Complete locked-in and locked-in patients: Command following assessment and communication with vibro-tactile P300 and motor imagery brain-computer interface tools

Many patients with locked-in syndrome (LIS) or complete locked-in syndrome (CLIS) also need brain-computer interface (BCI) platforms that do not rely on visual stimuli and are easy to use. We investigate command following and communication functions of mindBEAGLE with 9 LIS, 3 CLIS patients and three healthy controls. This tests were done with vibro-tactile stimulation with 2 or 3 stimulators (VT2 and VT3 mode) and with motor imagery (MI) paradigms. In VT2 the stimulators are fixed on the left and right wrist and the participant has the task to count the stimuli on the target hand in order to elicit a P300 response. In VT3 mode an additional stimulator is placed as a distractor on the shoulder and the participant is counting stimuli either on the right or left hand. In motor imagery mode the participant is instructed to imagine left or right hand movement. VT3 and MI also allow the participant to answer yes and no questions. Healthy controls achieved a mean assessment accuracy of 100% in VT2, 93% in VT3, and 73% in MI modes. They were able to communicate with VT3 (86.7%) and MI (83.3%) after 2 training runs. The patients achieved a mean accuracy of 76.6% in VT2, 63.1% in VT3, and 58.2% in MI modes after 1-2 training runs. 9 out of 12 LIS patients could communicate by using the vibro-tactile P300 paradigms (answered on average 8 out of 10 questions correctly) and 3 out of 12 could communicate with the motor imagery paradigm(answered correctly 4,7 out of 5 questions). 2 out of the 3 CLIS patients could use the system to communicate with VT3 (90 and 70% accuracy). The results show that paradigms based on non-visual evoked potentials and motor imagery can be effective for these users. It is also the first study that showed EEG-based BCI communication with CLIS patients and was able to bring 9 out of 12 patients to communicate with higher accuracies than reported before. More importantly this was achieved within less than 15-20 min

Ideas of perfection and the ethics of human enhancement

Whatever ethical stance one takes in the debate regarding the ethics of human enhancement, one or more reference points are required to assess its morality. Some have suggested looking at the bioethical notions of safety, justice, and/or autonomy to find such reference points. Others, arguing that those notions are limited with respect to assessing the morality of human enhancement, have turned to human nature, human authenticity, or human dignity as reference points, thereby introducing some perfectionist assumptions into the debate. In this article, we ask which perfectionist assumptions should be used in this debate. After a critique of views that are problematic, we take a positive approach, suggesting some perfectionist elements that can lend guidance to the practice of human enhancement, based on the work of Martha Nussbaum's Capability Approach. We suggest that the central capabilities can be used to define the human aspect of human enhancement and thereby allow a moral evaluation of enhancement interventions. These central capabilities can be maximized harmoniously to postulate what an ideal human would look like. Ultimately, the aim of this article is twofold. First, it seeks to make explicit the perfectionist assumptions found in the debate and eliminate those that are problematic. Second, the paper clarifies an element that is often neglected in the debate about human enhancement, the view of the ideal human towards which human enhancement should strive. Here, we suggest that some central capabilities that are essential for an ideal human being can be maximized harmoniously and can therefore serve as possible reference points to guide human enhancement

Effects of a Vibro-Tactile P300 Based Brain-Computer Interface on the Coma Recovery Scale-Revised in Patients With Disorders of Consciousness

Persons diagnosed with disorders of consciousness (DOC) typically suffer from motor and cognitive disabilities. Recent research has shown that non-invasive brain-computer interface (BCI) technology could help assess these patients’ cognitive functions and command following abilities. 20 DOC patients participated in the study and performed 10 vibro-tactile P300 BCI sessions over 10 days with 8–12 runs each day. Vibrotactile tactors were placed on the each patient’s left and right wrists and one foot. Patients were instructed, via earbuds, to concentrate and silently count vibrotactile pulses on either their left or right wrist that presented a target stimulus and to ignore the others. Changes of the BCI classification accuracy were investigated over the 10 days. In addition, the Coma Recovery Scale-Revised (CRS-R) score was measured before and after the 10 vibro-tactile P300 sessions. In the first run, 10 patients had a classification accuracy above chance level (>12.5%). In the best run, every patient reached an accuracy ≥60%. The grand average accuracy in the first session for all patients was 40%. In the best session, the grand average accuracy was 88% and the median accuracy across all sessions was 21%. The CRS-R scores compared before and after 10 VT3 sessions for all 20 patients, are showing significant improvement (p = 0.024). Twelve of the twenty patients showed an improvement of 1 to 7 points in the CRS-R score after the VT3 BCI sessions (mean: 2.6). Six patients did not show a change of the CRS-R and two patients showed a decline in the score by 1 point. Every patient achieved at least 60% accuracy at least once, which indicates successful command following. This shows the importance of repeated measures when DOC patients are assessed. The improvement of the CRS-R score after the 10 VT3 sessions is an important issue for future experiments to test the possible therapeutic applications of vibro-tactile and related BCIs with a larger patient group

Preserved somatosensory discrimination predicts consciousness recovery in unresponsive wakefulness syndrome

Objective: To assess somatosensory discrimination and command following using a vibrotactile P300-based Brain-Computer Interface (BCI) in Unresponsive Wakefulness Syndrome (UWS), and investigate the predictive role of this cognitive process on the clinical outcomes.Methods: Thirteen UWS patients and six healthy controls each participated in two experimental runs in which they were instructed to count vibrotactile stimuli delivered to the left or right wrist. A BCI determined each subject's task performance based on EEG measures. All of the patients were followed up six months after the BCI assessment, and correlations analysis between accuracy rates and clinical outcome were investigated.Results: Four UWS patients demonstrated clear EEG-based indices of task following in one or both paradigms, which did not correlate with clinical factors. The efficacy of somatosensory discrimination strongly correlated (VT2: R = 0.89, p = 0.0000002, VT3: R = 0.81, p = 0.002) with the clinical outcome at 6-months. The BCI system also yielded the expected results with healthy controls.Conclusions: Neurophysiological correlates of somatosensory discrimination can be detected in clinically unresponsive patients and are associated with recovery of behavioural responsiveness at six months.Significance: Quantitative measurements of somatosensory discrimination may increase the diagnostic accuracy of persons with DOCs and provide useful prognostic information. (C) 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved

MindBEAGLE - A new system for the assessment and communication with patients with disorders of consciousness and complete locked-in syndrom

peer reviewedPatients with disorders of consciousness (DOC) cannot reply to questions or clinical assessments using voluntary motor control, and therefore it is very difficult to assess their cognitive capabilities and conscious awareness. Patients who are locked-in (LIS) are instead fully conscious, and they can communicate with their preserved eye movements. However, when the residual oculomotor activity is also lost (e.g., patients with amyotrophic lateral sclerosis disease of very long duration), the locked-in status becomes complete (CLIS). In CLIS patients, detection of conscious awareness may become very challenging, similarly to the subjects with DOC. mindBEAGLE has a physiological testing battery that uses auditory, vibro-tactile and motor imagery paradigms and braincomputer interface (BCI) technology to assess these patients and even provide communication for some of them. The current study presents results from 5 DOC and 3 LIS patients. The auditory evoked potential (AEP) assessement led to classification accuracies between 0 and 90 %, the vibro-tactile P300 paradigms led to 0 % to 100 % accuracy and the motor imagery paradigms led to accuracies up to 83.3 %. Three of the eight patients could succcessfully establish communication with the mindBEAGLE system. The results show that an assessment battery with auditory, vibrotactile and motor imagery paradigms is able to identify cognitive functions of DOC and LIS patients. Patients showed substantial fluctuations in EEG measures, assessment results and communication reliability across different days and runs. Therefore, it is important to have a system available that can quickly and easily determine the status of a patient. Successful communication with these patients is also important. © 2017 IEEE

GLP-1 receptor signaling in astrocytes regulates fatty acid oxidation, mitochondrial integrity, and function

Astrocytes represent central regulators of brain glucose metabolism and neuronal function. They have recently been shown to adapt their function in response to alterations in nutritional state through responding to the energy state-sensing hormones leptin and insulin. Here, we demonstrate that glucagon-like peptide (GLP)-1 inhibits glucose uptake and promotes beta-oxidation in cultured astrocytes. Conversely, postnatal GLP-1 receptor (GLP-1R) deletion in glial fibrillary acidic protein (GFAP)-expressing astrocytes impairs astrocyte mitochondrial integrity and activates an integrated stress response with enhanced fibroblast growth factor (FGF)21 production and increased brain glucose uptake. Accordingly, central neutralization of FGF21 or astrocyte-specific FGF21 inactivation abrogates the improvements in glucose tolerance and learning in mice lacking GLP-1R expression in astrocytes. Collectively, these experiments reveal a role for astrocyte GLP-1R signaling in maintaining mitochondrial integrity, and lack of GLP-1R signaling mounts an adaptive stress response resulting in an improvement of systemic glucose homeostasis and memory formation