Human motor augmentation - spinal motor neurons control of redundant degrees-of-freedom

In 1963, Stan Lee introduced a new villain to the Spiderman Universe: Dr Octopus – a human equipped with multiple robotic arms that can be controlled seamlessly in coordination with his natural limbs. Throughout the last decades, turning such fiction into real-life applications gave rise to the research field of human motor augmentation, ultimately aiming to enable humans to perform motor tasks that are sheer impossible with our natural limbs alone. While a significant process was made in designing artificial supernumerary limbs, a central problem remains: identifying adequate bodily signals that allow moving supernumerary degrees-of-freedom together with our natural ones. So far, neural activity in the brain seems to hold the greatest potential for providing all the flexibility needed to ensure such coordination between natural and supernumerary degrees-of-freedom. However, accessing neural populations in the cortical regions is accompanied by an unacceptable risk for most users. A different group of neural cells can be found in the outmost layer of the motor pathway, driving the contraction of muscles and generation of force – spinal motor neurons. The development of novel neural interfaces has made it possible to study single motor neuron activity with minimal harm to the user. This allows a direct and non-invasive window into the neural activity orchestrating human movement. In this dissertation, I investigate whether these neurons innervating our muscles could provide supernumerary control signals. The results indicate, in essence, that features extracted non-invasively from motor neuron activity have the potential to overcome current limitations in supernumerary control and thus could significantly advance human motor augmentation.Open Acces

Robotic hand augmentation drives changes in neural body representation

Humans have long been fascinated by the opportunities afforded through augmentation. This vision not only depends on technological innovations but also critically relies on our brain's ability to learn, adapt, and interface with augmentation devices. Here, we investigated whether successful motor augmentation with an extra robotic thumb can be achieved and what its implications are on the neural representation and function of the biological hand. Able-bodied participants were trained to use an extra robotic thumb (called the Third Thumb) over 5 days, including both lab-based and unstructured daily use. We challenged participants to complete normally bimanual tasks using only the augmented hand and examined their ability to develop hand-robot interactions. Participants were tested on a variety of behavioral and brain imaging tests, designed to interrogate the augmented hand's representation before and after the training. Training improved Third Thumb motor control, dexterity, and hand-robot coordination, even when cognitive load was increased or when vision was occluded. It also resulted in increased sense of embodiment over the Third Thumb. Consequently, augmentation influenced key aspects of hand representation and motor control. Third Thumb usage weakened natural kinematic synergies of the biological hand. Furthermore, brain decoding revealed a mild collapse of the augmented hand's motor representation after training, even while the Third Thumb was not worn. Together, our findings demonstrate that motor augmentation can be readily achieved, with potential for flexible use, reduced cognitive reliance, and increased sense of embodiment. Yet, augmentation may incur changes to the biological hand representation. Such neurocognitive consequences are crucial for successful implementation of future augmentation technologies

Haptics: Science, Technology, Applications

This open access book constitutes the proceedings of the 13th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2022, held in Hamburg, Germany, in May 2022. The 36 regular papers included in this book were carefully reviewed and selected from 129 submissions. They were organized in topical sections as follows: haptic science; haptic technology; and haptic applications

Modular soft pneumatic actuator system design for compliance matching

The future of robotics is personal. Never before has technology been as pervasive as it is today, with advanced mobile electronics hardware and multi-level network connectivity pushing âsmartâ devices deeper into our daily lives through home automation systems, virtual assistants, and wearable activity monitoring. As the suite of personal technology around us continues to grow in this way, augmenting and offloading the burden of routine activities of daily living, the notion that this trend will extend to robotics seems inevitable. Transitioning robots from their current principal domain of industrial factory settings to domestic, workplace, or public environments is not simply a matter of relocation or reprogramming, however. The key differences between âtraditionalâ types of robots and those which would best serve personal, proximal, human interactive applications demand a new approach to their design. Chief among these are requirements for safety, adaptability, reliability, reconfigurability, and to a more practical extent, usability. These properties frame the context and objectives of my thesis work, which seeks to provide solutions and answers to not only how these features might be achieved in personal robotic systems, but as well what benefits they can afford. I approach the investigation of these questions from a perspective of compliance matching of hardware systems to their applications, by providing methods to achieve mechanical attributes complimentary to their environment and end-use. These features are fundamental to the burgeoning field of Soft Robotics, wherein flexible, compliant materials are used as the basis for the structure, actuation, sensing, and control of complete robotic systems. Combined with pressurized air as a power source, soft pneumatic actuator (SPA) based systems offers new and novel methods of exploiting the intrinsic compliance of soft material components in robotic systems. While this strategy seems to answer many of the needs for human-safe robotic applications, it also brings new questions and challenges: What are the needs and applications personal robots may best serve? Are soft pneumatic actuators capable of these tasks, or âusefulâ work output and performance? How can SPA based systems be applied to provide complex functionality needed for operation in diverse, real-world environments? What are the theoretical and practical challenges in implementing scalable, multiple degrees of freedom systems, and how can they be overcome? I present solutions to these problems in my thesis work, elucidated through scientific design, testing and evaluation of robotic prototypes which leverage and demonstrate three key features: 1) Intrinsic compliance: provided by passive elastic and flexible component material properties, 2) Extrinsic compliance: rendered through high number of independent, controllable degrees of freedom, and 3) Complementary design: exhibited by modular, plug and play architectures which combine both attributes to achieve compliant systems. Through these core projects and others listed below I have been engaged in soft robotic technology, its application, and solutions to the challenges which are critical to providing a path forward within the soft robotics field, as well as for the future of personal robotics as a whole toward creating a better society

The development of multisensory integration in autism spectrum disorders

In order to understand and interact with the world, our brains must integrate information from multiple sensory modalities to create coherent representations of scenes and events. The integration of visual, tactile and proprioceptive inputs underpins the subjective sense of self and body ownership. This, in turn, underlies the development of social processes including self-awareness, imitation and empathising, which are impaired in autism spectrum disorders (ASD). Evidence suggests that the social functioning deficits characterising ASD could contribute to atypical sensory integration underlying body representation. However, the exact mechanisms underlying sensory integration difficulties have not been specified. Moreover, it is not clear when, and how, visual, tactile and proprioceptive integration matures in typical development. This is important to establish, in order to compare how and why this integration may differ in ASD populations. This thesis firstly aimed to investigate the typical development of multisensory integration underlying body representation. Experiment One found that the ability to optimally integrate visual and proprioceptive inputs during hand localisation increases with age from very little integration in 4-year-olds to almost adult-like in typically developing 10- to 11-year-olds. Experiments Two and Three showed that sensitivity to the spatial constraints of visuo-proprioceptive integration, and sensitivity to the temporal constraints of visuo-tactile integration, develops with age in 4 to 11-year-olds. Together these studies suggest that the maturation of adult-like multisensory integration for body representation follows a protracted time course over childhood. The second aim of this thesis was to investigate the evidence for two prominent theories of atypical sensory integration underlying body representation in ASD. These are 1) an over-reliance on proprioception and 2) temporally extended sensory binding. Experiment Four examined whether trypically developing (TD) adults with a high number of autistic traits exhibit an over-reliance on proprioception. No evidence was found for this, which could indicate that atypical sensory integration is only present in individuals with a clinical diagnosis of ASD. Experiments Five and Six found evidence for temporally extended visuo-tactile integration in children with ASD, compared to TD control participants. Though no evidence was found for a fundamental over-reliance on proprioception, extended binding may have led to reduced processing of temporal synchrony over modality-specific information (i.e. proprioception). Experiment Seven and Eight found no evidence of proprioceptive over-reliance or temporally extended sensory binding in adults with ASD, relative to a TD control group. I conclude that children with ASD demonstrate temporally extended visuo-tactile binding. This represents a developmental delay rather than a life-long deficit; however, it could have a life-long impact on sensory sensitivities and social processing

Appearing Live: Spectatorship, Affect, and Liveness in Contemporary British Performance

The liveness of theatre is a much-debated topic in playwriting, arts policy, and performance studies. Discussions of liveness, by scholars such as Peggy Phelan, Richard Schechner, and Herbert Blau, have historically suggested that performance is an ephemeral medium, defining “liveness” as a descriptor of theatre’s transient existence, a phenomenon which disappears at the same moment it is performed. More recently, scholars such as Philip Auslander, Rebecca Schneider, and Amelia Jones have reconsidered this historical debate, suggesting that performance does not simply occur once and then disappear, but that its temporality must include repetition, reperformance, and memory. However, these approaches continue to theorize liveness in terms of its temporality. This dissertation intervenes in two ways: firstly, I reorient the definition of “liveness” away from temporality and toward affect: “liveness”, from my perspective, is a felt quality of performance, but is not restricted to the moment that performance takes place. Secondly, I analyze the relationship between the ways that affective liveness is invoked in performance and the UK.’s current socio-economic and political environment to suggest that the increasing desire for experiences which feel live is an index of that country’s neoliberal context. Informing my argument are theorists such as Bergson and Derrida, as well as affect theorists such as Massumi, Bennett, and Berlant. This dissertation addresses several case studies. Chapter one discusses playwright Martin Crimp’s Attempts on Her Life (1997) and The City (2008) as projections of capitalist promises and expectations of a “good life”, following Lauren Berlant. In chapter two, I analyze immersive theatre company Punchdrunk’s Sleep No More as a bodily, but purposefully individualistic, affective experience. The third and final chapter, I discuss ii several multi-form archival projects by performance collective Forced Entertainment, analyzing their attempts to make documentation live. In foregrounding their own liveness, these performances attempt to capitalize on the community feeling produced by collective experience. However, I conclude that liveness has been deployed in these performances in order to encourage a particularly neoliberal form of affective consumption, which privileges individual, entrepreneurial, and capitalistic forms of creation and spectatorship

The development of multisensory integration in autism spectrum disorders

In order to understand and interact with the world, our brains must integrate information from multiple sensory modalities to create coherent representations of scenes and events. The integration of visual, tactile and proprioceptive inputs underpins the subjective sense of self and body ownership. This, in turn, underlies the development of social processes including self-awareness, imitation and empathising, which are impaired in autism spectrum disorders (ASD). Evidence suggests that the social functioning deficits characterising ASD could contribute to atypical sensory integration underlying body representation. However, the exact mechanisms underlying sensory integration difficulties have not been specified. Moreover, it is not clear when, and how, visual, tactile and proprioceptive integration matures in typical development. This is important to establish, in order to compare how and why this integration may differ in ASD populations. This thesis firstly aimed to investigate the typical development of multisensory integration underlying body representation. Experiment One found that the ability to optimally integrate visual and proprioceptive inputs during hand localisation increases with age from very little integration in 4-year-olds to almost adult-like in typically developing 10- to 11-year-olds. Experiments Two and Three showed that sensitivity to the spatial constraints of visuo-proprioceptive integration, and sensitivity to the temporal constraints of visuo-tactile integration, develops with age in 4 to 11-year-olds. Together these studies suggest that the maturation of adult-like multisensory integration for body representation follows a protracted time course over childhood. The second aim of this thesis was to investigate the evidence for two prominent theories of atypical sensory integration underlying body representation in ASD. These are 1) an over-reliance on proprioception and 2) temporally extended sensory binding. Experiment Four examined whether trypically developing (TD) adults with a high number of autistic traits exhibit an over-reliance on proprioception. No evidence was found for this, which could indicate that atypical sensory integration is only present in individuals with a clinical diagnosis of ASD. Experiments Five and Six found evidence for temporally extended visuo-tactile integration in children with ASD, compared to TD control participants. Though no evidence was found for a fundamental over-reliance on proprioception, extended binding may have led to reduced processing of temporal synchrony over modality-specific information (i.e. proprioception). Experiment Seven and Eight found no evidence of proprioceptive over-reliance or temporally extended sensory binding in adults with ASD, relative to a TD control group. I conclude that children with ASD demonstrate temporally extended visuo-tactile binding. This represents a developmental delay rather than a life-long deficit; however, it could have a life-long impact on sensory sensitivities and social processing