Dear Karsten,Thank you so much for your kind and insightful thoughts."As you observed correctly, the movement within a session looks almost okay to me. "That's good to hear. However, my biggest concern is that monotonically increasing head movement with scanning time, which seems to me that the subject kept moving her head towards a certain direction. As a result, the motion parameter estimates become quite large by the end of each session. This problem also presents in another experimental data of ours. I tried registering the images to the mean image instead of the 1st image but it didn't improve much. Is it a rare and serious problem? If so, is there a way to tackle it?
"I guess you haven't entered the sessions not in a chronological order, isn't it?"I entered the sessions in chronological order in accordance with the timing of our data acquisition, i.e. (Run1 Run2 Run 3...) Will there be improvement if I do it differently?
"Was it a block design, you have used?"We used a fast ER design.P.S. According to your expertise, what are the acceptible maximum within-session head movements?
Many thanks and Best regards,
Ce
----- 原始邮件 -----
发件人:Karsten Specht <[log in to unmask]>
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主题:Re: [SPM] Weird excessive head movement in realigning multiple sessions
日期:2013年05月23日 00点32分