Dear Dolores,
there are many ways to achieve quiet periods in a scan, most scanners
allow you to do so either by providing an externel trigger signal that
starts the acquisition of a volume at a time or by
setting up the sequence so that all slices are being acquired at the
beginning of a longer TR and the remaining time is silent.
Many authors have published papers with this methodology, here is just one
example:
Haslinger et al.
"Silent event-related" fMRI reveals reduced sensorimotor activation in
laryngeal dystonia.
Neurology. 2005 Nov 22;65(10):1562-9.
Best
Peter
On Tue, 13 Nov 2007, dolores ma wrote:
>
> We are working on an fMRI experiment presenting auditory stimuli. We would like to time the cycle of the presentation so that the magnet comes on immediately after that, to avoid presentation in noise. Is there a way to do so or a way to lower the magnet noise?
> thank you in advance,Dolores
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