Single-trial analysis of oddball event-related potentials in simultaneous EEG-fMRI.
There has recently been a growing interest in the use of simultaneous electroencephalography (EEG) and functional MRI (fMRI) for evoked activity in cognitive paradigms, thereby obtaining functional datasets with both high spatial and temporal resolution. The simultaneous recording permits obtaining event-related potentials (ERPs) and MR images in the same environment, conditions of stimulation, and subject state; it also enables tracing the joint fluctuations of EEG and fMRI signals. The goal of this study was to investigate the possibility of tracking the trial-to-trial changes in event-related EEG activity, and of using this information as a parameter in fMRI analysis. We used an auditory oddball paradigm and obtained single-trial amplitude and latency features from the EEG acquired during fMRI scanning. The single-trial P300 latency presented significant correlation with parameters external to the EEG (target-to-target interval and reaction time). Moreover, we obtained significant fMRI activations for the modulation by P300 amplitude and latency, both at the single-subject and at the group level. Our results indicate that, in line with other studies, the EEG can bring a new dimension to the field of fMRI analysis by providing fine temporal information on the fluctuations in brain activity.
Bénar
Christian-G
CG
CNRS IFR131, Centre d'IRMf de Marseille, Marseille, France. Christian.benar@medecine.univ-mrs.fr
Schön
Daniele
D
Grimault
Stephan
S
Nazarian
Bruno
B
Burle
Boris
B
Roth
Muriel
M
Badier
Jean-Michel
JM
Marquis
Patrick
P
Liegeois-Chauvel
Catherine
C
Anton
Jean-Luc
JL
D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000502:physiology*; D001931:Brain Mapping; D004192:Discrimination, Psychological / Q000502:physiology; D004569:Electroencephalography; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D011930:Reaction Time / Q000502:physiology; D013997:Time Factors
D010100:Oxygen