TY  - JOUR
AU  - Shah, J. N.
AU  - Steinhoff, S.
AU  - Mirzazade, S.
AU  - Zafiris, O.
AU  - Grosse-Ruyken, M. L.
AU  - Jäncke, R. K.
AU  - Zilles, K.
TI  - The effect of sequence repeat time on auditory cortex stimulation during phonetic discrimination
JO  - NeuroImage
VL  - 12
SN  - 1053-8119
CY  - Orlando, Fla.
PB  - Academic Press
M1  - PreJuSER-56237
SP  - 100 - 108
PY  - 2000
N1  - Record converted from VDB: 12.11.2012
AB  - Acoustic noise generated by the MR scanner gradient system during fMRI studies of auditory function is a very significant potential confound. Despite these deleterious effects, fMRI of the auditory cortex has been successful and numerous practitioners have circumvented the problem of acoustic masking noise. In the context of auditory cortex fMRI, the sequence repeat time (TR) has the effect of altering the length of time during which the scanner is quiet. Indeed, the move to whole-brain fMRI makes the problem of acoustic noise more acute and points to the need to examine the role of TR and its influence on the BOLD signal. The aim of this study was to examine the effect of varying the TR time on activation of auditory cortex during presentation and performance of a phonetic discrimination task. The results presented here demonstrate that the influence of sequence repeat time is considerable. For a short repeat time it is likely that the noise from the scanner is a significant mask and hinders accurate task performance. At the other extreme, a repeat time of 9 s is also suboptimal, probably due to attentional effects and lack of concentration and not least because of the longer overall measurement times. The results of this study point to a complicated interplay between psychophysical factors as well as physical parameters; attention, acoustic noise, total duration of the experiment, consideration of the volume of acquisition, and overall difficulty of the task have to be assessed and balanced. For the paradigm used here, the results suggest an optimal TR of around 6 s for a 16-slice acquisition.
KW  - Artifacts
KW  - Auditory Cortex: physiology
KW  - Discrimination (Psychology): physiology
KW  - Humans
KW  - Magnetic Resonance Imaging: instrumentation
KW  - Male
KW  - Noise
KW  - Perceptual Masking
KW  - Phonetics
KW  - Time Factors
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:10875906
UR  - <Go to ISI:>//WOS:000088317700010
DO  - DOI:10.1006/nimg.2000.0588
UR  - https://juser.fz-juelich.de/record/56237
ER  -