Dear SPM members,
in our paradigm we presented a very short (100ms) auditory stimulus. Activation of the auditory cortex can be seen in some sessions, but not in others. We think that this might be caused by a suboptimal slice timing.
We measured 32 interleaved slices in an ascending order. As reference slice we used slice 31 which is from a temporal perspective in the middle of the acquisiton phase, from a spatial perspective almost at top of the brain. Does anyone know how we best have to choose microtime time resolution and onset during the specification process of the statistical model? Since the auditory stimulus is very short (100 ms) compared to the TR (2 s), the default values might be bad choice.
Regards,
Henrike
--
Der GMX SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen!
Ideal für Modem und ISDN: http://www.gmx.net/de/go/smartsurfer
|