Imperial College London
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Dr Karl (Gus) Zimmerman

Faculty of Medicine, Department of Brain Sciences

Research Associate
 
 
 
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Contact

 

karl.zimmerman11 Website

 
 
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Location

 

Sir Michael Uren HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Kurtin:2021:10.1016/j.brs.2021.08.004,
author = {Kurtin, DL and Violante, IR and Zimmerman, K and Leech, R and Hampshire, A and Patel, MC and Carmichael, DW and Sharp, DJ and Li, LM},
doi = {10.1016/j.brs.2021.08.004},
journal = {Brain Stimulation},
pages = {1261--1270},
title = {Investigating the interaction between white matter and brain state on tDCS-induced changes in brain network activity},
url = {http://dx.doi.org/10.1016/j.brs.2021.08.004},
volume = {14},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - BACKGROUND: Transcranial direct current stimulation (tDCS) is a form of noninvasive brain stimulation whose potential as a cognitive therapy is hindered by our limited understanding of how participant and experimental factors influence its effects. Using functional MRI to study brain networks, we have previously shown in healthy controls that the physiological effects of tDCS are strongly influenced by brain state. We have additionally shown, in both healthy and traumatic brain injury (TBI) populations, that the behavioral effects of tDCS are positively correlated with white matter (WM) structure. OBJECTIVES: In this study we investigate how these two factors, WM structure and brain state, interact to shape the effect of tDCS on brain network activity. METHODS: We applied anodal, cathodal and sham tDCS to the right inferior frontal gyrus (rIFG) of healthy (n=22) and TBI participants (n=34). We used the Choice Reaction Task (CRT) performance to manipulate brain state during tDCS. We acquired simultaneous fMRI to assess activity of cognitive brain networks and used Fractional Anisotropy (FA) as a measure of WM structure. RESULTS: We find that the effects of tDCS on brain network activity in TBI participants are highly dependent on brain state, replicating findings from our previous healthy control study in a separate, patient cohort. We then show that WM structure further modulates the brain-state dependent effects of tDCS on brain network activity. These effects are not unidirectional - in the absence of task with anodal and cathodal tDCS, FA is positively correlated with brain activity in several regions of the default mode network. Conversely, with cathodal tDCS during CRT performance, FA is negatively correlated with brain activity in a salience network region. CONCLUSIONS: Our results show that experimental and participant factors interact to have unexpected effects on brain network activity, and that these effects are not fully predictable by studying the fa
AU  - Kurtin,DL
AU  - Violante,IR
AU  - Zimmerman,K
AU  - Leech,R
AU  - Hampshire,A
AU  - Patel,MC
AU  - Carmichael,DW
AU  - Sharp,DJ
AU  - Li,LM
DO  - 10.1016/j.brs.2021.08.004
EP  - 1270
PY  - 2021///
SN  - 1876-4754
SP  - 1261
TI  - Investigating the interaction between white matter and brain state on tDCS-induced changes in brain network activity
T2  - Brain Stimulation
UR  - http://dx.doi.org/10.1016/j.brs.2021.08.004
UR  - https://www.ncbi.nlm.nih.gov/pubmed/34438046
UR  - http://hdl.handle.net/10044/1/91452
VL  - 14
ER  -
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