Investigating the Neural Basis of Audiovisual Speech Perception with Intracranial Recordings in Humans

Speech is inherently multisensory, containing auditory information from the voice and visual information from the mouth movements of the talker. Hearing the voice is usually sufficient to understand speech, however in noisy environments or when audition is impaired due to aging or disabilities, seeing mouth movements greatly improves speech perception. Although behavioral studies have well established this perceptual benefit, it is still not clear how the brain processes visual information from mouth movements to improve speech perception. To clarify this issue, I studied the neural activity recorded from the brain surfaces of human subjects using intracranial electrodes, a technique known as electrocorticography (ECoG). First, I studied responses to noisy speech in the auditory cortex, specifically in the superior temporal gyrus (STG). Previous studies identified the anterior parts of the STG as unisensory, responding only to auditory stimulus. On the other hand, posterior parts of the STG are known to be multisensory, responding to both auditory and visual stimuli, which makes it a key region for audiovisual speech perception. I examined how these different parts of the STG respond to clear versus noisy speech. I found that noisy speech decreased the amplitude and increased the across-trial variability of the response in the anterior STG. However, possibly due to its multisensory composition, posterior STG was not as sensitive to auditory noise as the anterior STG and responded similarly to clear and noisy speech. I also found that these two response patterns in the STG were separated by a sharp boundary demarcated by the posterior-most portion of the Heschl’s gyrus. Second, I studied responses to silent speech in the visual cortex. Previous studies demonstrated that visual cortex shows response enhancement when the auditory component of speech is noisy or absent, however it was not clear which regions of the visual cortex specifically show this response enhancement and whether this response enhancement is a result of top-down modulation from a higher region. To test this, I first mapped the receptive fields of different regions in the visual cortex and then measured their responses to visual (silent) and audiovisual speech stimuli. I found that visual regions that have central receptive fields show greater response enhancement to visual speech, possibly because these regions receive more visual information from mouth movements. I found similar response enhancement to visual speech in frontal cortex, specifically in the inferior frontal gyrus, premotor and dorsolateral prefrontal cortices, which have been implicated in speech reading in previous studies. I showed that these frontal regions display strong functional connectivity with visual regions that have central receptive fields during speech perception

Technologies for safe and resilient earthmoving operations: A systematic literature review

Resilience engineering relates to the ability of a system to anticipate, prepare, and respond to predicted and unpredicted disruptions. It necessitates the use of monitoring and object detection technologies to ensure system safety in excavation systems. Given the increased investment and speed of improvement in technologies, it is necessary to review the types of technology available and how they contribute to excavation system safety. A systematic literature review was conducted which identified and classified the existing monitoring and object detection technologies, and introduced essential enablers for reliable and effective monitoring and object detection systems including: 1) the application of multisensory and data fusion approaches, and 2) system-level application of technologies. This study also identified the developed functionalities for accident anticipation, prevention and response to safety hazards during excavation, as well as those that facilitate learning in the system. The existing research gaps and future direction of research have been discussed

Advancing automation and robotics technology for the Space Station and for the US economy. Volume 1: Executive overview

In response to Public Law 98-371, dated July 18, 1984, the NASA Advanced Technology Advisory Committee has studied automation and robotics for use in the Space Station. The Executive Overview, Volume 1 presents the major findings of the study and recommends to NASA principles for advancing automation and robotics technologies for the benefit of the Space Station and of the U.S. economy in general. As a result of its study, the Advanced Technology Advisory Committee believes that a key element of technology for the Space Station is extensive use of advanced general-purpose automation and robotics. These systems could provide the United States with important new methods of generating and exploiting space knowledge in commercial enterprises and thereby help preserve U.S. leadership in space

NASA space station automation: AI-based technology review

Research and Development projects in automation for the Space Station are discussed. Artificial Intelligence (AI) based automation technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics. AI technology will also be developed for the servicing of satellites at the Space Station, system monitoring and diagnosis, space manufacturing, and the assembly of large space structures

Wearable Sleep Technology in Clinical and Research Settings

The accurate assessment of sleep is critical to better understand and evaluate its role in health and disease. The boom in wearable technology is part of the digital health revolution and is producing many novel, highly sophisticated and relatively inexpensive consumer devices collecting data from multiple sensors and claiming to extract information about users' behaviors, including sleep. These devices are now able to capture different biosignals for determining, for example, HR and its variability, skin conductance, and temperature, in addition to activity. They perform 24/7, generating overwhelmingly large data sets (big data), with the potential of offering an unprecedented window on users' health. Unfortunately, little guidance exists within and outside the scientific sleep community for their use, leading to confusion and controversy about their validity and application. The current state-of-the-art review aims to highlight use, validation and utility of consumer wearable sleep-trackers in clinical practice and research. Guidelines for a standardized assessment of device performance is deemed necessary, and several critical factors (proprietary algorithms, device malfunction, firmware updates) need to be considered before using these devices in clinical and sleep research protocols. Ultimately, wearable sleep technology holds promise for advancing understanding of sleep health; however, a careful path forward needs to be navigated, understanding the benefits and pitfalls of this technology as applied in sleep research and clinical sleep medicine

Can biological quantum networks solve NP-hard problems?

There is a widespread view that the human brain is so complex that it cannot be efficiently simulated by universal Turing machines. During the last decades the question has therefore been raised whether we need to consider quantum effects to explain the imagined cognitive power of a conscious mind. This paper presents a personal view of several fields of philosophy and computational neurobiology in an attempt to suggest a realistic picture of how the brain might work as a basis for perception, consciousness and cognition. The purpose is to be able to identify and evaluate instances where quantum effects might play a significant role in cognitive processes. Not surprisingly, the conclusion is that quantum-enhanced cognition and intelligence are very unlikely to be found in biological brains. Quantum effects may certainly influence the functionality of various components and signalling pathways at the molecular level in the brain network, like ion ports, synapses, sensors, and enzymes. This might evidently influence the functionality of some nodes and perhaps even the overall intelligence of the brain network, but hardly give it any dramatically enhanced functionality. So, the conclusion is that biological quantum networks can only approximately solve small instances of NP-hard problems. On the other hand, artificial intelligence and machine learning implemented in complex dynamical systems based on genuine quantum networks can certainly be expected to show enhanced performance and quantum advantage compared with classical networks. Nevertheless, even quantum networks can only be expected to efficiently solve NP-hard problems approximately. In the end it is a question of precision - Nature is approximate.Comment: 38 page

Aerospace medicine and Biology: A continuing bibliography with indexes, supplement 177

This bibliography lists 112 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1978

Biomedical Sensing and Imaging

This book mainly deals with recent advances in biomedical sensing and imaging. More recently, wearable/smart biosensors and devices, which facilitate diagnostics in a non-clinical setting, have become a hot topic. Combined with machine learning and artificial intelligence, they could revolutionize the biomedical diagnostic field. The aim of this book is to provide a research forum in biomedical sensing and imaging and extend the scientific frontier of this very important and significant biomedical endeavor

Earth as Interface: Exploring chemical senses with Multisensory HCI Design for Environmental Health Communication

As environmental problems intensify, the chemical senses -that is smell and taste, are the most relevantsenses to evidence them.As such, environmental exposure vectors that can reach human beings comprise air,food, soil and water[1].Within this context, understanding the link between environmental exposures andhealth[2]is crucial to make informed choices, protect the environment and adapt to new environmentalconditions[3].Smell and taste lead therefore to multi-sensorial experiences which convey multi-layered information aboutlocal and global events[4]. However, these senses are usually absent when those problems are represented indigital systems. The multisensory HCIdesign framework investigateschemical sense inclusion withdigital systems[5]. Ongoing efforts tackledigitalization of smell and taste for digital delivery, transmission or substitution [6]. Despite experimentsproved technological feasibility, its dissemination depends on relevant applicationdevelopment[7].This thesis aims to fillthose gaps by demonstratinghow chemical senses provide the means to link environment and health based on scientific andgeolocation narratives [8], [9],[10]. We present a Multisensory HCI design process which accomplished symbolicdisplaying smell and taste and led us to a new multi-sensorial interaction system presented herein. We describe the conceptualization, design and evaluation of Earthsensum, an exploratory case study project.Earthsensumoffered to 16 participants in the study, environmental smell and taste experiences about real geolocations to participants of the study. These experiences were represented digitally using mobilevirtual reality (MVR) and mobile augmented reality (MAR). Its technologies bridge the real and digital Worlds through digital representations where we can reproduce the multi-sensorial experiences. Our study findings showed that the purposed interaction system is intuitive and can lead not only to a betterunderstanding of smell and taste perception as also of environmental problems. Participants comprehensionabout the link between environmental exposures and health was successful and they would recommend thissystem as education tools. Our conceptual design approach was validated and further developments wereencouraged.In this thesis,we demonstratehow to applyMultisensory HCI methodology to design with chemical senses. Weconclude that the presented symbolic representation model of smell and taste allows communicatingtheseexperiences on digital platforms. Due to its context-dependency, MVR and MAR platforms are adequatetechnologies to be applied for this purpose.Future developments intend to explore further the conceptual approach. These developments are centredon the use of the system to induce hopefully behaviourchange. Thisthesisopens up new application possibilities of digital chemical sense communication,Multisensory HCI Design and environmental health communication.À medida que os problemas ambientais se intensificam, os sentidos químicos -isto é, o cheiroe sabor, são os sentidos mais relevantes para evidenciá-los. Como tais, os vetores de exposição ambiental que podem atingir os seres humanos compreendem o ar, alimentos, solo e água [1]. Neste contexto, compreender a ligação entre as exposições ambientais e a saúde [2] é crucial para exercerescolhas informadas, proteger o meio ambiente e adaptar a novas condições ambientais [3]. O cheiroe o saborconduzemassima experiências multissensoriais que transmitem informações de múltiplas camadas sobre eventos locais e globais [4]. No entanto, esses sentidos geralmente estão ausentes quando esses problemas são representados em sistemas digitais. A disciplina do design de Interação Humano-Computador(HCI)multissensorial investiga a inclusão dossentidos químicos em sistemas digitais [9]. O seu foco atual residena digitalização de cheirose sabores para o envio, transmissão ou substituiçãode sentidos[10]. Apesar dasexperimentaçõescomprovarem a viabilidade tecnológica, a sua disseminação está dependentedo desenvolvimento de aplicações relevantes [11]. Estatese pretendepreencher estas lacunas ao demonstrar como os sentidos químicos explicitama interconexãoentre o meio ambiente e a saúde, recorrendo a narrativas científicas econtextualizadasgeograficamente[12], [13], [14]. Apresentamos uma metodologiade design HCImultissensorial que concretizouum sistema de representação simbólica de cheiro e sabor e nos conduziu a um novo sistema de interação multissensorial, que aqui apresentamos. Descrevemos o nosso estudo exploratório Earthsensum, que integra aconceptualização, design e avaliação. Earthsensumofereceu a 16participantes do estudo experiências ambientais de cheiro e sabor relacionadas com localizações geográficasreais. Essas experiências foram representadas digitalmente através derealidade virtual(VR)e realidade aumentada(AR).Estas tecnologias conectamo mundo real e digital através de representações digitais onde podemos reproduzir as experiências multissensoriais. Os resultados do nosso estudo provaramque o sistema interativo proposto é intuitivo e pode levar não apenas a uma melhor compreensão da perceção do cheiroe sabor, como também dos problemas ambientais. O entendimentosobre a interdependência entre exposições ambientais e saúde teve êxitoe os participantes recomendariam este sistema como ferramenta para aeducação. A nossa abordagem conceptual foi positivamentevalidadae novos desenvolvimentos foram incentivados. Nesta tese, demonstramos como aplicar metodologiasde design HCImultissensorialpara projetar com ossentidos químicos. Comprovamosque o modelo apresentado de representação simbólica do cheiroe do saborpermite comunicar essas experiênciasem plataformas digitais. Por serem dependentesdocontexto, as plataformas de aplicações emVR e AR são tecnologias adequadaspara este fim.Desenvolvimentos futuros pretendem aprofundar a nossa abordagemconceptual. Em particular, aspiramos desenvolvera aplicaçãodo sistema para promover mudanças de comportamento. Esta tese propõenovas possibilidades de aplicação da comunicação dos sentidos químicos em plataformas digitais, dedesign multissensorial HCI e de comunicação de saúde ambiental