Brandon Munn
banner
bmunn.bsky.social
Brandon Munn
@bmunn.bsky.social
Firstgen postdoc at USYD | Bit of physics and neuroscience 🔬 | I make very ordinary science papers; please, whatever you do, don't read them 📖
I can try! The brain is made of MANY cells creating everything that is us. When we look at a cell it seems to work very smart but independent yet when we look at all the cells they seem to work together + very safely. It seems cells interconnect in a complex ordered way that achieves both benefits!
December 30, 2024 at 9:13 PM
Thank you Linden!!
a man with long hair and a beard is smiling and saying thank you .
ALT: a man with long hair and a beard is smiling and saying thank you .
media.tenor.com
December 23, 2024 at 4:32 AM
Thank you for the interest!

shine-lab.org/wp-content/u...
shine-lab.org
December 19, 2024 at 9:17 AM
If you're collecting cool data and think this approach could be helpful to you or interested in the work, please reach out!

The code is all on GitHub. github.com/Bmunn/ICG

And, importantly, thank you to all the labs doing open science, permitting some Aussie scientists to test our crazy theories!
a man stands in front of a crowd with the words are you not entertained
ALT: a man stands in front of a crowd with the words are you not entertained
media.tenor.com
December 18, 2024 at 2:02 PM
Summary:

We found a conserved multiscale organisation trades-off efficient and resilient information processing regimes (spanning 1 billion years of phylogenetic diversity) and behaviourally functional neuronal reconfigurations, that are linked to the underlying structure.
a man in a suit and tie with the words pretty cool on the bottom right
ALT: a man in a suit and tie with the words pretty cool on the bottom right
media.tenor.com
December 18, 2024 at 2:02 PM
Finally, we showed how iterative coarse-graining (ICG) can identify informative neuronal reconfigurations related to task dynamics in the zebrafish.

I bet this approach will be helpful for future behavioural studies!
December 18, 2024 at 2:02 PM
These task induced zebrafish reconfigurations are most flexible and informative at the mesoscale (thousands of cells).

Interestingly, mice showed two distinct peaks of reconfiguration at the micro- and mesoscales, supporting the theory of multiple scale-dependent information processing streams.
December 18, 2024 at 2:02 PM
Not done there, we explored beyond rest into behaviour and found conserved static scaling but evidence of a privileged temporal scale in zebrafish aligned with the stimuli.

That is, a multiscale organisation permits flexibility to adapt to behaviourally relevant timescales.
December 18, 2024 at 2:02 PM
The few multiscale networks that recapitulated the diverging info theory regimes/nonGaussianity also revealed more beneficial features such as maximising dynamic range and communicability.
December 18, 2024 at 2:02 PM
Contrasting MANY network null models, we found that only hierarchical modular networks could controllably change the slope and reproduce the empirical static and dynamic scaling

Though geometric networks worked well up to a scale dependence. See some related recent Aussie work by Pang et al 2023
December 18, 2024 at 2:02 PM
We wanted to understand the origin of this scaling.

The C. elegans recordings contained tagged cells and a known anatomical connectivity, which let us show cross-scale functional pairings were far more likely if the cells had a physical connection.

That is multiscale structure and function!
December 18, 2024 at 2:02 PM
This multiscale organisation also provides a functional dial to operate across varying timescales!

Again, with a conserved slope (despite the noisier measure), from sparse and fast activity at the cellular scale to more continuous fluctuations at the macroscale.
December 18, 2024 at 2:02 PM
How could this pluralistic information capacity emerge?

We found evidence for a precise self-similar coordination consistent across species (invertebrates, fish, mammals) and balanced between two extremes (identical/independent).

This was unique against various nulls!
December 18, 2024 at 2:02 PM
We discovered a divergence in redundant information capacity at coarser scales.

This shows that the cellular scale is optimised for efficiency, while coarser ensembles support resiliency. This mirrored a shift from heavy-tailed to Gaussian correlation distributions.
December 18, 2024 at 2:02 PM
We opted for a Kadanoff iterative coarse-graining approach among the growing multiscale techniques. This was dyadic (maximal log spread), comparable to standard analyses (correlations), and fast. Letting me track activity across scales

Crazily, I applied this to as many species as possible!
December 18, 2024 at 2:02 PM
Mac, being the fantastic boss he is, let me pursue an initially very 'physicsy' project and listened to my unhinged arguments about how straight lines on logarithmic axes, particularly their subtle changes can have significant functional implications for this question.
a man in a blue shirt and tie is smoking a cigarette in front of a wall of papers .
ALT: a man in a blue shirt and tie is smoking a cigarette in front of a wall of papers .
media.tenor.com
December 18, 2024 at 2:02 PM
Inspired by multiscale analyses, I wanted to understand how both a macroscale/systems framework arguing for a resilient “population code” and a cellular/microscale perspective favouring a minimal redundant/efficient neuronal code can both simultaneously be consistent in neural data.
December 18, 2024 at 2:02 PM
When I began working with Mac, we had “strong discussions” about how the brain coordinates activity to process information. Our different perspectives and starting points of macroscale vs. microscale, led to assumptions and predictions that didn’t always align.
a baby is playing with a yellow toy that has a star in it
ALT: a baby is playing with a yellow toy that has a star in it
media.tenor.com
December 18, 2024 at 2:02 PM
This combines all the science I love physics, info theory, modelling, and multiple species to understand what makes the brain so special!

It’s been cooking for the past four years, and only possible with the dream team

@macshine.bsky.social
@drbreaky.bsky.social and co!
a close up of a man 's face with the words houston we have a dream team on it
ALT: a close up of a man 's face with the words houston we have a dream team on it
media.tenor.com
December 18, 2024 at 2:02 PM
Reposted by Brandon Munn
We were able to detect the slow-down of neural dynamics by adapting a measure that @macshine.bsky.social Brandon Munn and team developed for assessing energy landscapes in fMRI data (itself building on work by Bill Bialek) to use with our Neuropixels data. www.nature.com/articles/s41...
The ascending arousal system shapes neural dynamics to mediate awareness of cognitive states - Nature Communications
Models of brain organisation can overlook the role of the autonomic nervous system in cognitive processes. Here the authors show a link between the ascending arousal system and both low dimensional ne...
www.nature.com
December 17, 2024 at 10:51 AM