title: Time-course of the auditory BOLD response to scanner noise.
abstract: It is a concern for auditory fMRI studies that acoustic noise generated by the scanner produces an auditory response that can confound stimulus-induced activation. To establish how to minimize this problem, the present study mapped the time-course of the auditory response to a burst of acoustic scanner noise by employing a single-event method. Recorded bursts of scanner noise were interspersed with clustered-volume acquisitions at a range of stimulus-to-imaging delays to map the response with a temporal resolution of 1 sec. There were strong responses (1.5% signal change) to scanner noise in primary and secondary auditory cortex. In both cortical areas, the mean response rose to a peak by 4-5 sec after stimulus onset and decayed after a further 5-8 sec. The time course indicates that noise contamination in auditory fMRI can be substantially reduced by using a 9-12-sec repetition time, thus maximizing the dynamic range available for displaying the response to acoustical stimuli of interest.
authors.affiliation: MRC Institute of Hearing Research, University Park, Nottingham, UK.
authors.forename: D A
authors.initials: DA
authors.lastname: Hall
authors.forename: A Q
authors.initials: AQ
authors.lastname: Summerfield
authors.forename: M S
authors.initials: MS
authors.lastname: Gonçalves
authors.forename: J R
authors.initials: JR
authors.lastname: Foster
authors.forename: A R
authors.initials: AR
authors.lastname: Palmer
authors.forename: R W
authors.initials: RW
authors.lastname: Bowtell
mesh_terms: D000328:Adult; D016477:Artifacts; D001309:Auditory Threshold / Q000502:physiology*; D017352:Echo-Planar Imaging / Q000009:adverse effects* / Q000295:instrumentation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D011930:Reaction Time; D015203:Reproducibility of Results