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An EEG-based real-time cortical functional connectivity imaging system

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Abstract

In the present study, we introduce an EEG-based, real-time, cortical functional connectivity imaging system capable of monitoring and tracing dynamic changes in cortical functional connectivity between different regions of interest (ROIs) on the brain cortical surface. The proposed system is based on an EEG-based dynamic neuroimaging system, which is capable of monitoring spatiotemporal changes of cortical rhythmic activity at a specific frequency band by conducting real-time cortical source imaging. To verify the implemented system, we performed three test experiments in which we monitored temporal changes in cortical functional connectivity patterns in various frequency bands during structural face processing, finger movements, and working memory task. We also traced the changes in the number of connections between all possible pairs of ROIs whose correlations exceeded a predetermined threshold. The quantitative analysis results were consistent with those of previous off-line studies, thereby demonstrating the possibility of imaging cortical functional connectivity in real-time. We expect our system to be applicable to various potential applications, including real-time diagnosis of psychiatric diseases and EEG neurofeedback.

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References

  1. Astolfi L, Cincotti F, Mattia D, Fallani FDV, Tocci A, Colosimo A, Salinari S, Marciani MG, Hesse W, Witte H, Ursino M, Zavaglia M, Babiloni F (2008) Tracking the time-varying cortical connectivity patterns by adaptive multivariate estimators. IEEE Trans Biomed Eng 55(3):902–913

    Article  PubMed  CAS  Google Scholar 

  2. Bentin S, Allison T, Puce A, Perez E, McCarthy G (1996) Electrophysiological studies of face perception in humans. J Cogn Neurosci 8:551–565

    Article  PubMed  Google Scholar 

  3. Brunner C, Scherer R, Graimann B, Supp G, Pfurtscheller G (2006) Online control of a brain-computer interface using phase synchronization. IEEE Trans Biomed Eng 53(12):2501–2506

    Article  PubMed  Google Scholar 

  4. Coben R (2008) Assessment guided neurofeedback for ASD: EEG analyses. Appl Psychophys Biof 33:176

    Google Scholar 

  5. Coben R (2010) Efficacy of connectivity guided neurofeedback on language functions and IQ in autistic children. Appl Psychophys Biof 35:179

    Google Scholar 

  6. Coben R, Myers TE (2010) The relative efficacy of connectivity guided and symptom based EEG biofeedback for autistic disorders. Appl Psychophys Biof 35:13–23

    Article  Google Scholar 

  7. David O, Cosmelli D, Friston KJ (2004) Evaluation of different measures of functional connectivity using a neural mass model. Neuroimage 21(2):659–673

    Article  PubMed  Google Scholar 

  8. Delorme A, Makeig S (2004) EEGLAB: an open source toolbox for analysis of single-trial EEG dynamics including independent component analysis. J Neurosci Methods 134(1):9–21

    Article  PubMed  Google Scholar 

  9. Evans AC, Collins DL, Milner B (1992) An MRI-based stereotactic atlas from 250 young normal subjects. J Soc Neurosci Abstr (18):408

  10. Fingelkurts AA, Kallio S, Revonsuo A (2007) Cortex functional connectivity as a neurophysiological correlate of hypnosis: an EEG case study. Neuropsychologia 45(7):1452–1462

    Article  PubMed  Google Scholar 

  11. Fischl B, Sereno MI, Dale AM (1999) Cortical surface-based analysis. II: Inflation, flattening, and a surface-based coordinate system. Neuroimage 9(2):195–207

    Article  PubMed  CAS  Google Scholar 

  12. Fonteneau E, Davidoff J (2007) Neural correlates of colour categories. Neuroreport 18:1323–1327

    Article  PubMed  Google Scholar 

  13. Gow DW Jr, Segawa JA, Ahlfors SP, Lin FH (2008) Lexical influences on speech perception: a Granger causality analysis of MEG and EEG source estimates. Neuroimage 43(3):614–623

    Article  PubMed  Google Scholar 

  14. Gysels E, Celka P (2004) Phase synchronization for the recognition of mental tasks in a brain-computer interface. IEEE Trans Neural Syst Rehabil Eng 12(4):406–415

    Article  PubMed  Google Scholar 

  15. Hampson M, Peterson BS, Skudlarski P, Gatenby JC, Gore JC (2002) Detection of functional connectivity using temporal correlations in MR images. Hum Brain Mapp 15(4):247–262

    Article  PubMed  Google Scholar 

  16. Haueisen J, Ramon C, Eiselt M, Brauer H, Nowak H (1997) Influence of tissue resistivities on neuromagnetic fields and electric potentials studied with a finite element model of the head. IEEE Trans Biomed Eng 44(8):727–735

    Article  PubMed  CAS  Google Scholar 

  17. Hillyard SA, Anllo-Vento L (1998) Event-related brain potentials in the study of visual selective attention. Proc Natl Acad Sci USA 95:781–787

    Article  PubMed  CAS  Google Scholar 

  18. Hoechstetter K, Bornfleth H, Weckesser D, Ille N, Berg P, Scherg M (2004) BESA source coherence: a new method to study cortical oscillatory coupling. Brain Topogr 16(4):233–238

    Article  PubMed  Google Scholar 

  19. Holmes A, Franklin A, Clifford A, Davies I (2009) Neurophysiological evidence for categorical perception of color. Brain Cogn 69:426–434

    Article  PubMed  Google Scholar 

  20. Hwang HJ, Kwon K, Im CH (2009) Neurofeedback-based motor imagery training for brain-computer interface (BCI). J Neurosci Methods 179(1):150–156

    Article  PubMed  Google Scholar 

  21. Ibric VL, Dragomirescu LG, Hudspeth WJ (2009) Real-time changes in connectivities during neurofeedback. J Neurother 13:156–165

    Article  Google Scholar 

  22. Im CH, Hwang HJ, Che H, Lee S (2007) An EEG-based real-time cortical rhythmic activity monitoring system. Physiol Meas 28(9):1101–1113

    Article  PubMed  Google Scholar 

  23. Im CH, Jung YJ, Lee S, Koh D, Kim DW, Kim BM (2010) Estimation of directional coupling between cortical areas using near-infrared spectroscopy (NIRS). Opt Exp 18(6):5730–5739

    Article  CAS  Google Scholar 

  24. Kamousi B, Liu ZM, He B (2005) Classification of motor imagery tasks for brain-computer interface applications by means of two equivalent dipoles analysis. IEEE Trans Neural Syst Rehabil Eng 13(2):166–171

    Article  PubMed  Google Scholar 

  25. Kamousi B, Amini AN, He B (2007) Classification of motor imagery by means of cortical current density estimation and Von Neumann entropy. J Neural Eng 4(2):17–25

    Article  PubMed  Google Scholar 

  26. Keren AS, Yuval-Greenberg S, Deouell LY (2010) Saccadic spike potentials in gamma-band EEG: characterization, detection and suppression. Neuroimage 49:2248–2263

    Article  PubMed  Google Scholar 

  27. Kim KH, Choi JW, Yoon J (2009) Difference in gamma-band phase synchronization during semantic processing of visually presented words from primary and secondary languages. Brain Res 1291:82–91

    Article  PubMed  CAS  Google Scholar 

  28. Koenig T, Lehmann D, Saito N, Kuginuki T, Kinoshita T, Koukkou M (2001) Decreased functional connectivity of EEG theta-frequency activity in first-episode, neuroleptic-naive patients with schizophrenia: preliminary results. Schizophr Res 50(1–2):55–60

    Article  PubMed  CAS  Google Scholar 

  29. Korzeniewska A, Crainiceanu CM, Kus R, Franaszczuk PJ, Crone NE (2008) Dynamics of event-related causality in brain electrical activity. Hum Brain Mapp 29(10):1170–1192

    Article  PubMed  Google Scholar 

  30. Le Van Quyen M, Bragin A (2007) Analysis of dynamic brain oscillations: methodological advances. Trends Neurosci 30(7):365–373

    Article  PubMed  CAS  Google Scholar 

  31. Lee SH, Kim DW, Kim EY, Kim S, Im CH (2010) Dysfunctional gamma-band activity during face structural processing in schizophrenia patients. Schizophr Res 119:191–197

    Article  PubMed  Google Scholar 

  32. Leuchter AF, Newton TF, Cook IA, Walter DO, Rosenberg-Thompson S, Lachenbruch PA (1992) Changes in brain functional connectivity in Alzheimer-type and multi-infarct dementia. Brain 115(Pt 5):1543–1561

    Article  PubMed  Google Scholar 

  33. Lin FH, Witzel T, Hamalainen MS, Dale AM, Belliveau JW, Stufflebeam SM (2004) Spectral spatiotemporal imaging of cortical oscillations and interactions in the human brain. Neuroimage 23(2):582–595

    Article  PubMed  Google Scholar 

  34. Liu AK, Dale AM, Belliveau JW (2002) Monte Carlo simulation studies of EEG and MEG localization accuracy. Hum Brain Mapp 16:47–62

    Article  PubMed  CAS  Google Scholar 

  35. Manganotti P, Gerloff C, Toro C, Katsuta H, Sadato N, Zhuang P, Leocani L, Hallett M (1998) Task-related coherence and task-related spectral power changes during sequential finger movements. Electroencephalogr Clin Neurophysiol 109:50–62

    Article  PubMed  CAS  Google Scholar 

  36. Massimini M, Ferrarelli F, Huber R, Esser SK, Singh H, Tononi G (2005) Breakdown of cortical effective connectivity during sleep. Science 309(5744):2228–2232

    Article  PubMed  CAS  Google Scholar 

  37. Matsumoto A, Ichikawa Y, Kanayama N, Ohira H, Iidaka T (2006) Gamma band activity and its synchronization reflect the dysfunctional emotional processing in alexithymic persons. Psychophysiology 43(6):533–540

    Article  PubMed  Google Scholar 

  38. McMenamin BW, Shackman AJ, Maxwell JS, Bachhuber DRW, Koppenhaver AM, Greischar LL, Davidson RJ (2010) Validation of ICA-based myogenic artifact correction for scalp and source-localized EEG. Neuroimage 49:2416–2432

    Article  PubMed  Google Scholar 

  39. Menon V, Freeman WJ, Cutillo BA, Desmond JE, Ward MF, Bressler SL, Laxer KD, Barbaro N, Gevins AS (1996) Spatio-temporal correlations in human gamma band electrocorticograms. Electroencephalogr Clin Neurophysiol 98(2):89–102

    Article  PubMed  CAS  Google Scholar 

  40. Mormann F, Lehnertz K, David P, Elger CE (2000) Mean phase coherence as a measure for phase synchronization and its application to the EEG of epilepsy patients. Phys D 144(3–4):358–369

    Article  Google Scholar 

  41. Murias M, Webb SJ, Greenson J, Dawson G (2007) Resting state cortical connectivity reflected in EEG coherence in individuals with autism. Biol Psychiatry 62(3):270–273

    Article  PubMed  Google Scholar 

  42. Oostendorp TF, Delbeke J, Stegeman DF (2000) The conductivity of the human skull: results of in vivo and in vitro measurements. IEEE Trans Biomed Eng 47(11):1487–1492

    Article  PubMed  CAS  Google Scholar 

  43. Park YM, Che HJ, Im CH, Jung HT, Bae SM, Lee SH (2008) Decreased EEG synchronization and its correlation with symptom severity in Alzheimer’s disease. Neurosci Res 62(2):112–117

    Article  PubMed  Google Scholar 

  44. Peled A, Geva AB, Kremen WS, Blankfeld HM, Esfandiarfard R, Nordahl TE (2001) Functional connectivity and working memory in schizophrenia: an EEG study. Int J Neurosci 106(1–2):47–61

    Article  PubMed  CAS  Google Scholar 

  45. Pfurtscheller G, Andrew C (1999) Event-related changes of band power and coherence: methodology and interpretation. J Clin Neurophysiol 16(6):512–519

    Article  PubMed  CAS  Google Scholar 

  46. Reijneveld JC, Ponten SC, Berendse HW, Stam CJ (2007) The application of graph theoretical analysis to complex networks in the brain. Clin Neurophysiol 118(11):2317–2331

    Article  PubMed  Google Scholar 

  47. Rubinov M, Sporns O (2010) Complex network measures of brain connectivity: uses and interpretations. Neuroimage 52:1059–1069

    Article  PubMed  Google Scholar 

  48. Sarnthein J, Petsche H, Rappelsberger P, Shaw GL, von Stein A (1998) Synchronization between prefrontal and posterior association cortex during human working memory. Proc Natl Acad Sci USA 95:7092–7096

    Article  PubMed  CAS  Google Scholar 

  49. Schoffelen JM, Gross J (2009) Source connectivity analysis with MEG and EEG. Hum Brain Mapp 30(6):1857–1865

    Article  PubMed  Google Scholar 

  50. Shattuck DW, Leahy RM (2002) BrainSuite: an automated cortical surface identification tool. Med Image Anal 6(2):129–142

    Article  PubMed  Google Scholar 

  51. Spencer KM, Nestor PG, Niznikiewicz MA, Salisbury DF, Shenton ME, McCarley RW (2003) Abnormal neural synchrony in schizophrenia. J Neurosci 23(19):7407–7411

    PubMed  CAS  Google Scholar 

  52. Stam CJ, Jones BF, Nolte G, Breakspear M, Scheltens P (2007) Small-world networks and functional connectivity in Alzheimer’s disease. Cereb Cortex 17(1):92–99

    Article  PubMed  CAS  Google Scholar 

  53. Uhlhaas PJ, Linden DEJ, Singer W, Haenschel C, Lindner M, Maurer K, Rodriguez E (2006) Dysfunctional long-range coordination of neural activity during Gestalt perception in schizophrenia. J Neurosci 26(31):8168–8175

    Article  PubMed  CAS  Google Scholar 

  54. Verdoux H, Cougnard A, Grolleau S, Besson R, Delcroix F (2005) How do general practitioners manage subjects with early schizophrenia and collaborate with mental health professionals? A postal survey in South-Western France. Soc Psychiatry Psychiatr Epidemiol 40(11):892–898

    Article  PubMed  Google Scholar 

  55. Vuilleumier P, Pourtois G (2007) Distributed and interactive brain mechanisms during emotion face perception: evidence from functional neuroimaging. Neuropsychologia 45:174–194

    Article  PubMed  Google Scholar 

  56. Wei QG, Wang YJ, Gao XR, Gao SK (2007) Amplitude and phase coupling measures for feature extraction in an EEG-based brain-computer interface. J Neural Eng 4(2):120–129

    Article  PubMed  Google Scholar 

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Acknowledgments

This work was supported in part by the KRISS-WCL project (Development of Measurement Technology for Cognitive Process) and in part by the Original Technology Research Program for Brain Science through the National Research Foundation of Korea (NRF) grant funded by the Ministry of Education, Science and Technology (No. 2010-0018840)

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Correspondence to Chang-Hwan Im.

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H-.J. Hwang and K.-H. Kim are co-first authors and contributed equally to this work.

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Hwang, HJ., Kim, KH., Jung, YJ. et al. An EEG-based real-time cortical functional connectivity imaging system. Med Biol Eng Comput 49, 985–995 (2011). https://doi.org/10.1007/s11517-011-0791-6

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