Effect of mindfulness meditation on brain–computer interface performance

Electroencephalogram based brain–computer interfaces (BCIs) enable stroke and motor neuron disease patients to communicate and control devices. Mindfulness meditation has been claimed to enhance metacognitive regulation. The current study explores whether mindfulness meditation training can thus improve the performance of BCI users. To eliminate the possibility of expectation of improvement influencing the results, we introduced a music training condition. A norming study found that both meditation and music interventions elicited clear expectations for improvement on the BCI task, with the strength of expectation being closely matched. In the main 12 week intervention study, seventy-six healthy volunteers were randomly assigned to three groups: a meditation training group; a music training group; and a no treatment control group. The mindfulness meditation training group obtained a significantly higher BCI accuracy compared to both the music training and no-treatment control groups after the intervention, indicating effects of meditation above and beyond expectancy effects.     

Brainwave classification without the help of limb movement and any stimulus for character-writing application

Recently, Brain-Computer Interfaces (BCIs) have been extensively popular for employing Electroencephalography (EEG) signals to control devices with different applications. The use of BCIs currently involves for lots of applications to help the disabilities who cannot communicate with other people, as it is an alternative way for communication by passing the need of speech. Although the applications to spell the character with BCI systems (e.g., P300-speller, SSVEP-speller, Hex-O-spell) have been already developed, but these techniques are not flexible in the real scenarios because they require the stimulus all the time or stopping the activity to focus on the limb movement in order to provide the accuracy of brain responses. In this paper, the feasibility of brainwave classification for the applications of character-writing by considering only the EEG signals without the need of stimulus unlike the literature is newly introduced. This paper adopts a classification technique named Artificial Neural Network (ANN) and focuses on two different characters; straight line and circle. From the experimental results, the suitable position of electrodes are the pair of electrodes (F3 and F4) at the frontal lobe, which provide the best result as compared to other areas due to its important role in perception, maintenance and revival of the information. The experimental results indicate that the classification accuracy of the proposed technique is about 70%, which in turn leads to a significant achievement for the development of character-writing applications.     

Embodiment and Estrangement: Results from a First-in-Human “Intelligent BCI” Trial

While new generations of implantable brain computer interface (BCI) devices are being developed, evidence in the literature about their impact on the patient experience is lagging. In this article, we address this knowledge gap by analysing data from the first-in-human clinical trial to study patients with implanted BCI advisory devices. We explored perceptions of self-change across six patients who volunteered to be implanted with artificially intelligent BCI devices. We used qualitative methodological tools grounded in phenomenology to conduct in-depth, semi-structured interviews. Results show that, on the one hand, BCIs can positively increase a sense of the self and control; on the other hand, they can induce radical distress, feelings of loss of control, and a rupture of patient identity. We conclude by offering suggestions for the proactive creation of preparedness protocols specific to intelligent—predictive and advisory—BCI technologies essential to prevent potential iatrogenic harms.

     

Psychological variables in the control of brain-computer interfaces

BCI (Brain-Computer Interface) is a system that allows interaction between the human brain and a computer. It is based on analyzing electroencephalographic signals (EEG) and processing them to generate control commands. The study analyzed the possible influence of psychological variables, such as the imaginative kinesthetic capacity and anxiety, in relation to performance in a BCI. All participants (4 male and 19 female students) completed the questionnaires and carried out a session of BCI to control their EEG signals in a virtual setting of a car along a straight road. The group was divided into two subgroups according to their EEG signals or differential responses obtained in the left-right discrimination. Study results showed no significant differences in cognitive variables of imagination or in anxiety. By comparing the degree of participants' BCI control, a new quantitative parameter for comparing performances and making decisions in signal processing was found. The findings, the ongoing research process to refine the control of a BCI, and the interaction of psychological and computer procedures are discussed.     

An information theoretical approach to prefrontal executive function

The prefrontal cortex subserves executive control--that is, the ability to select actions or thoughts in relation to internal goals. Here, we propose a theory that draws upon concepts from information theory to describe the architecture of executive control in the lateral prefrontal cortex. Supported by evidence from brain imaging in human subjects, the model proposes that action selection is guided by hierarchically ordered control signals, processed in a network of brain regions organized along the anterior-posterior axis of the lateral prefrontal cortex. The theory clarifies how executive control can operate as a unitary function, despite the requirement that information be integrated across multiple distinct, functionally specialized prefrontal regions.     

Direct brain communication: neuroelectric and metabolic approaches at Tübingen

The brain–computer interface (BCI) provides users with the possibility of sending messages and commands to the external world without using their muscles, thus enabling communication to occur independent of movement. Such a possibility is of utmost importance for paralyzed patients who may otherwise lose their ability to communicate. Enhanced methodology and the development of faster computers have substantially improved applications and offer new possibilities in this field. To date, there have been over 20 BCI research groups working on different approaches. In this paper, we review our studies of BCI based on electric and metabolic activity of the brain.     

Changing the P300 brain computer interface.

Brain-computer interfaces (BCIs) are now feasible for use as an alternative control option for those with severe motor impairments. The P300 component of the evoked potential has proven useful as a control signal. Individuals do not need to be trained to produce the signal, and it is fairly stable and has a large evoked potential. Even with recent signal classification advances, on-line experiments with P300-based BCIs remain far from perfect. We present two potential methods for improving control accuracy. Experimental results in an evoked potential BCI, used to control items in a virtual apartment, show a reduced response exists when items are accidentally controlled. The presence of a P300-like signal in response to goal items means that it can be used for automatic error correction. Preliminary results from an interface experiment using three different button configurations for a yes/no BCI task show that the configuration of buttons may affect on-line signal classification. These results will be discussed in light of the special considerations needed when working with an amyotrophic lateral sclerosis (ALS) patient.     

Alcohol Counseling in Hospital Trauma: Examining Two Brief Interventions

Hospital trauma centers intervene with patients who incur alcohol‐related injuries. This prospective study, using professional counselors and trainees, investigated brief counseling interventions (BCIs). Participants were randomized to either a conventional BCI examining quantity and frequency of drinks or a personalized BCI exploring overintoxication. No statistically significant difference between risky drinkers randomized to either intervention in a hospital trauma center was observed. Findings indicate that a personalized BCI may be an alternative to a quantitative BCI in reducing risky alcohol consumption.     

言语想象的神经机制

言语想象不仅在大脑预处理机制方面起到重要的作用,还是目前脑机接口领域研究的热点。与正常言语产生过程相比,言语想象的理论模型、激活脑区、神经传导路径等均与其有较多相似之处。而言语障碍群体的言语想象、想象有意义的词语和句子时的脑神经机制与正常言语产生存在差异。鉴于人类言语系统的复杂性,言语想象的神经机制研究还面临一系列挑战,未来研究可在言语想象质量评价工具及神经解码范式、脑控制回路、激活通路、言语障碍群体的言语想象机制、词语和句子想象的脑神经信号等方面进一步探索,为有效提高脑机接口的识别率提供依据,为言语障碍群体的沟通提供便利。     

Executive control of gaze by the frontal lobes

Executive control requires controlling the initiation of movements, judging the consequences of actions, and adjusting performance accordingly. We have investigated the role of different areas in the frontal lobe in executive control expressed by macaque monkeys performing a saccade stop signal task. Certain neurons in the frontal eye field respond to visual stimuli, and others control the production of saccadic eye movements. Neurons in the supplementary eye field do not control directly the initiation of saccades but, instead, signal the production of errors, the anticipation and delivery of reinforcement, and the presence of response conflict. Neurons in the anterior cingulate cortex signal the production of errors and the anticipation and delivery of reinforcement, but not the presence of response conflict. Intracranial local field potentials in the anterior cingulate cortex of monkeys indicate that these medial frontal signals can contribute to event-related potentials related to performance monitoring. Electrical stimulation of the supplementary eye field improves performance in the task by elevating saccade latency. An interactive race model shows how interacting units produce behavior that can be described as the outcome of a race between independent processes and how conflict between gaze-holding and gaze-shifting neurons can be used to adjust performance.     

An optimized facial stimuli paradigm for hybrid SSVEP+P300 brain computer interface

In this paper, hybrid BCI that merges Event Related Potentials (P300) and Steady State visual Evoked Potentials (SSVEP) simultaneously is proposed to enhance the performance of Four-choice command system. Here we integrate human facial structure in external visual stimulus to evoke stronger cortical responses in hybrid SSVEP+P300 BCI & compare it with non-face stimuli. We also addressed question of feasibility of eliciting one potential by face & other by non-face stimuli. To evoke SSVEP & P300 responses, paradigms with non-face stimuli, neutral face stimuli, and facial expression changes stimuli are proposed. We also projected additional paradigm where SSVEP is elicited by non-face and P300 by flashing different facial expressions. Results proved the last paradigm evoke stronger cortical potentials and thereby improve system accuracy and ITR than other paradigms. Author discussed external stimulus parameters that might affect simultaneous evocation of multiple brain potentials and their deterioration effect on individual potentials.     

Neurocognitive mechanisms of cognitive control: the role of prefrontal cortex in action selection, response inhibition, performance monitoring, and reward-based learning

Convergent evidence highlights the differential contributions of various regions of the prefrontal cortex in the service of cognitive control, but little is understood about how the brain determines and communicates the need to recruit cognitive control, and how such signals instigate the implementation of appropriate performance adjustments. Here we review recent progress from cognitive neuroscience in examining some of the main constituent processes of cognitive control as involved in dynamic decision making: goal-directed action selection, response activation and inhibition, performance monitoring, and reward-based learning. Medial frontal cortex is found to be involved in performance monitoring: evaluating outcome vis-a-vis expectancy, and detecting performance errors or conflicting response tendencies. Lateral and orbitofrontal divisions of prefrontal cortex are involved in subsequently implementing appropriate adjustments.     

Conscious thought as simulation of behaviour and perception

A 'simulation' theory of cognitive function can be based on three assumptions about brain function. First, behaviour can be simulated by activating motor structures, as during an overt action but suppressing its execution. Second, perception can be simulated by internal activation of sensory cortex, as during normal perception of external stimuli. Third, both overt and covert actions can elicit perceptual simulation of their normal consequences. A large body of evidence supports these assumptions. It is argued that the simulation approach can explain the relations between motor, sensory and cognitive functions and the appearance of an inner world.     

Responses of the human motor system to observing actions across species: A transcranial magnetic stimulation study

Ample evidence suggests that the role of the mirror neuron system (MNS) in monkeys is to represent the meaning of actions. The MNS becomes active in monkeys during execution, observation, and auditory experience of meaningful, object-oriented actions, suggesting that these cells represent the same action based on a variety of cues. The present study sought to determine whether the human motor system, part of the putative human MNS, similarly represents and reflects the meaning of actions rather than simply the mechanics of the actions. To this end, transcranial magnetic stimulation (TMS) of primary motor cortex was used to generate motor-evoked potentials (MEPs) from muscles involved in grasping while participants viewed object-oriented grasping actions performed by either a human, an elephant, a rat, or a body-less robotic arm. The analysis of MEP amplitudes suggested that activity in primary motor cortex during action observation was greatest during observation of the grasping actions of the rat and elephant, and smallest for the human and robotic arm. Based on these data, we conclude that the human action observation system can represent actions executed by non-human animals and shows sensitivity to species-specific differences in action mechanics.     

Who's calling the shots? Intentional content and feelings of control

Based on Pacherie’s dynamic theory of intentions, this study investigated how the way an intention is formed and sustained affects action performance and the experience of control during acting. In Experiment 1, task-irrelevant verbal commands were given while participants responded to stimuli in a two-choice reaction time (RT) task. The commands referred to an action goal congruent or incongruent with the actor’s current intention, or ordered the initiation or abortion of the action. In Experiment 2, the same commands were given as participants freely chose between two actions. The distractors affected performance in the reactive task only. In both experiments, feelings of control were based on movement parameters as well as perceived (mis)matches between distractors and intended actions. These findings suggest that the way an intention is implemented affects how well it can be shielded against external perturbations and how much one feels in control.     

Concept-based behavioral planning and the lateral prefrontal cortex

Many lines of evidence implicate the lateral prefrontal cortex (LPFC) in the executive control of behavior. In early studies, neuronal activity in this area was thought to retain information about forthcoming movements for a short period until they were executed. However, later studies have stressed its role in the cognitive aspects of behavioral planning, such as behavioral significance, behavioral rules and behavioral goals. The consequence of the intended action (i.e. a change in the state of the target object), rather than the intended movement, is primarily represented in the LPFC during planning. Recent studies show that the LPFC is involved in more abstract aspects of conceptual processes, such as in representing categories of multiple actions at the stage of behavioral planning.     

Neural control of behavior: countermanding eye movements

Understanding the self-control of action entails knowledge about how actions are initiated, how planned actions are canceled and how the consequences of actions are registered. We have investigated neural correlates of these processes using the countermanding paradigm – a task that required subjects to occasionally cancel a planned speeded response, and an analysis that provides an estimate of the time needed to cancel a planned movement. By monitoring the activity of single neurons in the frontal cortex of macaque monkeys performing this task we have distinguished signals responding to the visual stimuli, other signals that control the production of movements, and still other signals that seem to monitor behavior. Received: 31 March 1999 / Accepted: 23 July 1999     

Effects of social context and predictive relevance on action outcome monitoring

Outcome monitoring is crucial for subsequent adjustments in behavior and is associated with a specific electrophysiological response, the feedback-related negativity (FRN). Besides feedback generated by one's own action, the performance of others may also be relevant for oneself, and the observation of outcomes for others' actions elicits an observer FRN (oFRN). To test how these components are influenced by social setting and predictive value of feedback information, we compared event-related potentials, as well as their topographies and neural generators, for performance feedback generated by oneself and others in a cooperative versus competitive context. Our results show that (1) the predictive relevance of outcomes is crucial to elicit an FRN in both players and observers, (2) cooperation increases FRN and P300 amplitudes, especially in individuals with high traits of perspective taking, and (3) contrary to previous findings on gambling outcomes, oFRN components are generated for both cooperating and competing observers, but with smaller amplitudes in the latter. Neural source estimation revealed medial prefrontal activity for both FRN and oFRN, but with additional generators for the oFRN in the dorsolateral and ventral prefrontal cortex, as well as the temporoparietal junction. We conclude that the latter set of brain regions could mediate social influences on action monitoring by representing agency and social relevance of outcomes and are, therefore, recruited in addition to shared prediction error signals generated in medial frontal areas during action outcome observation.     

Baby steps: investigating the development of perceptual–motor couplings in infancy

There are cells in our motor cortex that fire both when we perform and when we observe similar actions. It has been suggested that these perceptual‐motor couplings in the brain develop through associative learning during correlated sensorimotor experience. Although studies with adult participants have provided support for this hypothesis, there is no direct evidence that associative learning also underlies the initial formation of perceptual–motor couplings in the developing brain. With the present study we addressed this question by manipulating infants’ opportunities to associate the visual and motor representation of a novel action, and by investigating how this influenced their sensorimotor cortex activation when they observed this action performed by others. Pre‐walking 7–9‐month‐old infants performed stepping movements on an infant treadmill while they either observed their own real‐time leg movements (Contingent group) or the previously recorded leg movements of another infant (Non‐contingent control group). Infants in a second control group did not perform any steps and only received visual experience with the stepping actions. Before and after the training period we measured infants’ sensorimotor alpha suppression, as an index of sensorimotor cortex activation, while they watched videos of other infants’ stepping actions. While we did not find greater sensorimotor alpha suppression following training in the Contingent group as a whole, we nevertheless found that the strength of the visuomotor contingency experienced during training predicted the amount of sensorimotor alpha suppression at post‐test in this group. We did not find any effects of motor experience alone. These results suggest that the development of perceptual–motor couplings in the infant brain is likely to be supported by associative learning during correlated visuomotor experience.     

Limitations of distal effect anticipation when using tools

Modern technologies progressively create workplaces in which the execution of movements and the observation of their consequences are spatially separated. Challenging workplaces in which users act via technical equipment in a distant space include aviation, applied medical engineering and virtual reality. When using a tool, proprioceptive/tactile feedback from the moving hand (proximal action effect) and visual feedback from the moving effect point of the tool, such as the moving cursor on a display (the distal action effect) often do not correspond or are even in conflict. If proximal and distal feedback were equally important for controlling actions with tools, this discrepancy would be a constant source of interference. The human information processing system solves this problem by favoring the intended distal action effects while attenuating or ignoring proximal action effects. The study presents an overview of experiments aiming at the underlying motor and cognitive processes and the limitations of visual predominance in tool actions. The main findings are, that when transformations are in effect the awareness of one's own actions is quite low. This seems to be advantageous when using tools, as it allows for wide range of flexible sensorimotor adaptations and – may be more important – it evokes the feeling of being in control. Thus, the attenuation of perceiving one's own proximal action effects is an important precondition for using tools successfully. However, the ability to integrate discordant perception-action feedback has limits, especially, but not only, with complex transformations. When feature overlap between vision and proprioception is low, and when the existence of a transformation is obvious proximal action effects come to the fore and dominate action control in tool actions. In conclusion action–effect control plays an important role in understanding the constraints of the acquisition and application of tool transformations.