TY - JOUR A1 - Erlbeck, Helena A1 - Mochty, Ursula A1 - Kübler, Andrea A1 - Real, Ruben G. L. T1 - Circadian course of the P300 ERP in patients with amyotrophic lateral sclerosis - implications for brain-computer interfaces (BCI) JF - BMC Neurology N2 - Background: Accidents or neurodegenerative diseases like amyotrophic lateral sclerosis (ALS) can lead to progressing, extensive, and complete paralysis leaving patients aware but unable to communicate (locked-in state). Brain-computer interfaces (BCI) based on electroencephalography represent an important approach to establish communication with these patients. The most common BCI for communication rely on the P300, a positive deflection arising in response to rare events. To foster broader application of BCIs for restoring lost function, also for end-users with impaired vision, we explored whether there were specific time windows during the day in which a P300 driven BCI should be preferably applied. Methods: The present study investigated the influence of time of the day and modality (visual vs. auditory) on P300 amplitude and latency. A sample of 14 patients (end-users) with ALS and 14 healthy age matched volunteers participated in the study and P300 event-related potentials (ERP) were recorded at four different times (10, 12 am, 2, & 4 pm) during the day. Results: Results indicated no differences in P300 amplitudes or latencies between groups (ALS patients v. healthy participants) or time of measurement. In the auditory condition, latencies were shorter and amplitudes smaller as compared to the visual condition. Conclusion: Our findings suggest applicability of EEG/BCI sessions in patients with ALS throughout normal waking hours. Future studies using actual BCI systems are needed to generalize these findings with regard to BCI effectiveness/efficiency and other times of day. KW - brain computer interface KW - amyotrophic lateral sclerosis KW - ALS KW - P300 KW - auditory KW - visual KW - BCI Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-157423 VL - 17 IS - 3 ER - TY - JOUR A1 - Lugo, Zulay R. A1 - Quitadamo, Lucia R. A1 - Bianchi, Luigi A1 - Pellas, Fréderic A1 - Veser, Sandra A1 - Lesenfants, Damien A1 - Real, Ruben G. L. A1 - Herbert, Cornelia A1 - Guger, Christoph A1 - Kotchoubey, Boris A1 - Mattia, Donatella A1 - Kübler, Andrea A1 - Laureys, Steven A1 - Noirhomme, Quentin T1 - Cognitive Processing in Non-Communicative Patients: What Can Event-Related Potentials Tell Us? JF - Frontiers in Human Neuroscience N2 - Event-related potentials (ERP) have been proposed to improve the differential diagnosis of non-responsive patients. We investigated the potential of the P300 as a reliable marker of conscious processing in patients with locked-in syndrome (LIS). Eleven chronic LIS patients and 10 healthy subjects (HS) listened to a complex-tone auditory oddball paradigm, first in a passive condition (listen to the sounds) and then in an active condition (counting the deviant tones). Seven out of nine HS displayed a P300 waveform in the passive condition and all in the active condition. HS showed statistically significant changes in peak and area amplitude between conditions. Three out of seven LIS patients showed the P3 waveform in the passive condition and five of seven in the active condition. No changes in peak amplitude and only a significant difference at one electrode in area amplitude were observed in this group between conditions. We conclude that, in spite of keeping full consciousness and intact or nearly intact cortical functions, compared to HS, LIS patients present less reliable results when testing with ERP, specifically in the passive condition. We thus strongly recommend applying ERP paradigms in an active condition when evaluating consciousness in non-responsive patients. KW - P300 KW - event-related potentials KW - locked-in syndrome KW - vegetative state KW - unresponsive wakefulness syndrome KW - minimally conscious state Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165165 VL - 10 IS - 569 ER - TY - JOUR A1 - Meule, Adrian A1 - Fath, Katharina A1 - Real, Ruben G. L. A1 - Sütterlin, Stefan A1 - Vögele, Claus A1 - Kübler, Andrea T1 - Quality of life, emotion regulation, and heart rate variability in individuals with intellectual disabilities and concomitant impaired vision JF - Psychology of Well-Being: Theory, Research and Practice N2 - Background Positive associations have been found between quality of life, emotion regulation strategies, and heart rate variability (HRV) in people without intellectual disabilities. However, emotion regulation and HRV have rarely been investigated in people with intellectual disabilities. Assessment of subjectively reported quality of life and emotion regulation strategies in this population is even more difficult when participants are also visually impaired. Methods Subjective and objective quality of life, emotion regulation strategies, and HRV at rest were measured in a sample of people with intellectual disabilities and concomitant impaired vision (N = 35). Heart rate was recorded during a 10 min resting period. For the assessment of quality of life and emotion regulation, custom made tactile versions of questionnaire-based instruments were used that enabled participants to grasp response categories. Results The combined use of reappraisal and suppression as emotion regulation strategies was associated with higher HRV and quality of life. HRV was associated with objective quality of life only. Emotion regulation strategies partially mediated the relationship between HRV and quality of life. Conclusions Results replicate findings about associations between quality of life, emotion regulation, and HRV and extend them to individuals with intellectual disabilities. Furthermore, this study demonstrated that quality of life and emotion regulation could be assessed in such populations even with concomitant impaired vision with modified tactile versions of established questionnaires. HRV may be used as a physiological index to evaluate physical and affective conditions in this population. KW - Quality of life KW - Emotion regulation KW - Heart rate variability KW - Cardiac autonomic regulation KW - Intellectual disability KW - Impaired vision Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96247 UR - http://www.psywb.com/content/3/1/1 ER - TY - JOUR A1 - Real, Ruben G. L. A1 - Kotchoubey, Boris A1 - Kübler, Andrea T1 - Studentized continuous wavelet transform (t-CWT) in the analysis of individual ERPs: real and simulated EEG data N2 - This study aimed at evaluating the performance of the Studentized Continuous Wavelet Transform (t-CWT) as a method for the extraction and assessment of event-related brain potentials (ERP) in data from a single subject. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of the t-CWT were assessed and compared to a variety of competing procedures using simulated EEG data at six low signal-to-noise ratios. Results show that the t-CWT combines high sensitivity and specificity with favorable PPV and NPV. Applying the t-CWT to authentic EEG data obtained from 14 healthy participants confirmed its high sensitivity. The t-CWT may thus be well suited for the assessment of weak ERPs in single-subject settings. KW - electroencephalogram KW - wavelet KW - EEG KW - t-CWT KW - significance KW - detection KW - ERP Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-113581 ER - TY - JOUR A1 - Kübler, Andrea A1 - Hautzinger, Martin A1 - Ludolph, Albert A1 - Dickhaus, Thorsten A1 - Real, Ruben G. L. T1 - Well-being in amyotrophic lateral sclerosis: a pilot experience sampling study N2 - Objective: The aim of this longitudinal study was to identify predictors of instantaneous well-being in patients with amyotrophic lateral sclerosis (ALS). Based on flow theory well-being was expected to be highest when perceived demands and perceived control were in balance, and that thinking about the past would be a risk factor for rumination which would in turn reduce well-being. Methods: Using the experience sampling method, data on current activities, associated aspects of perceived demands, control, and well-being were collected from 10 patients with ALS three times a day for two weeks. Results: Results show that perceived control was uniformly and positively associated with well-being, but that demands were only positively associated with well-being when they were perceived as controllable. Mediation analysis confirmed thinking about the past, but not thinking about the future, to be a risk factor for rumination and reduced well-being. Discussion: Findings extend our knowledge of factors contributing to well-being in ALS as not only perceived control but also perceived demands can contribute to well-being. They further show that a focus on present experiences might contribute to increased well-being. KW - amyotrophic lateral sclerosis KW - ALS KW - coping KW - well-being KW - experience sampling KW - ESM KW - reminiscence KW - rumination Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-113057 ER -