Abstract
We investigated the spatial correspondence between functional MRI (fMRI) activations and cortical current density maps of event-related potentials (ERPs) reconstructed without fMRI priors. The presence of a significant spatial correspondence is a prerequisite for direct integration of the two modalities, enabling to combine the high spatial resolution of fMRI with the high temporal resolution of ERPs. Four separate tasks were employed: visual stimulation with a pattern-reversal chequerboard, recognition of images of nameable objects, recognition of written words, and auditory stimulation with a piano note. ERPs were acquired with 19 recording channels, and source localisation was performed using a realistic head model, a standard cortical mesh and the multiple sparse priors method. Spatial correspondence was evaluated at group level over 10 subjects, by means of a voxel-by-voxel test and a test on the distribution of local maxima. Although not complete, it was significant for the visual stimulation task, image and word recognition tasks (P < 0.001 for both types of test), but not for the auditory stimulation task. These findings indicate that partial but significant spatial correspondence between the two modalities can be found even with a small number of channels, for three of the four tasks employed. Absence of correspondence for the auditory stimulation task was caused by the unfavourable situation of the activated cortex being perpendicular to the overlying scalp, whose consequences were exacerbated by the small number of channels. The present study corroborates existing literature in this field, and may be of particular relevance to those interested in combining fMRI with ERPs acquired with the standard 10-20 system.
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Barnikol UB, Amunts K, Dammers J, Mohlberg H, Fieseler T, Malikovic A, Zilles K, Niedeggen M, Tass PA (2006) Pattern reversal visual evoked responses of V1/V2 and V5/MT as revealed by MEG combined with probabilistic cytoarchitectonic maps. NeuroImage 31:86–108
Bledowski C, Prvulovic D, Hoechstetter K, Scherg M, Wibral M, Goebel R, Linden DE (2004) Localizing P300 generators in visual target and distractor processing: a combined event-related potential and functional magnetic resonance imaging study. J␣Neurosci 24:9353–9360
Boynton GM, Engel SA, Glover GH, Heeger DJ (1996) Linear systems analysis of functional magnetic resonance imaging in human V1. J Neurosci 16:4207–4221
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 39:1104–1120
Gore JC, Horovitz SG, Cannistraci CJ, Skudlarski P (2006) Integration of fMRI, NIROT and ERP for studies of human brain function. Magn Reson Imag 24:507–513
Grova C, Daunizeau J, Lina JM, Bénar CG, Benali H, Gotman J (2006) Evaluation of EEG localization methods using realistic simulations of interictal spikes. NeuroImage 29:734–753
Halgren E, Dhond RP, Christensen N, Van Petten C, Marinkovic K, Lewine JD, Dale AM (2002) N400-like magnetoencephalography responses modulated by semantic context, word frequency, and lexical class in sentences. NeuroImage 17:1101–1116
Handwerker DA, Ollinger JM, D’Esposito M (2004) Variation of BOLD hemodynamic responses across subjects and brain regions and their effects on statistical analyses. NeuroImage 21:1639–1651
Huotilainen M, Winkler I, Alho K, Escera C, Virtanen J, Ilmoniemi RJ, Jääskeläinen IP, Pekkonen E, Näätänen R (1998) Combined mapping of human auditory EEG and MEG responses. Electroencephalogr Clin Neurophysiol 108:370–379
Kelley WM, Miezin FM, McDermott KB, Buckner RL, Raichle ME, Cohen NJ, Ollinger JM, Akbudak E, Conturo TE, Snyder AZ, Petersen SE (1998) Hemispheric specialization in human dorsal frontal cortex and medial temporal lobe for verbal and nonverbal memory encoding. Neuron 20:927–936
Khateb A, Pegna AJ, Michel CM, Landis T, Annoni JM (2002) Dynamics of brain activation during an explicit word and image recognition task: an electrophysiological study. Brain Topogr 14:197–213
Liu Z, He B (2008) fMRI-EEG integrated cortical source imaging by use of time-variant spatial constraints. NeuroImage 39:1198–1214
Logothetis NK, Pfeuffer J (2004) On the nature of the BOLD fMRI contrast mechanism. Magn Reson Imag 22:1517–1531
Michel CM, Murray MM, Lantz G, Gonzalez S, Spinelli L, Grave de Peralta R (2004) EEG source imaging. Clin Neurophysiol 115:2195–2222
Mulert C, Jaeger L, Schmitt R, Bussfeld P, Pogarell O, Moeller HJ, Juckel G, Hegerl U (2004) Integration of fMRI and simultaneous EEG: towards a comprehensive understanding of localization and time-course of brain activity in target detection. NeuroImage 22:83–94
Mulert C, Jäger L, Propp S, Karch S, Störmann S, Pogarell O, Möller HJ, Juckel G, Hegerl U (2005) Sound level dependence of the primary auditory cortex: simultaneous measurement with 61-channel EEG and fMRI. NeuroImage 28:49–58
Regan D (1989) Human brain electrophysiology: evoked potentials and evoked magnetic fields in science and medicine. Elsevier, New York
Seghier ML (2008) Laterality index in functional MRI: methodological issues. Magn Reson Imag 26:594–601
Shahin AJ, Roberts LE, Miller LM, McDonald KL, Alain C (2007) Sensitivity of EEG and MEG to the N1 and P2 auditory evoked responses modulated by spectral complexity of sounds. Brain Topogr 20:55–61
Shigeto H, Tobimatsu S, Yamamoto T, Kobayashi T, Kato M (1998) Visual evoked cortical magnetic responses to checkerboard pattern reversal stimulation: a study on the neural generators of N75, P100 and N145. J Neurol Sci 156:186–194
Shmuel A, Augath M, Oeltermann A, Logothetis NK (2006) Negative functional MRI response correlates with decreases in neuronal activity in monkey visual area V1. Nat Neurosci 9:569–577
Sommer M, Meinhardt J, Volz HP (2003) Combined measurement of event-related potentials (ERPs) and fMRI. Acta Neurobiol Exp 63:49–53
Spinnler H, Tognoni G (1987) Standardizzazione e taratura italiana di test neuropsicologici. Ital J Neurol Sci 8:S1–S120
Takeda Y, Yamanaka K, Yamamoto Y (2008) Temporal decomposition of EEG during a simple reaction time task into stimulus- and response-locked components. NeuroImage 39:742–754
Vanni S, Warnking J, Dojat M, Delon-Martin C, Bullier J, Segebarth C (2004) Sequence of pattern onset responses in the human visual areas: an fMRI constrained VEP source analysis. NeuroImage 21:801–817
Vitacco D, Brandeis D, Pascual-Marqui R, Martin E (2002) Correspondence of event-related potential tomography and functional magnetic resonance imaging during language processing. Hum Brain Mapp 17:4–12
Whittingstall K, Stroink G, Schmidt M (2007) Evaluating the spatial relationship of event-related potential and functional MRI sources in the primary visual cortex. Hum Brain Mapp 28:134–142
Zaehle T, Jancke L, Meyer M (2007) Electrical brain imaging evidences left auditory cortex involvement in speech and non-speech discrimination based on temporal features. Behav Brain Funct 3:63
Acknowledgment
The authors would like to thank two anonymous reviewers for insightful suggestions. C. Rosazza was supported by the Marie Curie Research and Training Network: Language and Brain (RTN:LAB) funded by the European Commission.
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Minati, L., Rosazza, C., Zucca, I. et al. Spatial Correspondence Between Functional MRI (fMRI) Activations and Cortical Current Density Maps of Event-Related Potentials (ERP): A Study with Four Tasks. Brain Topogr 21, 112–127 (2008). https://doi.org/10.1007/s10548-008-0064-3
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DOI: https://doi.org/10.1007/s10548-008-0064-3