Lessons learned from an fMRI-guided rTMS study on performance in a numerical Stroop task

• Published in: PloS one Vol. 19; no. 5; p. e0302660
• Main Authors: Beynel, Lysianne, Gura, Hannah, Rezaee, Zeynab, Ekpo, Ekaete C, Deng, Zhi-De, Joseph, Janet O, Taylor, Paul, Luber, Bruce, Lisanby, Sarah H
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 06-05-2024; Public Library of Science (PLoS)
• Subjects: Adult; Analysis; Biology and Life Sciences; Brain Mapping - methods; Cognition; Computational neuroscience; Decision making; Decision Making - physiology; Drift; Drift rate; Female; Functional magnetic resonance imaging; Humans; Intraparietal sulcus; Investigations; Magnetic brain stimulation; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Medical imaging; Medical research; Medicine and Health Sciences; Medicine, Experimental; Methods; Neuroimaging; Parietal Lobe - diagnostic imaging; Parietal Lobe - physiology; Reaction time; Reaction Time - physiology; Reaction time task; Research and Analysis Methods; Social Sciences; Stroop Test; Testing; Transcranial magnetic stimulation; Transcranial Magnetic Stimulation - methods; Young Adult; United States
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0302660

The Stroop task is a well-established tool to investigate the influence of competing visual categories on decision making. Neuroimaging as well as rTMS studies have demonstrated the involvement of parietal structures, particularly the intraparietal sulcus (IPS), in this task. Given its reliability, the numerical Stroop task was used to compare the effects of different TMS targeting approaches by Sack and colleagues (Sack AT 2009), who elegantly demonstrated the superiority of individualized fMRI targeting. We performed the present study to test whether fMRI-guided rTMS effects on numerical Stroop task performance could still be observed while using more advanced techniques that have emerged in the last decade (e.g., electrical sham, robotic coil holder system, etc.). To do so we used a traditional reaction time analysis and we performed, post-hoc, a more advanced comprehensive drift diffusion modeling approach. Fifteen participants performed the numerical Stroop task while active or sham 10 Hz rTMS was applied over the region of the right intraparietal sulcus (IPS) showing the strongest functional activation in the Incongruent > Congruent contrast. This target was determined based on individualized fMRI data collected during a separate session. Contrary to our assumption, the classical reaction time analysis did not show any superiority of active rTMS over sham, probably due to confounds such as potential cumulative rTMS effects, and the effect of practice. However, the modeling approach revealed a robust effect of rTMS on the drift rate variable, suggesting differential processing of congruent and incongruent properties in perceptual decision-making, and more generally, illustrating that more advanced computational analysis of performance can elucidate the effects of rTMS on the brain where simpler methods may not.