Connectome Harmonics
Connectome Harmonics: A Harmonic Language of the Mind
What if the brain could be understood like music—each moment of thought, perception, or awareness composed from harmonically organised patterns? That question sparked the development of connectome harmonics, a framework I introduced with Isaac Donnelly and Joel Pearson in Nature Communications (2016), and later explored in more depth with Morten Kringelbach and Gustavo Deco in The Neuroscientist (2017).
At the heart of this framework is the idea that the brain’s structure—its intricate network of connections—gives rise to a set of harmonic wave patterns. Much like the harmonic waves that emerge within a musical instrument for different musical notes (different frequencies), connectome harmonics are spatial wave patterns—the “natural vibration modes” of the human brain. Instead of the shape of a violin or a drum, these patterns are defined by the particular architecture of the brain’s structural connectivty. By applying the mathematical tools of harmonic analysis to the human brain’s connectivity, we revealed a set of harmonic waves - connectome harmonics - that naturally self-organise via the interplay between excitatory and inhibitory brain activity. These connectome harmonics patterns form a new basis—a harmonic language—through which we can decode and represent brain activity.
The connectome harmonics are not abstract theoretical constructs but spatial modes that emerge naturally when the brain’s connectome is treated like a resonant system. Much like the vibrational modes of a musical instrument (corresponding to different musical notes), these harmonics provide a principled, frequency-specific set of elementary building blocks from which any pattern of brain activity can be composed.
One of the most exciting discoveries about connectome harmonics was that some of these harmonic patterns aligned with well-known functional brain networks, including the default mode network. This revealed a powerful link between structure and function: the brain’s anatomy supports a repertoire of harmonic wave patterns that shape, and perhaps constrain, the way brain activity unfolds.
More than just a visualization, connectome harmonics allow us to decompose the brain activity accomponying various differrent states of consicousness —from daily awake consciousness to deeply altered states—into their constituent harmonic components. We called this approach connectome harmonic decomposition. It enables us to track how different experiences—from waking states to psychedelic journeys and deep meditation—emerge through shifting combinations of these spatial frequencies.
This interdisciplinary work was made possible through collaborations with brilliant colleagues including Isaac Donnelly, Joel Pearson, Gustavo Deco, Morten Kringelbach, and many others who helped shape the mathematical, neuroscientific, and philosophical foundations of this framework. Inspired by nature’s own patterns—mandalas, snowflakes, pufferfish nests—connectome harmonics invite us to see the brain not just as an organ, but as an evolving, self-tuning instrument of experience, while revealing the deep harmonic structure beneath the complexity of the mind.
If you want to dive deeper, see the related publications below and watch the selected talks:
• Atasoy, S., Donnelly, I., & Pearson, J. (2016). Human brain networks function in connectome-specific harmonic waves. Nature communications, 7(1), 1-10. doi:10.1038/ncomms10340.
• Atasoy, S., Roseman, L., Kaelen, M., Kringelbach, M. L., Deco, G., & Carhart-Harris, R. L. (2017). Connectome-harmonic decomposition of human brain activity reveals dynamical repertoire re-organization under LSD. Scientific reports, 7(1), 1-18.
• Atasoy, S., Deco, G., Kringelbach, M. L., & Pearson, J. (2018). Harmonic brain modes: a unifying framework for linking space and time in brain dynamics. The Neuroscientist, 24(3), 277-293.
• Atasoy, S., Vohryzek, J., G. Deco, G., Carhart-Harris, R. L., Kringelbach, M. L. (2018). Common neural signatures of psychedelics: Frequency-specific energy changes and repertoire expansion revealed using connectome-harmonic decomposition. Progress in brain research, 242, 97-120.
• Atasoy, S., Deco, G., & Kringelbach, M. L. (2020). Harmonic waves as the fundamental principle underlying temporo-spatial dynamics of brain and mind. Comment on" Is temporo-spatial dynamics the" common currency" of brain and mind? In Quest of" Spatiotemporal Neuroscience"" Georg Northoff et al. Physics of life reviews, 33, 67-69.
• Luppi, A. I., Vohryzek, J., Kringelbach, M. L., Mediano, P. A. M., Craig, M. M., Adapa, R., Carhart-Harris,R. L., Roseman, L., Pappas, I., Peattie, A. R. D., Manktelow, A. E., Sahakian, B. J., Finoia, P., Williams, G., B., Allanson, J., Pickard, J. D., Menon, D. K., Atasoy, S. & Stamatakis, E. A. (2021). Distributed harmonic patterns of structure-function dependence orchestrate human consciousness. Communications biology, 6(1), 117.
