Transcranial temporal interference stimulation (tTIS) influences event-related alpha activity during mental rotation

Area of Science:

• Neuroscience
• Cognitive Science
• Neuromodulation

Background:

• Non-invasive brain stimulation techniques are promising for neurological and psychiatric disorders.
• Current methods face limitations in stimulation depth, hindering access to deeper brain regions.
• Transcranial temporal interference stimulation (tTIS) is a novel technique designed to target deeper brain areas non-invasively.

Purpose of the Study:

• To evaluate the efficacy of tTIS in modulating alpha activity during a mental rotation task.
• To compare the effects of tTIS with transcranial alternating current stimulation (tACS) and a sham control.
• To assess the impact of tTIS and tACS on resting state alpha power, event-related desynchronization (ERD), and behavioral performance.

Main Methods:

• Participants were randomly assigned to tTIS, tACS, or sham groups.
• Stimulation (20 min) was adjusted to individual alpha frequency (IAF) during alternating resting and mental rotation tasks.
• Measurements included resting state alpha power, alpha ERD during mental rotation, and behavioral performance.

Main Results:

• Both tTIS and tACS effectively modulated cortical alpha activity during mental rotation, increasing ERD compared to sham.
• This increase in ERD was not correlated with improvements in mental rotation performance.
• Resting state alpha power remained unchanged across all groups.

Conclusions:

• tTIS and tACS can modulate cortical activity during cognitive tasks, evidenced by increased ERD.
• The observed modulation of brain activity did not translate to enhanced behavioral performance in the mental rotation task.
• The efficacy of tTIS and tACS appears more pronounced during active cognitive engagement than on resting neuronal systems, highlighting the complexity of their effects.