Theta-gamma transcranial alternating current stimulation
Theta-gamma transcranial alternating current stimulation has been studied in 3 papers since 2024: 3 trials in people. The newest paper, Apr 24, 2025: “Theta-gamma transcranial alternating current stimulation enhances ballistic motor performance in healthy young and older adults”.
3 papers study it9 findingsUpdated
“Despite no significant modulations in attention network efficiencies”
None of its findings points the other way.
- 2 independent labs in 2 countries
- Funders: Australian Research Council and 3 more
- 3 of 9 findings with company ties
- Human trial3
Studies in people
3 studies gave theta-gamma transcranial alternating current stimulation to people and measured what changed.
up: Improves ballistic motor performance
up: Increases motor evoked potentials
no change: Has no effect on short-interval intracortical inhibition
Trialyoung and older adults20 min
Older adults
Neurobiology of aging, Apr 24, 2025
no change: Has no effect on attention network efficiency
down: Impairs cognitive function
down: Impairs brain network connectivity
Randomized trial76 people55 to 8416-session
Older adults; during cognitive n-back training
Brain research, Mar 12, 2025
up: Improves motor skill acquisitionP < 0.001
up: Increases motor evoked potentialsP < 0.001
no change: Has no effect on short-interval intracortical inhibitionP = 0.40
Trial20 minutes
Older adults
bioRxiv (Cold Spring Harbor Laboratory), Oct 3, 2024
What did studies of Theta-gamma transcranial alternating current stimulation find?
7Studies of Theta-gamma transcranial alternating current stimulation measured 7 outcomes; the most studied are short-interval intracortical inhibition (2 studies), motor evoked potentials (2) and ballistic motor performance (1).
Short-interval intracortical inhibition
no changein humans2
2 studies
Short-interval intracortical inhibition
no changein humans2
Theta-gamma transcranial alternating current stimulation showed no clear effect on short-interval intracortical inhibition in humans.
“SICI did not vary between tACS sessions (P = 0.40)”
Human trial20 min
Neurobiology of aging
Theta-gamma transcranial alternating current stimulation showed no clear effect on short-interval intracortical inhibition in humans (P = 0.40).
“SICI did not vary between tACS sessions ( P = 0.40)”
Human trialprimary motor cortex20 minutes
bioRxiv (Cold Spring Harbor Laboratory)Preprint
Motor evoked potentials
upin humans2
2 studies
Motor evoked potentials
upin humans2
Theta-gamma transcranial alternating current stimulation increases motor evoked potentials in humans.
“Motor training was accompanied by greater MEP amplitudes with TG tACS compared to sham tACS in young and older adults (P < 0.001)”
Human trial20 min
Neurobiology of aging
Theta-gamma transcranial alternating current stimulation increases motor evoked potentials in humans (P < 0.001).
“Motor training was accompanied by greater MEP amplitudes with TG tACS compared to sham tACS in young and older adults ( P < 0.001)”
Human trialprimary motor cortex20 minutes
bioRxiv (Cold Spring Harbor Laboratory)Preprint
Ballistic motor performance
upin humans1
1 study
Ballistic motor performance
upin humans1
Theta-gamma transcranial alternating current stimulation improves ballistic motor performance in humans.
“TG tACS increased motor performance compared with sham tACS in young and older adults (P < 0.001)”
Human trial20 min
Neurobiology of aging
Brain network connectivity
downin humans1
1 study
Brain network connectivity
downin humans1
Theta-gamma transcranial alternating current stimulation impairs brain network connectivity in humans (post-intervention).
“active tACS disrupted network correlations post-intervention, particularly affecting the alerting network's interactions with the orienting and executive networks”
Human trialpost-interventionprefrontal cortex16-sessionn = 76
Theta-gamma tACS modulates attention network synchronization, not isolated network performance
Brain research
Cognitive function
downin humans1
1 study
Cognitive function
downin humans1
Theta-gamma transcranial alternating current stimulation impairs cognitive function in humans (compared to sham, during cognitive n-back training).
“active tACS negatively influenced overall reaction time (RT) improvements, resulting in poorer ANT performance compared to the sham group”
Human trialcompared to sham, during cognitive n-back trainingprefrontal cortex16-sessionn = 76
Theta-gamma tACS modulates attention network synchronization, not isolated network performance
Brain research
Attention network efficiency
no changein humans1
1 study
Attention network efficiency
no changein humans1
Theta-gamma transcranial alternating current stimulation showed no clear effect on attention network efficiency in humans during cognitive n-back training.
“Despite no significant modulations in attention network efficiencies”
Human trialduring cognitive n-back trainingprefrontal cortex16-sessionn = 76
Theta-gamma tACS modulates attention network synchronization, not isolated network performance
Brain research
Motor skill acquisition
upin humans1
1 study
Motor skill acquisition
upin humans1
Theta-gamma transcranial alternating current stimulation improves motor skill acquisition in humans (P < 0.001).
“TG tACS increased motor skill acquisition compared with sham tACS in young and older adults ( P < 0.001)”
Human trialprimary motor cortex20 minutes
bioRxiv (Cold Spring Harbor Laboratory)Preprint