Journal: eNeuro (Apr 2023)
Authors: Gaby S. Pell, Yiftach Roth, Hamutal Shachar, Moshe Isserles, Noam Barnea-Ygael, and Abraham Zangen
In previous studies investigating cognitive processes using transcranial magnetic stimulation (TMS), researchers have explored responses to various stimulation parameters, such as frequency and coil location. This study aims to introduce an additional parameter by leveraging the spatial profiles of TMS coils to infer regional information related to reward-related behavior. Different TMS coils were employed to modulate activity in the prefrontal cortex (PFC), with a focus on examining resulting changes in behavior and associated brain activity. Specifically, the Figure-8 coil was used to stimulate a portion of the dorsolateral PFC (DLPFC), while the H-Coil was utilized to stimulate a larger volume within the lateral PFC (LPFC).
Healthy human volunteers completed behavioral questionnaires (n = 29) or engaged in a reward-related decision-making functional MRI (fMRI) task (n = 21) immediately before and after acute high-frequency stimulation (10 Hz) with either a Figure-8 coil, H-Coil, or a sham coil.
Stimulation induced behavioral changes and alterations in brain activation within key nodes of the reward network. Notably, right LPFC stimulation, but not right DLPFC or sham stimulation, resulted in changes in both behavioral scores and brain activation within crucial nodes of the reward system.
In conclusion, this study supports the involvement of the right LPFC in reward-related behavior and suggests that the pathways generating these effects are situated outside the traditional DLPFC area targeted with TMS. These findings highlight the informative use of TMS coils with different spatial profiles in investigating the anatomical and functional correlates of behavior.