A comparison of five fMRI protocols for mapping speech comprehension systems. Epilepsia 2008 Dec;49(12):1980-97
Date
06/03/2008Pubmed ID
18513352Pubmed Central ID
PMC2645716DOI
10.1111/j.1528-1167.2008.01683.xScopus ID
2-s2.0-57449091098 (requires institutional sign-in at Scopus site) 165 CitationsAbstract
AIMS: Many fMRI protocols for localizing speech comprehension have been described, but there has been little quantitative comparison of these methods. We compared five such protocols in terms of areas activated, extent of activation, and lateralization.
METHODS: fMRI BOLD signals were measured in 26 healthy adults during passive listening and active tasks using words and tones. Contrasts were designed to identify speech perception and semantic processing systems. Activation extent and lateralization were quantified by counting activated voxels in each hemisphere for each participant.
RESULTS: Passive listening to words produced bilateral superior temporal activation. After controlling for prelinguistic auditory processing, only a small area in the left superior temporal sulcus responded selectively to speech. Active tasks engaged an extensive, bilateral attention, and executive processing network. Optimal results (consistent activation and strongly lateralized pattern) were obtained by contrasting an active semantic decision task with a tone decision task. There was striking similarity between the network of brain regions activated by the semantic task and the network of brain regions that showed task-induced deactivation, suggesting that semantic processing occurs during the resting state.
CONCLUSIONS: fMRI protocols for mapping speech comprehension systems differ dramatically in pattern, extent, and lateralization of activation. Brain regions involved in semantic processing were identified only when an active, nonlinguistic task was used as a baseline, supporting the notion that semantic processing occurs whenever attentional resources are not controlled. Identification of these lexical-semantic regions is particularly important for predicting language outcome in patients undergoing temporal lobe surgery.
Author List
Binder JR, Swanson SJ, Hammeke TA, Sabsevitz DSAuthors
Jeffrey R. Binder MD Professor in the Neurology department at Medical College of WisconsinThomas Hammeke PhD, MS Emeritus Professor in the Psychiatry and Behavioral Medicine department at Medical College of Wisconsin
Sara J. Swanson PhD Chief, Professor in the Neurology department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
Acoustic StimulationAdolescent
Adult
Analysis of Variance
Brain Mapping
Cerebral Cortex
Comprehension
Computer-Assisted Instruction
Decision Making
Female
Functional Laterality
Humans
Male
Oxygen
Psycholinguistics
Semantics
Speech
Speech Perception
Young Adult
