Webinar Review: The functional connectome across spatiotemporal scales

Our trainees review webinars in their given fields and share abstracts to help colleagues outside their discipline make an informed choice about watching them. As our program bridges diverse disciplines, these abstracts are beneficial for our own group in helping one another gain key knowledge in each other’s fields. We are happy to share these here for anyone else who may find them helpful.

The functional connectome across spatiotemporal scales: How integrating fMRI and (i)EEG changes our understanding of the human brain

Sepideh Sadaghiani, PhD, Psychology

03/05/2021

Beckman Institute

Summary and Analysis by Charles Marchini:

This webinar discusses the similarities and connections between fMRI and intracranial EEG (iEEG) data. The spatial relationship of the connectome shows how the brain is organized across space after averaging through time. The temporal relationship is how the brain activation changes through time. fMRI is more informative of the where (spatial relationship) and iEEG is more informative of the when (temporal relationship).

During the finger tapping task, the motor cortex regions corresponding to the fingers and the supplementary motor area are activated. During resting state, those same regions are also connected to each other by cross talking to each other. This is true for other connectivity networks as well. After looking at the correlation between all the connectivity networks, we can build a connectivity matrix (connectome). fMRI measures a signal that is a combination of many things including blood flow and the concentration of oxygenated to deoxygenated hemoglobin. Intracranial iEEG measurements are taken by inserting electrodes onto the surface of the brain to obtain functional information by measuring the electrical signals.

There is a moderate correlation between fMRI and iEEG data, which shows that fMRI is measuring more than vascular noise. But there is also a difference between the two signals, which shows that fMRI is measuring a different type of brain activity than iEEG. This webinar could be a good resource for anyone looking into how to measure functional brain activity and trying to figure out which tools are the best for what they’re trying to accomplish.