Reactive theories of responsibility see moral accountability as grounded on the capacity for feeling reactive-attitudes. I respond to a recent argument gaining ground in this tradition that excludes psychopaths from accountability. The argument relies on what Paul Russell has called the 'subjectivity requirement'. On this view, the capacity to feel and direct reactive-attitudes at oneself is a necessary condition for responsibility. I argue that even if moral attitudes like guilt are impossible for psychopaths to deploy, that psychopaths, especially the "successful" (...) and "secondary" subtypes of psychopathy, can satisfy the subjectivity requirement with regard to shame. I appeal to evidence that embarrassment and shame are grounded on the same affective process and data that psychopathic judgments about embarrassment are neurotypical. If I am right, then psychopaths ought to be open to shame-based forms of accountability including shame punishments. I conclude by considering why psychopaths rarely self-report shame. I argue that lacking a capacity to see oneself as flawed is a different sort of failure than lacking the capacity to feel. (shrink)

The notion of epistemic coherence is interpreted as involving not only consistency but also stability. The problem how to consolidate a belief system, i.e., revise it so that it becomes coherent, is studied axiomatically as well as in terms of set-theoretical constructions. Representation theorems are given for subtractive consolidation (where coherence is obtained by deleting beliefs) and additive consolidation (where coherence is obtained by adding beliefs).

Review of The Ethics of Virtual and Augmented Reality: Building Worlds, written by Erick Jose Ramirez.

This Article examines ability taxation, which is a tax on a person’s earning ability or potential earnings, rather than earned income. Despite this regime’s longstanding favor as a theoretical ideal for fair and efficient taxation among public finance economists, certain political philosophers, and tax law scholars, insufficient effort has been made to provide an analysis of what ‘potential earnings’ means. This Article explores competing understandings of this notion, and situates them within a multipart taxonomy. In so doing, it unearths a (...) tension at the core of the ability tax program involving a fundamental misalignment between the metaphysics (or correct conceptual analysis) of potential earnings and the economics of its taxation. It concludes that once we correctly understand its requirements, we should reject ability taxation as the first-best normative ideal it has been held out to be on the grounds that it is overly burdensome and unfair to certain individuals. (shrink)

We argue that moral judgment studies currently conducted utilizing virtual reality (VR) devices must confront a dilemma due to how virtual environments are designed and how those environments are experienced. We begin by first describing the contexts present in paradigmatic cases of naturalistic moral judgments. We then compare these contexts to current traditional (vignette-based) and VR-based moral judgment research. We show that, contra to paradigmatic cases, vignette-based and VR-based moral judgment research often fails to accurately model the situational features of (...) paradigmatic moral judgments. In particular, we compare and contrast six recent VR studies to support our view that only simulations high in context-realism and perspectival-fidelity can produce ‘virtually real experiences.’ After analyzing the constituents of a virtually-real experience, we go on to propose guidelines for the creation of VR studies. These guidelines serve two purposes. First, we aim to increase the ecological validity of such studies in order to advance our understanding of moral judgments. Second, we believe that such guidelines should inform how Institutional Review Boards assess VR research. We show that our guidelines are urgently needed given the current lax review standards in place. (shrink)

We study the impact of a kind of non‐archimedean stratifications (t‐stratifications) on tangent cones of definable sets in real closed fields. We prove that such stratifications induce stratifications of the same nature on the tangent cone of a definable set at a fixed point. As a consequence, the archimedean counterpart of a t‐stratification is shown to induce Whitney stratifications on the tangent cones of a semi‐algebraic set. Extensions of these results are proposed for real closed fields with further structure.

We study properties of definable sets and functions in power-bounded T -convex fields, proving that the latter have the multidimensional Jacobian property and that the theory of T -convex fields is b -minimal with centers. Through these results and work of I. Halupczok we ensure that a certain kind of geometrical stratifications exist for definable objects in said fields. We then discuss a number of applications of those stratifications, including applications to Archimedean o-minimal geometry.

The Gamer's Dilemma challenges us to find a distinction between virtual murder and virtual pedophilia. Without such a distinction, we are forced to conclude that either both are morally acceptable or that both should be morally illicit. This paper argues that the best way to solve the dilemma is, in one sense, to dissolve it. The Gamer's Dilemma rests on a misunderstanding in the sense that it does not distinguish between the form of a simulation and its surface content. A (...) greater appreciation of the way structural features of a simulation affect subject experience will help us see why only simulations of murder and pedophilia generating virtually real experiences are likely to be seen as wrong. I argue that a simulation’s structural elements powerfully affect how subjects experience simulated content and hence is an important, and previously neglected, variable necessary to dissolve the Gamer's Dilemma. Properly understood, virtually real simulations of murder and pedophilia are both likely to be treated by players as morally wrong. Similarly, virtually unreal murder and pedophilia will be less likely to be judged as wrong. Subject judgments are thus consistent once a simulation’s structural variables are accounted for. The Gamer's Dilemma dissolves as a dilemma once we acknowledge these structural features of simulations and how they affect experience and moral judgment. (shrink)

In this article, we apply the literature on the ethics of choice-architecture (nudges) to the realm of virtual reality (VR) to point out ethical problems with using VR for empathy-based nudging. Specifically, we argue that VR simulations aiming to enhance empathic understanding of others via perspective-taking will almost always be unethical to develop or deploy. We argue that VR-based empathy enhancement not only faces traditional ethical concerns about nudge (autonomy, welfare, transparency), but also a variant of the semantic variance problem (...) that arises for intersectional perspective-taking. VR empathy simulations deceive and manipulate their users about their experiences. Despite their often laudable goals, such simulations confront significant ethical challenges. In light of these goals and challenges, we conclude by proposing that VR designers shift from designing simulations aimed at producing empathic perspective-taking to designing simulations aimed at generating sympathy. These simulations, we claim, can avoid the most serious ethical issues associated with VR nudges, semantic variance, and intersectionality. (shrink)

In this paper, we argue that, under a specific set of circumstances, designing and employing certain kinds of virtual reality (VR) experiences can be unethical. After a general discussion of simulations and their ethical context, we begin our argu-ment by distinguishing between the experiences generated by different media (text, film, computer game simulation, and VR simulation), and argue that VR experiences offer an unprecedented degree of what we call “perspectival fidelity” that prior modes of simulation lack. Additionally, we argue that (...) when VR experiences couple this perspectival fidelity with what we call “context realism,” VR experiences have the ability to produce “virtually real experiences.” We claim that virtually real experiences generate ethical issues for VR technologies that are unique to the medium. Because subjects of these experiences treat them as if they were real, a higher degree of ethical scrutiny should be applied to any VR scenario with the potential to generate virtually real experiences. To mitigate this unique moral hazard, we propose and defend what we call “The Equivalence Principle.” This principle states that “if it would be wrong to allow subjects to have a certain experience in reality, then it would be wrong to allow subjects to have that experience in a virtually real setting.” We argue that such a principle, although limited in scope, should be part of the risk analysis conducted by any Institutional Review Boards, psychologists, empirically oriented philosophers, or game designers who are using VR technology in their work. (shrink)

© 2015 Thessen et al.Understanding the interplay between environmental conditions and phenotypes is a fundamental goal of biology. Unfortunately, data that include observations on phenotype and environment are highly heterogeneous and thus difficult to find and integrate. One approach that is likely to improve the status quo involves the use of ontologies to standardize and link data about phenotypes and environments. Specifying and linking data through ontologies will allow researchers to increase the scope and flexibility of large-scale analyses aided by (...) modern computing methods. Investments in this area would advance diverse fields such as ecology, phylogenetics, and conservation biology. While several biological ontologies are well-developed, using them to link phenotypes and environments is rare because of gaps in ontological coverage and limits to interoperability among ontologies and disciplines. In this manuscript, we present use cases from diverse disciplines to illustrate questions that could be answered more efficiently using a robust linkage between phenotypes and environments, two proof-of-concept analyses that show the value of linking phenotypes to environments in fishes and amphibians, and two proposed example data models for linking phenotypes and environments using the extensible observation ontology and the Biological Collections Ontology ; these provide a starting point for the development of a data model linking phenotypes and environments. (shrink)

This article criticizes what it calls perspectival thought experiments, which require subjects to mentally simulate a perspective before making judgments from within it. Examples include Judith Thomson's violinist analogy, Philippa Foot's trolley problem, and Bernard Williams's Jim case. The article argues that advances in the philosophical and psychological study of empathy suggest that the simulative capacities required by perspectival thought experiments are all but impossible. These thought experiments require agents to consciously simulate necessarily unconscious features of subjectivity. To complete these (...) experiments subjects must deploy theory-theoretical frameworks to predict what they think they would do. These outputs, however, systematically mislead subjects and are highly prone to error. They are of negligible probative value, and this bodes poorly for their continued use. The article ends with two suggestions. First, many thought experiments are not problematically perspectival. Second, it should be possible to carry out “in-their-shoes” perspectival thought experiments by off-loading simulations onto virtual environments into which philosophers place subjects. (shrink)

In popular culture psychopaths are inaccurately portrayed as serial killers or homicidal maniacs. Most real-world psychopaths are neither killers nor maniacs. Psychologists currently understand psychopathy as an affective disorder that leads to repeated criminal and antisocial behavior. Counter to this prevailing view, I claim that psychopathy is not necessarily linked with criminal behavior. Successful psychopaths, an intriguing new category of psychopathic agent, support this conception of psychopathy. I then consider reactive attitude theories of moral responsibility. Within this tradition, psychopaths are (...) thought to be blameless as a result of their pronounced affective deficits. Psychopaths are considered morally blind because they lack the moral emotions that make us sensitive to moral reasons. I argue that, even if they are morally blind, psychopaths remain open to forms of blame stemming from non-moral reactive attitudes. These reactive attitudes remain appropriate because psychopaths can express hateful, disgusting, or contemptible non-moral values in their judgments. (shrink)

This volume highlights interdisciplinary research on the ethical, metaphysical, and experimental dimensions of extended reality technologies, including virtual and augmented realities. It explores themes connected to the nature of virtual objects, the value of virtual experiences and relationships, experimental ethics, moral psychology in the metaverse, and game/simulation design. -/- Extended reality (XR) refers to a family of technologies aiming to augment (AR) or virtually replace (VR) human experience. The chapters in this volume represent cutting-edge research on XR experiences from a (...) wide range of approaches including philosophy, psychology, Africana studies, and cognitive sciences. They are organized around three guiding questions. Part 1, “What is Extended Reality?”, contains a series of chapters examining metaphysical questions about virtual objects, actions, and worlds. Part 2, “Is There an Ethics for Extended Realities?”, includes chapters that address ethical questions that arise within XR experiences. Finally, Part 3, “What Can We Do with Extended Realities?”, features chapters from a diverse group of social scientists on the potential uses of XR as an investigative and educational tool, including its strengths and pitfalls. (shrink)

I argue that psychopathy undermines three common assumptions typically invoked in favor of moderate reasons responsive theories of moral responsibility. First, I propose a theory of psychopathic agency and claim that psychopathic agency suggests that the systems underlying receptivity to reason bifurcate into at least two sub-systems of receptivity. Next, I claim that the bifurcation of systems for receptivity suggests that reactivity is not “all of a piece” but that it too decomposes into at least two subsystems. Lastly, I argue (...) that prior attempts by Fischer and Ravizza to address these concerns contain an appeal to internalism. Since Fischer and Ravizza want their theory to remain agnostic about the nature of reasons for action, this appeal to internalism is problematic for their view. I close by suggesting that if we are to make sense of when and why psychopaths are responsible then a mechanism-based theory of responsibility must be able to explain how different systems of receptivity and reactivity come together to constitute a single mechanism that grounds responsibility ascriptions for action and they must do so without tacitly appealing to implausible forms of internalism about reasons for action. (shrink)

We aim to generate a dilemma for virtual reality-based research that we motivate through an extended case study of Judith Thomson’s (1985) Bridge variant of the trolley problem. Though the problem we generate applies more broadly than the Bridge problem, we believe it makes a good exemplar of the kind of case we believe is problematic. First, we argue that simulations of these thought experiments run into a practicality horn that makes it practically impossible to produce them. These problems revolve (...) around concepts that we call “perspectival fidelity”and “context realism.” Moral dilemmas that include features present in the Bridge variant will, as a result, be practically impossible to simulate. We also argue that, should we be wrong about the practical impossibility of creating a VR simulation of Bridge, such a simulation must face an ethical horn which renders these simulations ethically impermissible to develop or use. For these reasons, we argue that it is virtually impossible to simulate the bridge problem (and other thought experiments with similar features) both practically and ethically in VR. (shrink)

In this paper, we assess the impact of extended reality technologies as they relate to sexual forms of harassment. We begin with a brief history of the nature of sexual harassment itself. We then offer an account of extended reality technologies focusing specifically on psychological and hardware elements most likely to comprise what has been referred to as “the metaverse”. Although different forms of virtual spaces exist (i.e., private, semi-private, and public), we focus on public social metaverse spaces. We do (...) this to better explain how the concept of sexual harassment must be adjusted to such spaces and how approaches aimed at mitigating harassment must be sensitive to the type of metaverse spaces users utilize. We then offer a typology of sexual harassment for the metaverse focusing on three distinct forms of sexual harassment: (1) invariant (2) mixed variance or modified and (3) unique or metaverse specific. Although existing normative and legal frameworks may function well with respect to the first and, possibly, second forms of harassment, we argue such frameworks will not helpfully address metaverse-specific harassment. Ultimately, the changing nature of privately owned public spaces (POPS) which metaverses are likely to represent pose distinct ethical and regulatory challenges. (shrink)

This paper makes two essential claims about the nature of shame and shame punishment. I argue that, if we properly understand the nature of shame, that it is sometimes justifiable to shame others in the context of a pluralistic multicultural society. I begin by assessing the accounts of shame provided by Cheshire Calhoun (2004) and Julien Deonna, Raffaele Rodogno, & Fabrice Teroni (2012). I argue that both views have problems. I defend a theory of shame and embarrassment that connects both (...) emotions to “whole-self” properties. Shame and embarrassment, I claim, are products of the same underlying emotion. I distinguish between moralized and nonmoralized shame in order to show when, and how, moral and non-moral shame may be justly deployed. Shame is appropriate, I argue, if and only if it targets malleable moral or non-moral normative imperfections of a person’s ‘whole-self.’ Shame is unjustifiable when it targets durable aspects of a person’s “whole-self.” I conclude by distinguishing shame punishments from guilt punishments and show that my account can explain why it is wrong to shame individuals on account of their race, sex, gender, or body while permitting us to sometimes levy shame and shame punishment against others, even those otherwise immune to moral reasons. (shrink)

I argue that deep brain stimulation (DBS) is a bad approach for incarcerated psychopaths for two reasons. First, given what we know about psychopathy, empathy, and DBS, it is unlikely to function as an effective treatment for the moral problems that characterize psychopathy. Second, considerations of neurodiversity speak against seeing psychopathy as a mental illness in the first place.

In this chapter, we consider, and reject, the claim that all elderly patients’ desires for suicide are irrational. The same reasons that have led to a growing acceptance for the rationality of suicide in terminal cases should lead us to view other desires for suicide as possibly rational. In both cases, desires for suicide can and do materialize in the absence of mental illness. Furthermore, we claim that desires for suicide can remain rational even in the face of some mental (...) illnesses so long as four criteria are met: individuals must demonstrate rationality, have realistic information and judgments about their life-world, be in a state of mind (e.g., their emotions and will) that is not be severely compromised by mental illness, and make choices that are congruent with their fundamental values and critical interests. We conclude that some rational suicides can be ethically justifiable. (shrink)

Jesse Prinz's The Emotional Construction of Morals is an ambitious and intriguing contribution to the debate about the nature and role of emotion within moral psychology. I review Prinz's recent claims surrounding the nature of emotional concepts as ?embodied representations of concern? and survey his later arguments meant to establish a form of cultural relativism. Although I suggest that other theories of emotional representation (i.e. prototype views) would better serve Prinz's aims, the underlying meta-ethical relativism that results is well defended (...) and represents a significant advance for constructivist Sentimentalists. (shrink)

A virtual reality module that incorporates a training room (for subjects to become accommodated to virtual environments) and VR translations of Philippa Foot's Trolley Problem and Judith Thomson's Violinist thought experiment. -/- These modules are free to use for classroom or research/x-phi purposes. This set of modules is optimized for the HTC Vive. If you have an Oculus Rift, please see our VR modules optimized for the rift. -/- *Requires an HTC Vive and VR capable computer. To access the simulation, (...) uncompress the .zip folder and run the executable (.exe) file. (shrink)

Philosophy of Mental Illness The Philosophy of Mental Illness is an interdisciplinary field of study that combines views and methods from the philosophy of mind, psychology, neuroscience, and moral philosophy in order to analyze the nature of mental illness. Philosophers of mental illness are concerned with examining the ontological, epistemological, and normative issues arising from […].

A virtual reality translation of Robert Nozick's "Experience Machine" thought experiment from his "Anarchy, State, and Utopia" (1974). These modules are free to download and use in the classroom and for research/x-phi purposes. NPCs are randomized for gender during startup of each run. *Requires an Oculus Rift or HTC Vive and VR capable computer. To open the files, uncompress the downloaded .zip folder and run the executable (.exe) file. -/- V1.2 Fixed missing projector video footage during experience machine sales pitch.

A virtual reality translation of Philippa Foot's original "Trolley Problem." These modules are free to download and use in the classroom and for research/x-phi purposes. -/- *Requires an Oculus Rift or HTC Vive and VR capable computer. To open the files, uncompress the downloaded .zip folder and run the executable (.exe) file.

This is a virtual reality simulation that imagines its subject as emerging from a long stint in Robert Nozick's "Experience Machine." The simulation is an interview (with many branching paths) meant to gauge the subject's views on the metaphysics of virtual objects and the ethics of virtual actions. It draws heavily from the published work of David Chalmers, Mark Silcox, Jon Cogburn, Morgan Luck, and Nick Bostrom. *Requires an Oculus Rift (or Rift-S) or HTC Vive and a VR capable computer. (...) To open the files, uncompress the downloaded .zip folder and run the executable (.exe) file. **This module is made possible due to an APA Small Grant and a grant from Oculus Education. (shrink)

A virtual reality translation of Judith Thomson's Violinist Analogy. These modules are free to download and use in the classroom and for research/x-phi purposes. -/- *Requires an Oculus Rift or HTC Vive and VR capable computer. To open the files, uncompress the downloaded .zip folder and run the executable (.exe) file.

Philosophers and psychologists often claim that moral agency is connected with the ability to feel, understand, and deploy moral emotions. In this chapter, I investigate the nature of these emotions and their connection with moral agency. First, I examine the degree to which these emotional capacities are innate and/or ‘basic’ in a philosophically important sense. I examine three senses in which an emotion might be basic: developmental, compositional, and phylogenetic. After considering the evidence for basic emotion, I conclude that emotions (...) are not basic in a philosophically important sense. Emotions, I argue, are best understood as socially constructed concepts. I then investigate whether these emotions are necessary for moral agency. In order to do this I examine the philosophical and psychological literature on psychopathy and autism (two conditions defined in terms of empathic and emotional deficits). Persons with psychopathy appear incapable of distinguishing moral from non-moral norms. Additionally, while persons with autism often struggle to develop their empathic capacities, they are capable of understanding and deploying moral emotions like guilt and shame. I conclude that, in line with the conceptual act theories of emotion, that only contagion-based empathy is necessary for the acquisition of moral concepts. (shrink)

The commercial VR/AR marketplace is gaining ground and is becoming an ever larger and more significant component of the global economy. While much attention has been paid to the commercial promise of VR/AR, comparatively little attention has been given to the ethical issues that VR/AR technologies introduce. We here examine existing codes of ethics proposed by the ACM and IEEE and apply them to the unique ethical facets that VR/AR introduces. We propose a VR/AR code of ethics for developers and (...) apply this code to several commercial applications. (shrink)

This book offers new ways of thinking about and assessing the impact of virtual reality on its users. It argues that we must go beyond traditional psychological concepts of VR "presence" to better understand the many varieties of virtual experiences. -/- The author provides compelling evidence that VR simulations are capable of producing "virtually real" experiences in people. He also provides a framework for understanding when and how simulations induce virtually real experiences. From these insights, the book shows that virtually (...) real experiences are responsible for several unaddressed ethical issues in VR research and design. Experimental philosophers, moral psychologists, and institutional review boards must become sensitive to the ethical issues involved between designing "realistic" virtual dilemmas, for good data collection, and avoiding virtually real trauma. Ethicists and game designers must do more to ensure that their simulations don’t inculcate harmful character traits. Virtually real experiences, the author claims, can make virtual relationships meaningful, productive, and conducive to welfare but they can also be used to systematically mislead and manipulate users about the nature of their experiences. -/- The Ethics of Virtual and Augmented Reality will appeal to philosophers working in applied ethics, philosophy of technology, and aesthetics, as well as researchers and students interested in game studies and game design. (shrink)

El objeto de este artículo es tratar el tema del fin último o felicidad en la ética de Aritótles, y específicamente en la Ética a Nicómaco, pero distinguiéndolo en tres temas que no deben confundirse: el fin de la política como disciplina arquitectónica, el fin de la vida humana buena y la felicidad. Aunque estos dos fines y la felicidad, según Aristóteles, son lo mismo, podría decirse, usando una expresión muy suya, que “su esencia no es lo misma”. El tratamiento (...) separado de estos aspectos puede clarificar más de una confusión u oscuridad, y su articulación, una vez distinguidos, permite ordenar los principales temas generales de la ética aristotélica. (shrink)

© 2015 Elsevier B.V.This article demonstrates an instrumented mouthguard capable of non-invasively monitoring salivary uric acid levels. The enzyme -modified screen printed electrode system has been integrated onto a mouthguard platform along with anatomically-miniaturized instrumentation electronics featuring a potentiostat, microcontroller, and a Bluetooth Low Energy transceiver. Unlike RFID-based biosensing systems, which require large proximal power sources, the developed platform enables real-time wireless transmission of the sensed information to standard smartphones, laptops, and other consumer electronics for on-demand processing, diagnostics, or storage. (...) The mouthguard biosensor system offers high sensitivity, selectivity, and stability towards uric acid detection in human saliva, covering the concentration ranges for both healthy people and hyperuricemia patients. The new wireless mouthguard biosensor system is able to monitor SUA level in real-time and continuous fashion, and can be readily expanded to an array of sensors for different analytes to enable an attractive wearable monitoring system for diverse health and fitness applications. (shrink)

The Wnt/β-catenin pathway is constitutively activated in more than 90% of human colorectal cancer. Activated β-catenin stimulates cell proliferation and survival, however, its antiapoptotic mechanisms are not fully understood. We show here that activated β-catenin is required to suppress caspase-8 activation, but only in colon cancer cells that are resistant to tumor necrosis factor-a -induced apoptosis. We found that lysosomal delivery of internalized TNF occurred at a faster pace in apoptosis-resistant than in apoptosis-sensitive colon cancer cells. Retardation of endosomal trafficking (...) through vacuolar ATPase inhibition enhanced caspase-8 activation in apoptosis-resistant but not apoptosis-sensitive cells. Interestingly, knockdown of β-catenin also prolonged TNF association with the early endosome and enhanced caspase-8 activation in apoptosis-resistant but not apoptosis-sensitive colon cancer cells. In a mouse model of inflammation-associated colon tumors, we found nuclear expression of β-catenin, resistance to TNF-induced apoptosis, and reactivation of apoptosis in vivo after cotreatment of TNF with a V-ATPase inhibitor. Together these results suggest that activated β-catenin can facilitate endosomal trafficking of internalized TNF to suppress caspase-8 activation in colon cancer cells. © 2013 Han et al. (shrink)

Burnout is characterized by emotional exhaustion and caused by exposure to excessive and prolonged stress related to job conditions. Moreover, burnout is highly prevalent among health care professionals. The aim of this study is, first, to examine the mediating role of social support over the effect of burnout in health care professionals and, second, to explore potential gender differences. A convenience sample of 1,035 health professionals from Ecuador, including 608 physicians and 427 nurses, was surveyed using the Maslach Burnout Inventory, (...) Social Support Survey, and General Health Questionnaire as measures of burnout, social support, and general health, respectively. Social support was found to mediate the negative effects of burnout on health regardless of gender. Differences across the three dimensions of burnout and health are further discussed, along with their implications for designing effective burnout interventions for health care professionals in Ecuador. (shrink)

Background: Treating medication-refractory freezing of gait in Parkinson’s disease remains challenging despite several trials reporting improvements in motor symptoms using subthalamic nucleus or globus pallidus internus deep brain stimulation. Pedunculopontine nucleus region DBS has been used for medication-refractory FoG, with mixed findings. FoG, as a paroxysmal phenomenon, provides an ideal framework for the possibility of closed-loop DBS.Methods: In this clinical trial, five subjects with medication-refractory FoG underwent bilateral GPi DBS implantation to address levodopa-responsive PD symptoms with open-loop stimulation. Additionally, PPN (...) DBS leads were implanted for CL-DBS to treat FoG. The primary outcome of the study was a 40% improvement in medication-refractory FoG in 60% of subjects at 6 months when “on” PPN CL-DBS. Secondary outcomes included device feasibility to gauge the recruitment potential of this four-lead DBS approach for a potentially larger clinical trial. Safety was judged based on adverse events and explantation rate.Findings: The feasibility of this approach was demonstrated as we recruited five subjects with both “on” and “off” medication freezing. The safety for this population of patients receiving four DBS leads was suboptimal and associated with a high explantation rate of 40%. The primary clinical outcome in three of the five subjects was achieved at 6 months. However, the group analysis of the primary clinical outcome did not reveal any benefit.Interpretation: This study of a human PPN CL-DBS trial in medication-refractory FoG showed feasibility in recruitment, suboptimal safety, and a heterogeneous clinical effect in FoG outcomes. (shrink)