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You Y, Li Y, Yu B, Ying A, Zhou H, Zuo G, Xu J. A study on EEG differences between active counting and focused breathing tasks for more sensitive detection of consciousness. Front Neurosci 2024; 18:1341986. [PMID: 38533445 PMCID: PMC10963484 DOI: 10.3389/fnins.2024.1341986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 02/26/2024] [Indexed: 03/28/2024] Open
Abstract
Introduction In studies on consciousness detection for patients with disorders of consciousness, difference comparison of EEG responses based on active and passive task modes is difficult to sensitively detect patients' consciousness, while a single potential analysis of EEG responses cannot comprehensively and accurately determine patients' consciousness status. Therefore, in this paper, we designed a new consciousness detection paradigm based on a multi-stage cognitive task that could induce a series of event-related potentials and ERD/ERS phenomena reflecting different consciousness contents. A simple and direct task of paying attention to breathing was designed, and a comprehensive evaluation of consciousness level was conducted using multi-feature joint analysis. Methods We recorded the EEG responses of 20 healthy subjects in three modes and reported the consciousness-related mean event-related potential amplitude, ERD/ERS phenomena, and the classification accuracy, sensitivity, and specificity of the EEG responses under different conditions. Results The results showed that the EEG responses of the subjects under different conditions were significantly different in the time domain and time-frequency domain. Compared with the passive mode, the amplitudes of the event-related potentials in the breathing mode were further reduced, and the theta-ERS and alpha-ERD phenomena in the frontal region were further weakened. The breathing mode showed greater distinguishability from the active mode in machine learning-based classification. Discussion By analyzing multiple features of EEG responses in different modes and stimuli, it is expected to achieve more sensitive and accurate consciousness detection. This study can provide a new idea for the design of consciousness detection methods.
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Affiliation(s)
- Yimeng You
- Cixi Biomedical Research Institute, Wenzhou Medical University, Ningbo, Zhejiang, China
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, China
- Ningbo Cixi Institute of Biomedical Engineering, Ningbo, Zhejiang, China
| | - Yahui Li
- Cixi Biomedical Research Institute, Wenzhou Medical University, Ningbo, Zhejiang, China
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, China
- Ningbo Cixi Institute of Biomedical Engineering, Ningbo, Zhejiang, China
| | - Baobao Yu
- Cixi Biomedical Research Institute, Wenzhou Medical University, Ningbo, Zhejiang, China
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, China
- Ningbo Cixi Institute of Biomedical Engineering, Ningbo, Zhejiang, China
| | - Ankai Ying
- Cixi Biomedical Research Institute, Wenzhou Medical University, Ningbo, Zhejiang, China
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, China
- Ningbo Cixi Institute of Biomedical Engineering, Ningbo, Zhejiang, China
| | - Huilin Zhou
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, China
- Ningbo Cixi Institute of Biomedical Engineering, Ningbo, Zhejiang, China
| | - Guokun Zuo
- Cixi Biomedical Research Institute, Wenzhou Medical University, Ningbo, Zhejiang, China
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, China
- Ningbo Cixi Institute of Biomedical Engineering, Ningbo, Zhejiang, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jialin Xu
- Cixi Biomedical Research Institute, Wenzhou Medical University, Ningbo, Zhejiang, China
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, China
- Ningbo Cixi Institute of Biomedical Engineering, Ningbo, Zhejiang, China
- University of Chinese Academy of Sciences, Beijing, China
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Séguin P, Maby E, Fouillen M, Otman A, Luauté J, Giraux P, Morlet D, Mattout J. The challenge of controlling an auditory BCI in the case of severe motor disability. J Neuroeng Rehabil 2024; 21:9. [PMID: 38238759 PMCID: PMC10795353 DOI: 10.1186/s12984-023-01289-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 11/29/2023] [Indexed: 01/22/2024] Open
Abstract
BACKGROUND The locked-in syndrome (LIS), due to a lesion in the pons, impedes communication. This situation can also be met after some severe brain injury or in advanced Amyotrophic Lateral Sclerosis (ALS). In the most severe condition, the persons cannot communicate at all because of a complete oculomotor paralysis (Complete LIS or CLIS). This even prevents the detection of consciousness. Some studies suggest that auditory brain-computer interface (BCI) could restore a communication through a « yes-no» code. METHODS We developed an auditory EEG-based interface which makes use of voluntary modulations of attention, to restore a yes-no communication code in non-responding persons. This binary BCI uses repeated speech sounds (alternating "yes" on the right ear and "no" on the left ear) corresponding to either frequent (short) or rare (long) stimuli. Users are instructed to pay attention to the relevant stimuli only. We tested this BCI with 18 healthy subjects, and 7 people with severe motor disability (3 "classical" persons with locked-in syndrome and 4 persons with ALS). RESULTS We report online BCI performance and offline event-related potential analysis. On average in healthy subjects, online BCI accuracy reached 86% based on 50 questions. Only one out of 18 subjects could not perform above chance level. Ten subjects had an accuracy above 90%. However, most patients could not produce online performance above chance level, except for two people with ALS who obtained 100% accuracy. We report individual event-related potentials and their modulation by attention. In addition to the classical P3b, we observed a signature of sustained attention on responses to frequent sounds, but in healthy subjects and patients with good BCI control only. CONCLUSIONS Auditory BCI can be very well controlled by healthy subjects, but it is not a guarantee that it can be readily used by the target population of persons in LIS or CLIS. A conclusion that is supported by a few previous findings in BCI and should now trigger research to assess the reasons of such a gap in order to propose new and efficient solutions. CLINICAL TRIAL REGISTRATIONS No. NCT02567201 (2015) and NCT03233282 (2013).
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Affiliation(s)
- Perrine Séguin
- Lyon Neuroscience Research Center, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000, Lyon, France
- University Hospital of Saint-Etienne, 42000, Saint-Etienne, France
- Jean Monnet University, 42000, Saint-Etienne, France
| | - Emmanuel Maby
- Lyon Neuroscience Research Center, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000, Lyon, France
| | - Mélodie Fouillen
- Lyon Neuroscience Research Center, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000, Lyon, France
| | - Anatole Otman
- Lyon Neuroscience Research Center, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000, Lyon, France
| | - Jacques Luauté
- Lyon Neuroscience Research Center, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000, Lyon, France
- Hospices Civils de Lyon, 69000, Lyon, France
| | - Pascal Giraux
- Lyon Neuroscience Research Center, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000, Lyon, France
- University Hospital of Saint-Etienne, 42000, Saint-Etienne, France
- Jean Monnet University, 42000, Saint-Etienne, France
| | - Dominique Morlet
- Lyon Neuroscience Research Center, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000, Lyon, France
| | - Jérémie Mattout
- Lyon Neuroscience Research Center, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000, Lyon, France.
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Cepeda-Zapata LK, Corona-González CE, Alonso-Valerdi LM, Ibarra-Zarate DI. Binaural Beat Effects on Attention: A Study Based on the Oddball Paradigm. Brain Topogr 2023; 36:671-685. [PMID: 37490130 DOI: 10.1007/s10548-023-00990-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 07/11/2023] [Indexed: 07/26/2023]
Abstract
The impact of binaural beats (BBs) on human cognition and behavior remains and various methods have been used to measure their effect, including neurophysiological, psychometric, and human performance evaluations. The few approaches where the level of neural synchronicity and connectivity were measured by neuroimaging techniques have only been undertaken in spontaneous mode. The present research proposes an approach based on the oddball paradigm to study BB effect by estimating the level of attention induced by BBs. Evoked activity of 25 young adults between 19 and 24 years old with no hearing impairments nor clinical neurological history were analyzed. The experiment was conducted in two different sessions of 24.5 min. The first part consisted of 20-min BB stimulation in either theta (BBθ) or beta (BBβ). After the BB stimulation, an oddball paradigm was applied in each BB condition to assess the attentional effect induced by BBs. Attention enhancement is expected for BBβ with respect to BBθ. Target event related potentials (ERPs) were mainly analyzed in the time and time-frequency domains. The frequency analysis was based on continuous wavelet transform (CWT), event-related spectral perturbation (ERSP), and inter-trial phase coherence (ITPC). The study revealed that the P300 component was not significantly different between conditions (BBθ vs. BBβ). However, the target grand average ERP in BBθ condition was mainly composed of 8 Hz-frequency components, appearing before 400 ms post-stimulus, and mainly on the centro-parietal regions. In contrast, the target grand average ERP in BBβ condition was mainly composed of frequency components below 6 Hz, mainly appearing at 400 ms post-stimulus on the parieto-occipital regions. Furthermore, ERPs in the BBθ condition were more phase locked than the BBβ condition.
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Affiliation(s)
- Luis Kevin Cepeda-Zapata
- Tecnológico de Monterrey, School of Engineering and Sciences Monterrey, Av. Eugenio Garza Sada 2501 Sur Col. Tecnológico, CP 64849, Monterrey, NL, Mexico
| | - César E Corona-González
- Tecnológico de Monterrey, School of Engineering and Sciences Monterrey, Av. Eugenio Garza Sada 2501 Sur Col. Tecnológico, CP 64849, Monterrey, NL, Mexico
| | - Luz María Alonso-Valerdi
- Tecnológico de Monterrey, School of Engineering and Sciences Monterrey, Av. Eugenio Garza Sada 2501 Sur Col. Tecnológico, CP 64849, Monterrey, NL, Mexico
| | - David I Ibarra-Zarate
- Tecnológico de Monterrey, School of Engineering and Sciences Monterrey, Av. Eugenio Garza Sada 2501 Sur Col. Tecnológico, CP 64849, Monterrey, NL, Mexico.
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Morlet D, Mattout J, Fischer C, Luauté J, Dailler F, Ruby P, André-Obadia N. Infraclinical detection of voluntary attention in coma and post-coma patients using electrophysiology. Clin Neurophysiol 2023; 145:151-161. [PMID: 36328928 DOI: 10.1016/j.clinph.2022.09.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/15/2022] [Accepted: 09/25/2022] [Indexed: 11/03/2022]
Abstract
OBJECTIVE Early functional evaluation and prognosis of patients with disorders of consciousness is a major challenge that clinical assessments alone cannot solve. Objective measures of brain activity could help resolve this uncertainty. We used electroencephalogram at bedside to detect voluntary attention with a paradigm previously validated in healthy subjects. METHODS Using auditory-oddball sequences, our approach rests on detecting known attentional modulations of Event Related Potentials that reflect compliance with verbal instructions. Sixty-eight unresponsive patients were tested in their first year after coma onset (37 coma and 31 first year post-coma patients). Their evolution 6 months after the test was considered. RESULTS Fourteen of the 68 patients, showed a positive response. Nine were in a coma and 5 in a minimally conscious state (MCS). Except for one who died early, all responders evolved to exit-MCS within 6 months (93%), while 35 (65%) among non-responders only. CONCLUSIONS Among those patients for whom the outcome is highly uncertain, 21% responded positively to this simple but cognitively demanding test. Strikingly, some coma patients were among responders. SIGNIFICANCE The proposed paradigm revealed cognitive-motor dissociation in some coma patients. This ability to sustain attention on demand predicted awakening within 6 months and represents an immediately useful information for relatives and caregivers.
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Affiliation(s)
- Dominique Morlet
- Lyon Neuroscience Research Centre, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000 Lyon, France
| | - Jérémie Mattout
- Lyon Neuroscience Research Centre, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000 Lyon, France
| | - Catherine Fischer
- Lyon Neuroscience Research Centre, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000 Lyon, France; Neurophysiology & Epilepsy Unit, Neurological Hospital P. Wertheimer, Hospices Civils de Lyon, Lyon, France
| | - Jacques Luauté
- Lyon Neuroscience Research Centre, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000 Lyon, France; Physical Medicine and Rehabilitation Department, Henry-Gabrielle Hospital, Hospices Civils de Lyon, 69230 Saint Genis Laval, France
| | - Frédéric Dailler
- Neuro-Intensive Care Unit, Hospices Civils de Lyon, Neurological Hospital Pierre-Wertheimer, Lyon, France
| | - Perrine Ruby
- Lyon Neuroscience Research Centre, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000 Lyon, France
| | - Nathalie André-Obadia
- Lyon Neuroscience Research Centre, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69000 Lyon, France; Neurophysiology & Epilepsy Unit, Neurological Hospital P. Wertheimer, Hospices Civils de Lyon, Lyon, France.
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Macambira YKDS, Menezes PDL, Frizzo ACF, Griz SMS, Menezes DC, Advíncula KP. Cortical auditory evoked potentials using the speech stimulus /ma/. REVISTA CEFAC 2022. [DOI: 10.1590/1982-0216/20222439021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Spontaneous eye blinking as a diagnostic marker in prolonged disorders of consciousness. Sci Rep 2021; 11:22393. [PMID: 34789832 PMCID: PMC8599689 DOI: 10.1038/s41598-021-01858-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 11/01/2021] [Indexed: 11/26/2022] Open
Abstract
Clinical diagnosis of patients with prolonged disorders of consciousness is very challenging. As spontaneous eye blink rate (EBR) is reliably correlated with cognitive activity in healthy individuals, we investigated whether EBR could serve as a marker of patients' level of consciousness. We assessed ten patients in prolonged Vegetative State/Unresponsive Wakefulness Syndrome (VS/UWS; three females; mean age = 50.3 ± 17.8 years) and fourteen patients in Minimally Conscious State (MCS; three females; mean age = 52.9 ± 17.5 years) at their admission to a rehabilitation unit after the acute phase. During two separate 3-min rest conditions, we recorded patients' EBR by integrating on-line visual and off-line electro-oculographic count. We also assessed EBR during two auditory oddball tasks, i.e. passive listening and active counting of target tones in a sub-group of patients. EBR was significantly higher in MCS than in VS/UWS; moreover, EBR positively correlated with a validated index of responsiveness derived from the Coma Recovery Scale-Revised. Patients' mean EBR showed no significant differences within sessions and across experimental conditions of the oddball task, in both VS/UWS and MCS. Our findings suggest that, at least in the post-acute phase, observing patients' EBR for 3 min at rest could help to discriminate between VS/UWS and MCS, improving accuracy of clinical diagnosis.
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Magliacano A, Fiorenza S, Estraneo A, Trojano L. Eye blink rate increases as a function of cognitive load during an auditory oddball paradigm. Neurosci Lett 2020; 736:135293. [PMID: 32771601 DOI: 10.1016/j.neulet.2020.135293] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/08/2020] [Accepted: 08/03/2020] [Indexed: 01/21/2023]
Abstract
Previous evidence suggests that changes in spontaneous eye blink rate (EBR) in human adults might reflect the amount of attentional demand (i.e. cognitive load) during cognitive tasks. However, the actual direction of this relation is uncertain, since most studies investigated the role of cognitive load on EBR by employing visual tasks only. Here we aimed at elucidating the relationship between EBR and cognitive load in non-visual tasks. Sixteen healthy participants performed two auditory oddball tasks, i.e. passive listening to auditory tones versus active counting of target tones; each oddball task was immediately followed by a rest phase. Throughout the oddball tasks we assessed EBR and recorded the P300 on ERPs as an electrophysiological measure of attention. The results showed that participants' EBR increased during the active task compared to the respective rest phase. Amplitude and latency of the P300 too differed between passive and active tasks, but changes in EBR and P300 features were not correlated with each other. Our findings demonstrated that an increase in cognitive load is associated with an increase in EBR in cognitive tasks not involving visual attention. These findings are consistent with previous evidence suggesting shared neurobiological bases between attention and EBR.
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Affiliation(s)
- Alfonso Magliacano
- Department of Psychology, University of Campania "Luigi Vanvitelli", Caserta, Italy.
| | - Salvatore Fiorenza
- Istituti Clinici Scientifici Maugeri IRCCS, SB S.p.A., Laboratorio di Valutazione Multimodale dei Disordini della Coscienza, Telese Terme BN, Italy
| | | | - Luigi Trojano
- Department of Psychology, University of Campania "Luigi Vanvitelli", Caserta, Italy
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Kotchoubey B, Pavlov YG. A Signature of Passivity? An Explorative Study of the N3 Event- Related Potential Component in Passive Oddball Tasks. Front Neurosci 2019; 13:365. [PMID: 31068776 PMCID: PMC6491624 DOI: 10.3389/fnins.2019.00365] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 03/29/2019] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Many passive oddball experiments show a sharp negative deflection N3 after P3b, peaking between 400 and 500 ms, but this wave has never been analyzed properly. We conducted five passive oddball experiments, in which the number of deviants (i.e., one or two), their alleged meaning, and their distinctiveness varied. RESULTS Mastoid- or common-referenced waveforms showed a fronto-central N3 in all experiments. The data were CSD (Current Source Density) transformed and underwent a Principal Component Analysis (PCA). The PCA revealed N3 containing two subcomponents with very stable peak latencies of about 415 and 455 ms, respectively. Both topography of the subcomponents and their variation with experimental conditions were very similar, indicating a midfrontal sink and a posterior temporal source. An analysis of P3a and P3b components replicated previously known effects. CONCLUSION We discuss the similarities and differences between the passive N3 and other components including the MMN, N1, late positive Slow Wave, and reorienting negativity. We also make general hypotheses about a possible functional meaning of N3; on this basis, specific hypotheses are formulated and further experiments are suggested to test these hypotheses.
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Affiliation(s)
- Boris Kotchoubey
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
| | - Yuri G. Pavlov
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
- Department of Psychology, Ural Federal University, Yekaterinburg, Russia
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Rosburg T, Schmidt A. Potential Mechanisms for the Ketamine-Induced Reduction of P3b Amplitudes. Front Behav Neurosci 2018; 12:308. [PMID: 30618662 PMCID: PMC6297878 DOI: 10.3389/fnbeh.2018.00308] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 11/27/2018] [Indexed: 12/12/2022] Open
Abstract
In specific dosages, the N-methyl-D-aspartate receptor (NMDA) antagonist ketamine can be used to model transient psychotic symptoms in healthy individuals that resemble those of schizophrenia. Ketamine administration also temporarily impairs cognitive functions, which can be studied by event-related potentials (ERPs). ERPs also allow dissecting what stages of information processing are affected by ketamine and what stages remain functional. For tasks requiring the differentiation of targets and non-targets, it has repeatedly been shown that ketamine administration in healthy individuals leads to decreased amplitudes of the ERP component P3b in response to target stimuli. However, it could be argued that this ketamine-induced P3b reduction is the consequence of an increased difficulty to differentiate targets from non-targets, primarily mediated by ketamine's psychotomimetic rather than pharmacological effects. The current review of ERP studies seeks to clarify the issue whether P3b effects of ketamine may indeed be explained as the consequence of an experienced increase in task difficulty or whether alternative mechanisms are perhaps more plausible. The review first summarizes the effects of task difficulty on ERP components related to intentional stimulus categorization (P3b), involuntary attention switches to distractors (P3a), as well as sensory processing (P1, N1). Secondly, the ERP effects of task difficulty are contrasted with those observed in ketamine studies in healthy individuals. Findings show that P3b amplitudes are consistently diminished by an increased task difficulty, as well as after ketamine administration. In contrast and as most important difference, increased task difficulty leads to increased P3a amplitudes to distractors presented in same modality as targets, whereas ketamine leads to reduced P3a amplitudes for such distractors. This dissociation indicates that the decreased P3b amplitudes after ketamine cannot be explained by a drug-induced increase in task difficulty. The conjoint reductions of P3a and P3b amplitudes instead suggest that working memory operations, in particular working memory updating are impaired after ketamine, which is in line with previous behavioral findings.
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Affiliation(s)
- Timm Rosburg
- Forensic Department, University Psychiatric Clinics Basel, Basel, Switzerland
| | - André Schmidt
- Department of Psychiatry, University Psychiatric Clinics Basel, Basel, Switzerland
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A framework for the extended monitoring of levels of cognitive function in unresponsive patients. PLoS One 2018; 13:e0200793. [PMID: 30024945 PMCID: PMC6053194 DOI: 10.1371/journal.pone.0200793] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 07/03/2018] [Indexed: 11/19/2022] Open
Abstract
Generally, prognostication of coma outcome currently combines behavioral, reflex, and possibly neuroimaging tests that are interpreted by an attending physician. Electroencephalography, particularly, event-related brain potentials (ERP) have received attention due to evidence demonstrating the positive predictive value of certain ERP including the mismatch negativity (MMN) and the P3a, for coma emergence. We describe a set of ERP paradigms designed to require and reflect increasing levels of cognitive processing with the added objective of determining the influence of each paradigm's context strength on its ability to elicit ERPs. These paradigms were then used without explicit instructions to participants to attend to the stimuli to determine which paradigms possessed sufficient context "strength" to elicit ERPs in the absence of active participation on the part of the subject; a circumstance often encountered in brain injury patients. These paradigms were then validated on two groups of adults-younger and older, and the difference due to active participation was validated on another group of younger adults. Results show that paradigms with stronger stimulus context features performed better than those with weaker contexts, and that older adults generally had significantly attenuated and delayed responses compared to younger adults. Based on these findings, it is recommended the use of the auditory oddball paradigm that includes novel stimuli to elicit the mismatch negativity and P300, and semantic violation sentences to elicit the N400. These findings also reinforce the procedure of instructing participants about the requirements of a protocol-regardless of the patient's diagnosis or apparent state-in order to help those who are able to attend to show the most robust responses possible.
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André-Obadia N, Zyss J, Gavaret M, Lefaucheur JP, Azabou E, Boulogne S, Guérit JM, McGonigal A, Merle P, Mutschler V, Naccache L, Sabourdy C, Trébuchon A, Tyvaert L, Vercueil L, Rohaut B, Delval A. Recommendations for the use of electroencephalography and evoked potentials in comatose patients. Neurophysiol Clin 2018; 48:143-169. [DOI: 10.1016/j.neucli.2018.05.038] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/07/2018] [Indexed: 12/21/2022] Open
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