title: Detection of cortical activation during averaged single trials of a cognitive task using functional magnetic resonance imaging.
abstract: Functional neuroimaging studies in human subjects using positron emission tomography or functional magnetic resonance imaging (fMRI) are typically conducted by collecting data over extended time periods that contain many similar trials of a task. Here methods for acquiring fMRI data from single trials of a cognitive task are reported. In experiment one, whole brain fMRI was used to reliably detect single-trial responses in a prefrontal region within single subjects. In experiment two, higher temporal sampling of a more limited spatial field was used to measure temporal offsets between regions. Activation maps produced solely from the single-trial data were comparable to those produced from blocked runs. These findings suggest that single-trial paradigms will be able to exploit the high temporal resolution of fMRI. Such paradigms will provide experimental flexibility and time-resolved data for individual brain regions on a trial-by-trial basis.
authors.affiliation: Department of Radiology, Massachusetts General Hospital Nuclear Magnetic Resonance Center, Charlestown 02129, USA. buckner@nmr.mgh.harvard.edu
authors.forename: R L
authors.initials: RL
authors.lastname: Buckner
authors.forename: P A
authors.initials: PA
authors.lastname: Bandettini
authors.forename: K M
authors.initials: KM
authors.lastname: O'Craven
authors.forename: R L
authors.initials: RL
authors.lastname: Savoy
authors.forename: S E
authors.initials: SE
authors.lastname: Petersen
authors.forename: M E
authors.initials: ME
authors.lastname: Raichle
authors.forename: B R
authors.initials: BR
authors.lastname: Rosen
mesh_terms: D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000502:physiology*; D019336:Cognitive Science; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male