129 research outputs found

    Affective Brain-Computer Interfaces

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    Hybridizing 3-dimensional multiple object tracking with neurofeedback to enhance preparation, performance, and learning

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    Le vaste domaine de l’amĂ©lioration cognitive traverse les applications comportementales, biochimiques et physiques. Aussi nombreuses sont les techniques que les limites de ces premiĂšres : des Ă©tudes de pauvre mĂ©thodologie, des pratiques Ă©thiquement ambiguĂ«s, de faibles effets positifs, des effets secondaires significatifs, des couts financiers importants, un investissement de temps significatif, une accessibilitĂ© inĂ©gale, et encore un manque de transfert. L’objectif de cette thĂšse est de proposer une mĂ©thode novatrice d’intĂ©gration de l’une de ces techniques, le neurofeedback, directement dans un paradigme d’apprentissage afin d’amĂ©liorer la performance cognitive et l’apprentissage. Cette thĂšse propose les modalitĂ©s, les fondements empiriques et des donnĂ©es Ă  l’appui de ce paradigme efficace d’apprentissage ‘bouclé’. En manipulant la difficultĂ© dans une tĂąche en fonction de l’activitĂ© cĂ©rĂ©brale en temps rĂ©el, il est dĂ©montrĂ© que dans un paradigme d’apprentissage traditionnel (3-dimentional multiple object tracking), la vitesse et le degrĂ© d’apprentissage peuvent ĂȘtre amĂ©liorĂ©s de maniĂšre significative lorsque comparĂ©s au paradigme traditionnel ou encore Ă  un groupe de contrĂŽle actif. La performance amĂ©liorĂ©e demeure observĂ©e mĂȘme avec un retrait du signal de rĂ©troaction, ce qui suggĂšre que les effets de l’entrainement amĂ©liorĂ© sont consolidĂ©s et ne dĂ©pendent pas d’une rĂ©troaction continue. Ensuite, cette thĂšse rĂ©vĂšle comment de tels effets se produisent, en examinant les corrĂ©lĂ©s neuronaux des Ă©tats de prĂ©paration et de performance Ă  travers les conditions d’état de base et pendant la tĂąche, de plus qu’en fonction du rĂ©sultat (rĂ©ussite/Ă©chec) et de la difficultĂ© (basse/moyenne/haute vitesse). La prĂ©paration, la performance et la charge cognitive sont mesurĂ©es via des liens robustement Ă©tablis dans un contexte d’activitĂ© cĂ©rĂ©brale fonctionnelle mesurĂ©e par l’électroencĂ©phalographie quantitative. Il est dĂ©montrĂ© que l’ajout d’une assistance- Ă -la-tĂąche apportĂ©e par la frĂ©quence alpha dominante est non seulement appropriĂ©e aux conditions de ce paradigme, mais influence la charge cognitive afin de favoriser un maintien du sujet dans sa zone de dĂ©veloppement proximale, ce qui facilite l’apprentissage et amĂ©liore la performance. Ce type de paradigme d’apprentissage peut contribuer Ă  surmonter, au minimum, un des limites fondamentales du neurofeedback et des autres techniques d’amĂ©lioration cognitive : le manque de transfert, en utilisant une mĂ©thode pouvant ĂȘtre intĂ©grĂ©e directement dans le contexte dans lequel l’amĂ©lioration de la performance est souhaitĂ©e.The domain of cognitive enhancement is vast, spanning behavioral, biochemical and physical applications. The techniques are as numerous as are the limitations: poorly conducted studies, ethically ambiguous practices, limited positive effects, significant side-effects, high financial costs, significant time investment, unequal accessibility, and lack of transfer. The purpose of this thesis is to propose a novel way of integrating one of these techniques, neurofeedback, directly into a learning context in order to enhance cognitive performance and learning. This thesis provides the framework, empirical foundations, and supporting evidence for a highly efficient ‘closed-loop’ learning paradigm. By manipulating task difficulty based on a measure of cognitive load within a classic learning scenario (3-dimentional multiple object tracking) using real-time brain activity, results demonstrate that over 10 sessions, speed and degree of learning can be substantially improved compared with a classic learning system or an active sham-control group. Superior performance persists even once the feedback signal is removed, which suggests that the effects of enhanced training are consolidated and do not rely on continued feedback. Next, this thesis examines how these effects occur, exploring the neural correlates of the states of preparedness and performance across baseline and task conditions, further examining correlates related to trial results (correct/incorrect) and task difficulty (slow/medium/fast speeds). Cognitive preparedness, performance and load are measured using well-established relationships between real-time quantified brain activity as measured by quantitative electroencephalography. It is shown that the addition of neurofeedback-based task assistance based on peak alpha frequency is appropriate to task conditions and manages to influence cognitive load, keeping the subject in the zone of proximal development more often, facilitating learning and improving performance. This type of learning paradigm could contribute to overcoming at least one of the fundamental limitations of neurofeedback and other cognitive enhancement techniques : a lack of observable transfer effects, by utilizing a method that can be directly integrated into the context in which improved performance is sought

    Coupled Correlates of Attention and Consciousness

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    Introduction: Brain Computer Interfaces (BCIs) have been shown to restore lost motor function that occurs in stroke using electrophysiological signals. However, little evidence exists for the use of BCIs to restore non-motor stroke deficits, such as the attention deficits seen in hemineglect. Attention is a cognitive function that selects objects or ideas for further neural processing, presumably to facilitate optimal behavior. Developing BCIs for attention is different from developing motor BCIs because attention networks in the brain are more distributed and associative than motor networks. For example, hemineglect patients have reduced levels of arousal, which exacerbates their attentional deficits. More generally, attention is a state of high arousal and salient conscious experience. Current models of consciousness suggest that both slow wave sleep and Propofol-induced unconsciousness lie at one end of the consciousness spectrum, while attentive states lie at the other end. Accordingly, investigating the electrophysiology underlying attention and the extremes of consciousness will further the development of attentional BCIs. Phase amplitude coupling (PAC) of neural oscillations has been suggested as a mechanism for organizing local and global brain activity across regions. While evidence suggests that delta-high-gamma PAC, which includes very low frequencies (i.e. delta, 1-3 Hz) coupled with very high frequencies (i.e. gamma 70-150 Hz), is implicated in attention, less evidence exists for the involvement of coupled mid-range frequencies (i.e. theta, 4-7Hz, alpha: 8-15 Hz, beta: 15-30 Hz and low-gamma: 30-50 Hz, aka TABL PAC). We found that TABL PAC correlates with reaction time in an attention task. These mid-range frequencies are important because they can be used in non-invasive electroencephalography (EEG) BCI’s. Therefore, we investigated the origins of these mid-frequency interactions in both attention and consciousness. In this work, we evaluate the relationship between PAC to attention and arousal, with emphasis on developing control signals for an attentional BCI. Objective: To understand how PAC facilitates attention and arousal for building BCI’s that restore lost attentional function. More generally, our objective was to discover and understand potential control features for BCIs that enhance attention and conscious experience. Methods: We used four electrophysiological datasets in human subjects. The first dataset included six subjects with invasive ECoG recordings while subjects engaged in a Posner cued spatial attention task. The second dataset included five subjects with ECoG recordings during sleep and awake states. The third dataset included 6 subjects with invasively monitored ECoG during induction and emergence from Propofol anesthesia. We validated findings from the second dataset with an EEG dataset that included 39 subjects with EEG and sleep scoring. We developed custom, wavelet-based, signal processing algorithms designed to optimally calculate differences in mid-frequency-range (i.e. TABL) PAC and compare them to DH PAC across different attentional and conscious states. We developed non-parametric cluster-based permutation tests to infer statistical significance while minimizing the false-positive rate. In the attention experiment, we used the location of cued spatial stimuli and reaction time (RT) as markers of attention. We defined stimulus-related and behaviorally-related cortical sites and compared their relative PAC magnitudes. In the sleep dataset, we compared PAC across sleep states (e.g. Wake vs Slow Wave Sleep). In the anesthesia dataset, we compared the beginning and ending of induction and emergence (e.g. Wake vs Propofol Induced Loss of Consciousness) Results: We found different patterns of activity represented by TABL PAC and DH PAC in both attention and sleep datasets. First, during a spatial attention task TABL PAC robustly predicted whether a subject would respond quickly or slowly. TABL PAC maintained a consistent phase-preference across all cortical sites and was strongest in behaviorally-relevant cortical sites. In contrast, DH PAC represented the location of attention in spatially-relevant cortical sites. Furthermore, we discovered that sharp waves caused TABL PAC. These sharp waves appeared to be transient beta (50ms) waves that occurred at ~140 ms intervals, corresponding to a theta oscillation. In the arousal dataset DH PAC increased in both slow wave sleep (SWS) and Propofol-induced loss of consciousness (PILOC) states. However, TABL PAC increased only during PILOC and decreased during SWS, when compared to waking states. We provide evidence that TABL PAC represents “gating by inhibition” in the human brain. Conclusions: Our goal was to develop electrophysiological signals representing attention and to understand how these features explain the relationship between attention and low-arousal states. We found a novel biomarker, TABL PAC, that predicted non-spatial aspects of attention and discriminated between two states of unconsciousness. The evidence suggested that TABL PAC represents inhibitory activity that filters out irrelevant information in attention tasks. This inhibitory mechanism of was confirmed by significant increases in TABL PAC during Propofol anesthesia, when compared to SWS or waking brain activity. We conclude that TABL PAC informs the development of electrophysiological control signals for attention and the discrimination of unconscious states

    Social and Affective Neuroscience of Everyday Human Interaction

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    This Open Access book presents the current state of the art knowledge on social and affective neuroscience based on empirical findings. This volume is divided into several sections first guiding the reader through important theoretical topics within affective neuroscience, social neuroscience and moral emotions, and clinical neuroscience. Each chapter addresses everyday social interactions and various aspects of social interactions from a different angle taking the reader on a diverse journey. The last section of the book is of methodological nature. Basic information is presented for the reader to learn about common methodologies used in neuroscience alongside advanced input to deepen the understanding and usability of these methods in social and affective neuroscience for more experienced readers

    Neurological and Mental Disorders

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    Mental disorders can result from disruption of neuronal circuitry, damage to the neuronal and non-neuronal cells, altered circuitry in the different regions of the brain and any changes in the permeability of the blood brain barrier. Early identification of these impairments through investigative means could help to improve the outcome for many brain and behaviour disease states.The chapters in this book describe how these abnormalities can lead to neurological and mental diseases such as ADHD (Attention Deficit Hyperactivity Disorder), anxiety disorders, Alzheimer’s disease and personality and eating disorders. Psycho-social traumas, especially during childhood, increase the incidence of amnesia and transient global amnesia, leading to the temporary inability to create new memories.Early detection of these disorders could benefit many complex diseases such as schizophrenia and depression

    Social and Affective Neuroscience of Everyday Human Interaction

    Get PDF
    This Open Access book presents the current state of the art knowledge on social and affective neuroscience based on empirical findings. This volume is divided into several sections first guiding the reader through important theoretical topics within affective neuroscience, social neuroscience and moral emotions, and clinical neuroscience. Each chapter addresses everyday social interactions and various aspects of social interactions from a different angle taking the reader on a diverse journey. The last section of the book is of methodological nature. Basic information is presented for the reader to learn about common methodologies used in neuroscience alongside advanced input to deepen the understanding and usability of these methods in social and affective neuroscience for more experienced readers

    User variations in attention and brain-computer interface performance

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    Electrical fingerprint of the amygdala guides neurofeedback training for stress resilience

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    Real-time functional magnetic resonance imaging (rt-fMRI) has revived the translational perspective of neurofeedback (NF)1. Particularly for stress management, targeting deeply located limbic areas involved in stress processing2 has paved new paths for brain-guided interventions. However, the high cost and immobility of fMRI constitute a challenging drawback for the scalability (accessibility and cost-effectiveness) of the approach, particularly for clinical purposes3. The current study aimed to overcome the limited applicability of rt-fMRI by using an electroencephalography (EEG) model endowed with improved spatial resolution, derived from simultaneous EEG–fMRI, to target amygdala activity (termed amygdala electrical fingerprint (Amyg-EFP))4,5,6. Healthy individuals (n = 180) undergoing a stressful military training programme were randomly assigned to six Amyg-EFP-NF sessions or one of two controls (control-EEG-NF or NoNF), taking place at the military training base. The results demonstrated specificity of NF learning to the targeted Amyg-EFP signal, which led to reduced alexithymia and faster emotional Stroop, indicating better stress coping following Amyg-EFP-NF relative to controls. Neural target engagement was demonstrated in a follow-up fMRI-NF, showing greater amygdala blood-oxygen-level-dependent downregulation and amygdala–ventromedial prefrontal cortex functional connectivity following Amyg-EFP-NF relative to NoNF. Together, these results demonstrate limbic specificity and efficacy of Amyg-EFP-NF during a stressful period, pointing to a scalable non-pharmacological yet neuroscience-based training to prevent stress-induced psychopathology

    Electrostimulation Contingencies and Attention, Electrocortical Activity and Neurofeedback

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    There is a growing body of evidence for diverse ways of modulating neuronal processing to improve cognitive performance. These include brain-based feedback, self-regulation techniques such as EEG-neurofeedback, and stimulation strategies, alone or in combination. The thesis goal was to determine whether a combined strategy would have advantages for normal cognitive function; specifically operant control of EEG activity in combination with transcutaneous electro-acustimulation. In experiment one the association between transcutaneous electroacustimulation (EA) and improved perceptual sensitivity was demonstrated with a visual GO/NOGO attention task (Chen et al, 2011). Furthermore reduced commission errors were related to an electrocortical motor inhibition component during and after alternating high and low frequency EA, whereas habituation in the control group with sham stimulation was related to different independent components. Experiment two applied frequency-domain ICA to detect changes in EEG power spectra from the eyes-closed to the eyes-open state (Chen et al, 2012). A multiple step approach was provided for analysing the spatiotemporal dynamics of default mode and resting state networks of cerebral EEG sources, preferable to conventional scalp EEG data analysis. Five regions were defined, compatible with fMRI studies. In experiment three the EA approach of Exp I was combined with sensorimotor rhythm (SMR) neurofeedback. SMR training improved perceptual sensitivity, an effect not found in a noncontingent feedback group. However, non-significant benefits resulted from EA. With ICA spectral power analysis changes in frontal beta power were associated with contingent SMR training. Possible long-term effects on an attention network in the resting EEG were also found after SMR training, compared with mock SMR training. In conclusion, this thesis has supplied novel evidence for significant cognitive and electrocortical effects of neurofeedback training and transcutaneous electro-acustimulation in healthy humans. Possible implications of these findings and suggestions for future research are considered
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