thanks Jon,
i didn't know that a simple block design analysis is possible to compute the visual area boundaries... (which is the reason why I tried to fit it into the standard sfa-sess analysis)... could you explain me (shortly) what to do than with my data
regards, Lars.
-design info: 8hz flickering checkerbords, 20 scans at horizontal meridian, 20 scans vertical..x10 repetitions...
Jonathan Polimeni schrieb:
hi lars,
the FSFast retinotopy analysis stream is geared towards temporal phase encoded data analysis, which produces field sign maps that can be used to define area boundaries.
if you opt to use stationary wedge stimuli to activate the horizontal and vertical meridian representations in visual cortex rather than the traditional phase encoding stimulus paradigm, since the vertical and horizontal meridian representations also lie along area boundaries, you can identify them in your data through a standard block design paradigm analysis. this is straightforward but outside the retinotopy stream. instead you can use 'mkanalysis-sess' and 'selxavg3-sess' as described on the fswiki.
of course it is possible to interpret your periodic stimulus as temporally phase encoded and run the usual frequency analysis (i.e., 'sfa-sess'), but i think that the block design analysis is more appropriate for your data.
hope this helps!
-jon
Lars Kuchinke, PhD Freie Universität Berlin Allgemeine Psychologie Habelschwerdter Allee 45 14195 Berlin
kuchinke@zedat.fu-berlin.de www.fu-berlin.de/allgpsy Tel: 030 838 55776