Hi, I'm new to using this amazing toolbox, and I would greatly appreciate some help.
I am currently conducting a longitudinal DTI study involving two time points: pre and post-treatment. I utilized NBS to examine the differences between the pre and post measurements for 14 subjects using repeated measures and exchange block analyses. Through this analysis, the toolbox discovered a network that exhibited significant differences. My ultimate goal is to provide results and interpretations at the individual subject level. Is there a method in NBS to perform a significance test on a single subject with only two time points? Additionally, can I leverage the group results to draw conclusions about individual subjects?
Thank you for all your assistance!
Best regards,
Batel
Hi Batel,
The NBS is desgined for group level inference. Performing inference on a single subject is difficult because variance of the measure is difficult to define. However, you could investigate how far the subject's measurement is positioned from the mean of the group. This can provide insight into individual subjects and how far they deviate from the mean. You would need to write some code the perform this kind of investigation - it is not directly available in the NBS.
best wishes and thanks for your support,
andrew
Originally posted by batel:
Hi, I'm new to using this amazing toolbox, and I would greatly appreciate some help.
I am currently conducting a longitudinal DTI study involving two time points: pre and post-treatment. I utilized NBS to examine the differences between the pre and post measurements for 14 subjects using repeated measures and exchange block analyses. Through this analysis, the toolbox discovered a network that exhibited significant differences. My ultimate goal is to provide results and interpretations at the individual subject level. Is there a method in NBS to perform a significance test on a single subject with only two time points? Additionally, can I leverage the group results to draw conclusions about individual subjects?
Thank you for all your assistance!
Best regards,
Batel
Thanks, Andrew, for the fast response!
When you mention 'how far from the mean of the group,' I would like to clarify which measurement you are referring to. The group analysis provided information about significant differences in brain connectivity across various brain areas. It's not simply based on FA or the number of fibers originating from a single ROI. Instead, it involves multiple brain areas. I would greatly appreciate it if you could provide more details and elaborate on this concept.
Thank you so much!
Batel
Hi Batel,
you may want to consider some of the literature on normative modelling:
https://pubmed.ncbi.nlm.nih.gov/31201374/
https://pubmed.ncbi.nlm.nih.gov/26927419/
The deviation measurement that I refer to is not available as part of ther NBS. The NBS is for group-level inference. It is not for single-subject inference.
best,
Andrew
Originally posted by batel:
Thanks, Andrew, for the fast response!
When you mention 'how far from the mean of the group,' I would like to clarify which measurement you are referring to. The group analysis provided information about significant differences in brain connectivity across various brain areas. It's not simply based on FA or the number of fibers originating from a single ROI. Instead, it involves multiple brain areas. I would greatly appreciate it if you could provide more details and elaborate on this concept.
Thank you so much!
Batel