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Titolo:
The effect of sequence repeat time on auditory cortex stimulation during phonetic discrimination
Autore:
Shah, NJ; Steinhoff, S; Mirzazade, S; Zafiris, O; Grosse-Ruyken, ML; Jancke, L; Zilles, K;
Indirizzi:
KFA Julich GmbH, Forschungszentrum, Inst Med, D-52425 Julich, Germany KFA Julich GmbH Julich Germany D-52425 Inst Med, D-52425 Julich, Germany Univ Magdeburg, Inst Gen Psychol, D-39106 Magdeburg, Germany Univ Magdeburg Magdeburg Germany D-39106 hol, D-39106 Magdeburg, Germany
Titolo Testata:
NEUROIMAGE
fascicolo: 1, volume: 12, anno: 2000,
pagine: 100 - 108
SICI:
1053-8119(200007)12:1<100:TEOSRT>2.0.ZU;2-N
Fonte:
ISI
Lingua:
ENG
Soggetto:
EVENT-RELATED FMRI; ACOUSTIC NOISE; FUNCTIONAL MRI; CORTICAL ACTIVATION; BRAIN; ATTENTION; SYSTEMS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
44
Recensione:
Indirizzi per estratti:
Indirizzo: Shah, NJ KFA Julich GmbH, Forschungszentrum, Inst Med, Postfach 1913, D-52425 Julich, Germany KFA Julich GmbH Postfach 1913 Julich Germany D-52425 ch, Germany
Citazione:
N.J. Shah et al., "The effect of sequence repeat time on auditory cortex stimulation during phonetic discrimination", NEUROIMAGE, 12(1), 2000, pp. 100-108

Abstract

Acoustic noise generated by the MR scanner gradient system during fMRI studies of auditory function is a very significant potential confound. Despitethese deleterious effects, fMRI of the auditory cortex has been successfuland 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 scanneris 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 a for a 16-slice acquisition. (C) 2000 Academic Press.

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Documento generato il 06/04/20 alle ore 01:53:47