Stimulation priming and psychological state shape functional connectivity following prefrontal theta-burst...

Area of Science:

• Neuroscience
• Neuromodulation
• Cognitive Science

Background:

• Intermittent theta-burst stimulation (iTBS) modulates prefrontal cortex (e.g., DLPFC) excitability.
• High response variability and modest clinical efficacy limit iTBS application.
• Theta-burst stimulation (TBS) priming aims to enhance efficacy and reduce variability, but neurobiological effects are unclear.

Purpose of the Study:

• Investigate the effects of TBS priming on resting-state functional connectivity.
• Examine how different priming protocols (iTBS-iTBS, cTBS-iTBS) influence connectivity compared to iTBS alone.
• Assess the interaction between TBS priming, connectivity changes, and psychological states like perseverative thinking.

Main Methods:

• Within-subjects study with 47 healthy participants.
• Four counterbalanced sessions: sham-sham, iTBS alone, iTBS-iTBS priming, cTBS-iTBS priming.
• Resting-state fMRI acquired before and after each condition.
• Assessed self-reported mood and perseverative thinking.

Main Results:

• cTBS-iTBS priming reduced connectivity changes near stimulation and in temporal areas.
• iTBS-iTBS priming reduced prefrontal connectivity changes compared to iTBS alone.
• Increased perseverative thinking correlated with decreased left prefrontal connectivity after cTBS-iTBS priming.

Conclusions:

• Prefrontal TBS priming exerts complex effects on functional connectivity.
• Connectivity changes are dependent on the priming protocol and stimulation intensity.
• Psychological states interact with neuromodulation, emphasizing the need to consider state dependency.