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2.
Nat Biomed Eng ; 7(11): 1350-1373, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37414976

RESUMO

The mechanisms by which physical exercise benefits brain functions are not fully understood. Here, we show that vertically oscillating head motions mimicking mechanical accelerations experienced during fast walking, light jogging or treadmill running at a moderate velocity reduce the blood pressure of rats and human adults with hypertension. In hypertensive rats, shear stresses of less than 1 Pa resulting from interstitial-fluid flow induced by such passive head motions reduced the expression of the angiotensin II type-1 receptor in astrocytes in the rostral ventrolateral medulla, and the resulting antihypertensive effects were abrogated by hydrogel introduction that inhibited interstitial-fluid movement in the medulla. Our findings suggest that oscillatory mechanical interventions could be used to elicit antihypertensive effects.


Assuntos
Anti-Hipertensivos , Hipertensão , Adulto , Ratos , Humanos , Animais , Pressão Sanguínea , Anti-Hipertensivos/metabolismo , Anti-Hipertensivos/farmacologia , Hipertensão/terapia , Hipertensão/metabolismo , Bulbo/metabolismo
3.
Neurosci Res ; 196: 23-31, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37302715

RESUMO

The diagnosis of unresponsive wakefulness syndrome depends mostly on the motor response following verbal commands. However, there is a potential for misdiagnosis in patients who understand verbal commands (passive response) but cannot perform voluntary movements (active response). To evaluate passive and active responses in such patients, this study used an approach combining functional magnetic resonance imaging and passive listening tasks to evaluate the level of speech comprehension, with portable brain-computer interface modalities that were applied to elicit an active response to attentional modulation tasks at the bedside. We included ten patients who were clinically diagnosed as unresponsive wakefulness syndrome. Two of ten patients showed no significant activation, while limited activation in the auditory cortex was found in six patients. The remaining two patients showed significant activation in language areas, and were able to control the brain-computer interface with reliable accuracy. Using a combined passive/active approach, we identified unresponsive wakefulness syndrome patients who showed both active and passive neural responses. This suggests that some patients with unresponsive wakefulness syndrome diagnosed behaviourally are both wakeful and responsive, and the combined approach is useful for distinguishing a minimally conscious state from unresponsive wakefulness syndrome physiologically.


Assuntos
Estado Vegetativo Persistente , Vigília , Humanos , Estado Vegetativo Persistente/diagnóstico por imagem , Imageamento por Ressonância Magnética , Eletroencefalografia/métodos
4.
Front Behav Neurosci ; 15: 680206, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34177481

RESUMO

Rubber hand illusion (RHI), a kind of body ownership illusion, is sometimes atypical in individuals with autism spectrum disorder; however, the brain regions associated with the illusion are still unclear. We previously reported that mice responded as if their own tails were being touched when rubber tails were grasped following synchronous stroking to rubber tails and their tails (a "rubber tail illusion", RTI), which is a task based on the human RHI; furthermore, we reported that the RTI response was diminished in Ca2+-dependent activator protein for secretion 2-knockout (Caps2-KO) mice that exhibit autistic-like phenotypes. Importance of the posterior parietal cortex in the formation of illusory perception has previously been reported in human imaging studies. However, the local neural circuits and cell properties associated with this process are not clear. Therefore, we aimed to elucidate the neural basis of the RTI response and its impairment by investigating the c-Fos expression in both wild-type (WT) and Caps2-KO mice during the task since the c-Fos expression occurred soon after the neural activation. Immediately following the delivery of the synchronous stroking to both rubber tails and actual tails, the mice were perfused. Subsequently, whole brains were cryo-sectioned, and each section was immunostained with anti-c-Fos antibody; finally, c-Fos positive cell densities among the groups were compared. The c-Fos expression in the posterior parietal cortex was significantly lower in the Caps2-KO mice than in the WT mice. Additionally, we compared the c-Fos expression in the WT mice between synchronous and asynchronous conditions and found that the c-Fos-positive cell densities were significantly higher in the claustrum and primary somatosensory cortex of the WT mice exposed to the synchronous condition than those exposed to the asynchronous condition. Hence, the results suggest that decreased c-Fos expression in the posterior parietal cortex may be related to impaired multisensory integrations in Caps2-KO mice.

5.
J Agric Food Chem ; 69(32): 8981-8990, 2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-33570932

RESUMO

Lipids exhibit functional bioactivities based on their polar and acyl chain properties; humans obtain lipids from dietary plant product intake. Therefore, the identification of different molecular species facilitates the evaluation of biological functions and nutrition levels and new phenotype-modulating lipid structures. As a rapid screening strategy, we performed untargeted lipidomics for 155 agricultural products in 58 species from 23 plant families, wherein product-specific lipid diversities were shown using computational mass spectrometry. We characterized 716 lipid species, for which the profiles revealed the National Center for Biotechnology Information-established organismal classification and unique plant tissue metabotypes. Moreover, we annotated unreported subclasses in plant lipidology; e.g., triacylglycerol estolide (TG-EST) was detected in rice seeds (Oryza sativa) and several plant species. TG-EST is known as the precursor molecule producing the fatty acid ester of hydroxy fatty acid, which lowers ambient glycemia and improves glucose tolerance. Hence, our method can identify agricultural plant products containing valuable lipid ingredients.


Assuntos
Lipidômica , Oryza , Ácidos Graxos , Humanos , Lipídeos , Espectrometria de Massas
6.
No Shinkei Geka ; 48(7): 615-620, 2020 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-32694231

RESUMO

BACKGROUND: After carotid artery stenting(CAS)in a tortuous artery, the geometrics and elongation of the carotid artery sometimes change. It is not clear whether these changes induce post stent re-stenosis. We report a case of re-stenosis that occurred two years after CAS in a tortuous artery that required carotid endarterectomy with removal of the stent. CASE PRESENTATION: CAS was performed on a 78-year-old male who presented with symptoms of severe stenosis of a tortuous internal carotid artery. Eighteen months after stenting, the echogram revealed moderate stenosis at the distal end of the stent. Six months later, this developed into severe stenosis. Carotid angiography showed that the end of the stent was touching the wall of the internal carotid artery, and blood was passing through the stent wall. A re-CAS was difficult to perform;hence carotid endarterectomy with removal of the stent was performed successfully. He was discharged without any new neurological deficits. CONCLUSION: CAS on a tortuous carotid artery sometimes results in changes to the geometry and elongation of the artery. Potentially, this can lead to changes in the positional relationship between the stent and the artery, alteration of the wall shear stress and re-stenosis. Careful follow-up is needed after CAS on a tortuous artery.


Assuntos
Estenose das Carótidas , Endarterectomia das Carótidas , Idoso , Artéria Carótida Primitiva , Artéria Carótida Interna , Humanos , Masculino , Stents , Resultado do Tratamento
7.
Sci Rep ; 8(1): 16787, 2018 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-30429511

RESUMO

Brain-computer interfaces (BCIs) enable communication with others and allow machines or computers to be controlled in the absence of motor activity. Clinical studies evaluating neural prostheses in amyotrophic lateral sclerosis (ALS) patients have been performed; however, to date, no study has reported that ALS patients who progressed from locked-in syndrome (LIS), which has very limited voluntary movement, to a completely locked-in state (CLIS), characterized by complete loss of voluntary movements, were able to continue controlling neural prostheses. To clarify this, we used a BCI system to evaluate three late-stage ALS patients over 27 months. We employed steady-state visual evoked brain potentials elicited by flickering green and blue light-emitting diodes to control the BCI system. All participants reliably controlled the system throughout the entire period (median accuracy: 83.3%). One patient who progressed to CLIS was able to continue operating the system with high accuracy. Furthermore, this patient successfully used the system to respond to yes/no questions. Thus, this CLIS patient was able to operate a neuroprosthetic device, suggesting that the BCI system confers advantages for patients with severe paralysis, including those exhibiting complete loss of muscle movement.


Assuntos
Esclerose Lateral Amiotrófica/terapia , Interfaces Cérebro-Computador , Próteses Neurais , Encéfalo/fisiologia , Progressão da Doença , Potenciais Evocados Visuais/fisiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Quadriplegia/terapia
8.
Plant Cell ; 30(8): 1887-1905, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29967047

RESUMO

Under heat stress, polyunsaturated acyl groups, such as α-linolenate (18:3) and hexadecatrienoate (16:3), are removed from chloroplastic glycerolipids in various plant species. Here, we showed that a lipase designated HEAT INDUCIBLE LIPASE1 (HIL1) induces the catabolism of monogalactosyldiacylglycerol (MGDG) under heat stress in Arabidopsis thaliana leaves. Using thermotolerance tests, a T-DNA insertion mutant with disrupted HIL1 was shown to have a heat stress-sensitive phenotype. Lipidomic analysis indicated that the decrease of 34:6-MGDG under heat stress was partially impaired in the hil1 mutant. Concomitantly, the heat-induced increment of 54:9-triacylglycerol in the hil1 mutant was 18% lower than that in the wild-type plants. Recombinant HIL1 protein digested MGDG to produce 18:3-free fatty acid (18:3-FFA), but not 18:0- and 16:0-FFAs. A transient assay using fluorescent fusion proteins confirmed chloroplastic localization of HIL1. Transcriptome coexpression network analysis using public databases demonstrated that the HIL1 homolog expression levels in various terrestrial plants are tightly associated with chloroplastic heat stress responses. Thus, HIL1 encodes a chloroplastic MGDG lipase that releases 18:3-FFA in the first committed step of 34:6 (18:3/16:3)-containing galactolipid turnover, suggesting that HIL1 has an important role in the lipid remodeling process induced by heat stress in plants.


Assuntos
Arabidopsis/metabolismo , Galactolipídeos/metabolismo , Folhas de Planta/metabolismo , Ácido alfa-Linolênico/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Resposta ao Choque Térmico/genética , Resposta ao Choque Térmico/fisiologia , Folhas de Planta/genética
9.
R Soc Open Sci ; 5(5): 172170, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29892405

RESUMO

Understanding how we consciously experience our bodies is a fundamental issue in cognitive neuroscience. Two fundamental components of this are the sense of body ownership (the experience of the body as one's own) and the sense of agency (the feeling of control over one's bodily actions). These constructs have been used to investigate the incorporation of prostheses. To date, however, no evidence has been provided showing whether representations of ownership and agency in amputees are altered when operating a robotic prosthesis. Here we investigated a robotic arm using myoelectric control, for which the user varied the joint position continuously, in a rubber hand illusion task. Fifteen able-bodied participants and three trans-radial amputees were instructed to contract their wrist flexors/extensors alternately, and to watch the robotic arm move. The sense of ownership in both groups was extended to the robotic arm when the wrists of the real and robotic arm were flexed/extended synchronously, with the effect being smaller when they moved in opposite directions. Both groups also experienced a sense of agency over the robotic arm. These results suggest that these experimental settings induced successful incorporation of the prosthesis, at least for the amputees who took part in the present study.

10.
Front Hum Neurosci ; 12: 228, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29928196

RESUMO

Severe motor impairments can affect the ability to communicate. The ability to see has a decisive influence on the augmentative and alternative communication (AAC) systems available to the user. To better understand the initial impressions users have of AAC systems we asked naïve healthy participants to compare two visual (a visual P300 brain-computer interface (BCI) and an eye-tracker) and two non-visual systems (an auditory and a tactile P300 BCI). Eleven healthy participants performed 20 selections in a five choice task with each system. The visual P300 BCI used face stimuli, the auditory P300 BCI used Japanese Hiragana syllables and the tactile P300 BCI used a stimulator on the small left finger, middle left finger, right thumb, middle right finger and small right finger. The eye-tracker required a dwell time of 3 s on the target for selection. We calculated accuracies and information-transfer rates (ITRs) for each control method using the selection time that yielded the highest ITR and an accuracy above 70% for each system. Accuracies of 88% were achieved with the visual P300 BCI (4.8 s selection time, 20.9 bits/min), of 70% with the auditory BCI (19.9 s, 3.3 bits/min), of 71% with the tactile BCI (18 s, 3.4 bits/min) and of 100% with the eye-tracker (5.1 s, 28.2 bits/min). Performance between eye-tracker and visual BCI correlated strongly, correlation between tactile and auditory BCI performance was lower. Our data showed no advantage for either non-visual system in terms of ITR but a lower correlation of performance which suggests that choosing the system which suits a particular user is of higher importance for non-visual systems than visual systems.

11.
Sci Rep ; 8(1): 1753, 2018 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-29379140

RESUMO

A brain-computer interface (BCI) or brain-machine interface is a technology that enables the control of a computer and other external devices using signals from the brain. This technology has been tested in paralysed patients, such as those with cervical spinal cord injuries or amyotrophic lateral sclerosis, but it has not been tested systematically in Duchenne muscular dystrophy (DMD), which is a severe type of muscular dystrophy due to the loss of dystrophin and is often accompanied by progressive muscle weakness and wasting. Here, we investigated the efficacy of a P300-based BCI for patients with DMD. Eight bedridden patients with DMD and eight age- and gender-matched able-bodied controls were instructed to input hiragana characters. We used a region-based, two-step P300-based BCI with green/blue flicker stimuli. EEG data were recorded, and a linear discriminant analysis distinguished the target from other non-targets. The mean online accuracy of inputted characters (accuracy for the two-step procedure) was 71.6% for patients with DMD and 80.6% for controls, with no significant difference between the patients and controls. The P300-based BCI was operated successfully by individuals with DMD in an advanced stage and these findings suggest that this technology may be beneficial for patients with this disease.


Assuntos
Encéfalo/fisiopatologia , Potenciais Evocados P300/fisiologia , Distrofia Muscular de Duchenne/fisiopatologia , Adulto , Encéfalo/metabolismo , Interfaces Cérebro-Computador , Análise Discriminante , Distrofina/metabolismo , Eletroencefalografia/métodos , Humanos , Masculino , Distrofia Muscular de Duchenne/metabolismo , Estimulação Luminosa/métodos , Adulto Jovem
12.
Prog Brain Res ; 236: 225-241, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29157413

RESUMO

Understanding how we consciously experience our bodies is a fundamental issue in both psychology and neuroscience. To date, the incorporation of nonbody objects into the body representation has been investigated extensively, and the incorporation of prosthetic arms in amputees has been demonstrated using the rubber hand illusion. In this study, we investigated the incorporation of prosthetic arms in amputees using the crossed hands illusion, in which successive somatosensory stimuli are delivered, one to each arm, at intervals of 300ms or less, and where arm crossing often causes inversion of perceived tactile temporal order. The induced reversal illusion was greater with a prosthetic limb than without in three amputees. With a shorter prosthetic arm (i.e., one that did not reach the contralateral limb), the illusion induced by vision of the short prosthetic arm was significantly reduced as compared to that seen when the long prosthetic arm crossed over the other arm. These results therefore suggest that the somatosensory signals were referred to the spatial location of the tips of the prosthetic arm, which was incorporated into the body representation by the amputees.


Assuntos
Amputados , Braço/fisiopatologia , Membros Artificiais , Ilusões/fisiologia , Percepção do Tato/fisiologia , Percepção Visual/fisiologia , Idoso , Humanos , Masculino , Pessoa de Meia-Idade
13.
Front Neurosci ; 11: 522, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28983235

RESUMO

Gaze-independent brain computer interfaces (BCIs) are a potential communication tool for persons with paralysis. This study applies affective auditory stimuli to investigate their effects using a P300 BCI. Fifteen able-bodied participants operated the P300 BCI, with positive and negative affective sounds (PA: a meowing cat sound, NA: a screaming cat sound). Permuted stimuli of the positive and negative affective sounds (permuted-PA, permuted-NA) were also used for comparison. Electroencephalography data was collected, and offline classification accuracies were compared. We used a visual analog scale (VAS) to measure positive and negative affective feelings in the participants. The mean classification accuracies were 84.7% for PA and 67.3% for permuted-PA, while the VAS scores were 58.5 for PA and -12.1 for permuted-PA. The positive affective stimulus showed significantly higher accuracy and VAS scores than the negative affective stimulus. In contrast, mean classification accuracies were 77.3% for NA and 76.0% for permuted-NA, while the VAS scores were -50.0 for NA and -39.2 for permuted NA, which are not significantly different. We determined that a positive affective stimulus with accompanying positive affective feelings significantly improved BCI accuracy. Additionally, an ALS patient achieved 90% online classification accuracy. These results suggest that affective stimuli may be useful for preparing a practical auditory BCI system for patients with disabilities.

14.
Clin Neurophysiol Pract ; 2: 147-153, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-30214988

RESUMO

OBJECTIVE: We investigated the efficacy of a P300-based brain-computer interface (BCI) for patients with spinocerebellar ataxia (SCA), which is often accompanied by cerebellar impairment. METHODS: Eight patients with SCA and eight age- and gender-matched healthy controls were instructed to input Japanese hiragana characters using the P300-based BCI with green/blue flicker. All patients depended on some assistance in their daily lives (modified Rankin scale: mean 3.5). The chief symptom was cerebellar ataxia; no cognitive deterioration was present. A region-based, two-step P300-based BCI was used. During the P300 task, eight-channel EEG data were recorded, and a linear discriminant analysis distinguished the target from other nontarget regions of the matrix. RESULTS: The mean online accuracy in BCI operation was 82.9% for patients with SCA and 83.2% for controls; no significant difference was detected. CONCLUSION: The P300-based BCI was operated successfully not only by healthy controls but also by individuals with SCA. SIGNIFICANCE: These results suggest that the P300-based BCI may be applicable for patients with SCA.

15.
Plant Biotechnol (Tokyo) ; 34(1): 57-63, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-31275009

RESUMO

Lipid remodeling in soybean under phosphorus (P)-limitation stress was investigated via lipidomic analysis. Principle component analysis of lipidome data from plants with 4 unfolded trifoliate leaves revealed that each leaf responded to P-limitation stress differently. Upon P limitation, a substantial decrease in phospholipids was observed particularly in the 1st and 2nd trifoliate leaves, while 3rd, and especially 4th, trifoliate leaves showed lipid profiles similar to those from control plants grown under P sufficiency. Under P-limited conditions, non-phosphorus glycoglycerolipid, glucuronosyldiacylglycerol (GlcADG), significantly increased in the 1st and 2nd trifoliate leaves. The levels of some other non-phosphorus glycoglycerolipids, including monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and sulfoquinovosyldiacylglycerol (SQDG), were elevated under P-limited growth conditions, while there were only slight changes in the total levels of these lipid classes upon P limitation. These results indicate that the lipid metabolic pathway in tissues of soybean plants does not uniformly respond to P-limitation stress, where lipid remodeling is very active in older leaves and phosphate appears to be preferentially remobilized to the younger tissues under P-limited conditions.

16.
J Neurosci ; 36(43): 11133-11137, 2016 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-27798192

RESUMO

The ownership of one's body parts represents a fundamental aspect of self-consciousness. Accumulating empirical evidence supports the existence of this concept in humans and nonhuman primates, but it is unclear whether nonprimate mammals experience similar feelings. Therefore, the present study used rubber tails to investigate body ownership in rodents. When the real tails and rubber tails were synchronously stroked, the mice responded as if their own tails were touched when the rubber tails were grasped. In contrast, when the stimuli were delivered asynchronously, there was a significantly lower mean response rate when the rubber tail was grasped. These findings suggest that mice may experience body ownership of their tails, suggestive of the rubber hand illusion in humans. SIGNIFICANCE STATEMENT: To explore the manner in which the ownership of body parts is experienced, this study specifically used the rubber hand illusion (RHI), in which self-consciousness can be extended out of one's own body. Accumulating empirical evidence supports the existence of this concept in humans and nonhuman primates, but it remains unclear whether nonprimate mammals experience similar feelings. This study demonstrated for the first time that mice may experience body ownership of their tails, which is suggestive of the RHI in humans and provides evidence that may highlight how humans experience the ownership of body parts.


Assuntos
Imagem Corporal/psicologia , Ilusões/fisiologia , Ilusões/psicologia , Cauda/fisiologia , Tato/fisiologia , Percepção Visual/fisiologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL
17.
Front Neurosci ; 10: 446, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27746716

RESUMO

Gaze-independent brain-computer interfaces (BCIs) are a possible communication channel for persons with paralysis. We investigated if it is possible to use auditory stimuli to create a BCI for the Japanese Hiragana syllabary, which has 46 Hiragana characters. Additionally, we investigated if training has an effect on accuracy despite the high amount of different stimuli involved. Able-bodied participants (N = 6) were asked to select 25 syllables (out of fifty possible choices) using a two step procedure: First the consonant (ten choices) and then the vowel (five choices). This was repeated on 3 separate days. Additionally, a person with spinal cord injury (SCI) participated in the experiment. Four out of six healthy participants reached Hiragana syllable accuracies above 70% and the information transfer rate increased from 1.7 bits/min in the first session to 3.2 bits/min in the third session. The accuracy of the participant with SCI increased from 12% (0.2 bits/min) to 56% (2 bits/min) in session three. Reliable selections from a 10 × 5 matrix using auditory stimuli were possible and performance is increased by training. We were able to show that auditory P300 BCIs can be used for communication with up to fifty symbols. This enables the use of the technology of auditory P300 BCIs with a variety of applications.

18.
Physiol Plant ; 155(1): 33-42, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25677193

RESUMO

Glucuronosyldiacylglycerol (GlcADG) is a plant glycolipid that accumulates in Arabidopsis and rice in response to phosphorus (P) starvation. It has been suggested that GlcADG functions to mitigate the stress induced by P depletion. Biosynthesis of GlcADG requires sulfolipid (SQDG) synthase, which is coded for in plant genomes. This indicates the possibility that GlcADG may be a general constituent of membrane lipids in plants. In this study, we investigated the SQDG synthases found in the genomes of higher plants, ferns, mosses, algae and cyanobacteria. In addition, we analyzed GlcADG accumulation, and the expression of SQDG synthase homologs in tomato and soybean plants grown under P-limited conditions. LC-MS analysis of lipids from these plants confirmed that GlcADG accumulated during P deprivation, as previously observed in Arabidopsis and rice. We also observed upregulation of SQDG synthase transcripts in these plants during P deprivation. These data suggest that GlcADG is present not only in model plants, but also in various other plant species, and that this lipid molecule performs an important physiological function as a mitigator of P-deprivation stress in plants.


Assuntos
Glycine max/metabolismo , Glicolipídeos/metabolismo , Fósforo/metabolismo , Solanum lycopersicum/metabolismo , Sequência de Aminoácidos , Cromatografia Líquida , Hexosiltransferases/classificação , Hexosiltransferases/genética , Hexosiltransferases/metabolismo , Lipídeos/análise , Solanum lycopersicum/genética , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Glycine max/genética , Espectrometria de Massas em Tandem
19.
Front Neurol ; 5: 74, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24860546

RESUMO

The visual P300 brain-computer interface (BCI), a popular system for electroencephalography (EEG)-based BCI, uses the P300 event-related potential to select an icon arranged in a flicker matrix. In earlier studies, we used green/blue (GB) luminance and chromatic changes in the P300-BCI system and reported that this luminance and chromatic flicker matrix was associated with better performance and greater subject comfort compared with the conventional white/gray (WG) luminance flicker matrix. To highlight areas involved in improved P300-BCI performance, we used simultaneous EEG-fMRI recordings and showed enhanced activities in bilateral and right lateralized parieto-occipital areas. Here, to capture coherent activities of the areas during P300-BCI, we collected whole-head 306-channel magnetoencephalography data. When comparing functional connectivity between the right and left parieto-occipital channels, significantly greater functional connectivity in the alpha band was observed under the GB flicker matrix condition than under the WG flicker matrix condition. Current sources were estimated with a narrow-band adaptive spatial filter, and mean imaginary coherence was computed in the alpha band. Significantly greater coherence was observed in the right posterior parietal cortex under the GB than under the WG condition. Re-analysis of previous EEG-based P300-BCI data showed significant correlations between the power of the coherence of the bilateral parieto-occipital cortices and their performance accuracy. These results suggest that coherent activity in the bilateral parieto-occipital cortices plays a significant role in effectively driving the P300-BCI.

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