Skip to main content

An Introduction to MEG Connectivity Measurements

  • Chapter
  • First Online:

Abstract

Researchers are beginning to appreciate the brain as more than a mere collection of loosely connected, highly specialised components. While there is clear specialisation among regions of the cortex, the true power of the brain appears to arise from the ability of those regions to work together across a range of spatial scales as a richly interconnected and complex network. On all levels, the study of brain connectivity seeks to understand how different regions of the cortex communicate, what the emerging networks signify functionally, and why these are important for normal behaviour. The use of MEG in this endeavour is an attempt to understand these processes on the broad, interregional scale, and in that respect MEG is an ideal tool. It has a good deal of spatial resolution, enough to distinguish between brain areas ~1 cm apart, and exquisite temporal resolution, enough to record even the fastest electrical oscillations the brain can generate. This chapter begins with a brief overview of the history of electrophysiological measures and their application to the study of brain connectivity. We then describe some of the core theory underlying the measurement of magnetic fields generated by the brain and practical considerations of measuring correlated activity with MEG. Some notable applications of MEG to the study of brain networks will then be described and a comparison will be made between MEG to other methods such as ECoG. The chapter will also explore some of the principal mathematical techniques used by researchers to probe different aspects of connectivity ranging from simple correlational approaches to more involved concepts such as multivariate autoregressive models (MAR). Finally, we will discuss limitations of using MEG to study connectivity and also give some insight into the exciting prospects the future might hold for MEG connectivity research.

This is a preview of subscription content, log in via an institution.

Buying options

Chapter
USD   29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD   129.00
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD   169.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Learn about institutional subscriptions

Notes

  1. 1.

    Note, that this problem is avoided when the connectivity to be estimated is between MEG and an externally measured signal such as LFP or EMG recordings.

References

  • Arroyo S, Lesser RP (1993) PET, MRI, and epilepsy. Neurology 43(10):2156

    Google Scholar 

  • Astolfi L, Cincotti F, Mattia D, Babiloni C, Carducci F, Basilisco A, Rossini PM, Salinari S, Ding L, Ni Y, He B, Babiloni F (2005) Assessing cortical functional connectivity by linear inverse estimation and directed transfer function: simulations and application to real data. Clin Neurophysiol: Off J Int Fed Clin Neurophysiol 116(4):920–932

    Google Scholar 

  • Astolfi L, Cincotti F, Mattia D, De Vico Fallani F, 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

    Google Scholar 

  • Baker AH, Luckhoo et al (2012) Investigating the temporal dynamics of resting state brain connectivity using magnetoencephalography. Proceeding of HBM conference

    Google Scholar 

  • Bartel P, Blom M, van der Meyden C, de Klerk S (1988) Effects of single doses of diazepam, chlorpromazine, imipramine and trihexyphenidyl on visual-evoked potentials. Neuropsychobiology 20(4):212–217

    Google Scholar 

  • Beckmann CF, DeLuca M, Devlin JT, Smith SM (2005) Investigations into resting-state connectivity using independent component analysis. Philos Trans R Soc Lond B Biol Sci 360(1457):1001–1013

    Google Scholar 

  • Berger H (1929) Uber das elektrenephalogramm des menschen. Arch Psychiatr Nervenkrankheiten 87:527–570

    Google Scholar 

  • Birn RM, Diamond JB, Smith MA, Bandettini PA (2006) Separating respiratory-variation-related fluctuations from neuronal-activity-related fluctuations in fMRI. NeuroImage 31(4):1536–1548

    Google Scholar 

  • Birn RM, Murphy K, Bandettini PA (2008) The effect of respiration variations on independent component analysis results of resting state functional connectivity. Hum Brain Mapp 29(7):740–750

    Google Scholar 

  • Biswal B, Yetkin FZ, Haughton VM, Hyde JS (1995) Functional connectivity in the motor cortex of resting human brain using echo-planar MRI. Magn Reson Med: Off J Soc Magn Reson Med/Soc Magn Reson Med 34(4):537–541

    Google Scholar 

  • Bloom AS, Hoffmann RG, Fuller SA, Pankiewicz J, Harsch HH, Stein EA (1999) Determination of drug-induced changes in functional MRI signal using a pharmacokinetic model. Hum Brain Mapp 8(4):235–244

    Google Scholar 

  • Bob P, Palus M, Susta M, Glaslova K (2008) EEG phase synchronization in patients with paranoid schizophrenia. Neurosci Lett 447(1):73–77

    Google Scholar 

  • Breakspear M, Heitmann S, Daffertshofer A (2010) Generative models of cortical oscillations: neurobiological implications of the kuramoto model. Front Hum Neurosci 4:190

    Google Scholar 

  • Breiter HC, Gollub RL, Weisskoff RM, Kennedy DN, Makris N, Berke JD, Goodman JM, Kantor HL, Gastfriend DR, Riorden JP, Mathew RT, Rosen BR, Hyman SE (1997) Acute effects of cocaine on human brain activity and emotion. Neuron 19(3):591–611

    Google Scholar 

  • Bressler SL, Kelso JA (2001) Cortical coordination dynamics and cognition. Trends Cogn Sci 5(1):26–36

    Google Scholar 

  • Britz J, Van De Ville D, Michel CM (2010) BOLD correlates of EEG topography reveal rapid resting-state network dynamics. NeuroImage 52(4):1162–1170

    Google Scholar 

  • Broca P (2011) Remarks on the seat of spoken language, followed by a case of Aphasia (1861). Neuropsychol Rev 21(3):227–229

    Google Scholar 

  • Brookes MJ, Gibson AM, Hall SD, Furlong PL, Barnes GR, Hillebrand A, Singh KD, Holliday IE, Francis ST, Morris PG (2005) GLM-beamformer method demonstrates stationary field, alpha ERD and gamma ERS co-localisation with fMRI BOLD response in visual cortex. NeuroImage 26(1):302–308

    Google Scholar 

  • Brookes MJ, Hale JR, Zumer JM, Stevenson CM, Francis ST, Barnes GR, Owen JP, Morris PG, Nagarajan SS (2011a) Measuring functional connectivity using MEG: methodology and comparison with fcMRI. NeuroImage 56(3):1082–1104

    Google Scholar 

  • Brookes MJ, Liddle EB, Hale JR, Woolrich MW, Luckhoo H, Liddle PF, Morris PG (2012a) Task induced modulation of neural oscillations in electrophysiological brain networks. NeuroImage 63(4):1918–1930

    Google Scholar 

  • Brookes MJ, Vrba J, Robinson SE, Stevenson CM, Peters AM, Barnes GR, Hillebrand A, Morris PG (2008) Optimising experimental design for MEG beamformer imaging. NeuroImage 39(4):1788–1802

    Google Scholar 

  • Brookes MJ, Woolrich M, Luckhoo H, Price D, Hale JR, Stephenson MC, Barnes GR, Smith SM, Morris PG (2011b) Investigating the electrophysiological basis of resting state networks using magnetoencephalography. Proc Natl Acad Sci USA 108(40):16783–16788

    Google Scholar 

  • Brookes MJ, Woolrich MW, Barnes GR (2012b) Measuring functional connectivity in MEG: a multivariate approach insensitive to linear source leakage. NeuroImage 63(2):910–920

    Google Scholar 

  • Brookes MJ, Zumer JM, Stevenson CM, Hale JR, Barnes GR, Vrba J, Morris PG (2010) Investigating spatial specificity and data averaging in MEG. NeuroImage 49(1):525–538

    Google Scholar 

  • Cabral J, Hugues E, Sporns O, Deco G (2011) Role of local network oscillations in resting-state functional connectivity. NeuroImage 57(1):130–139

    Google Scholar 

  • Cabral J, Luckhoo H, et al (2013) Revealing underlying neural mechanisms of spontaneous MEG functional connectivity: oscillatory network interactions can lead to structured band-limited power fluctuations. Under Revision

    Google Scholar 

  • Canolty RT, Edwards E, Dalal SS, Soltani M, Nagarajan SS, Kirsch HE, Berger MS, Barbaro NM, Knight RT (2006) High gamma power is phase-locked to theta oscillations in human neocortex. Science 313(5793):1626–1628

    Google Scholar 

  • Chang C, Glover GH (2010) Time-frequency dynamics of resting-state brain connectivity measured with fMRI. NeuroImage 50(1):81–98

    Google Scholar 

  • Craddock RC, Holtzheimer PE 3rd, Hu XP, Mayberg HS (2009) Disease state prediction from resting state functional connectivity. Magn Reson Med: Off J Society Magn Reson Med/Soc Magn Reson Med 62(6):1619–1628

    Google Scholar 

  • Dauwels J, Vialatte F, Cichocki A (2010a) Diagnosis of Alzheimer’s disease from EEG signals: where are we standing? Curr Alzheimer Res 7(6):487–505

    Google Scholar 

  • Dauwels J, Vialatte F, Musha T, Cichocki A (2010b) A comparative study of synchrony measures for the early diagnosis of Alzheimer’s disease based on EEG. NeuroImage 49(1):668–693

    Google Scholar 

  • David O, Kiebel SJ, Harrison LM, Mattout J, Kilner JM, Friston KJ (2006) Dynamic causal modeling of evoked responses in EEG and MEG. NeuroImage 30(4):1255–1272

    Google Scholar 

  • de Pasquale F, Della Penna S, Snyder AZ, Lewis C, Mantini D, Marzetti L, Belardinelli P, Ciancetta L, Pizzella V, Romani GL, Corbetta M (2010) Temporal dynamics of spontaneous MEG activity in brain networks. Proc Natl Acad Sci USA 107(13):6040–6045

    Google Scholar 

  • de Pasquale F, Della Penna S, Snyder AZ, Marzetti L, Pizzella V, Romani GL, Corbetta M (2012) A cortical core for dynamic integration of functional networks in the resting human brain. Neuron 74(4):753–764

    Google Scholar 

  • Deco G, Jirsa VK, Robinson PA, Breakspear M, Friston K (2008) The dynamic brain: from spiking neurons to neural masses and cortical fields. PLoS Comput Biol 4(8):e1000092

    Google Scholar 

  • Engel AK, Fries P, Singer W (2001) Dynamic predictions: oscillations and synchrony in top-down processing. Nat Rev Neurosci 2(10):704–716

    Google Scholar 

  • Fox MD, Snyder AZ, Zacks JM, Raichle ME (2006) Coherent spontaneous activity accounts for trial-to-trial variability in human evoked brain responses. Nat Neurosci 9(1):23–25

    Google Scholar 

  • Friedman J, Hastie T, Tibshirani R (2008) Sparse inverse covariance estimation with the graphical lasso. Biostatistics 9(3):432–441

    MATH  Google Scholar 

  • Fries P (2005) A mechanism for cognitive dynamics: neuronal communication through neuronal coherence. Trends Cogn Sci 9(10):474–480

    Google Scholar 

  • Friston K, Harrison L, Daunizeau J, Kiebel S, Phillips C, Trujillo-Barreto N, Henson R, Flandin G, Mattout J (2008) Multiple sparse priors for the M/EEG inverse problem. NeuroImage 39(3):1104–1120

    Google Scholar 

  • Friston KJ (1999) Schizophrenia and the disconnection hypothesis. Acta Psychiatr Scand Suppl 395:68–79

    Google Scholar 

  • Friston KJ (2011) Functional and effective connectivity: a review. Brain Connect 1(1):13–36

    MathSciNet  Google Scholar 

  • Friston KJ, Harrison L, Penny W (2003) Dynamic causal modelling. NeuroImage 19(4):1273–1302

    Google Scholar 

  • Friston KJ, Li B, Daunizeau J, Stephan KE (2011) Network discovery with DCM. NeuroImage 56(3):1202–1221

    Google Scholar 

  • Gaetz W, Edgar JC, Wang DJ, Roberts TP (2011) Relating MEG measured motor cortical oscillations to resting gamma-aminobutyric acid (GABA) concentration. NeuroImage 55(2):616–621

    Google Scholar 

  • Gevins A, Cutillo B, Desmond J, Ward M, Bressler S, Barbero N, Laxer K (1994) Subdural grid recordings of distributed neocortical networks involved with somatosensory discrimination. Electroencephalogr Clin Neurophysiol 92(4):282–290

    Google Scholar 

  • 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

    Google Scholar 

  • Gray CM, Konig P, Engel AK, Singer W (1989) Oscillatory responses in cat visual cortex exhibit inter-columnar synchronization which reflects global stimulus properties. Nature 338(6213):334–337

    Google Scholar 

  • Greenblatt DJ, Harmatz JS, von Moltke LL, Wright CE, Shader RI (2004) Age and gender effects on the pharmacokinetics and pharmacodynamics of triazolam, a cytochrome P450 3A substrate. Clin Pharmacol Ther 76(5):467–479

    Google Scholar 

  • Gross J, Kujala J, Hamalainen M, Timmermann L, Schnitzler A, Salmelin R (2001) Dynamic imaging of coherent sources: Studying neural interactions in the human brain. Proc Natl Acad Sci USA 98(2):694–699

    Google Scholar 

  • Guggisberg AG, Honma SM, Findlay AM, Dalal SS, Kirsch HE, Berger MS, Nagarajan SS (2008) Mapping functional connectivity in patients with brain lesions. Ann Neurol 63(2):193–203

    Google Scholar 

  • Hale JR, Brookes MJ, Hall EL, Zumer JM, Stevenson CM, Francis ST, Morris PG (2010) Comparison of functional connectivity in default mode and sensorimotor networks at 3 and 7T. Magn Reson Mater Phy 23(5–6):339–349

    Google Scholar 

  • Hall EL, Woolrich MW, Thomaz CE, Morris PG, Brookes MJ (2013) Using variance information in magnetoencephalography measures of functional connectivity. NeuroImage 67:203–212

    Google Scholar 

  • Hall SD, Barnes GR, Furlong PL, Seri S, Hillebrand A (2010) Neuronal network pharmacodynamics of GABAergic modulation in the human cortex determined using pharmaco-magnetoencephalography. Hum Brain Mapp 31(4):581–594

    Google Scholar 

  • Hall SD, Holliday IE, Hillebrand A, Singh KD, Furlong PL, Hadjipapas A, Barnes GR (2005) The missing link: analogous human and primate cortical gamma oscillations. NeuroImage 26(1):13–17

    Google Scholar 

  • Hämäläinen MS, Ilmoniemi RJ (1994) Interpreting magnetic fields of the brain: minimum norm estimates. Med Biol Eng Comput 32(1):35–42

    Google Scholar 

  • Harrison L, Penny WD, Friston K (2003) Multivariate autoregressive modeling of fMRI time series. NeuroImage 19(4):1477–1491

    Google Scholar 

  • Hipp JF, Hawellek DJ, Corbetta M, Siegel M, Engel AK (2012) Large-scale cortical correlation structure of spontaneous oscillatory activity. Nat Neurosci 15(6):884–890

    Google Scholar 

  • Ioannides AA, Liu LC, Kwapien J, Drozdz S, Streit M (2000) Coupling of regional activations in a human brain during an object and face affect recognition task. Hum Brain Mapp 11(2):77–92

    Google Scholar 

  • Jeong J, Gore JC, Peterson BS (2001) Mutual information analysis of the EEG in patients with Alzheimer’s disease. Clinical Neurophysiol: Off J Int Fed Clin Neurophysiol 112(5):827–835

    Google Scholar 

  • Jerbi K, Lachaux JP, N’Diaye K, Pantazis D, Leahy RM, Garnero L, Baillet S (2007) Coherent neural representation of hand speed in humans revealed by MEG imaging. Proc Natl Acad Sci USA 104(18):7676–7681

    Google Scholar 

  • Kaminski M, Liang H (2005) Causal influence: advances in neurosignal analysis. Crit Rev Biomed Eng 33(4):347–430

    Google Scholar 

  • Koch MA, Norris DG, Hund-Georgiadis M (2002) An investigation of functional and anatomical connectivity using magnetic resonance imaging. NeuroImage 16(1):241–250

    Google Scholar 

  • Koenig T, Studer D, Hubl D, Melie L, Strik WK (2005) Brain connectivity at different time-scales measured with EEG. Philos Trans R Soc Lond B Biol Sci 360(1457):1015–1023

    Google Scholar 

  • Kopell N, Ermentrout GB, Whittington MA, Traub RD (2000) Gamma rhythms and beta rhythms have different synchronization properties. Proc Natl Acad Sci USA 97(4):1867–1872

    Google Scholar 

  • Kopell N, Kramer MA, Malerba P, Whittington MA (2010) Are different rhythms good for different functions? Front Hum Neurosci 4:187

    Google Scholar 

  • Kujala J, Pammer K, Cornelissen P, Roebroeck A, Formisano E, Salmelin R (2007) Phase coupling in a cerebro-cerebellar network at 8–13 Hz during reading. Cereb Cortex 17(6):1476–1485

    Google Scholar 

  • Lachaux JP, Rodriguez E, Martinerie J, Varela FJ (1999) Measuring phase synchrony in brain signals. Hum Brain Mapp 8(4):194–208

    Google Scholar 

  • Leopold DA, Murayama Y, Logothetis NK (2003) Very slow activity fluctuations in monkey visual cortex: implications for functional brain imaging. Cereb Cortex 13(4):422–433

    Google Scholar 

  • Locatelli T, Cursi M, Liberati D, Franceschi M, Comi G (1998) EEG coherence in Alzheimer’s disease. Electroencephalogr Clin Neurophysiol 106(3):229–237

    Google Scholar 

  • Loughnan BL, Sebel PS, Thomas D, Rutherfoord CF, Rogers H (1987) Evoked potentials following diazepam or fentanyl. Anaesthesia 42(2):195–198

    Google Scholar 

  • Luckhoo H, Hale JR, Stokes MG, Nobre AC, Morris PG, Brookes MJ, Woolrich MW (2012) Inferring task-related networks using independent component analysis in magnetoencephalography. NeuroImage 62(1):530–541

    Google Scholar 

  • Maharajh K, Teale P, Rojas DC, Reite ML (2010) Fluctuation of gamma-band phase synchronization within the auditory cortex in schizophrenia. Clin Neurophysiol: Off J Int Fed Clin Neurophysiol 121(4):542–548

    Google Scholar 

  • Marreiros AC, Kiebel SJ, Friston KJ (2010) A dynamic causal model study of neuronal population dynamics. NeuroImage 51(1):91–101

    Google Scholar 

  • Marrelec G, Krainik A, Duffau H, Pelegrini-Issac M, Lehericy S, Doyon J, Benali H (2006) Partial correlation for functional brain interactivity investigation in functional MRI. NeuroImage 32(1):228–237

    Google Scholar 

  • Matsuzaki N, Juhasz C, Asano E (2013) Cortico-cortical evoked potentials and stimulation-elicited gamma activity preferentially propagate from lower- to higher-order visual areas. Clin Neurophysiol: Off J Int Fed Clin Neurophysiol 124(7):1290–1296

    Google Scholar 

  • Moran RJ, Stephan KE, Dolan RJ, Friston KJ (2011) Consistent spectral predictors for dynamic causal models of steady-state responses. NeuroImage 55(4):1694–1708

    Google Scholar 

  • Moran RJ, Stephan KE, Kiebel SJ, Rombach N, O’Connor WT, Murphy KJ, Reilly RB, Friston KJ (2008) Bayesian estimation of synaptic physiology from the spectral responses of neural masses. NeuroImage 42(1):272–284

    Google Scholar 

  • Moran RJ, Stephan KE, Seidenbecher T, Pape HC, Dolan RJ, Friston KJ (2009) Dynamic causal models of steady-state responses. NeuroImage 44(3):796–811

    Google Scholar 

  • Muthukumaraswamy SD, Edden RA, Jones DK, Swettenham JB, Singh KD (2009) Resting GABA concentration predicts peak gamma frequency and fMRI amplitude in response to visual stimulation in humans. Proc Natl Acad Sci USA 106(20):8356–8361

    Google Scholar 

  • Nir Y, Mukamel R, Dinstein I, Privman E, Harel M, Fisch L, Gelbard-Sagiv H, Kipervasser S, Andelman F, Neufeld MY, Kramer U, Arieli A, Fried I, Malach R (2008) Interhemispheric correlations of slow spontaneous neuronal fluctuations revealed in human sensory cortex. Nat Neurosci 11(9):1100–1108

    Google Scholar 

  • Nolte G, Bai O, Wheaton L, Mari Z, Vorbach S, Hallett M (2004) Identifying true brain interaction from EEG data using the imaginary part of coherency. Clin Neurophysiol: Off J Int Fed Clin Neurophysiol 115(10):2292–2307

    Google Scholar 

  • Nolte G, Ziehe A, Nikulin VV, Schlogl A, Kramer N, Brismar T, Muller KR (2008) Robustly estimating the flow direction of information in complex physical systems. Phys Rev Lett 100(23):234101

    Google Scholar 

  • Owen JP, Wipf DP, Attias HT, Sekihara K, Nagarajan SS (2012) Performance evaluation of the Champagne source reconstruction algorithm on simulated and real M/EEG data. NeuroImage 60(1):305–323

    Google Scholar 

  • Penny WD, Stephan KE, Mechelli A, Friston KJ (2004) Comparing dynamic causal models. NeuroImage 22(3):1157–1172

    Google Scholar 

  • Phillips WA, Silverstein SM (2003) Convergence of biological and psychological perspectives on cognitive coordination in schizophrenia. Behav Brain Sci 26(1):65–82; Discussion 82–137

    Google Scholar 

  • Restuccia D, Valeriani M, Grassi E, Gentili G, Mazza S, Tonali P, Mauguiere F (2002) Contribution of GABAergic cortical circuitry in shaping somatosensory evoked scalp responses: specific changes after single-dose administration of tiagabine. Clin Neurophysiol: Off J Int Fed Clin Neurophysiol 113(5):656–671

    Google Scholar 

  • Robinson S, Vrba J (1998) Functional neuroimaging by synthetic aperture magnetometry (SAM). In: Yoshimoto T, Kotani M, Kuriki S, Karibe H, Nakasato N (eds) Recent advances in biomagnetism. Tohoku University Press, Sendai, Japan, pp 302–305

    Google Scholar 

  • Rodriguez E, George N, Lachaux JP, Martinerie J, Renault B, Varela FJ (1999) Perception’s shadow: long-distance synchronization of human brain activity. Nature 397(6718):430–433

    Google Scholar 

  • Roelfsema PR, Engel AK, Konig P, Singer W (1997) Visuomotor integration is associated with zero time-lag synchronization among cortical areas. Nature 385(6612):157–161

    Google Scholar 

  • Roopun AK, Cunningham MO, Racca C, Alter K, Traub RD, Whittington MA (2008) Region-specific changes in gamma and beta2 rhythms in NMDA receptor dysfunction models of schizophrenia. Schizophr Bull 34(5):962–973

    Google Scholar 

  • Sakkalis V (2011) Review of advanced techniques for the estimation of brain connectivity measured with EEG/MEG. Comput Biol Med 41(12):1110–1117

    Google Scholar 

  • Schlögl A, Supp G (2006) Analyzing event-related EEG data with multivariate autoregressive parameters. Prog Brain Res 159:135–147

    Google Scholar 

  • Schnitzler A, Gross J (2005) Normal and pathological oscillatory communication in the brain. Nat Rev Neurosci 6(4):285–296

    Google Scholar 

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

    Google Scholar 

  • Scholvinck ML, Friston KJ, Rees G (2012) The influence of spontaneous activity on stimulus processing in primary visual cortex. NeuroImage 59(3):2700–2708

    Google Scholar 

  • Scholvinck ML, Leopold DA, Brookes MJ, Khader PH (2013) The contribution of electrophysiology to functional connectivity mapping. NeuroImage 80:297–306

    Google Scholar 

  • Sekihara K, Hild KE 2nd, Nagarajan SS (2006) A novel adaptive beamformer for MEG source reconstruction effective when large background brain activities exist. IEEE Trans Biomed Eng 53(9):1755–1764

    Google Scholar 

  • Sekihara K, Nagarajan SS, Poeppel D, Marantz A, Miyashita Y (2001) Reconstructing spatio-temporal activities of neural sources using an MEG vector beamformer technique. IEEE Trans Biomed Eng 48(7):760–771

    Google Scholar 

  • Shanahan M (2010) Metastable chimera states in community-structured oscillator networks. Chaos 20(1):013108

    MathSciNet  Google Scholar 

  • Singer W (1999) Neuronal synchrony: a versatile code for the definition of relations? Neuron 24(1):49–65, 111–125

    Google Scholar 

  • Singer W, Gray CM (1995) Visual feature integration and the temporal correlation hypothesis. Annu Rev Neurosci 18:555–586

    Google Scholar 

  • Singh KD, Barnes GR, Hillebrand A, Forde EM, Williams AL (2002) Task-related changes in cortical synchronization are spatially coincident with the hemodynamic response. NeuroImage 16(1):103–114

    Google Scholar 

  • Smith SM, Fox PT, Miller KL, Glahn DC, Fox PM, Mackay CE, Filippini N, Watkins KE, Toro R, Laird AR, Beckmann CF (2009) Correspondence of the brain’s functional architecture during activation and rest. Proc Natl Acad Sci USA 106(31):13040–13045

    Google Scholar 

  • Smith SM, Miller KL, Moeller S, Xu J, Auerbach EJ, Woolrich MW, Beckmann CF, Jenkinson M, Andersson J, Glasser MF, van Essen DC, Feinberg DA, Yacoub ES, Ugurbil K (2012) Temporally-independent functional modes of spontaneous brain activity. Proc Natl Acad Sci USA 109(8):3131–3136

    Google Scholar 

  • Smith SM, Miller KL, Salimi-Khorshidi G, Webster M, Beckmann CF, Nichols TE, Ramsey JD, Woolrich MW (2011) Network modelling methods for FMRI. NeuroImage 54(2):875–891

    Google Scholar 

  • Stam CJ, Nolte G, Daffertshofer A (2007) Phase lag index: assessment of functional connectivity from multi channel EEG and MEG with diminished bias from common sources. Hum Brain Mapp 28(11):1178–1193

    Google Scholar 

  • Stam CJ, van Dijk BW (2002) Synchronization likelihood: an unbiased measure of generalized synchronization in multivariate data sets. Physica D 163(3–4):236–251

    MATH  MathSciNet  Google Scholar 

  • Stephan KE, Weiskopf N, Drysdale PM, Robinson PA, Friston KJ (2007) Comparing hemodynamic models with DCM. NeuroImage 38(3):387–401

    Google Scholar 

  • Tass P, Rosenblum MG, Weule J, Kurths J, Pikovsky A, Volkmann J, Schnitzler A, Freund HJ (1998) Detection of n:m phase locking from noisy data: application to magnetoencephalography. Phys Rev Lett 81(15):3291–3294

    Google Scholar 

  • Towle VL, Carder RK, Khorasani L, Lindberg D (1999) Electrocorticographic coherence patterns. J Clin Neurophysiol 16(6):528–547

    Google Scholar 

  • Van de Ville D, Britz J, Michel CM (2010) EEG microstate sequences in healthy humans at rest reveal scale-free dynamics. Proc Natl Acad Sci USA 107(42):18179–18184

    Google Scholar 

  • Van Veen BD, vanDrongelen W, Yuchtman M, Suzuki A (1997) Localization of brain electrical activity via linearly constrained minimum variance spatial filtering. IEEE Trans Biomed Eng 44(9):867–880

    Google Scholar 

  • Varela F, Lachaux JP, Rodriguez E, Martinerie J (2001) The brainweb: phase synchronization and large-scale integration. Nat Rev Neurosci 2(4):229–239

    Google Scholar 

  • von Stein A, Chiang C, Konig P (2000) Top-down processing mediated by interareal synchronization. Proc Natl Acad Sci USA 97(26):14748–14753

    Google Scholar 

  • Wharton S, Bowtell R (2012) Fiber orientation-dependent white matter contrast in gradient echo MRI. Proc Natl Acad Sci USA 109(45):18559–18564

    Google Scholar 

  • Whittington MA, Traub RD, Jefferys JGR (1995) Synchronized oscillations in interneuron networks driven by metabotropic glutamate-receptor activation. Nature 373(6515):612–615

    Google Scholar 

  • Winterer G, Carver FW, Musso F, Mattay V, Weinberger DR, Coppola R (2007) Complex relationship between BOLD signal and synchronization/desynchronization of human brain MEG oscillations. Hum Brain Mapp 28(9):805–816

    Google Scholar 

  • Wise RG, Tracey I (2006) The role of fMRI in drug discovery. J Magn Reson Imaging 23(6):862–876

    Google Scholar 

  • Womelsdorf T, Schoffelen JM, Oostenveld R, Singer W, Desimone R, Engel AK, Fries P (2007) Modulation of neuronal interactions through neuronal synchronization. Science 316(5831):1609–1612

    Google Scholar 

  • Woolrich M, Hunt L, Groves A, Barnes G (2011) MEG beamforming using Bayesian PCA for adaptive data covariance matrix regularization. NeuroImage 57(4):1466–1479

    Google Scholar 

  • Woolrich MW, Baker A, Luckhoo H, Mohseni H, Barnes G, Brookes M, Rezek I (2013) Dynamic state allocation for MEG source reconstruction. NeuroImage 77:77–92

    Google Scholar 

  • Woolrich MW, Stephan KE (2013) Biophysical network models and the human connectome. NeuroImage 80:330–338

    Google Scholar 

  • Wyler AR, Ojemann GA, Lettich E, Ward AA (1984) Subdural Strip Electrodes for Localizing Epileptogenic Foci. J Neurosurg 60(6):1195–1200

    Google Scholar 

  • Zumer J, Stevenson C, Brookes M, Francis S, Morris P (2009) Deconvolved fMRI correlates with source-localised MEG as a function of neural frequency oscillation. In: Proceedings of the international society for magnetic resonance in medicine 2009, p 1672

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Matthew J. Brookes .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2014 Springer-Verlag Berlin Heidelberg

About this chapter

Cite this chapter

Brookes, M.J., Woolrich, M.W., Price, D. (2014). An Introduction to MEG Connectivity Measurements. In: Supek, S., Aine, C. (eds) Magnetoencephalography. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-33045-2_16

Download citation

  • DOI: https://doi.org/10.1007/978-3-642-33045-2_16

  • Published:

  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-642-33044-5

  • Online ISBN: 978-3-642-33045-2

  • eBook Packages: EngineeringEngineering (R0)

Publish with us

Policies and ethics