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Deep video-to-video transformations for accessibility with an application to photosensitivity. Pattern Recognit Lett 2020. [DOI: 10.1016/j.patrec.2019.01.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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52
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Brinciotti M, Mittica A, Matricardi M. Characteristics of visual evoked potentials related to the electro-clinical expression of reflex seizures in photosensitive patients with idiopathic occipital lobe epilepsy. Epilepsy Res 2020; 164:106345. [DOI: 10.1016/j.eplepsyres.2020.106345] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/30/2020] [Accepted: 04/22/2020] [Indexed: 11/24/2022]
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53
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Yan W, Xu G. Brain-computer interface method based on light-flashing and motion hybrid coding. Cogn Neurodyn 2020; 14:697-708. [PMID: 33014182 DOI: 10.1007/s11571-020-09616-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 06/29/2020] [Accepted: 07/07/2020] [Indexed: 12/16/2022] Open
Abstract
The human best response frequency band for steady-state visual evoked potential stimulus is limited. This results in a reduced number of encoded targets. To circumvent this, we proposed a brain-computer interface (BCI) method based on light-flashing and motion hybrid coding. The hybrid paradigm pattern consisted of a circular light-flashing pattern and a motion pattern located in the inner ring of light-flashing pattern. The motion and light-flashing patterns had different frequencies. This study used five frequencies to encode nine targets. The motion frequency and the light-flashing frequency of the hybrid paradigm consisted of two frequencies in five frequencies. The experimental results showed that the hybrid paradigm could induce stable motion frequency, light-flashing frequency and its harmonic components. Moreover, the modulation between motion and light-flashing was weak. The average accuracy was 92.96% and the information transfer rate was 26.10 bits/min. The experimental results showed that the proposed method could be considered for practical BCI systems.
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Affiliation(s)
- Wenqiang Yan
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.,State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Guanghua Xu
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.,State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, China
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54
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A review on the synthesis and applications of molecules as anticonvulsant drug agent candidates. Med Chem Res 2020. [DOI: 10.1007/s00044-020-02595-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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55
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van Win OA, Barnes JG, Ferrier CF, Booth F, Prasad AN, Kasteleijn-Nolst Trenite DGA. A study of the significance of photoparoxysmal responses and spontaneous epileptiform discharges in the EEG in childhood epilepsy. Epilepsy Behav 2020; 107:107046. [PMID: 32304987 DOI: 10.1016/j.yebeh.2020.107046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 03/14/2020] [Accepted: 03/15/2020] [Indexed: 12/26/2022]
Abstract
AIM In clinical practice, there is a prevailing notion that photosensitivity mostly occurs in children with epilepsy (CWE) with idiopathic generalized epilepsy. We investigated the distribution of epilepsy types and etiology in photosensitive children and the associations with specific clinical and electroencephalogram (EEG) variables. METHODS In this retrospective cohort study, clinical data were acquired from all children that showed photosensitivity during systematic intermittent photic stimulation (IPS), over a 10-year interval at a tertiary level Children's Hospital, Winnipeg. Patient demographics, EEG findings, and clinical data and symptoms during IPS were abstracted. Classification of diagnoses using the International League Against Epilepsy (ILAE) 2017 guidelines was done by an expert panel. RESULTS Seventy-eight photosensitive children were identified. Forty (51.3%) had generalized epilepsy (idiopathic: 27, structural: 2, other: 11) compared with 19 (24.4%) focal (idiopathic: 1, structural: 2, other: 16), 8 (10.3%) combined focal and generalized (structural: 4, other: 4), and 11 (14.1%) unknown epilepsy (other: 11); (χ2 (3) = 32.1, p = .000). Self-sustaining or outlasting photoparoxysmal responses (PPRs) occurred in association with all epilepsy types; however, the EEGs of focal CWE without treatment comprised almost solely of PPRs which outlasted the stimulus (8/10), in contrast to only 8/17 of focal CWE with treatment and to 13/26 of generalized epilepsy without treatment. Most frequency intervals in individual patients were less under treatment: a decrease in standardized photosensitivity range (SPR) was seen in 5 CWE, an increase in 2, and no change in 1 during treatment. Both CWE with focal and generalized epilepsy showed abnormal activity on EEG during hyperventilation (40% vs 65.7%). Thirteen out of 14 CWE with clinical signs during IPS had independent spontaneous epileptiform discharges (SEDs) in the EEG recording. CONCLUSION Photosensitivity occurs in all types of epilepsy rather than in idiopathic generalized epilepsy alone. Surprisingly, there is a tendency for focal epilepsy to be associated with self-sustaining PPRs, especially when no treatment is used. Treatment tends to make the PPR more self-limiting and decrease the SPR. There is a tendency that clinical signs during IPS occur in EEGs in individuals with SEDs.
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Affiliation(s)
- Odile Alexandra van Win
- Department of Neurology & Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
| | - Jeffrey G Barnes
- Section of Neurology, Health Sciences Centre, St Boniface Hospital, 409 Tache Ave, Winnipeg, MB R2H 2A6, Canada
| | - Cyrille F Ferrier
- Department of Neurology & Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Fran Booth
- Section of Pediatric Neurology from Division of Pediatric Clinical Neurosciences, Children's Hospital, Health Sciences Centre, Winnipeg, Canada
| | - Asuri N Prasad
- Division of Pediatric Neurology and Clinical Neurosciences, Department of Pediatrics, Children's Hospital, London Health Sciences Centre, London, Ontario, Canada
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A novel motion coupling coding method for brain-computer interfaces. BIOMED ENG-BIOMED TE 2020; 65:531-541. [DOI: 10.1515/bmt-2019-0257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/31/2020] [Indexed: 11/15/2022]
Abstract
AbstractObjectivesThe best frequency response band for the steady-state visual evoked potential (SSVEP) stimulus for humans is limited. This results in a reduced number of encoded targets.MethodsTo circumvent these limitations, we propose a motion-coupled, steady-state motion visual evoked potential (SSMVEP) method. We designed a stimulus paradigm that couples both sinusoidal and square wave motions. The paradigm performs a spiral motion with a higher frequency in the form of sinusoidal wave, and alters the size of the lower frequency via the square wave form.ResultsThe motion-coupled SSMVEP method could simultaneously induce stable motion frequency and coupling frequency, and there was no loss of frequency component.ConclusionsThe proposed method has been evaluated to have substantial potential for increasing the number of coding targets, which is an effective supplement to the existing studies.
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57
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Yoshimoto S, Jiang F, Takeuchi T, Wilkins AJ, Webster MA. Visual discomfort from flicker: Effects of mean light level and contrast. Vision Res 2020; 173:50-60. [PMID: 32474213 DOI: 10.1016/j.visres.2020.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 05/11/2020] [Accepted: 05/11/2020] [Indexed: 11/18/2022]
Abstract
Uncomfortable images generally have a particular spatial structure, which deviates from a reciprocal relationship between amplitude and spatial frequency (f) in the Fourier domain (1/f). Although flickering patterns with similar temporal structure also appear uncomfortable, the discomfort is affected by not only the amplitude spectrum but also the phase spectrum. Here we examined how discomfort from flicker with differing temporal profiles also varies as a function of the mean light level and luminance contrast of the stimulus. Participants were asked to rate discomfort for a 17° flickering uniform field at different light levels from scotopic to photopic. The flicker waveform was varied with a square wave or random phase spectrum and filtered by modulating the slope of the amplitude spectrum relative to 1/f. At photopic levels, the 1/f square wave flicker appeared most comfortable, whereas the discomfort from the random flicker increased monotonically as the slope of the amplitude spectrum decreased. This special status for the 1/f square wave condition was limited to photopic light levels. At the lower mesopic or scotopic levels, the effect of phase spectrum on the discomfort was diminished, with both phase spectra showing a monotonic change with the slope of the amplitude spectrum. We show that these changes cannot be accounted for by changes in the effective luminance contrast of the stimuli or by the responses from a linear model based on the temporal impulse responses under different light levels. However, discomfort from flicker is robustly correlated with judgments of the perceived naturalness of flicker across different contrasts and mean luminance levels.
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Affiliation(s)
- Sanae Yoshimoto
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Kagamiyama 1-7-1, Higashi-Hiroshima, Hiroshima 739-8521, Japan.
| | - Fang Jiang
- Department of Psychology, University of Nevada, Reno, 1664 N. Virginia Street, Reno, Nevada 89557, USA
| | - Tatsuto Takeuchi
- Department of Psychology, Japan Women's University, Tama-ku Nishi-ikuta 1-1-1, Kawasaki, Kanagawa 214-8565, Japan
| | - Arnold J Wilkins
- Department of Psychology, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | - Michael A Webster
- Department of Psychology, University of Nevada, Reno, 1664 N. Virginia Street, Reno, Nevada 89557, USA
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Luo C, Ding N. Visual target detection in a distracting background relies on neural encoding of both visual targets and background. Neuroimage 2020; 216:116870. [PMID: 32339773 DOI: 10.1016/j.neuroimage.2020.116870] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 04/11/2020] [Accepted: 04/17/2020] [Indexed: 02/06/2023] Open
Abstract
The ability to detect visual targets in complex background varies across individuals and are affected by factors such as stimulus saliency and top-down attention. Here, we investigated how the saliency of visual background (naturalistic cartoon video vs. blank screen) and top-down attention (single vs. dual tasks) separately affect individual ability to detect visual targets. Behaviorally, we found that target detection accuracy decreased and reaction time elongated when the background was salient or during dual tasking. The EEG response to visual background was recorded using a novel stimulus tagging technique. This response was strongest in occipital electrodes and was sensitive to background saliency but not dual tasking. In contrast, the event-related potential (ERP) evoked by the visual target was strongest in central electrodes, and was affected by both background saliency and dual tasking. With a cartoon background, the EEG responses to visual targets, presented in the central visual field, and the EEG responses to peripheral visual background could both predict individual target detection performance. When these two responses were combined, better prediction was achieved. These results suggest that neural processing of visual targets and background jointly contribute to individual visual target detection performance.
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Affiliation(s)
- Cheng Luo
- Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Sciences, Zhejiang University, Hangzhou, 310027, China
| | - Nai Ding
- Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Sciences, Zhejiang University, Hangzhou, 310027, China; Research Center for Advanced Artificial Intelligence Theory, Zhejiang Lab, Hangzhou, 311121, China.
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Benlier N, Ozer G, Orhan N. Relation between serum amylin level and epilepsy. THE EGYPTIAN JOURNAL OF NEUROLOGY, PSYCHIATRY AND NEUROSURGERY 2020. [DOI: 10.1186/s41983-020-00164-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Abstract
Background
Epilepsy is a neurological disorder characterized by convulsions. Identification of biological pathways underlying epilepsy and novel genes may shed light on the pathogenesis of epilepsy as well as new targets for treatment.
Objectives
Amylin is cosecreted with insulin from the pancreatic β-cells in a pulsatile manner as a response to nutrient stimuli. In vitro studies have shown the neurotoxicity potential of amylin. We aimed to investigate serum amylin levels between epilepsy patients and a healthy control group.
Subjects and methods
For this study, 45 patients with epilepsy and 60 healthy controls were enrolled. Routine blood analysis and electroencephalography scan were performed for all participants. Five cc venous blood sample was collected from each participant. Sera were isolated and stored at − 80 °C until the time of amylin analysis with the enzyme-linked immunosorbent assay.
Results
Gender distribution of the two groups was as follows: 44.4% males and 55.6% females among epileptic patients and 53.3% males and 46.7% females for control subjects.
Body mass index was 23.09 ± 3.99 kg/m2 for epileptic patients and 26.29 ± 4.83 kg/m2 for controls, with a statistically significantly higher body mass index in control subjects (p ˂ 0.001). With regard to serum amylin levels, a statistically significant difference was observed between the two groups (p ˂ 0.001). The median serum amylin concentration was 226.62 ng/ml (69.49–6961.19 (min–max)) for epileptic patients and 103.66 ng/ml (37.42–607.11 (min–max)) for controls (p ˂ 0.001).
Conclusion
In the present study, a significant difference was observed between patient and control groups in serum amylin concentrations, which were considerably higher in epileptic patients.
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Tychsen L, Thio LL. Concern of Photosensitive Seizures Evoked by 3D Video Displays or Virtual Reality Headsets in Children: Current Perspective. Eye Brain 2020; 12:45-48. [PMID: 32104130 PMCID: PMC7023866 DOI: 10.2147/eb.s233195] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 12/12/2019] [Indexed: 11/23/2022] Open
Abstract
This review assesses the risk of a photic-induced seizure in a child during viewing of 3D (binocular 3 dimensional, stereoscopic) movies or games, either on standard video displays or when wearing a virtual reality (VR) headset. Studies published by pediatric epilepsy experts emphasize the low risk of 3D viewing even for children with known photosensitive epilepsy (PSE). The low incidence of PSE is noteworthy because the number of hours devoted to 2D or 3D screen viewing and/or VR headset use by children worldwide has increased markedly over the last decade. The medical literature does not support the notion that VR headset use poses a risk for PSE.
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Affiliation(s)
- Lawrence Tychsen
- Department of Ophthalmology and Visual Sciences
- Department of Pediatrics
- Department of Neuroscience
| | - Liu Lin Thio
- Department of Pediatrics
- Department of Neuroscience
- Department of Neurology, St. Louis Children’s Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
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61
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Ng C, Tsoi JKH, Lo ECM, Matinlinna JP. Safety and Design Aspects of Powered Toothbrush-A Narrative Review. Dent J (Basel) 2020; 8:dj8010015. [PMID: 32033270 PMCID: PMC7148448 DOI: 10.3390/dj8010015] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/10/2019] [Accepted: 12/27/2019] [Indexed: 11/19/2022] Open
Abstract
The powered toothbrush has become a modern dental tool that is available in the supermarket. Indeed, the design of the powered toothbrush, e.g., mechanical and electrical, would affect not only the efficacy but also the safety of the products. This narrative review attempted to view the powered toothbrush from design, safety, and application points with respect to tufts, filaments, handles, mechanics, motions, and materials interactions from various available sources. Different brands and models of powered toothbrushes have their own designs that might affect the clinical outcome. The rotational design was advocated to be clinically more effective than the manual one, some modern models might be designed with vibrational or oscillation (or mixed) tufts head that might be useful in patients with specific needs, such as having xerostomia or for the elderly. To conclude, tuft retention design is important in the powered toothbrush as it contributes significantly to safety as the fallen off tufts, filaments and metal parts might cause injury. Tests revealing the retention force of brush head plates and brush head bristles will be significant references for consumers to determine which design of powered toothbrushes is relatively safer.
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Chabuda A, Dovgialo M, Duszyk A, Stróż A, Pawlisz M, Durka P. Successful BCI communication via high-frequency SSVEP or visual, audio or tactile P300 in 30 tested volunteers. Acta Neurobiol Exp (Wars) 2020. [DOI: 10.21307/ane-2019-039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
PURPOSE OF REVIEW This article reviews the management of patients with medically responsive epilepsy, including discussion of factors that may lead to transient breakthrough seizures and patient and physician strategies to maintain freedom from seizures. RECENT FINDINGS Imperfect adherence, unanticipated changes in ongoing medical therapy, inadvertent use of proconvulsants or concurrent medications that alter epilepsy medication kinetics, and a variety of seizure precipitants such as stress or sleep deprivation may alter long-term seizure control. SUMMARY The majority of patients with epilepsy are medically responsive. Many potential factors may lead to breakthrough seizures in these patients. Identification of these factors, patient education, and use of self-management techniques including mindfulness therapy and cognitive-behavioral therapy may play a role in protecting patients with epilepsy against breakthrough seizures.
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Bartolini E, Sander JW. Dealing with the storm: An overview of seizure precipitants and spontaneous seizure worsening in drug-resistant epilepsy. Epilepsy Behav 2019; 97:212-218. [PMID: 31254841 DOI: 10.1016/j.yebeh.2019.05.036] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/21/2019] [Accepted: 05/28/2019] [Indexed: 10/26/2022]
Abstract
In drug-resistant epilepsy, periods of seizure stability may alternate with abrupt worsening, with frequent seizures limiting the individual's independence and physical, social, and psychological well-being. Here, we review the literature focusing on different clinical scenarios related to seizure aggravation in people with drug-resistant epilepsy. The role of antiseizure medication (ASM) changes is examined, especially focusing on paradoxical seizure aggravation after increased treatment. The external provocative factors that unbalance the brittle equilibrium of seizure control are reviewed, distinguishing between unspecific triggering factors, specific precipitants, and 'reflex' mechanisms. The chance of intervening surgical or medical conditions, including somatic comorbidities and epilepsy surgery failure, causing increased seizures is discussed. Spontaneous exacerbation is also explored, emphasizing recent findings on subject-specific circadian and ultradian rhythms. Awareness of external precipitants and understanding the subject-specific spontaneous epilepsy course may allow individuals to modify their lifestyles. It also allows clinicians to counsel appropriately and to institute suitable medical treatment to avoid sudden loss of seizure control.
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Affiliation(s)
- Emanuele Bartolini
- USL Centro Toscana, Neurology Unit, Nuovo Ospedale Santo Stefano, via suor Niccolina Infermiera 20, 59100 Prato, Italy.
| | - Josemir W Sander
- NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, London WC1N 3BG, United Kingdom; Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, United Kingdom; Stichting Epilepsie Instelligen Nederland (SEIN), Achterweg 5, Heemstede 2103 SW, the Netherlands.
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65
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Xiao J, Xie Q, Lin Q, Yu T, Yu R, Li Y. Assessment of Visual Pursuit in Patients With Disorders of Consciousness Based on a Brain-Computer Interface. IEEE Trans Neural Syst Rehabil Eng 2019; 26:1141-1151. [PMID: 29877838 DOI: 10.1109/tnsre.2018.2835813] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Visual pursuit assessment is extensively applied in the behavioral scale-based clinical examination of patients with disorders of consciousness (DOC). However, this assessment is challenging because it relies on behavioral markers, and these patients severely lack behavioral responses. Brain-computer interfaces (BCIs) may provide a potential solution to detect brain responses to external stimuli without requiring behavioral expressions. A BCI system was designed to simulate visual pursuit detection in the coma recovery scale-revised (CRS-R). The graphical user interface included four buttons, one that moved on the screen and three that did not. These buttons flashed in a random order. The patients were prompted to follow the moving button. Based on the collected electroencephalography data, the algorithm determined whether the patient focused on the moving target. Among the 14 DOC patients who participated in the assessments based on the BCI system and the CRS-R, four patients exhibited visual pursuit, and three were nonresponsive in both assessments. More importantly, seven patients who did not exhibit visual pursuit in CRS-R were detected to be responsive to the moving target stimuli in the BCI assessment. Furthermore, five out of seven recovered consciousness to some degree and showed visual pursuit in the second CRS-R assessment. The proposed BCI system is better able to detect visual pursuit than the behavioral scale-based assessment and thus can assist in clinically evaluating the challenging population of DOC patients.
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66
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Harnarinesingh RE, Syan CS. Investigation of the mirrored-word reading paradigm for BCI implementation. BIOMED ENG-BIOMED TE 2019; 64:325-337. [DOI: 10.1515/bmt-2017-0223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 06/01/2018] [Indexed: 11/15/2022]
Abstract
Abstract
Brain-computer interface (BCI) applications such as keyboard control and vehicular navigation present significant assistive merit for disabled individuals. However, there are limitations associated with BCI paradigms which restrict a wider adoption of BCI technology. For example, rapid serial visual presentation (RSVP) paradigms can induce seizures in photosensitive epileptic subjects. This paper evaluates the novel mirrored-word reading paradigm (MWRP) for BCI implementation using an offline experimental study. The offline study obtained an average single-trial classification accuracy of 74.10%. The results also demonstrate that the use of multiple trials for classification can increase the accuracy as is common with BCIs. The developed MWRP-based BCI also utilized a low presentation frequency which averts the possibility of paradigm induced photosensitivity. However, there are multiple avenues for future work. The MWRP can be implemented in the online format for real-time device control. For example, a vehicular application platform can be used where the word orientation represents directions for travel. The MWRP can also be investigated across a wider range of stimulus presentation parameters such as timing, color and stimulus size. Such studies can be used to suggest further improvements to the paradigm which can enhance its applicability for online device control.
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67
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Yoshimoto S, Jiang F, Takeuchi T, Wilkins AJ, Webster MA. Adaptation and visual discomfort from flicker. Vision Res 2019; 160:99-107. [PMID: 31091424 DOI: 10.1016/j.visres.2019.04.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 04/21/2019] [Accepted: 04/24/2019] [Indexed: 10/26/2022]
Abstract
Spatial images with unnatural amplitude spectra tend to appear uncomfortable. Analogous effects are found in the temporal domain, yet discomfort in flickering patterns is also strongly dependent on the phase spectrum. Here we examined how discomfort in temporal flicker is affected by adaptation to different amplitude and phase spectra. Adapting and test flicker were square wave or random phase transitions in a uniform field filtered by increasing (blurred) or decreasing (sharpened) the slope of the amplitude spectrum. Participants rated the level of discomfort or sharpness/blur for the test flicker. Before adaptation, square wave transitions were rated as most comfortable when they had "focused" edges, which were defined as characterized by 1/f amplitude spectra, while random phase transitions instead appeared more comfortable the more blurred they were. After adapting to blurred or sharpened transitions, both square wave and random phase flicker appeared more sharpened or blurred, respectively, and these effects were consistent with renormalization of perceived temporal focus. In comparison, adaptation affected discomfort in the two waveforms in qualitatively different ways, and exposure to the adapting stimulus tended to increase rather than decreased its perceived discomfort. These results point to a dissociation between the perceived amplitude spectrum and perceived discomfort, suggesting they in part depend on distinct processes. The results further illustrate the importance of the phase spectrum in determining visual discomfort from flickering patterns.
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Affiliation(s)
- Sanae Yoshimoto
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Kagamiyama 1-7-1, Higashi-Hiroshima, Hiroshima 739-8521, Japan.
| | - Fang Jiang
- Department of Psychology, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA.
| | - Tatsuto Takeuchi
- Department of Psychology, Japan Women's University, Tama-ku Nishi-ikuta 1-1-1, Kawasaki, Kanagawa 214-8565, Japan.
| | - Arnold J Wilkins
- Department of Psychology, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK.
| | - Michael A Webster
- Department of Psychology, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA.
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Sohanian Haghighi H, Markazi AHD. Dynamic origin of spike and wave discharges in the brain. Neuroimage 2019; 197:69-79. [PMID: 31022569 DOI: 10.1016/j.neuroimage.2019.04.047] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 04/13/2019] [Accepted: 04/17/2019] [Indexed: 02/07/2023] Open
Abstract
Spike and wave discharges are the main electrographic characteristic of a number of epileptic brain disorders including childhood absence epilepsy and photosensitive epilepsy. The basic dynamic mechanism that underlies the occurrence of these abnormal electrical patterns in the brain is not well understood. The current paper aims to provide a dynamic explanation for features and generation mechanism of spike and wave discharges in the brain. The main proposition of this study is that epileptic seizures could be interpreted as a resonance phenomenon rather than a limit cycle behavior. To shows this, a revised version of Jansen-Rit neural mass model is employed. The system can switch between monostable and bistable regimes, which are considered in this paper as wake and sleep states of the brain, respectively. In particular, it is shown that, in monostable region, the model can depict the alpha rhythm and alpha rhythm suppression due to mental activity. Frequency responses of the model near the bistable regime demonstrate that high amplitude harmonic excitation may lead to spike and wave like oscillations. Based on the computational results and the concept of stochastic resonance, a model for absence epilepsy is presented which can simulate spontaneous transitions between ictal and interictal states. Finally, it is shown that spike and wave discharges during epileptic seizures can be explained as a resonance phenomenon in a nonlinear system.
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Affiliation(s)
| | - Amir H D Markazi
- School of Mechanical Engineering, Iran University of Science and Technology, Tehran, 16844, Iran.
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Okada S, Saito H, Matsuura Y, Mikuzuki L, Sugawara S, Onose H, Asaka J, Ohara K, Lee J, Iinuma T, Katagiri A, Iwata K. Upregulation of calcitonin gene-related peptide, neuronal nitric oxide synthase, and phosphorylated extracellular signal-regulated kinase 1/2 in the trigeminal ganglion after bright light stimulation of the eye in rats. J Oral Sci 2019; 61:146-155. [PMID: 30918211 DOI: 10.2334/josnusd.18-0031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Bright light stimulation of the eye activates trigeminal subnucleus caudalis (Vc) neurons in rats. Sensory information is conveyed to the Vc via the trigeminal ganglion (TG). Thus, it is likely that TG neurons respond to photic stimulation and are involved in photic hypersensitivity. However, the mechanisms underlying this process are unclear. Therefore, the hypothesis in this study is bright light stimulation enhances the excitability of TG neurons involved in photic hypersensitivity. Expressions of calcitonin gene-related peptide (CGRP) and neuronal nitric oxide synthase (nNOS) were significantly higher in TG neurons from 5 min to 12 h after photic stimulation of the eye. Phosphorylation of extracellular signal-regulated kinase1/2 (pERK1/2) was enhanced in TG neurons within 5 min after photic stimulation, while pERK1/2 immunoreactivity in satellite glial cells (SGCs) persisted for more than 12 h after the stimulus. Activation of SGCs was observed from 5 min to 2 h. Expression of CGRP, nNOS, and pERK1/2 was observed in small and medium TG neurons, and activation of SGCs and pERK1/2-immunoreactive SGCs encircling large TG neurons was accelerated after stimulation. These results suggest that upregulation of CGRP, nNOS, and pERK1/2 within the TG is involved in photic hypersensitivity.
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Affiliation(s)
- Shinji Okada
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry.,Department of Physiology, Nihon University School of Dentistry
| | - Hiroto Saito
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry.,Department of Physiology, Nihon University School of Dentistry
| | - Yutaka Matsuura
- Department of Oral Physiology, Osaka University Graduate School of Dentistry
| | - Lou Mikuzuki
- Department of Physiology, Nihon University School of Dentistry.,Department of Psychosomatic Dentistry, Tokyo Medical and Dental University, Graduate School
| | - Shiori Sugawara
- Department of Physiology, Nihon University School of Dentistry.,Department of Psychosomatic Dentistry, Tokyo Medical and Dental University, Graduate School
| | - Hiroki Onose
- Department of Physiology, Nihon University School of Dentistry
| | - Junichi Asaka
- Department of Physiology, Nihon University School of Dentistry
| | - Kinuyo Ohara
- Department of Endodontics, Nihon University School of Dentistry
| | - Jun Lee
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry
| | - Toshimitsu Iinuma
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry
| | - Ayano Katagiri
- Department of Physiology, Nihon University School of Dentistry.,Department of Oral Physiology, Osaka University Graduate School of Dentistry
| | - Koichi Iwata
- Department of Physiology, Nihon University School of Dentistry
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70
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Saidi P, Vosoughi A, Atia G. Detection of brain stimuli using Ramanujan periodicity transforms. J Neural Eng 2019; 16:036021. [PMID: 30897556 DOI: 10.1088/1741-2552/ab123a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The ability to efficiently match the frequency of the brain's response to repetitive visual stimuli in real time is the basis for reliable SSVEP-based brain-computer-interfacing (BCI). APPROACH The detection of different stimuli is posed as a composite hypothesis test, where SSVEPs are assumed to admit a sparse representation in a Ramanujan periodicity transform (RPT) dictionary. For the binary case, we develop and analyze the performance of an RPT detector based on a derived generalized likelihood ratio test. Our approach is extended to multi-hypothesis multi-electrode settings, where we capture the spatial correlation between the electrodes using pre-stimulus data. We also introduce a new metric for evaluating SSVEP detection schemes based on their achievable efficiency and discrimination rate tradeoff for given system resources. MAIN RESULTS We obtain exact distributions of the test statistic in terms of confluent hypergeometric functions. Results based on extensive simulations with both synthesized and real data indicate that the RPT detector substantially outperforms spectral-based methods. Its performance also surpasses the calibration-free state-of-the-art canonical correlation analysis (CCA) and filter bank CCA (FBCCA) methods with respect to accuracy and sample complexity in short data lengths regimes crucial for real-time applications. The proposed approach is asymptotically optimal as it closes the gap to a perfect measurement bound as the data length increases. In contrast to existing supervised methods which are highly data-dependent, the RPT detector only uses pre-stimulus data to estimate the per-subject spatial correlation, thereby dispensing with considerable overhead associated with data collection for a large number of subjects and stimuli. SIGNIFICANCE Our work advances the theory and practice of emerging real-time BCI and affords a new framework for comparing SSVEP detection schemes across a wider spectrum of operating regimes.
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Affiliation(s)
- Pouria Saidi
- Department of Electrical and Computer Engineering, University of Central Florida, Orlando, FL 32816, United States of America
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71
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Shirzhiyan Z, Keihani A, Farahi M, Shamsi E, GolMohammadi M, Mahnam A, Haidari MR, Jafari AH. Introducing chaotic codes for the modulation of code modulated visual evoked potentials (c-VEP) in normal adults for visual fatigue reduction. PLoS One 2019; 14:e0213197. [PMID: 30840671 PMCID: PMC6402685 DOI: 10.1371/journal.pone.0213197] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 02/16/2019] [Indexed: 11/19/2022] Open
Abstract
Code modulated Visual Evoked Potentials (c-VEP) based BCI studies usually employ m-sequences as a modulating codes for their broadband spectrum and correlation property. However, subjective fatigue of the presented codes has been a problem. In this study, we introduce chaotic codes containing broadband spectrum and similar correlation property. We examined whether the introduced chaotic codes could be decoded from EEG signals and also compared the subjective fatigue level with m-sequence codes in normal subjects. We generated chaotic code from one-dimensional logistic map and used it with conventional 31-bit m-sequence code. In a c-VEP based study in normal subjects (n = 44, 21 females) we presented these codes visually and recorded EEG signals from the corresponding codes for their four lagged versions. Canonical correlation analysis (CCA) and spatiotemporal beamforming (STB) methods were used for target identification and comparison of responses. Additionally, we compared the subjective self-declared fatigue using VAS caused by presented m-sequence and chaotic codes. The introduced chaotic code was decoded from EEG responses with CCA and STB methods. The maximum total accuracy values of 93.6 ± 11.9% and 94 ± 14.4% were achieved with STB method for chaotic and m-sequence codes for all subjects respectively. The achieved accuracies in all subjects were not significantly different in m-sequence and chaotic codes. There was significant reduction in subjective fatigue caused by chaotic codes compared to the m-sequence codes. Both m-sequence and chaotic codes were similar in their accuracies as evaluated by CCA and STB methods. The chaotic codes significantly reduced subjective fatigue compared to the m-sequence codes.
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Affiliation(s)
- Zahra Shirzhiyan
- Medical Physics & Biomedical Engineering Department, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Research Center for Biomedical Technologies and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmadreza Keihani
- Medical Physics & Biomedical Engineering Department, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Research Center for Biomedical Technologies and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran, Iran
| | - Morteza Farahi
- Medical Physics & Biomedical Engineering Department, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Research Center for Biomedical Technologies and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran, Iran
| | - Elham Shamsi
- Medical Physics & Biomedical Engineering Department, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Research Center for Biomedical Technologies and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran, Iran
| | - Mina GolMohammadi
- Research Center for Biomedical Technologies and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran, Iran
| | - Amin Mahnam
- Department of Biomedical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, Iran
| | - Mohsen Reza Haidari
- Section of Neuroscience, Department of Neurology, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Amir Homayoun Jafari
- Medical Physics & Biomedical Engineering Department, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Research Center for Biomedical Technologies and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran, Iran
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72
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Abstract
After more than 85 years of development and use in clinical practice, the electroencephalogram (EEG) remains a dependable, inexpensive, and useful diagnostic tool for the investigation of the electrophysiologic activity of the brain. The advent of digital technology has led to greater sophistication and multiple software applications to extend the utility of EEG beyond the confines of the laboratory. Despite the discovery of new waveforms, basic neurophysiologic principles remain essential to the clinical care of patients. Patterns in the interictal EEG make it possible to clarify the differential diagnosis of paroxysmal neurological events, classify seizure type and epilepsy syndromes, and characterize and quantify seizures when ictal recordings are obtained. EEG can also demonstrate cerebral dysfunction when structural imaging is normal to detect focal or lateralized abnormalities in patients with encephalopathy. High-density EEG with electrical source imaging has improved localization in candidates for epilepsy surgery. Quantitative EEG and broadband EEG are advancing our understanding of the functional processes of the brain itself.
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Affiliation(s)
- Anteneh M Feyissa
- Department of Neurology, Mayo Clinic College of Medicine and Health Sciences, Jacksonville, FL, United States.
| | - William O Tatum
- Department of Neurology, Mayo Clinic College of Medicine and Health Sciences, Jacksonville, FL, United States
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73
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Zhang X, Xu G, Zhang X, Wu Q. A Light Spot Humanoid Motion Paradigm Modulated by the Change of Brightness to Recognize the Stride Motion Frequency. Front Hum Neurosci 2018; 12:377. [PMID: 30374295 PMCID: PMC6196316 DOI: 10.3389/fnhum.2018.00377] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Accepted: 09/03/2018] [Indexed: 11/30/2022] Open
Abstract
The steady-state visual evoked potential (SSVEP)-based brain–computer interface (BCI) usually has the advantages of high information transfer rate (ITR) and no need for training. However, low frequencies, such as the human stride motion frequency, cannot easily induce SSVEP. To solve this problem, a light spot humanoid motion paradigm modulated by the change of brightness was designed in this study. The characteristics of the brain response to the motion paradigm modulated by the change of brightness were analyzed for the first time. The results showed that the designed paradigm could induce not only the high flicker frequency but also the modulation frequencies between the change of brightness and the motion in the primary visual cortex. Thus, the stride motion frequency can be recognized through the modulation frequencies by using the designed paradigm. Also, in an online experiment, this paradigm was employed to control a lower limb robot to achieve same frequency stimulation, which meant that the visual stimulation frequency was the same as the motion frequency of the robot. Also, canonical correlation analysis (CCA) was used to distinguish three different stride motion frequencies. The average accuracies of the classification in three walking speeds using the designed paradigm with the same and different high frequencies reached 87 and 95% respectively. Furthermore, the angles of the knee joint of the robot were obtained to demonstrate the feasibility of the electroencephalograph (EEG)-driven robot with same stimulation.
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Affiliation(s)
- Xin Zhang
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Guanghua Xu
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.,State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Xun Zhang
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Qingqiang Wu
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China
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74
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Toyama Y, Kawamata J, Shimohama S. [Two cases of photosensitive seizure induced by barcode readers with red flashing lights]. Rinsho Shinkeigaku 2018; 58:626-630. [PMID: 30270339 DOI: 10.5692/clinicalneurol.cn-001185] [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] [Indexed: 06/08/2023]
Abstract
The patient in Case 1 was a 25-year-old female nurse. While she was working at a day-care, she fell down shortly after using a barcode reader. This was followed by a tonic-clonic seizure. The seizure spontaneously stopped after approximately 5 minutes. However, consciousness impairment continued for about 30 minutes. The patient in Case 2 was a 30-year-old female nurse. During the night shift at her workplace, she found it impossible to stand up after staring at the red flashing lights from a barcode reader. The patient was also disoriented, as indicated by her inability to recall her colleague's name. The patient's condition gradually improved and she became fully conscious soon after the episode. We believe that the barcode reader led to photosensitivity in both cases. Barcode readers that emit red flashing lights are thought to have a high potential for triggering photosensitivity. A person is highly likely to display photosensitivity while using the device in a hospital ward. Therefore, special attention is required to avoid photosensitive seizures induced by barcode readers with red flashing lights.
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Affiliation(s)
- Yuichiro Toyama
- Department of Neurology, Sapporo Medical University School of Medicine
| | - Jun Kawamata
- Department of Neurology, Sapporo Medical University School of Medicine
| | - Shun Shimohama
- Department of Neurology, Sapporo Medical University School of Medicine
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75
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Kunduri G, Turner-Evans D, Konya Y, Izumi Y, Nagashima K, Lockett S, Holthuis J, Bamba T, Acharya U, Acharya JK. Defective cortex glia plasma membrane structure underlies light-induced epilepsy in cpes mutants. Proc Natl Acad Sci U S A 2018; 115:E8919-E8928. [PMID: 30185559 PMCID: PMC6156639 DOI: 10.1073/pnas.1808463115] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Seizures induced by visual stimulation (photosensitive epilepsy; PSE) represent a common type of epilepsy in humans, but the molecular mechanisms and genetic drivers underlying PSE remain unknown, and no good genetic animal models have been identified as yet. Here, we show an animal model of PSE, in Drosophila, owing to defective cortex glia. The cortex glial membranes are severely compromised in ceramide phosphoethanolamine synthase (cpes)-null mutants and fail to encapsulate the neuronal cell bodies in the Drosophila neuronal cortex. Expression of human sphingomyelin synthase 1, which synthesizes the closely related ceramide phosphocholine (sphingomyelin), rescues the cortex glial abnormalities and PSE, underscoring the evolutionarily conserved role of these lipids in glial membranes. Further, we show the compromise in plasma membrane structure that underlies the glial cell membrane collapse in cpes mutants and leads to the PSE phenotype.
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Affiliation(s)
- Govind Kunduri
- Cancer and Developmental Biology Laboratory, National Cancer Institute, Frederick, MD 21702
| | | | - Yutaka Konya
- Department of Metabolomics, Kyushu University, Fukuoka 812-8582, Japan
| | - Yoshihiro Izumi
- Department of Metabolomics, Kyushu University, Fukuoka 812-8582, Japan
| | - Kunio Nagashima
- Electron Microscopy Laboratory, National Cancer Institute, Frederick, MD 21702
| | - Stephen Lockett
- Optical Microscopy and Analysis Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD 21702
| | - Joost Holthuis
- Molecular Cell Biology Division, University of Osnabrück, 49074 Osnabrück, Germany
| | - Takeshi Bamba
- Department of Metabolomics, Kyushu University, Fukuoka 812-8582, Japan
| | - Usha Acharya
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Jairaj K Acharya
- Cancer and Developmental Biology Laboratory, National Cancer Institute, Frederick, MD 21702;
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76
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Abstract
Certain visual images, even in the absence of motion or flicker, can trigger seizures in patients with photosensitive epilepsy. As of yet, there is no systematic explanation as to why some static images are likely to provoke seizures, while others pose little or no risk. Here, we examined the neurophysiology literature to assess whether the pattern of neural responses in healthy visual cortex is predictive of the pathological responses in photosensitive epilepsy. Previous studies have suggested that gamma oscillations (30-80 Hz) measured in human visual cortex may play a role in seizure generation [1,2]. Recently, we and others have shown that increases in gamma band power can come from two very different cortical signals, one that is oscillatory (with a narrow peak between 30 Hz and 80 Hz), and another that is broadband[3]. The oscillatory signal arises from neuronal synchrony in the local population, while the broadband signal reflects the level of asynchronous neuronal activity, and is correlated with multiunit spiking [4]. These two responses have different biological origins and different selectivity for image properties. Here, we followed up on the previous proposals [1,2] to ask whether the image features that increase seizure likelihood in photosensitive epilepsy are linked to narrowband gamma oscillations specifically, or are associated with any kind of increase in visual activity. Based on published work, we compared pairs of image classes on a number of dimensions, and show that the type of image that elicits larger narrowband gamma oscillations in healthy visual cortex is also more likely to provoke seizures or pre-seizure activity in patients with photosensitive epilepsy. In contrast, images that elicit larger broadband, multiunit, or fMRI responses are much less predictive of seizure activity. We propose that a risk factor for seizures in patients with photosensitive epilepsy is engagement of the circuitry that produces gamma oscillations.
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77
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Kuratani J, Pearl PL, Sullivan LR, Riel-Romero RMS, Cheek J, Stecker MM, Orta DSJ, Selioutski O, Sinha SR, Drislane FW, Tsuchida TN. American Clinical Neurophysiology Society Guideline 5: Minimum Technical Standards for Pediatric Electroencephalography. Neurodiagn J 2018; 56:266-275. [PMID: 28436801 DOI: 10.1080/21646821.2016.1245568] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
This revision to the EEG Guidelines is an update incorporating the current electroencephalography technology and practice. It was previously published as Guideline 2. Similar to the prior guideline, it delineates the aspects of Guideline 1 that should be modified for neonates and young children. Recording conditions for photic stimulation and hyperventilation are revised to enhance the provocation of epileptiform discharges. Revisions recognize the difficulties involved in performing an EEG under sedation in young children. Recommended neonatal EEG montages are displayed for the reduced set of electrodes only since the montages in Guideline 3 should be used for a 21-electrode 10-20 system array. Neonatal documentation is updated to use current American Academy of Pediatrics term "postmenstrual age" rather than "conceptional age." Finally, because therapeutic hypothermia alters the prognostic value of neonatal EEG, the necessity of documenting the patient's temperature at the time of recording is emphasized.
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Affiliation(s)
- John Kuratani
- a The Permanente Medical Group , Department of Pediatric Neuroscience , Kaiser Permanente, Santa Clara , California
| | - Phillip L Pearl
- b Department of Epilepsy and Clinical Neurophysiology , Boston Children's Hospital , Boston , Massachusetts.,c Department of Neurology , Harvard Medical School , Boston , Massachusetts
| | | | - Rosario Maria S Riel-Romero
- e Departments of Neurology and Pediatrics, Ark-La-Tex Epilepsy Monitoring Unit , Louisiana State University Health Sciences Center, School of Medicine in Shreveport , Shreveport , Louisiana
| | | | | | - Daniel San Juan Orta
- h Clinical Neurophysiology Department , National Institute of Neurology and Neurosurgery , Mexico City , Mexico
| | - Olga Selioutski
- i Strong Epilepsy Center, Department of Neurology , University of Rochester , Rochester , New York
| | - Saurabh R Sinha
- j Department of Neurology , Duke University Medical Center , Durham , North Carolina.,k Neurodiagnostic Center, Veterans Affairs Medical Center , Durham , North Carolina
| | - Frank W Drislane
- l Department Neurology , Harvard Medical School , Boston , Massachusetts.,m Comprehensive Epilepsy Center , Beth Israel Deaconess Medical Center , Boston , Massachusetts
| | - Tammy N Tsuchida
- n Departments of Neurology and Pediatrics , George Washington University School of Medicine and Health Sciences , Washington , District of Columbia.,o Division of Neurophysiology , Epilepsy and Critical Care, Center for Neuroscience and Behavioral Health , Washington , District of Columbia
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78
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Mezzomo NJ, Fontana BD, Kalueff AV, Barcellos LJ, Rosemberg DB. Understanding taurine CNS activity using alternative zebrafish models. Neurosci Biobehav Rev 2018; 90:471-485. [DOI: 10.1016/j.neubiorev.2018.04.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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79
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Representation of steady-state visual evoked potentials elicited by luminance flicker in human occipital cortex: An electrocorticography study. Neuroimage 2018; 175:315-326. [DOI: 10.1016/j.neuroimage.2018.04.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 01/22/2018] [Accepted: 04/03/2018] [Indexed: 11/19/2022] Open
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80
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Norton JJS, Mullins J, Alitz BE, Bretl T. The performance of 9-11-year-old children using an SSVEP-based BCI for target selection. J Neural Eng 2018; 15:056012. [PMID: 29952751 DOI: 10.1088/1741-2552/aacfdd] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE In this paper, we report the performance of 9-11-year-old children using a steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) and provide control data collected from adults for comparison. Children in our study achieved a much higher performance (79% accuracy; average age 9.64 years old) than the only previous investigation of children using an SSVEP-based BCI (∼50% accuracy; average age 9.86 years old). APPROACH Experiments were conducted in two phases, a short calibration phase and a longer experimental phase. An offline analysis of the data collected during the calibration phase was used to set two parameters for a classifier and to screen participants who did not achieve a minimum accuracy of 85%. MAIN RESULTS Eleven of the 14 children and all 11 of the adults who completed the calibration phase met the minimum accuracy requirement. During the experimental phase, children selected targets with a similar accuracy (79% for children versus 78% for adults), latency (2.1 s for children versus 1.9 s for adults), and bitrate (0.50 bits s-1 for children and 0.56 bits s-1 for adults) as adults. SIGNIFICANCE This study shows that children can use an SSVEP-based BCI with higher performance than previously believed and is the first to report the performance of children using an SSVEP-based BCI in terms of latency and bitrate. The results of this study imply that children with severe motor disabilities (such as locked-in syndrome) may use an SSVEP-based BCI to restore/replace the ability to communicate.
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Affiliation(s)
- James J S Norton
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, PO Box 22002, Albany, NY 12201, United States of America. Department of Neurology, Stratton VA Medical Center, 113 Holland Ave, Albany, NY 12208, United States of America. Department of Electrical and Computer Engineering, University of Illinois, 306 N Wright St, Urbana, IL 61801, United States of America
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81
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Recommendations for Integrating a P300-Based Brain Computer Interface in Virtual Reality Environments for Gaming. COMPUTERS 2018. [DOI: 10.3390/computers7020034] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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82
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Taurine Protects from Pentylenetetrazole-Induced Behavioral and Neurochemical Changes in Zebrafish. Mol Neurobiol 2018; 56:583-594. [DOI: 10.1007/s12035-018-1107-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 05/03/2018] [Indexed: 12/22/2022]
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83
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Algin Dİ, Erdinç OO. Impaired Visual Habituation in Idiopathic Generalized Epilepsy with Photosensitivity Patients. ACTA ACUST UNITED AC 2018; 57:108-112. [PMID: 32550775 DOI: 10.29399/npa.23047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 03/16/2018] [Indexed: 11/07/2022]
Abstract
Introduction In this study, our goal was to analyze further the cortical excitability levels in idiopathic generalized epilepsy (IGE) patients with and without photosensitivity. Methods Forty-two patients (16 men and 26 women; mean age 30±8 years; range: 18-43 years) with IGE and thirty healthy age-matched control subjects (15 men and 15 women; mean age 35±3 years; range: 20-45 years) were enrolled for the investigation. We investigated the following two groups: 18 subjects with IGE with photosensitivity (IGE+PS), and 24 patients with IGE without photosensitivity (IGE-PS). Pattern reversal and potential inter-peak amplitudes, N75-P100 and P100-N145, as well as the corresponding latencies (N75, P100, and N145) for one hundred responses were measured 6 times. A linear regression slope was used for N75-P100 and P100-N145. Results Statistical analysis showed difference between groups where the IGE+PS had reduced N75-P100 compared to IGE-PS and controls. In IGE+PS group, the amplitude of N75-P100 was drastically reduced receiving antiepileptic therapy compared to those not receiving any anti-epileptic treatment (p=0.035). Conclusion These results show that the IGE+PS group has a different photoparoxysmal response phenotype driven by an unknown and distinct molecular mechanism. Pre-activation cortical excitability may be increased in IGE+PS patients compared to the IGE-PS or in healthy group. PR-VEP habituation may project the pathophysiological mechanisms underlying photosensitivity and it may be potential biomarker in patients with IGE+PS.
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Affiliation(s)
- Demet İlhan Algin
- Department of Neurology, Eskişehir Osmangazi University Faculty of Medicine, Eskişehir, Turkey
| | - Oğuz Osman Erdinç
- Department of Neurology, Eskişehir Osmangazi University Faculty of Medicine, Eskişehir, Turkey
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84
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Genetic (idiopathic) epilepsy with photosensitive seizures includes features of both focal and generalized seizures. Sci Rep 2018; 8:6254. [PMID: 29674629 PMCID: PMC5908879 DOI: 10.1038/s41598-018-24644-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 04/05/2018] [Indexed: 12/01/2022] Open
Abstract
Clinically, some patients having genetic (idiopathic) epilepsy with photosensitive seizures were difficult to be diagnosed. We aimed to discuss whether the genetic (idiopathic) epilepsy with photosensitive seizures is a focal entity, a generalized entity or a continuum. Twenty-two patients with idiopathic epilepsies and photoconvulsive response (PCR) were retrospectively recruited. In the medical records, the seizure types included “generalized tonic-clonic seizures (GTCS)” in 15, “partial secondarily GTCS (PGTCS)” in 3, partial seizures (PS) in 3, myoclonic seizures in 2, eyelid myoclonus in one, and only febrile seizures in one. Seizure types of PCR included GTCS (1/22), PGTCS (6/22), PS (9/22), electrical seizures (ES) (3/22) and GTCS/PGTCS (3/22). Combined the medical history with PCR results, they were diagnosed as: idiopathic (photosensitive) occipital lobe epilepsy (I(P)OE) in 12, genetic (idiopathic) generalized epilepsy (GGE) in one, GGE/I(P)OE in 5, pure photosensitive seizure in one, and epilepsy with undetermined generalized or focal seizure in 3. So, the dichotomy between generalized and focal seizures might have been out of date regarding to pathophysiological advances in epileptology. To some extent, it would be better to recognize the idiopathic epilepsy with photosensitive seizures as a continuum between focal and generalized seizures.
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85
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EEG-based neglect assessment: A feasibility study. J Neurosci Methods 2018; 303:169-177. [PMID: 29614297 DOI: 10.1016/j.jneumeth.2018.03.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/30/2018] [Accepted: 03/30/2018] [Indexed: 11/20/2022]
Abstract
BACKGROUND Spatial neglect (SN) is a neuropsychological syndrome that impairs automatic attention orienting to stimuli in the contralesional visual space of stroke patients. SN is commonly assessed using paper and pencil tests. Recently, computerized tests have been proposed to provide a dynamic assessment of SN. However, both paper- and computer-based methods have limitations. NEW METHOD Electroencephalography (EEG) shows promise for overcoming the limitations of current assessment methods. The aim of this work is to introduce an objective passive BCI system that records EEG signals in response to visual stimuli appearing in random locations on a screen with a dynamically changing background. Our preliminary experimental studies focused on validating the system using healthy participants with intact brains rather than employing it initially in more complex environments with patients having cortical lesions. Therefore, we designed a version of the test in which we simulated SN by hiding target stimuli appearing on the left side of the screen so that the subject's attention is shifted to the right side. RESULTS Results showed that there are statistically significant differences between EEG responses due to right and left side stimuli reflecting different processing and attention levels towards both sides of the screen. The system achieved average accuracy, sensitivity and specificity of 74.24%, 75.17% and 71.36% respectively. COMPARISON WITH EXISTING METHODS The proposed test can examine both presence and severity of SN, unlike traditional paper and pencil tests and computer-based methods. CONCLUSIONS The proposed test is a promising objective SN evaluation method.
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Evaluating the Influence of Chromatic and Luminance Stimuli on SSVEPs from Behind-the-Ears and Occipital Areas. SENSORS 2018; 18:s18020615. [PMID: 29462975 PMCID: PMC5855130 DOI: 10.3390/s18020615] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/05/2018] [Accepted: 02/14/2018] [Indexed: 01/23/2023]
Abstract
This work presents a study of chromatic and luminance stimuli in low-, medium-, and high-frequency stimulation to evoke steady-state visual evoked potential (SSVEP) in the behind-the-ears area. Twelve healthy subjects participated in this study. The electroencephalogram (EEG) was measured on occipital (Oz) and left and right temporal (TP9 and TP10) areas. The SSVEP was evaluated in terms of amplitude, signal-to-noise ratio (SNR), and detection accuracy using power spectral density analysis (PSDA), canonical correlation analysis (CCA), and temporally local multivariate synchronization index (TMSI) methods. It was found that stimuli based on suitable color and luminance elicited stronger SSVEP in the behind-the-ears area, and that the response of the SSVEP was related to the flickering frequency and the color of the stimuli. Thus, green-red stimulus elicited the highest SSVEP in medium-frequency range, and green-blue stimulus elicited the highest SSVEP in high-frequency range, reaching detection accuracy rates higher than 80%. These findings will aid in the development of more comfortable, accurate and stable BCIs with electrodes positioned on the behind-the-ears (hairless) areas.
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Abstract
Reflex epilepsies (REs) are identified as epileptic seizures that are consistently induced by identifiable and objective-specific triggers, which may be an afferent stimulus or by the patient's own activity. RE may have different subtypes depending on the stimulus characteristic. There are significant clinical and electrophysiologic differences between different RE types. Visual stimuli-sensitive or photosensitive epilepsies constitute a large proportion of the RE and are mainly related to genetic causes. Reflex epilepsies may present with focal or generalized seizures due to specific triggers, and sometimes seizures may occur spontaneously. The stimuli can be external (light flashes, hot water), internal (emotion, thinking), or both and should be distinguished from triggering precipitants, which most epileptic patients could report such as emotional stress, sleep deprivation, alcohol, and menstrual cycle. Different genetic and acquired factors may play a role in etiology of RE. This review will provide a current overview of the triggering factors and management of reflex seizures.
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Affiliation(s)
| | - Çiğdem Özkara
- Department of Neurology and Clinical Neurophysiology, Cerrahpasa Faculty of Medicine, University of Istanbul, Istanbul, Turkey
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88
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Fontana BD, Mezzomo NJ, Kalueff AV, Rosemberg DB. The developing utility of zebrafish models of neurological and neuropsychiatric disorders: A critical review. Exp Neurol 2018; 299:157-171. [DOI: 10.1016/j.expneurol.2017.10.004] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 09/15/2017] [Accepted: 10/04/2017] [Indexed: 12/30/2022]
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89
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Zheng YM, Chen B, Jiang JD, Zhang JP. Syntaxin 1B Mediates Berberine's Roles in Epilepsy-Like Behavior in a Pentylenetetrazole-Induced Seizure Zebrafish Model. Front Mol Neurosci 2018; 11:378. [PMID: 30534049 PMCID: PMC6275243 DOI: 10.3389/fnmol.2018.00378] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 09/21/2018] [Indexed: 11/13/2022] Open
Abstract
Epilepsy is a neuronal dysfunction syndrome characterized by transient and diffusely abnormal discharges of neurons in the brain. Previous studies have shown that mutations in the syntaxin 1b (stx1b) gene cause a familial, fever-associated epilepsy syndrome. It is unclear as to whether the stx1b gene also correlates with other stimulations such as flashing and/or mediates the effects of antiepileptic drugs. In this study, we found that the expression of stx1b was present mainly in the brain and was negatively correlated with seizures in a pentylenetetrazole (PTZ)-induced seizure zebrafish model. The transcription of stx1b was inhibited by PTZ but rescued by valproate, a broad-spectrum epilepsy treatment drug. In the PTZ-seizure zebrafish model, stx1b knockdown aggravated larvae hyperexcitatory swimming and prompted abnormal trajectory movements, particularly under lighting stimulation; at the same time, the expression levels of the neuronal activity marker gene c-fos increased significantly in the brain. In contrast, stx1b overexpression attenuated seizures and decreased c-fos expression levels following PTZ-induced seizures in larvae. Thus, we speculated that a deficiency of stx1b gene expression may be related with the onset occurrence of clinical seizures, particularly photosensitive seizures. In addition, we found that berberine (BBR) reduced larvae hyperexcitatory locomotion and abnormal movement trajectory in a concentration-dependent manner, slowed down excessive photosensitive seizure-like swimming, and assisted in the recovery of the expression levels of STX1B. Under the downregulation of STX1B, BBR's roles were limited: specifically, it only slightly regulated the levels of the two genes stx1b and c-fos and the hyperexcitatory motion of zebrafish in dark conditions and had no effect on the overexcited swimming behavior seen in conjunction with lighting stimulation. These findings further demonstrate that STX1B protein levels are negatively correlated with a seizure and can decrease the sensitivity of the photosensitive response in a PTZ-induced seizure zebrafish larvae; furthermore, STX1B may partially mediate the anticonvulsant effect of BBR. Additional investigation regarding the relationship between STX1B, BBR, and seizures could provide new cues for the development of novel anticonvulsant drugs.
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Affiliation(s)
- Yang-Min Zheng
- NHC Key Laboratory of Biotechnology of Antibiotics, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Bo Chen
- NHC Key Laboratory of Biotechnology of Antibiotics, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Jian-Dong Jiang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Jing-Pu Zhang
- NHC Key Laboratory of Biotechnology of Antibiotics, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
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90
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Chabuda A, Durka P, Zygierewicz J. High Frequency SSVEP-BCI With Hardware Stimuli Control and Phase-Synchronized Comb Filter. IEEE Trans Neural Syst Rehabil Eng 2017; 26:344-352. [PMID: 28961117 DOI: 10.1109/tnsre.2017.2734164] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We present an efficient implementation of brain-computer interface (BCI) based on high-frequency steady state visually evoked potentials (SSVEP). Individual shape of the SSVEP response is extracted by means of a feedforward comb filter, which adds delayed versions of the signal to itself. Rendering of the stimuli is controlled by specialized hardware (BCI Appliance). Out of 15 participants of the study, nine were able to produce stable response in at least eight out of ten frequencies from the 30-39 Hz range. They achieved on average 96±4% accuracy and 47±5 bit/min information transfer rate (ITR) for an optimized simple seven-letter speller, while generic full-alphabet speller allowed in this group for 89±9% accuracy and 36±9 bit/min ITR. These values exceed the performances of high-frequency SSVEP-BCI systems reported to date. Classical approach to SSVEP parameterization by relative spectral power in the frequencies of stimulation, implemented on the same data, resulted in significantly lower performance. This suggests that specific shape of the response is an important feature in classification. Finally, we discuss the differences in SSVEP responses of the participants who were able or unable to use the interface, as well as the statistically significant influence of the layout of the speller on the speed of BCI operation.
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91
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Understanding taurine CNS activity using alternative zebrafish models. Neurosci Biobehav Rev 2017; 83:525-539. [PMID: 28916270 DOI: 10.1016/j.neubiorev.2017.09.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 08/08/2017] [Accepted: 09/02/2017] [Indexed: 12/11/2022]
Abstract
Taurine is a highly abundant "amino acid" in the brain. Despite the potential neuroactive role of taurine in vertebrates has long been recognized, the underlying molecular mechanisms related to its pleiotropic effects in the brain remain poorly understood. Due to the genetic tractability, rich behavioral repertoire, neurochemical conservation, and small size, the zebrafish (Danio rerio) has emerged as a powerful candidate for neuropsychopharmacology investigation and in vivo drug screening. Here, we summarize the main physiological roles of taurine in mammals, including neuromodulation, osmoregulation, membrane stabilization, and antioxidant action. In this context, we also highlight how zebrafish models of brain disorders may present interesting approaches to assess molecular mechanisms underlying positive effects of taurine in the brain. Finally, we outline recent advances in zebrafish drug screening that significantly improve neuropsychiatric translational researches and small molecule screens.
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92
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Yoshimoto S, Garcia J, Jiang F, Wilkins AJ, Takeuchi T, Webster MA. Visual discomfort and flicker. Vision Res 2017; 138:18-28. [PMID: 28709920 DOI: 10.1016/j.visres.2017.05.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 04/11/2017] [Accepted: 05/25/2017] [Indexed: 11/18/2022]
Abstract
Flickering lights can be uncomfortable to look at and can induce seizures in observers with photosensitive epilepsy. However, the temporal characteristics contributing to these effects are not fully known. In the spatial domain, one identified source of visual discomfort is when images have Fourier amplitude spectra that deviate from the natural (∼1/frequency, 1/f) statistical characteristics of natural scenes, especially if they contain excess energy at the medium frequencies at which the visual system is most sensitive. We tested for analogous effects in the temporal domain, manipulating both the amplitude and phase spectra of the flicker. Participants judged the relative discomfort of temporal luminance variations in a pair of uniform 17° fields with different temporal modulations. In general, discomfort increased with deviations from natural amplitude spectra, particularly those with excess energy at medium frequencies or biased toward sharper spectra. These ratings of discomfort were also consistent with ratings of how natural the modulations appeared. However, the temporal discomfort judgments were also strongly affected by the phase spectra of the flicker, with fixed vs. random spectra producing very different responses. This was not due to the perceived regularity or predictability of the flicker, but could arise from a number of other potential factors. Our findings suggest that, like spatial patterns, visual discomfort in time-varying patterns depends in part on how similar they are to the amplitude spectra of temporal variations in the natural visual environment, but also point to the critical role of the phase spectrum in the perceived discomfort of flicker.
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Affiliation(s)
- Sanae Yoshimoto
- School of Psychology, Chukyo University, Showa-ku Yagotohonmachi 101-2, Nagoya, Aichi 466-8666, Japan; Department of Psychology, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA.
| | - Jesel Garcia
- Department of Psychology, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA.
| | - Fang Jiang
- Department of Psychology, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA.
| | - Arnold J Wilkins
- Department of Psychology, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK.
| | - Tatsuto Takeuchi
- Department of Psychology, Japan Women's University, Tama-ku Nishi-ikuta 1-1-1, Kawasaki, Kanagawa 214-8565, Japan.
| | - Michael A Webster
- Department of Psychology, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA.
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93
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Cotrina A, Benevides AB, Castillo-Garcia J, Benevides AB, Rojas-Vigo D, Ferreira A, Bastos-Filho TF. A SSVEP-BCI Setup Based on Depth-of-Field. IEEE Trans Neural Syst Rehabil Eng 2017; 25:1047-1057. [DOI: 10.1109/tnsre.2017.2673242] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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94
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Giovanni A, Capone F, di Biase L, Ferreri F, Florio L, Guerra A, Marano M, Paolucci M, Ranieri F, Salomone G, Tombini M, Thut G, Di Lazzaro V. Oscillatory Activities in Neurological Disorders of Elderly: Biomarkers to Target for Neuromodulation. Front Aging Neurosci 2017; 9:189. [PMID: 28659788 PMCID: PMC5468377 DOI: 10.3389/fnagi.2017.00189] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 05/26/2017] [Indexed: 12/13/2022] Open
Abstract
Non-invasive brain stimulation (NIBS) has been under investigation as adjunct treatment of various neurological disorders with variable success. One challenge is the limited knowledge on what would be effective neuronal targets for an intervention, combined with limited knowledge on the neuronal mechanisms of NIBS. Motivated on the one hand by recent evidence that oscillatory activities in neural systems play a role in orchestrating brain functions and dysfunctions, in particular those of neurological disorders specific of elderly patients, and on the other hand that NIBS techniques may be used to interact with these brain oscillations in a controlled way, we here explore the potential of modulating brain oscillations as an effective strategy for clinical NIBS interventions. We first review the evidence for abnormal oscillatory profiles to be associated with a range of neurological disorders of elderly (e.g., Parkinson's disease (PD), Alzheimer's disease (AD), stroke, epilepsy), and for these signals of abnormal network activity to normalize with treatment, and/or to be predictive of disease progression or recovery. We then ask the question to what extent existing NIBS protocols have been tailored to interact with these oscillations and possibly associated dysfunctions. Our review shows that, despite evidence for both reliable neurophysiological markers of specific oscillatory dis-functionalities in neurological disorders and NIBS protocols potentially able to interact with them, there are few applications of NIBS aiming to explore clinical outcomes of this interaction. Our review article aims to point out oscillatory markers of neurological, which are also suitable targets for modification by NIBS, in order to facilitate in future studies the matching of technical application to clinical targets.
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Affiliation(s)
- Assenza Giovanni
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | | | - Lazzaro di Biase
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
- Nuffield Department of Clinical Neurosciences, University of OxfordOxford, United Kingdom
| | - Florinda Ferreri
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
- Department of Clinical Neurophysiology, Kuopio University Hospital, University of Eastern FinlandKuopio, Finland
| | - Lucia Florio
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | - Andrea Guerra
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
- Nuffield Department of Clinical Neurosciences, University of OxfordOxford, United Kingdom
| | - Massimo Marano
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | - Matteo Paolucci
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | - Federico Ranieri
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | - Gaetano Salomone
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | - Mario Tombini
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | - Gregor Thut
- Centre for Cognitive Neuroimaging (CCNi), Institute of Neuroscience and Psychology, University of GlasgowGlasgow, United Kingdom
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95
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American Clinical Neurophysiology Society Guideline 5: Minimum Technical Standards for Pediatric Electroencephalography. J Clin Neurophysiol 2017; 33:320-3. [PMID: 27482791 DOI: 10.1097/wnp.0000000000000321] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
This revision to the EEG Guidelines is an update incorporating the current electroencephalography technology and practice. It was previously published as Guideline 2. Similar to the prior guideline, it delineates the aspects of Guideline 1 that should be modified for neonates and young children. Recording conditions for photic stimulation and hyperventilation are revised to enhance the provocation of epileptiform discharges. Revisions recognize the difficulties involved in performing an EEG under sedation in young children. Recommended neonatal EEG montages are displayed for the reduced set of electrodes only since the montages in Guideline 3 should be used for a 21-electrode 10-20 system array. Neonatal documentation is updated to use current American Academy of Pediatrics term "postmenstrual age" rather than "conceptional age." Finally, because therapeutic hypothermia alters the prognostic value of neonatal EEG, the necessity of documenting the patient's temperature at the time of recording is emphasized.
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96
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Poleon S, Szaflarski JP. Photosensitivity in generalized epilepsies. Epilepsy Behav 2017; 68:225-233. [PMID: 28215998 DOI: 10.1016/j.yebeh.2016.10.040] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 10/26/2016] [Accepted: 10/29/2016] [Indexed: 11/24/2022]
Abstract
Photosensitivity, which is the hallmark of photosensitive epilepsy (PSE), is described as an abnormal EEG response to visual stimuli known as a photoparoxysmal response (PPR). The PPR is a well-recognized phenomenon, occurring in 2-14% of patients with epilepsy but its pathophysiology is not clearly understood. PPR is electrographically described as 2-5Hz spike, spike-wave, or slow wave complexes with frontal and paracentral prevalence. Diagnosis of PPR is confirmed using intermittent photic stimulation (IPS) as well as video monitoring. The PPR can be elicited by certain types of visual stimuli including flicker, high contrast gratings, moving patterns, and rapidly modulating luminance patterns which may be encountered during e.g., watching television, playing video games, or attending discotheques. Photosensitivity may present in different idiopathic (genetic) epilepsy syndromes e.g. juvenile myoclonic epilepsy (JME) as well as non-IGE syndromes e.g. severe myoclonic epilepsy of infancy. Consequently, PPR is present in patients with diverse seizure types including absence, myoclonic, and generalized tonic-clonic (GTC) seizures. Across syndromes, abnormalities in structural connectivity, functional connectivity, cortical excitability, cortical morphology, and behavioral and neuropsychological function have been reported. Treatment of photosensitivity includes antiepileptic drug administration, and the use of non-pharmacological agents, e.g. tinted or polarizing glasses, as well as occupational measures, e.g. avoidance of certain stimuli.
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Affiliation(s)
- Shervonne Poleon
- University of Alabama at Birmingham, Department of Neurology and UAB Epilepsy Center, Birmingham, AL, USA.
| | - Jerzy P Szaflarski
- University of Alabama at Birmingham, Department of Neurology and UAB Epilepsy Center, Birmingham, AL, USA
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97
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"Selfie-epilepsy": A novel photosensitivity. Seizure 2017; 47:5-8. [PMID: 28273589 DOI: 10.1016/j.seizure.2017.02.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/23/2016] [Accepted: 02/17/2017] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Photosensitivity is a well-described phenomenon; affecting a relatively small proportion of individuals with epilepsy. Typically people with photosensitive epilepsies are at risk of seizures induced by shimmering natural light, strobe lights and with particular patterns or flicker frequencies on television and video games. METHODS & RESULTS We present a novel case of photosensitivity captured during video EEG monitoring showing reproducible photosensitivity with the ever-popular social phenomenon; the "selfie." The patient had previously demonstrated photosensitive myoclonus with intermittent photic stimulation on routine EEG. CONCLUSION This case suggests that taking "selfies" may represent a new area of caution for those with photosensitive epilepsies.
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98
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Pourmand A, Lombardi K, Kuhl E, O'Connell F. Videogame-Related Illness and Injury: A Review of the Literature and Predictions for Pokémon GO! Games Health J 2017; 6:9-18. [PMID: 28135114 DOI: 10.1089/g4h.2016.0090] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE Reports of videogame-related illness and injury soon emerged in the literature with the inception of videogame systems and subsequent development of novel gaming platforms and technologies. In an effort to better detail the impacts of these phenomena and provide recommendations for injury prevention as it relates to Pokémon Go and the larger world of augmented reality games, we conducted an extensive systems-based review of past trends in videogame-related illness and injury from the literature. MATERIALS AND METHODS A literature review using PubMed, Medline, and PsycInfo databases with search terms "Pokémon GO," "videogame injuries," "augmented reality injuries," and "Nintendo Injury" was performed. The search was limited to the English language, and the Boolean were used to combine the search terms. RESULTS The literature search yielded 359 peer-reviewed articles, 44 of which met the study criteria and included in the review. Seventeen additional popular press reports detailing injuries related to Pokémon Go were also incorporated. Videogame-related injuries and illness include both physical trauma as well as psychological and behavioral disorder with unique patterns of injury and illness linked to specific gaming platforms. CONCLUSIONS As videogames become increasingly advanced and immersive, they expose players to unique and often more serious injury and illness. Augmented reality games, such as Pokémon GO, are the next step in the evolution of this trend and likely portend a future in which many pathologic processes may become increasingly common.
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Affiliation(s)
- Ali Pourmand
- Department of Emergency Medicine, George Washington University , Washington, District of Columbia
| | - Kevin Lombardi
- Department of Emergency Medicine, George Washington University , Washington, District of Columbia
| | - Evan Kuhl
- Department of Emergency Medicine, George Washington University , Washington, District of Columbia
| | - Francis O'Connell
- Department of Emergency Medicine, George Washington University , Washington, District of Columbia
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99
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Stimulator Selection in SSVEP-Based Spatial Selective Attention Study. COMPUTATIONAL INTELLIGENCE AND NEUROSCIENCE 2017; 2016:6410718. [PMID: 28044073 PMCID: PMC5156793 DOI: 10.1155/2016/6410718] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Revised: 09/29/2016] [Accepted: 11/01/2016] [Indexed: 11/24/2022]
Abstract
Steady-State Visual Evoked Potentials (SSVEPs) are widely used in spatial selective attention. In this process the two kinds of visual simulators, Light Emitting Diode (LED) and Liquid Crystal Display (LCD), are commonly used to evoke SSVEP. In this paper, the differences of SSVEP caused by these two stimulators in the study of spatial selective attention were investigated. Results indicated that LED could stimulate strong SSVEP component on occipital lobe, and the frequency of evoked SSVEP had high precision and wide range as compared to LCD. Moreover a significant difference between noticed and unnoticed frequencies in spectrum was observed whereas in LCD mode this difference was limited and selectable frequencies were also limited. Our experimental finding suggested that average classification accuracies among all the test subjects in our experiments were 0.938 and 0.853 in LED and LCD mode, respectively. These results indicate that LED simulator is appropriate for evoking the SSVEP for the study of spatial selective attention.
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100
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Chien YY, Lin FC, Zao JK, Chou CC, Huang YP, Kuo HY, Wang Y, Jung TP, Shieh HPD. Polychromatic SSVEP stimuli with subtle flickering adapted to brain-display interactions. J Neural Eng 2016; 14:016018. [PMID: 28000607 DOI: 10.1088/1741-2552/aa550d] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Interactive displays armed with natural user interfaces (NUIs) will likely lead the next breakthrough in consumer electronics, and brain-computer interfaces (BCIs) are often regarded as the ultimate NUI-enabling machines to respond to human emotions and mental states. Steady-state visual evoked potentials (SSVEPs) are a commonly used BCI modality due to the ease of detection and high information transfer rates. However, the presence of flickering stimuli may cause user discomfort and can even induce migraines and seizures. With the aim of designing visual stimuli that can be embedded into video images, this study developed a novel approach to induce detectable SSVEPs using a composition of red/green/blue flickering lights. APPROACH Based on the opponent theory of colour vision, this study used 32 Hz/40 Hz rectangular red-green or red-blue LED light pulses with a 50% duty cycle, balanced/equal luminance and 0°/180° phase shifts as the stimulating light sources and tested their efficacy in producing SSVEP responses with high signal-to-noise ratios (SNRs) while reducing the perceived flickering sensation. MAIN RESULTS The empirical results from ten healthy subjects showed that dual-colour lights flickering at 32 Hz/40 Hz with a 50% duty cycle and 180° phase shift achieved a greater than 90% detection accuracy with little or no flickering sensation. SIGNIFICANCE As a first step in developing an embedded SSVEP stimulus in commercial displays, this study provides a foundation for developing a combination of three primary colour flickering backlights with adjustable luminance proportions to create a subtle flickering polychromatic light that can elicit SSVEPs at the basic flickering frequency.
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Affiliation(s)
- Yu-Yi Chien
- Department of Photonics, National Chiao Tung University, 30010 Hsinchu, Taiwan
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