Open AccessEvent‐related fMRI of tasks involving brief motion
Author(s) -
Birn Rasmus M.,
Bandettini Peter A.,
Cox Robert W.,
Shaker Reza
Publication year - 1999
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/(sici)1097-0193(1999)7:2<106::aid-hbm4>3.0.co;2-o
Subject(s) - functional magnetic resonance imaging , stimulus (psychology) , neuroscience , haemodynamic response , psychology , blood oxygenation , artifact (error) , brain activity and meditation , brain mapping , electroencephalography , cognitive psychology , medicine , heart rate , blood pressure , radiology
The assessment of brain function by blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) for tasks involving motion near the field of view is compromised by artifacts arising from the motion. The aim of this study is to demonstrate that these artifacts can be reduced by acquiring the average response from a brief stimulus (a “single‐trial,” or “event‐related,” paradigm) as opposed to alternating blocks of repeated task with rest (a “block‐trial” paradigm). The basis of this technique is that the NMR signal changes from neuronal activation are delayed relative to the motion due to a slow hemodynamic response. By acquiring the average response from a brief stimulus, motion‐induced signal changes occur prior to neuronal activation‐induced signal changes, and the two can thus be distinguished. This technique is applied to the tasks of speaking out loud, swallowing, jaw clenching, and tongue movement. Functional activation maps derived from the single‐trial paradigm contain significantly less artifact than functional activation maps derived from a more traditional block‐trial paradigm. Hum. Brain Mapping 7:106–114, 1999. © 1999 Wiley‐Liss, Inc.