing so was important for advancing the field. However, those who are sharing reported a variety of sharing partners, suggesting heterogeneity in sharing practices and lack of the broad sharing that would reflect principles of open science. Researchers described several concerns and barriers related to sharing, including privacy and confidentiality, the usability of shared data by others, ownership and control of data (including potential commercialization), and limited resources for sharing. They also suggested potential solutions to these challenges, including additional safeguards to address privacy issues, standardization and transparency in analysis to address issues of data usability, professional norms and heightened cooperation to address issues of ownership and control, and streamlining of data transmission to address resource limitations. Researchers also offered a range of views on the sensitivity of neural activity data (NAD) and data related to mental health in the context of sharing. These findings are an important input to deliberations by researchers, policymakers, neuroethicists, and other stakeholders as they navigate ethics and policy questions related to aDBS research. (shrink)

Although philosophers have explored several connections between neuroscience and moral responsibility, the issue of how real-world neurological modifications, such as Deep Brain Stimulation, impact moral responsibility has received little attention. In this article, we draw on debates about the relevance of history and manipulation to moral responsibility to argue that certain kinds of neurological modification can diminish the responsibility of the agents so modified. We argue for a historicist position - a version of the history-sensitive reflection view - and defend (...) that account against a rival, relational view of responsibility. We conclude that DBS can, under certain conditions, diminish responsibility, and explore the circumstances under which this might be so. We conclude by suggesting that philosophical debates about moral responsibility, manipulation, and history have greater practical relevance than is sometimes thought, and that attention to practical cases can help inform and deepen this body of scholarship. (shrink)

Many studies have discussed the neural basis of asset bubbles. They found that the dorsolateral prefrontal cortex (DLPFC) played an important role in bubble formation, but whether a causal relationship exists and the mechanism of the effect of the DLPFC on bubbles remains unsettled. Using transcranial direct current stimulation (tDCS), we modulated the activity of the DLPFC and investigated the causal relationship between the DLPFC and the asset bubble in the classical learning-to-forecast experiment. 126 subjects were randomly divided into three (...) groups and received different stimulations (left anodal/right cathodal, right anodal/left cathodal or sham stimulation) respectively. We also conducted a 2-back task before and after stimulation to measure changes in subjects’ cognitive abilities and explore in detail the cognitive mechanism of the effect of DLPFC stimulation on asset bubbles. Based on our results, we found that the bubble of the left anodal/right cathodal stimulation group was significantly smaller than that of the sham stimulation group. In the meantime, subjects performed significantly better in the 2-back task after left anodal/right cathodal stimulation but not right anodal/left cathodal or sham stimulation, which is consistent with their performance in the learning-to-forecast experiment, supporting the cognitive mechanism to some extent. Furthermore, we examined different forecasting rules across individuals and discovered that the left anodal/right cathodal stimulation group preferred the adaptive learning rule, while the sham and right anodal/left cathodal stimulation groups adopted a pure trend-following rule that tended to intensify market volatility aggressively. (shrink)

The goal of this article is to shed light on Deep Brain Stimulation (DBS) postoperative suicidality risk factors within Treatment Resistant Depression (TRD) patients, in particular by focusing on the ethical concern of enrolling patient with history of self-estrangement, suicide attempts and impulsive–aggressive inclinations. In order to illustrate these ethical issues we report and review a clinical case associated with postoperative feelings of self-estrangement, self-harm behaviours and suicide attempt leading to the removal of DBS devices. Could prospectively identifying and excluding (...) patients with suicidality risk factors from DBS experimental trials—such as history of self-estrangement, suicide attempts and impulsive–aggressive inclinations—lead to minimizing the risk of suicidality harm? (shrink)

Elevations in brain stimulation reward (BSR) thresholds have been observed in rats undergoing nicotine withdrawal and have been proposed as a sensitive measure of the negative affective state associated with nicotine withdrawal. mGluR are presynaptic autoreceptors that decrease glutamate release when stimulated. The aim of this study was to examine the role of glutamate neurotransmission in nicotine dependence. The mGluR agonist LY314582 (2.5–7.5 mg/kg) precipitated nicotine withdrawal as measured by elevations in BSR thresholds in nicotine-treated rats but not in controls. (...) It was hypothesized that LY314582 precipitated nicotine withdrawal by decreasing glutamatergic tone at postsynaptic glutamate receptors. Therefore, the effects of MPEP (0.5–2 mg/kg), an mGluR antagonist, and MK-801 (0.01–1 mg/kg), an NMDA receptor antagonist, were examined. MPEP elevated BSR thresholds by an equal magnitude in control and nicotine-treated rats. At low doses, MK-801 (0.01–0.2 mg/kg) lowered BSR thresholds to a similar extent in control and nicotine-treated rats. At higher doses, MK-801 (0.25–1 mg/kg) disrupted performance in nicotine-treated and control rats. These data indicate that mGluR and NMDA receptors regulate BSR in opposite directions in non-dependent animals, and chronic nicotine treatment does not alter these effects. Most importantly, the data demonstrate that the mGluR is involved in nicotine dependence, but mGluR and NMDA receptors do not mediate mGluR actions in nicotine dependence. (shrink)

Attentional selection biases the processing of higher visual areas to particular parts of a scene. Recent experiments show how stimulation of neurons in the frontal eye fields can mimic this process.

Researchers are enthusiastically concerned about neural stem cell (NSC) therapy in a wide array of diseases, including stroke, neurodegenerative disease, spinal cord injury (SCI) and depression. Although enormous evidences have demonstrated that neurobehavioral improvement may benefit from NSC-supporting regeneration in animal models, approaches to endogenous and transplanted NSCs are blocked by hurdles of migration, proliferation, maturation and integration of NSCs. Electrical stimulation (ES) may be a selective nondrug approach for mobilizing NSCs in the central nervous system (CNS). This technique is (...) suitable for clinic application, because it is well established and its potential complications are manageable. Here, we provide a comprehensive review of the emerging positive role of different electrical cues in regulating NSC biology in vitro and in vivo, as well as biomaterial-based and chemical stimulation of NSCs. In the future, ES combined with stem cell therapy or other cues probably becomes an approach for promoting brain repair. (shrink)