アイテム詳細

要旨

Semantic cognition is central to communication and our understanding of the world. It is usually well preserved in healthy aging. However, semantic control processes, which guide semantic access and retrieval, decline with age. The present study explored the potential of intermittent theta burst stimulation (iTBS) to enhance semantic cognition in healthy middle-aged to older adults. Using an individualized stimulation approach, we applied iTBS to the pre-supplementary motor area (pre-SMA) and assessed task-specific effects on semantic judgments in functional neuroimaging. We found increased activation after effective relative to sham stimulation only for the semantic task in visual and dorsal attention networks. Further, iTBS increased functional connectivity in domain-general executive networks. Notably, stimulation-induced changes in activation and connectivity related differently to behavior: While increased activation of the parietal dorsal attention network was linked to poorer semantic performance, its enhanced coupling with the pre-SMA was associated with more efficient semantic processing. Our findings indicate differential effects of iTBS on activity and connectivity. We show that iTBS modulates networks in a task-dependent manner and generates remote network effects. Stimulating the pre-SMA was linked to more efficient but not better performance, indicating a role in domain-general semantic control processes distinct to domain-specific semantic control.