Luna,

I do not understand entirely your question.

In principle, you build your experiment as you normally would do for a behavioral psychological experiment, with the addition of jittering (a random addition between say 1-2 seconds) in the inter trial/stimulus intervals for better estimation of the BOLD function.

In SPM, you determine for each condition a regressor with as onset times of the stimulus onsets in each condition, and the duration of the stimulus (which you can interpret as a single peak, hence duration = 0; or for the whole length of the stimulus, hence duration = 2 s)

I hope this answers your question,

Frank

Van: SPM (Statistical Parametric Mapping) <[log in to unmask]> Namens Luna Sato
Verzonden: woensdag 27 maart 2024 20:38
Aan: [log in to unmask]
Onderwerp: [SPM] How to determine the optimal stimulus sequence for a slow-event fMRI experiment?

Hi all,

In my experiment, there are six conditions belong to two independent variables (2x3).

We are interested into the interaction effect of 2x3 ANOVA on activation (beta values) of six conditions.

A slow event design will be used: each event lasting two seconds, with intervals between events ranging from 8 to 14 seconds. Each session comprises 32 events.

Are there any tools or MATLAB codes available to help determine the best stimulus sequence for this slow event design?

Thank you!

Best,

Luna