TR in rest state fMRI

Dear colleagues I am beginner in rest state fMRI experiments, my question might look silly for you, I saw many rest fMRI protocols they mentioned that TR should not exceed 3000ms, is it technical issue or it has some relation to mechanism of the brain networking and MR signal, and what they mean by Default mode network shows up in resting fMRI as areas with temporally correlated baseline activity, 0.01 Hz < frequency < 0.08 Hz. thank you for your contribution.

Hi  abujamea,

TR that is larger 3000ms is not recommended when collecting fMRI data since the sampling rate will be too low to accurately capture hemodynamic responses.

what you are asking about the "default mode network" can be seen as operational defination of DMN. 

It seems that you need to read on some more fundmental material of the field (no offends). If you are interested, there are some courses that Dr. Chao-gan Yan released on this site teaching about resting state fMRI and data processing software, please see [here]. If you want to start with some more basic fMRI training, I recommend you read this book: Handbook of Functional MRI Analysis by Dr. Russell A. Poldrack. [Website of the book]( or watch these video: Training Course in fMRI [Website](


Hope these are helpful.


Thank you Yang soo much for your informative response. 

Sent from Samsung Mobile

-------- Original message --------
From: The R-fMRI Network
Date:10/09/2014 23:39 (GMT+03:00)
Subject: Re: [RFMRI] TR in rest state fMRI