Afferent information modulates spinal network activity in vitro and in preclinical animal models

Primary afferents are responsible for the transmission of peripheral sensory information to the spinal cord. Spinal circuits involved in sensory processing and in motor activity are directly modulated by incoming input conveyed by afferent fibres. Current neurorehabilitation exploits primary afferent information to induce plastic changes within lesioned spinal circuitries. Plasticity and neuromodulation promoted by activity-based interventions are suggested to support both the functional recovery of locomotion and pain relief in subjects with sensorimotor disorders. The present study was aimed at assessing spinal modifications mediated by afferent information. At the beginning of my PhD project, I adopted a simplified in vitro model of isolated spinal cord from the newborn rat. In this preparation, dorsal root (DR) fibres were repetitively activated by delivering trains of electrical stimuli. Responses of dorsal sensory-related and ventral motor-related circuits were assessed by extracellular recordings. I demonstrated that electrostimulation protocols able to activate the spinal CPG for locomotion, induced primary afferent hyperexcitability, as well. Thus, evidence of incoming signals in modulating spinal circuits was provided. Furthermore, a robust sensorimotor interplay was reported to take place within the spinal cord. I further investigated hyperexcitability conditions in a new in vivo model of peripheral neuropathic pain. Adult rats underwent a surgical procedure where the common peroneal nerve was crushed using a calibrated nerve clamp (modified spared nerve injury, mSNI). Thus, primary afferents of the common peroneal nerve were activated through the application of a noxious compression, which presumably elicited ectopic activity constitutively generated in the periphery. One week after surgery, animals were classified into two groups, with (mSNI+) and without (mSNI-) tactile hypersensitivity, based on behavioral tests assessing paw withdrawal threshold. Interestingly, the efficiency of the mSNI in inducing tactile hypersensitivity was halved with respect to the classical SNI model. Moreover, mSNI animals with tactile hypersensitivity (mSNI+) showed an extensive neuroinflammation within the dorsal horn, with activated microglia and astrocytes being significantly increased with respect to mSNI animals without tactile hypersensitivity (mSNI-) and to sham-operated animals. Lastly, RGS4 (regulator of G protein signaling 4) was reported to be enhanced in lumbar dorsal root ganglia (DRGs) and dorsal horn ipsilaterally to the lesion in mSNI+ animals. Thus, a new molecular marker was demonstrated to be involved in tactile hypersensitivity in our preclinical model of mSNI. Lastly, we developed a novel in vitro model of newborn rat, where hindlimbs were functionally connected to a partially dissected spinal cord and passively-driven by a robotic device (Bipedal Induced Kinetic Exercise, BIKE). I aimed at studying whether spinal activity was influenced by afferent signals evoked during passive cycling. I first demonstrated that BIKE could actually evoke an afferent feedback from the periphery. Then, I determined that spinal circuitries were differentially affected by training sessions of different duration. On one side, a short exercise session could not directly activate the locomotor CPG, but was able to transiently facilitate an electrically-induced locomotor-like activity. Moreover, no changes in reflex or spontaneous activity of dorsal and ventral networks were promoted by a short training. On the other side, a long BIKE session caused a loss in facilitation of spinal locomotor networks and a depression in the area of motor reflexes. Furthermore, activity in dorsal circuits was long-term enhanced, with a significant increase in both electrically-evoked and spontaneous antidromic discharges. Thus, the persistence of training-mediated effects was different, with spinal locomotor circuits being only transiently modulated, whereas dorsal activity being strongly and stably enhanced. Motoneurons were also affected by a prolonged training, showing a reduction in membrane resistance and an increase in the frequency of post-synaptic currents (PSCs), with both fast- and slow-decaying synaptic inputs being augmented. Changes in synaptic transmission onto the motoneuron were suggested to be responsible for network effects mediated by passive training. In conclusion, I demonstrated that afferent information might induce changes within the spinal cord, involving both neuronal and glial cells. In particular, spinal networks are affected by incoming peripheral signals, which mediate synaptic, cellular and molecular modifications. Moreover, a strong interplay between dorsal and ventral spinal circuits was also reported. A full comprehension of basic mechanisms underlying sensory-mediated spinal plasticity and bidirectional interactions between functionally different spinal networks might lead to the development of neurorehabilitation strategies which simultaneously promote locomotor recovery and pain relief

Designing for self-transcendent experiences in virtual reality

This thesis contributes to Psychology and Human-Computer Interaction (HCI) research with a focus on the design of immersive experiences that support self-transcendence. Self-transcendence is defined as a decrease in a sense of self and a increase in unity with the world. It can change what individuals know and value, their perspective on the world and life, evolving them as a grown person. Consequently, self-transcendence is gaining attention in Psychology, Philosophy, and Neuroscience. But, we are still far from understanding the complex phenomenological and neurocognitive aspects of self-transcendence, as well as its implications for individual growth and psychological well-being. In reviewing the methods for studying self-transcendence, we found differing conceptual models determine different ways for understanding and studying self-transcendence. Understanding self-transcendence is made especially challenging because of its ineffable qualities and extraordinary conditions in which it takes place. For that reason, researchers have began to look at technological solutions for both eliciting self-transcendence to better study it under controlled and replicable conditions as well as giving people greater access to the experience. We reviewed immersive, interactive technologies that aim to support positive experiences such as self-transcendence and extracted a set of design considerations that were prevalent across experiences. We then explored two different focuses of self-transcendence: awe and lucid dreaming. First, we took an existing VR experience designed specifically to support the self-transcendent experience of awe and looked at how the mindset and physical setting surrounding that VR experience might better support the experience of and accommodation of awe. Second, we delved deep into lucid dreaming to better understand the aspects that could help inform the design of an immersive experience that supports self-transcendence. We put those design ideas into practice by developing a neurofeedback system that aims to support lucid dreaming practices in an immersive experience. Through these review papers and design explorations, we contribute to the understanding of how one might design and evaluate immersive technological experiences that support varieties of self-transcendence. We hope to inspire more work in this area that holds promise in better understanding human nature and living our best lives

SERENITY: THE FUTURE OF COGNITIVE MODULATION FOR THE HYPER ENABLED OPERATOR

In the Special Operations community, cognitive enhancement and resilience is at the forefront of the 2035 Hyper Enabled Operator Program (HEO). The United States Special Operations Command’s vision is to combine cutting-edge communications and data capabilities into a next generation tactical system for the end user. Using algorithms and autonomous systems to enhance the ability to make rational decisions faster can ultimately determine life or death on the battlefield. Over the past several years, cognitive enhancement with the introduction of brain computer interface (BCI) technology has had major breakthroughs in the medical and science fields. This thesis looks to analyze BCI technology for future cognitive dominance and cognitive overmatch in the Hyper Enabled Operator. Machine-assisted cognitive enhancement is not beyond reach for special operations; throughout the research and after multiple interviews with subject matter experts, it has been concluded that interfaces using transcranial alternating current stimulation (tACS), median nerve stimulation (MNS), or several other exploratory procedures have been successful with enhancing cognition and reducing cognitive load. Special Operations should not shy away from transformational innovative technology or wait for commercial or lab-tested solutions. To start, Special Operations should foster avant-garde theories that provide solutions and evolve ideas into unsophisticated prototypes that can be fielded immediately.Major, United States ArmyApproved for public release. Distribution is unlimited

On the use of Phantom Motor Execution for the treatment of Phantom Limb Pain

Phantom limb pain (PLP) is a common complaint among amputees and despite having been studiedfor centuries, it remains a mysterious object of debate among researcher. To date, a vast number ofways to treat PLP has been proposed in the literature, however none of them has proven to beuniversally effective, thus creating uncertainty on how to operate clinically. The uncertainty is largelyattributable to the scarcity of well conducted randomized controlled trials (RCTs) to prove the efficacyof PLP treatments.Phantom Motor Execution (PME) -exertion of voluntary phantom limb movements – aims at restoringthe control over the phantom limb and the exercise of such control has been hypothesized to reverseneural changes implicated in PLP. Preliminary evidence supporting this hypothesis has been providedby clinical investigations on upper limb amputees. The main purpose of this Licentiate thesis was toenable a RCT on the use of PME for the treatment of PLP in order to provide robust and unbiasedevidence for clinical practice. However, the implementation and kick-off of this clinical investigationrequired to complete few preparatory steps. For example, most amputees and PLP patients have lowerlimb amputation, thus PME needed to be adapted and validated for this population. Further, the RCTprotocol needed to be carefully planned and made openly accessible, as per guidelines for conductingand publishing clinical RCT. Finally, a secondary aim of this thesis emerged with the need of providinglong term relief from PLP to patient. Preliminary evidence seemed to indicate that in order to maintainpain relief, periodic rehearsal of the phantom motor skills acquired through PME is necessary. Thisraised the question of whether it is beneficial and possible to translate the technology from clinic tohome use, question that was explored employing both quantitative and qualitative methods fromengineering, medical anthropology, and user interface design.The work conducted within this thesis resulted in the extension of PME to lower limb patients byproposal and validation of a new and more user-friendly recording configuration to record EMG signals.The use of PME was then shown to be efficacious in relieving PLP with a case study on a patient. Theprotocol for the RCT was then designed and published. These two first steps permitted theestablishment of the RCT, which is currently ongoing and expected to close in March 2021. With regardto the secondary aim of this thesis, the work conducted enabled PME to be used by the patients in thecomfort of their home, while it also allowed investigate the benefits and challenges generally faced(not only by PME) in the transition from the clinic to home and its effects on treatment adherence. Thework conducted is presented in the three appended publications.Future work includes the presentation of the results of the RCT. Further, having a way to modulate PLPis an incredibly useful tool to study the neural basis of PLP. By capitalizing on this tool, we are currentlyconducting brain imaging studies using fMRI and electroencephalography that are the main focus ofthe work that lies ahead

Brain Waves, A Cultural History: Oscillations of Neuroscience, Technology, Telepathy, and Transcendence

This project proceeds from a narrow question: What, if anything, is a brain wave? Beguiling in its simplicity, this question prompts a cultural-historical investigation that spans over 150 years of science, technology, and society. Proposed in 1869, the original theory of brain waves cites etheric undulations to explain reports of apparent thought transference. Though most modern thinkers no longer believe in outright telepathy, I argue that dreams of thought transmission and other mental miracles subtly persist—not in obscure and occult circles, but at the forefront of technoscience. A hybrid of science and fiction, brain waves represent an ideal subject through which to explore the ways in which technical language shrouds spiritual dreams. Today, the phrase “brain waves” often function as shorthand for electrical changes in the brain, particularly in the context of technologies that purport to “read” some aspect of mental function, or to transmit neural data to a digital device. While such technologies appear uniquely modern, the history of brain waves reveals that they are merely the millennial incarnation of a much older hope—a hope for transmission and transcendence via the brain’s emanations

Enhancing interaction in mixed reality

With continuous technological innovation, we observe mixed reality emerging from research labs into the mainstream. The arrival of capable mixed reality devices transforms how we are entertained, consume information, and interact with computing systems, with the most recent being able to present synthesized stimuli to any of the human senses and substantially blur the boundaries between the real and virtual worlds. In order to build expressive and practical mixed reality experiences, designers, developers, and stakeholders need to understand and meet its upcoming challenges. This research contributes a novel taxonomy for categorizing mixed reality experiences and guidelines for designing mixed reality experiences. We present the results of seven studies examining the challenges and opportunities of mixed reality experiences, the impact of modalities and interaction techniques on the user experience, and how to enhance the experiences. We begin with a study determining user attitudes towards mixed reality in domestic and educational environments, followed by six research probes that each investigate an aspect of reality or virtuality. In the first, a levitating steerable projector enables us to investigate how the real world can be enhanced without instrumenting the user. We show that the presentation of in-situ instructions for navigational tasks leads to a significantly higher ability to observe and recall real-world landmarks. With the second probe, we enhance the perception of reality by superimposing information usually not visible to the human eye. In amplifying the human vision, we enable users to perceive thermal radiation visually. Further, we examine the effect of substituting physical components with non-functional tangible proxies or entirely virtual representations. With the third research probe, we explore how to enhance virtuality to enable a user to input text on a physical keyboard while being immersed in the virtual world. Our prototype tracked the user’s hands and keyboard to enable generic text input. Our analysis of text entry performance showed the importance and effect of different hand representations. We then investigate how to touch virtuality by simulating generic haptic feedback for virtual reality and show how tactile feedback through quadcopters can significantly increase the sense of presence. Our final research probe investigates the usability and input space of smartphones within mixed reality environments, pairing the user’s smartphone as an input device with a secondary physical screen. Based on our learnings from these individual research probes, we developed a novel taxonomy for categorizing mixed reality experiences and guidelines for designing mixed reality experiences. The taxonomy is based on the human sensory system and human capabilities of articulation. We showcased its versatility and set our research probes into perspective by organizing them inside the taxonomic space. The design guidelines are divided into user-centered and technology-centered. It is our hope that these will contribute to the bright future of mixed reality systems while emphasizing the new underlining interaction paradigm.Mixed Reality (vermischte Realitäten) gehen aufgrund kontinuierlicher technologischer Innovationen langsam von der reinen Forschung in den Massenmarkt über. Mit der Einführung von leistungsfähigen Mixed-Reality-Geräten verändert sich die Art und Weise, wie wir Unterhaltungsmedien und Informationen konsumieren und wie wir mit Computersystemen interagieren. Verschiedene existierende Geräte sind in der Lage, jeden der menschlichen Sinne mit synthetischen Reizen zu stimulieren. Hierdurch verschwimmt zunehmend die Grenze zwischen der realen und der virtuellen Welt. Um eindrucksstarke und praktische Mixed-Reality-Erfahrungen zu kreieren, müssen Designer und Entwicklerinnen die künftigen Herausforderungen und neuen Möglichkeiten verstehen. In dieser Dissertation präsentieren wir eine neue Taxonomie zur Kategorisierung von Mixed-Reality-Erfahrungen sowie Richtlinien für die Gestaltung von solchen. Wir stellen die Ergebnisse von sieben Studien vor, in denen die Herausforderungen und Chancen von Mixed-Reality-Erfahrungen, die Auswirkungen von Modalitäten und Interaktionstechniken auf die Benutzererfahrung und die Möglichkeiten zur Verbesserung dieser Erfahrungen untersucht werden. Wir beginnen mit einer Studie, in der die Haltung der nutzenden Person gegenüber Mixed Reality in häuslichen und Bildungsumgebungen analysiert wird. In sechs weiteren Fallstudien wird jeweils ein Aspekt der Realität oder Virtualität untersucht. In der ersten Fallstudie wird mithilfe eines schwebenden und steuerbaren Projektors untersucht, wie die Wahrnehmung der realen Welt erweitert werden kann, ohne dabei die Person mit Technologie auszustatten. Wir zeigen, dass die Darstellung von in-situ-Anweisungen für Navigationsaufgaben zu einer deutlich höheren Fähigkeit führt, Sehenswürdigkeiten der realen Welt zu beobachten und wiederzufinden. In der zweiten Fallstudie erweitern wir die Wahrnehmung der Realität durch Überlagerung von Echtzeitinformationen, die für das menschliche Auge normalerweise unsichtbar sind. Durch die Erweiterung des menschlichen Sehvermögens ermöglichen wir den Anwender:innen, Wärmestrahlung visuell wahrzunehmen. Darüber hinaus untersuchen wir, wie sich das Ersetzen von physischen Komponenten durch nicht funktionale, aber greifbare Replikate oder durch die vollständig virtuelle Darstellung auswirkt. In der dritten Fallstudie untersuchen wir, wie virtuelle Realitäten verbessert werden können, damit eine Person, die in der virtuellen Welt verweilt, Text auf einer physischen Tastatur eingeben kann. Unser Versuchsdemonstrator detektiert die Hände und die Tastatur, zeigt diese in der vermischen Realität an und ermöglicht somit die verbesserte Texteingaben. Unsere Analyse der Texteingabequalität zeigte die Wichtigkeit und Wirkung verschiedener Handdarstellungen. Anschließend untersuchen wir, wie man Virtualität berühren kann, indem wir generisches haptisches Feedback für virtuelle Realitäten simulieren. Wir zeigen, wie Quadrokopter taktiles Feedback ermöglichen und dadurch das Präsenzgefühl deutlich steigern können. Unsere letzte Fallstudie untersucht die Benutzerfreundlichkeit und den Eingaberaum von Smartphones in Mixed-Reality-Umgebungen. Hierbei wird das Smartphone der Person als Eingabegerät mit einem sekundären physischen Bildschirm verbunden, um die Ein- und Ausgabemodalitäten zu erweitern. Basierend auf unseren Erkenntnissen aus den einzelnen Fallstudien haben wir eine neuartige Taxonomie zur Kategorisierung von Mixed-Reality-Erfahrungen sowie Richtlinien für die Gestaltung von solchen entwickelt. Die Taxonomie basiert auf dem menschlichen Sinnessystem und den Artikulationsfähigkeiten. Wir stellen die vielseitige Verwendbarkeit vor und setzen unsere Fallstudien in Kontext, indem wir sie innerhalb des taxonomischen Raums einordnen. Die Gestaltungsrichtlinien sind in nutzerzentrierte und technologiezentrierte Richtlinien unterteilt. Es ist unsere Anliegen, dass diese Gestaltungsrichtlinien zu einer erfolgreichen Zukunft von Mixed-Reality-Systemen beitragen und gleichzeitig die neuen Interaktionsparadigmen hervorheben

Haptics: Science, Technology, Applications

This open access book constitutes the proceedings of the 12th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2020, held in Leiden, The Netherlands, in September 2020. The 60 papers presented in this volume were carefully reviewed and selected from 111 submissions. The were organized in topical sections on haptic science, haptic technology, and haptic applications. This year's focus is on accessibility

Haptic Media Scenes

The aim of this thesis is to apply new media phenomenological and enactive embodied cognition approaches to explain the role of haptic sensitivity and communication in personal computer environments for productivity. Prior theory has given little attention to the role of haptic senses in influencing cognitive processes, and do not frame the richness of haptic communication in interaction design—as haptic interactivity in HCI has historically tended to be designed and analyzed from a perspective on communication as transmissions, sending and receiving haptic signals. The haptic sense may not only mediate contact confirmation and affirmation, but also rich semiotic and affective messages—yet this is a strong contrast between this inherent ability of haptic perception, and current day support for such haptic communication interfaces. I therefore ask: How do the haptic senses (touch and proprioception) impact our cognitive faculty when mediated through digital and sensor technologies? How may these insights be employed in interface design to facilitate rich haptic communication? To answer these questions, I use theoretical close readings that embrace two research fields, new media phenomenology and enactive embodied cognition. The theoretical discussion is supported by neuroscientific evidence, and tested empirically through case studies centered on digital art. I use these insights to develop the concept of the haptic figura, an analytical tool to frame the communicative qualities of haptic media. The concept gauges rich machine- mediated haptic interactivity and communication in systems with a material solution supporting active haptic perception, and the mediation of semiotic and affective messages that are understood and felt. As such the concept may function as a design tool for developers, but also for media critics evaluating haptic media. The tool is used to frame a discussion on opportunities and shortcomings of haptic interfaces for productivity, differentiating between media systems for the hand and the full body. The significance of this investigation is demonstrating that haptic communication is an underutilized element in personal computer environments for productivity and providing an analytical framework for a more nuanced understanding of haptic communication as enabling the mediation of a range of semiotic and affective messages, beyond notification and confirmation interactivity

UNBODY: A Poetry Escape Room in Augmented Reality

The integration of augmented reality (AR) technology into personal computing is happening fast, and augmented workplaces for professionals in areas such as Industry 4.0 or digital health can reasonably be expected to form liminal zones that push the boundary of what currently possible. The application potential in the creative industries, however, is vast and can target broad audiences, so with UNBODY, we set out to push boundaries of a different kind and depart from the graphic-centric worlds of AR to explore textual and aural dimensions of an extended reality, in which words haunt and re-create our physical selves. UNBODY is an AR installation for smart glasses that embeds poetry in the user’s surroundings. The augmented experience turns reality into a medium where holographic texts and film clips spill from dayglow billboards and totems. In this paper, we develop a blueprint for an AR escape room dedicated to the spoken and written word, with its open source code facilitating uptake by others into existing or new AR escape rooms. We outline the user-centered process of designing, building, and evaluating UNBODY. More specifically, we deployed a system usability scale (SUS) and a spatial interaction evaluation (SPINE) in order to validate its wider applicability. In this paper, we also describe the composition and concept of the experience, identifying several components (trigger posters, posters with video overlay, word dropper totem, floating object gallery, and a user trail visualization) as part of our first version before evaluation. UNBODY provides a sense of situational awareness and immersivity from inside an escape room. The recorded average mean for the SUS was 59.7, slightly under the recommended 68 average but still above ‘OK’ in the zone of low marginal acceptable. The findings for the SPINE were moderately positive, with the highest scores for output modalities and navigation support. This indicated that the proposed components and escape room concept work. Based on these results, we improved the experience, adding, among others, an interactive word composer component. We conclude that a poetry escape room is possible, outline our co-creation process, and deliver an open source technical framework as a blueprint for adding enhanced support for the spoken and written word to existing or coming AR escape room experiences. In an outlook, we discuss additional insight on timing, alignment, and the right level of personalization