Summary
DISORDERS
In this study, we sought to understand how varying received doses of transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique, influence brain function as measured by functional magnetic resonance imaging (fMRI). We explored this "dose-response" relationship in participants with methamphetamine use disorders, using them as a representative clinical sample. Leveraging computational models based on individual MRI scans, we predicted cortical electric fields (EFs) as indicators of the received stimulation dose for each participant. Our study aimed to uncover the relationship between these EFs and changes in brain function at various levels: from individual brain locations (voxels) to broader network connections. While no significant correlation emerged between EFs and brain activity when focusing on individual voxels, specific regions of interest, or clusters, a notable correlation was observed at the broader network level, particularly between EFs and the frontoparietal connectivity during drug cue exposure. These results suggest that the effects of tDCS might be more effectively understood by examining wider brain networks rather than just individual points or regions. This research sheds light on the potential of individualized treatment plans using tDCS, underscoring the significance of comprehending its impact on interconnected brain networks.