Neurofeedback training (NFT) is gaining attention as a noninvasive method to teach the brain how to regulate its own activity. Through real-time EEG feedback, people can learn to modify certain brain rhythms linked to focus, relaxation, or emotional balance. A recent pilot study published in Psychophysiology explored whether pairing olfactory learning and neurofeedback training could enhance relaxation and memory by reactivating brain patterns during sleep.
Understanding Neurofeedback and SMR Training
In neurofeedback, individuals view visual or auditory cues that reflect their brainwave activity. When they produce desirable brainwave patterns, such as the sensorimotor rhythm (SMR) — a frequency associated with calm alertness — they receive positive feedback. Over time, this process can help improve concentration, reduce stress, and support better sleep quality.
In this study, researchers focused on SMR training, comparing it to random-frequency feedback. They aimed to see whether adding olfactory cues (specific scents linked to the training experience) and reintroducing those scents during sleep could help reinforce brain learning, similar to how certain smells can trigger memories.
The Role of Olfactory Reactivation During Sleep
Memory reactivation during sleep is a fascinating area of neuroscience. Studies show that when sensory cues — like smells — are presented during certain sleep stages, they can strengthen learning and memory consolidation.
In the experiment, participants trained in neurofeedback over two weeks and spent several nights in a sleep lab. Some participants were exposed to scent cues associated with their neurofeedback sessions while they slept. Researchers measured EEG activity and sleep quality across sessions, checking whether the combination of olfactory learning and neurofeedback training produced lasting effects.
Key Findings from the Study
While immediate effects on neurofeedback performance were modest, intriguing patterns emerged. The SMR groups, especially those with olfactory reactivation, showed trends toward improved sleep efficiency and higher alpha activity — markers linked to relaxation and stable wakefulness.
At a 10-month follow-up, participants in the SMR plus olfactory reactivation condition performed best, suggesting that sleep-based reactivation might strengthen long-term neurofeedback learning. This points to the brain’s potential to consolidate training effects beyond the waking state, much like how athletes’ skills improve after rest.
Why This Matters for Interventional Psychiatry
Although preliminary, these findings highlight how combining neurofeedback with sensory cues could open new pathways for personalized mental health interventions. Neurofeedback is already being explored for insomnia, ADHD, anxiety, and depression. Enhancing it through sleep-based memory reactivation could deepen its therapeutic impact.
Future research may expand this method by testing different scents, longer training durations, or patient populations with psychiatric conditions. If confirmed, this approach could lead to new integrative treatments — blending brain-computer training, sleep science, and sensory therapy — to improve mental health and cognitive function.
The Road Ahead
As interventional psychiatry continues to evolve, combining traditional and novel techniques is key. This pilot study offers an early glimpse into how olfactory learning and neurofeedback training might converge to help people achieve better sleep, relaxation, and self-regulation. It’s a reminder that even subtle sensory experiences — like smell — can play powerful roles in how the brain learns, heals, and adapts.
Citations
- Lechinger, J., Newe, C., Nadler, S., et al. (2025). Effects of olfactory learning context reactivation during sleep on training success in a double-blind randomized controlled sensorimotor rhythm neurofeedback protocol: A pilot study. Psychophysiology. https://onlinelibrary.wiley.com/doi/10.1111/psyp.70154
- Bar, E., Marmelshtein, A., Arzi, A., et al. (2020). Local targeted memory reactivation in human sleep. Current Biology, 30(8), 1435–1446. https://doi.org/10.1016/j.cub.2020.02.057