Evaluating an acoustically quiet EPI sequence for use in fMRI studies of speech and auditory processing

Jonathan E. Peelle, Rowena J. Eason, Sebastian Schmitter, Christian Schwarzbauer, Matthew H. Davis

Research output: Contribution to journalArticle

47 Scopus citations

Abstract

Echoplanar MRI is associated with significant acoustic noise, which can interfere with the presentation of auditory stimuli, create a more challenging listening environment, and increase discomfort felt by participants. Here we investigate a scanning sequence that significantly reduces the amplitude of acoustic noise associated with echoplanar imaging (EPI). This is accomplished using a constant phase encoding gradient and a sinusoidal readout echo train to produce a narrow-band acoustic frequency spectrum, which is adapted to the scanner's frequency response function by choosing an optimum gradient switching frequency. To evaluate the effect of these nonstandard parameters we conducted a speech experiment comparing four different EPI sequences: Quiet, Sparse, Standard, and Matched Standard (using the same readout duration as Quiet). For each sequence participants listened to sentences and signal-correlated noise (SCN), which provides an unintelligible amplitude-matched control condition. We used BOLD sensitivity maps to quantify sensitivity loss caused by the longer EPI readout duration used in the Quiet and Matched Standard EPI sequences. We found that the Quiet sequence provided more robust activation for SCN in primary auditory areas and comparable activation in frontal and temporal regions for Sentences >SCN, but less sentence-related activity in inferotemporal cortex. The increased listening effort associated with the louder Standard sequence relative to the Quiet sequence resulted in increased activation in the left temporal and inferior parietal cortices. Together, these results suggest that the Quiet sequence is suitable, and perhaps preferable, for many auditory studies. However, its applicability depends on the specific brain regions of interest.

Original languageEnglish
Pages (from-to)1410-1419
Number of pages10
JournalNeuroImage
Volume52
Issue number4
DOIs
StatePublished - Oct 1 2010
Externally publishedYes

Keywords

  • BOLD sensitivity
  • Listening effort
  • Quiet EPI
  • Sparse imaging

Fingerprint Dive into the research topics of 'Evaluating an acoustically quiet EPI sequence for use in fMRI studies of speech and auditory processing'. Together they form a unique fingerprint.

  • Cite this