Hi Martin,

Thanks for the reply.

What are the units of the B matrix values? Is an increase of 1.7 units considered a strong increase?

My second question was with regards to comparing two different conditions where there is no clear baseline. The way I understand it, in this type of set up, you use a design matrix of [-1 1] instead of [0 1] to model the difference between the two conditions. In the [-1 1] design, the “baseline” is created by averaging the activity in the two conditions and the same modulation factor is subtracted from the baseline connections to model the first condition, and added to the baseline connections to model the second condition (this is from Litvak et al, EEG and MEG Data Analysis in SPM8, 2011). My question would be what exactly does a B matrix value of 1.7 from AàB signify now.

1)      The coupling strength of 1.7 is subtracted from that particular baseline connection to fit condition 1; and 1.7 is added to that same baseline connection to model condition 2?

2)      Or would it mean that 0.85 is subtracted from baseline to fit condition 1, and 0.85 is added to baseline to fit condition 2; and therefore the difference between the two conditions is modeled by an increase of 1.7 units of coupling strength?

Thanks,

Vivek

Hi Vivek,
 

no, it means, connectivity (or coupling strength) increases by 1.7.

i am not sure, what you mean

Best,
Martin


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