29 research outputs found

    Análisis de conectividad funcional de la dinámica neuroenergética del TDAH = Functional Connectivity Analysis of Neuroenergetic Dynamics for ADHD

    Get PDF
    A fast and economic pilot study for measuring the neuroenergetic dynamics in an ADHD-diagnosed sample is performed. Based in a simplified connectome version, a graph theory application for neural connectivity, the performance and subjective states are linked through brain activity analysis during a behavioral attention test. ADHD is a neurobehavioral disorder related to a deficient filtering of stimuli, inefficacy performing in sustained activities and difficulties responding to unpredictable situations. There are two main strategies to evaluate this disorder: (1) behavioral tests and (2) neural biomarkers. Behavioral tests provide a criterion for classifying responses in a collection of tasks, looking for unstructured and inconsistent responses to given instructions or rules. Hyperactivity, inattention and impulsivity are some criteria analyzed. By the other hand, neural biomarkers are measurable indicators for particular states or diseases set up from EEG data. Since 2013, the theta/beta ratio was accepted as the ADHD biomarker, suggesting a misbalance of electrical brain activity. In this study, brain connectivity on sustained attention task performed by children between 7 to 13 years old from a public school. Ten participants were ADHD-diagnosed and five were selected for the control group to compare EEG signals collected with low-cost neuroheadset. Graphs show different connectivity dynamics in both groups for Theta (4-8 Hz), SMR (12-15 Hz) and Beta (15-20 Hz), indicating connectivity variations in brain regions according to the neuroenergetics theory. The connectivity in the ADHD group is reduced in lower frequencies first (Theta), then SMR and finally Beta. In contrast, the control graphs for Theta and SMR brainwaves are closer to the small-world networks and it can be noticed by comparing the measurements of the different graphs among themselves. The decay process corresponds to the bottom-up approach, where random stimuli trigger transitions from one state to the other, which is in this case the transition from attention to inattention. The declining of resources placed for disposal at the randomized SART stage might imply a limitation regulating the production of the required resources for the tasks fulfillment, as it has been reported in previous studies where other techniques are implemented

    Detecting fatigue in car drivers and aircraft pilots by using eye-motion metrics

    Full text link
    Fatigue is widely recognised for risking the safety of aviation and ground transportation. To enhance transport safety, fatigue detection systems based on psychophysiological measures have been under development for many years. However, a reliable and robust fatigue detection system is still missing. This thesis starts with a literature review of fatigue concepts in the transportation field and the current psychophysiological measures to fatigue, and narrows down the focus to improving fatigue detection systems using eye-motion measures. A research gap was identified between current fatigue systems only focusing on part of sleepy symptoms and a comprehensive fatigue detection system including mental fatigue needed. To address this gap, four studies were conducted to reshape the understanding of fatigue in transportation and explore effective eye-motion metrics for indicating fatigue considering different causal factors. Studies 1 and 2 investigated the influence of two types of task-related fatigue on eye movement. Twenty participants completed a vigilance task before and after a 1-h simulator-based drive with a secondary task. Forty participants, divided equally into two groups, finished the same task before and after a 1-h and 1.5-h monotonous driving task. The results demonstrated that two types of task-related fatigue caused by cognitive overload and prolonged underload induced different physiological responses to eye-motion metrics. The results also proved that the increased mental fatigue decreased driver’s vigilance. Studies 3 and 4 simulated two hazardous fatigue scenarios for pilots. Study 3 explored the relationship between eye-motion metrics and pilot fatigue in an underload flight condition with sleep deprivation (low workload and sleep pressure). Study 4 explored the effective eye-motion metrics to estimate pilot’s cognitive fatigue imposed by time on task and high workload. The results suggested different eye-motion metrics to indicate sleepiness and mental fatigue. In addition, based on the sleepiness and mental fatigue indicators in Studies 3 and 4, several classifiers were built and evaluated to accurately detect sleepiness and mental fatigue. These findings show that considering casual factors such as sleep pressure, time on task and workload when using eye-motion metrics to detect fatigue can improve the accuracy and face validity of the current fatigue detection systems

    Análisis de conectividad funcional de la dinámica neuroenergética del TDAH = Functional Connectivity Analysis of Neuroenergetic Dynamics for ADHD

    Get PDF
    A fast and economic pilot study for measuring the neuroenergetic dynamics in an ADHD-diagnosed sample is performed. Based in a simplified connectome version, a graph theory application for neural connectivity, the performance and subjective states are linked through brain activity analysis during a behavioral attention test. ADHD is a neurobehavioral disorder related to a deficient filtering of stimuli, inefficacy performing in sustained activities and difficulties responding to unpredictable situations. There are two main strategies to evaluate this disorder: (1) behavioral tests and (2) neural biomarkers. Behavioral tests provide a criterion for classifying responses in a collection of tasks, looking for unstructured and inconsistent responses to given instructions or rules. Hyperactivity, inattention and impulsivity are some criteria analyzed. By the other hand, neural biomarkers are measurable indicators for particular states or diseases set up from EEG data. Since 2013, the theta/beta ratio was accepted as the ADHD biomarker, suggesting a misbalance of electrical brain activity. In this study, brain connectivity on sustained attention task performed by children between 7 to 13 years old from a public school. Ten participants were ADHD-diagnosed and five were selected for the control group to compare EEG signals collected with low-cost neuroheadset. Graphs show different connectivity dynamics in both groups for Theta (4-8 Hz), SMR (12-15 Hz) and Beta (15-20 Hz), indicating connectivity variations in brain regions according to the neuroenergetics theory. The connectivity in the ADHD group is reduced in lower frequencies first (Theta), then SMR and finally Beta. In contrast, the control graphs for Theta and SMR brainwaves are closer to the small-world networks and it can be noticed by comparing the measurements of the different graphs among themselves. The decay process corresponds to the bottom-up approach, where random stimuli trigger transitions from one state to the other, which is in this case the transition from attention to inattention. The declining of resources placed for disposal at the randomized SART stage might imply a limitation regulating the production of the required resources for the tasks fulfillment, as it has been reported in previous studies where other techniques are implemented

    Sixth Annual Workshop on Space Operations Applications and Research (SOAR 1992), volume 2

    Get PDF
    This document contains papers presented at the Space Operations, Applications, and Research Symposium (SOAR) hosted by the U.S. Air Force (USAF) on 4-6 Aug. 1992. The symposium was cosponsored by the Air Force Material Command and by NASA/JSC. Key technical areas covered during the symposium were robotics and telepresence, automation and intelligent systems, human factors, life sciences, and space maintenance and servicing. The SOAR differed from most other conferences in that it was concerned with Government-sponsored research and development relevant to aerospace operations. Symposium proceedings include papers covering various disciplines presented by experts from NASA, the USAF, universities, and industry

    Attention Restraint, Working Memory Capacity, and Mind Wandering: Do Emotional Valence or Intentionality Matter?

    Get PDF
    Attention restraint appears to mediate the relationship between working memory capacity (WMC) and mind wandering (Kane et al., 2016). Prior work has identifed two dimensions of mind wandering—emotional valence and intentionality. However, less is known about how WMC and attention restraint correlate with these dimensions. Te current study examined the relationship between WMC, attention restraint, and mind wandering by emotional valence and intentionality. A confrmatory factor analysis demonstrated that WMC and attention restraint were strongly correlated, but only attention restraint was related to overall mind wandering, consistent with prior fndings. However, when examining the emotional valence of mind wandering, attention restraint and WMC were related to negatively and positively valenced, but not neutral, mind wandering. Attention restraint was also related to intentional but not unintentional mind wandering. Tese results suggest that WMC and attention restraint predict some, but not all, types of mind wandering

    Autocalibrating vision guided navigation of unmanned air vehicles via tactical monocular cameras in GPS denied environments

    Get PDF
    This thesis presents a novel robotic navigation strategy by using a conventional tactical monocular camera, proving the feasibility of using a monocular camera as the sole proximity sensing, object avoidance, mapping, and path-planning mechanism to fly and navigate small to medium scale unmanned rotary-wing aircraft in an autonomous manner. The range measurement strategy is scalable, self-calibrating, indoor-outdoor capable, and has been biologically inspired by the key adaptive mechanisms for depth perception and pattern recognition found in humans and intelligent animals (particularly bats), designed to assume operations in previously unknown, GPS-denied environments. It proposes novel electronics, aircraft, aircraft systems, systems, and procedures and algorithms that come together to form airborne systems which measure absolute ranges from a monocular camera via passive photometry, mimicking that of a human-pilot like judgement. The research is intended to bridge the gap between practical GPS coverage and precision localization and mapping problem in a small aircraft. In the context of this study, several robotic platforms, airborne and ground alike, have been developed, some of which have been integrated in real-life field trials, for experimental validation. Albeit the emphasis on miniature robotic aircraft this research has been tested and found compatible with tactical vests and helmets, and it can be used to augment the reliability of many other types of proximity sensors

    Augmentation of Brain Function: Facts, Fiction and Controversy. Volume III: From Clinical Applications to Ethical Issues and Futuristic Ideas

    Get PDF
    The final volume in this tripartite series on Brain Augmentation is entitled “From Clinical Applications to Ethical Issues and Futuristic Ideas”. Many of the articles within this volume deal with translational efforts taking the results of experiments on laboratory animals and applying them to humans. In many cases, these interventions are intended to help people with disabilities in such a way so as to either restore or extend brain function. Traditionally, therapies in brain augmentation have included electrical and pharmacological techniques. In contrast, some of the techniques discussed in this volume add specificity by targeting select neural populations. This approach opens the door to where and how to promote the best interventions. Along the way, results have empowered the medical profession by expanding their understanding of brain function. Articles in this volume relate novel clinical solutions for a host of neurological and psychiatric conditions such as stroke, Parkinson’s disease, Huntington’s disease, epilepsy, dementia, Alzheimer’s disease, autism spectrum disorders (ASD), traumatic brain injury, and disorders of consciousness. In disease, symptoms and signs denote a departure from normal function. Brain augmentation has now been used to target both the core symptoms that provide specificity in the diagnosis of a disease, as well as other constitutional symptoms that may greatly handicap the individual. The volume provides a report on the use of repetitive transcranial magnetic stimulation (rTMS) in ASD with reported improvements of core deficits (i.e., executive functions). TMS in this regard departs from the present-day trend towards symptomatic treatment that leaves unaltered the root cause of the condition. In diseases, such as schizophrenia, brain augmentation approaches hold promise to avoid lengthy pharmacological interventions that are usually riddled with side effects or those with limiting returns as in the case of Parkinson’s disease. Brain stimulation can also be used to treat auditory verbal hallucination, visuospatial (hemispatial) neglect, and pain in patients suffering from multiple sclerosis. The brain acts as a telecommunication transceiver wherein different bandwidth of frequencies (brainwave oscillations) transmit information. Their baseline levels correlate with certain behavioral states. The proper integration of brain oscillations provides for the phenomenon of binding and central coherence. Brain augmentation may foster the normalization of brain oscillations in nervous system disorders. These techniques hold the promise of being applied remotely (under the supervision of medical personnel), thus overcoming the obstacle of travel in order to obtain healthcare. At present, traditional thinking would argue the possibility of synergism among different modalities of brain augmentation as a way of increasing their overall effectiveness and improving therapeutic selectivity. Thinking outside of the box would also provide for the implementation of brain-to-brain interfaces where techniques, proper to artificial intelligence, could allow us to surpass the limits of natural selection or enable communications between several individual brains sharing memories, or even a global brain capable of self-organization. Not all brains are created equal. Brain stimulation studies suggest large individual variability in response that may affect overall recovery/treatment, or modify desired effects of a given intervention. The subject’s age, gender, hormonal levels may affect an individual’s cortical excitability. In addition, this volume discusses the role of social interactions in the operations of augmenting technologies. Finally, augmenting methods could be applied to modulate consciousness, even though its neural mechanisms are poorly understood. Finally, this volume should be taken as a debate on social, moral and ethical issues on neurotechnologies. Brain enhancement may transform the individual into someone or something else. These techniques bypass the usual routes of accommodation to environmental exigencies that exalted our personal fortitude: learning, exercising, and diet. This will allow humans to preselect desired characteristics and realize consequent rewards without having to overcome adversity through more laborious means. The concern is that humans may be playing God, and the possibility of an expanding gap in social equity where brain enhancements may be selectively available to the wealthier individuals. These issues are discussed by a number of articles in this volume. Also discussed are the relationship between the diminishment and enhancement following the application of brain-augmenting technologies, the problem of “mind control” with BMI technologies, free will the duty to use cognitive enhancers in high-responsibility professions, determining the population of people in need of brain enhancement, informed public policy, cognitive biases, and the hype caused by the development of brain- augmenting approaches
    corecore