>Simply create T-contrasts for [1 0 -1 0] (canonical: before - after) and
> [0 1 0 -1]
>(derivative: before - after) and enter the resulting contrast images into
> a (two-way)
>ANOVA (no constant term; no within subject effects), and evaluate the F-
> contrast
>for the effects of interest.
] Rik,
]
] Should one do the sphericity correction, a la "Random Effects Analyses
] with Multiple Basis Functions Per Subject" (Henson and Penny)?
Yes indeed - sorry I forgot the mention this - because the two basis functions
are likely to be correlated (over subjects) and are very likely to have different
scalings and hence variances (compare the size of typical betas).
Rik
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Dr Richard Henson
MRC Cognition & Brain Sciences Unit
15 Chaucer Road
Cambridge
CB2 2EF, UK
Tel: +44 (0)1223 355 294 x522
Fax: +44 (0)1223 359 062
http://www.mrc-cbu.cam.ac.uk/~rik.henson
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