Individualized single-session iTBS modulates functional networks and neural activation to predict cognitive gain

Area of Science:

• Neuroscience
• Cognitive Science
• Neuroimaging

Background:

• Intermittent theta burst stimulation (iTBS) targeting the dorsolateral prefrontal cortex (DLPFC) is a promising non-invasive brain stimulation technique for cognitive enhancement.
• Previous studies show inconsistent behavioral findings, potentially due to methodological limitations and lack of individualized targeting.
• The impact of iTBS on resting-state functional networks and its relationship with individual variability remain underexplored.

Purpose of the Study:

• To investigate the effects of individualized iTBS on cognitive performance and functional brain networks using fMRI.
• To explore the role of individual variability in neural responsiveness to iTBS.
• To examine how iTBS modulates neural activity and functional connectivity during a cognitive task.

Main Methods:

• Utilized fMRI during an N-back task to identify individualized left DLPFC stimulation targets.
• Randomly assigned 56 healthy participants to receive active or sham iTBS.
• Acquired resting-state and task-based fMRI data before and after stimulation.

Main Results:

• Active iTBS increased neural activity in the middle cingulate cortex (MCC) and calcarine cortex during a 3-back task compared to sham.
• iTBS modulated functional connectivity (FC), increasing target-insula FC and decreasing default mode network (DMN) FC.
• Enhanced MCC activation and target-insula FC correlated with faster reaction times, while DMN FC reduction correlated with improved accuracy.

Conclusions:

• Individualized iTBS effectively modulates neural activity and distributed functional networks to support cognitive improvement.
• The effects are particularly pronounced in individuals with lower baseline cognitive abilities.
• These findings support the potential of individualized iTBS for personalized cognitive interventions.