The Theory
Forty-hertz (40-Hz) oscillations are high-frequency gamma brainwaves generated by synchronized neural network activity. These oscillations appear to be attenuated in the brains of Alzheimer's disease (AD) patients.
Research pioneered by Tsai's group at MIT showed that 40-Hz sensory stimulation can induce gamma oscillations in the brain, which may:
- 1.Enhance glymphatic clearance - Increases astrocyte aquaporin-4 polarization, enhances arterial pulsatility, and dilates meningeal lymphatic vessels
- 2.Accelerate CSF flow - Promotes cerebrospinal fluid influx into brain tissue and efflux of interstitial fluid
- 3.Clear amyloid-beta - Enhanced fluid dynamics help remove Aβ proteins and other metabolic waste from the brain
PNAS 2026 Primate Study
A January 2026 study from the Kunming Institute of Zoology provided the first non-human primate evidence for 40-Hz auditory stimulation therapy. Published in the Proceedings of the National Academy of Sciences.
205%
Aβ42 increase in CSF
5+ weeks
Effect persistence
Subjects: Nine aged rhesus macaques (26-31 years) with naturally-developed amyloid plaques
Protocol: 1 hour of 40-Hz auditory stimulation daily for 7 consecutive days
Significance: Unlike rodent studies where effects disappeared after 7 days, the elevated Aβ levels in primates persisted for more than 5 weeks
Cognitive Enhancement
Gamma Waves & Peak Performance
Gamma oscillations (30-80 Hz) are associated with:
- Heightened focus
- Flow states
- Enhanced working memory
- Cross-brain communication
Exploratory Pilot Study
40-Hz entrainment improved mood, memory, and cognition, with participants showing mean cognitive score improvements from 75% to 85%.
View studyMIT GENUS Research
Gamma Entrainment Using Sensory Stimulation (GENUS) has shown benefits extending beyond Alzheimer's to general brain health.
Learn moreHow It May Enhance Focus
- 1.Neural synchronization increases across brain regions
- 2.Information binding improves - the brain more effectively combines sensory inputs
- 3.Attentional resources are enhanced for demanding tasks
- 4.Default mode network activity may decrease, reducing mind-wandering
Audio Modes
Click Train (PNAS Study Protocol)
Replicates the exact auditory stimulus parameters from the PNAS 2026 primate study: 1ms bursts of a 1kHz pure tone, repeated 40 times per second.
Best for: Research protocol replication, direct auditory stimulation
Click Train Pattern (1ms bursts at 40Hz)
1ms burst of 1kHz tone, repeated every 25ms (40 times per second)
Binaural Beats (Cognitive Enhancement)
Uses the psychoacoustic phenomenon of binaural beats. Two slightly different frequencies are played to each ear, and your brain perceives a "phantom" beat at the frequency difference.
Best for: Focus, flow states, meditation, cognitive enhancement
Binaural Beats Pattern (Headphones Required)
Your brain perceives the 40Hz difference between the two frequencies
Which Mode Should I Use?
References
Key Research Papers
- Wang et al. (2026). Long-term effects of forty-hertz auditory stimulation as a treatment of Alzheimer's disease. PNAS
- Carstensen et al. (2020). Gamma entrainment frequency affects mood, memory and cognition. BMC Neuroscience
- Shen et al. (2022). Cognitive tasks propagate neural entrainment in response to visual 40 Hz stimulation. Frontiers in Aging Neuroscience
- Iaccarino et al. (2016). Gamma frequency entrainment attenuates amyloid load and modifies microglia. Nature
Disclaimer: This app is for personal experimental use only. It is not a medical device and has not been evaluated by any regulatory agency. Do not use if you have epilepsy or other neurological conditions without consulting a healthcare professional.