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> no shifting ... the shifting occurs because of the convolution by the > hrf, with FIR it is simply a series of stick functions > > Cyril > >> Dear SPMers, >> >> A quick --but crucial- question concerning FIR approach. >> >> Let's consider a time window of 18 seconds after stimulus onset, >> divided into 9 bins of 2 seconds each. If I look at activations >> related to BIN 1 (seconds 1-2) will I see: >> >> a.Activations related to seconds 1-2 after stimulus presentation in >> REAL terms >> >> b.Activations related to 4-5 seconds before stimulus onset. >> >> In other words, does the FIR model take the haemodynamic delay into >> account or just show what is going on in the brain without "shifting" >> time forward of 5-6 seconds? >> >> Sorry for the naïve question, but I did not find any clear reply (at >> least, it wasn't clear to me) in the forum. >> >> Thank you in advance for your help, >> >> Chiara >>