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Multimodal imaging of repetition priming: Using fMRI, MEG, and intracranial EEG to reveal spatiotemporal profiles of word processing. Neuroimage 2010 Nov 01;53(2):707-17

Date

07/14/2010

Pubmed ID

20620212

Pubmed Central ID

PMC2930128

DOI

10.1016/j.neuroimage.2010.06.069

Scopus ID

2-s2.0-77956060829   65 Citations

Abstract

Repetition priming is a core feature of memory processing whose anatomical correlates remain poorly understood. In this study, we use advanced multimodal imaging (functional magnetic resonance imaging (fMRI) and magnetoencephalography; MEG) to investigate the spatiotemporal profile of repetition priming. We use intracranial electroencephalography (iEEG) to validate our fMRI/MEG measurements. Twelve controls completed a semantic judgment task with fMRI and MEG that included words presented once (new, 'N') and words that repeated (old, 'O'). Six patients with epilepsy completed the same task during iEEG recordings. Blood-oxygen level dependent (BOLD) responses for N vs. O words were examined across the cortical surface and within regions of interest. MEG waveforms for N vs. O words were estimated using a noise-normalized minimum norm solution, and used to interpret the timecourse of fMRI. Spatial concordance was observed between fMRI and MEG repetition effects from 350 to 450 ms within bilateral occipitotemporal and medial temporal, left prefrontal, and left posterior temporal cortex. Additionally, MEG revealed widespread sources within left temporoparietal regions, whereas fMRI revealed bilateral reductions in occipitotemporal and left superior frontal, and increases in inferior parietal, precuneus, and dorsolateral prefrontal activity. BOLD suppression in left posterior temporal, left inferior prefrontal, and right occipitotemporal cortex correlated with MEG repetition-related reductions. IEEG responses from all three regions supported the timecourse of MEG and localization of fMRI. Furthermore, iEEG decreases to repeated words were associated with decreased gamma power in several regions, providing evidence that gamma oscillations are tightly coupled to cognitive phenomena and reflect regional activations seen in the BOLD signal.

Author List

McDonald CR, Thesen T, Carlson C, Blumberg M, Girard HM, Trongnetrpunya A, Sherfey JS, Devinsky O, Kuzniecky R, Dolye WK, Cash SS, Leonard MK, Hagler DJ Jr, Dale AM, Halgren E

Author

Chad Carlson MD Professor in the Neurology department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Adolescent
Adult
Cerebral Cortex
Cues
Data Interpretation, Statistical
Decision Making
Electroencephalography
Epilepsy
Evoked Potentials
Female
Functional Laterality
Humans
Image Processing, Computer-Assisted
Language
Magnetic Resonance Imaging
Magnetoencephalography
Male
Mental Processes
Middle Aged
Reading
Reproducibility of Results
Semantics
Young Adult