help > RE: Strong connections at high thresholds
May 2, 2018  11:05 PM | Andrew Zalesky
RE: Strong connections at high thresholds
Hi Katerina,

Yes - this is correct. You can use a t-test to assess the group x time interaction. For the contrast, you should place a 1 or -1 in the interaction column and 0s everywhere else. Depending how you have coded your design matrix, a significant result with 1 in the contrast vector means greater connectivity in group 1 at time 2, whereas -1 means greater connectivity in group 2 at time 2.

Andrew


Originally posted by hex_dex:
Dear Andrew,

thank you very much for your response. I will perform one of the checks described and see how it goes. Until then, may I ask you something else... Can I run a t-test with 1 in the column corresponding to time by group difference and the rest 0s and detect this way if the null hypothesis exists? I do that and I get significant results when I use 1 but no significant ones with -1. Does this mean that the connectivity is higher in the group 1 than group -1?


Thank you very much,
Katerina

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hex_dex Apr 28, 2018
hex_dex May 3, 2018
Andrew Zalesky Apr 29, 2018
hex_dex Apr 30, 2018
RE: Strong connections at high thresholds
Andrew Zalesky May 2, 2018
hex_dex Apr 28, 2018
hex_dex Apr 28, 2018