As my first PhD proj I’m v happy to finally share our findings with the world! It’s been a ride, and I am immensely grateful to the tireless @jwvogel.bsky.social for putting up with me + our team for all support: DeMON lab (@xiaoyucaly.bsky.social ‪@anlijuncn.bsky.social‬ and ppl not here)

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Why does this happen?

We hypothesize that the reason for these divergent patterns may be due to the brain trying to compensate for compromised cognitive function

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Why does this matter?

Because these gradient-aligned FC alterations were also strongly related to cognitive function – independently of age or AD

They could be signals of cognitive strain

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Importantly, we see longitudinal increase in AD pathology leading to similar FC patterns

Using a sliding window approach in the longitudinal subsample, we also replicate the non-linear pattern seen above

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Much work has pointed to FC increasing in early AD only to later decline

Using non-linear modelling we show that gradient-alignment seems to follow a similar trajectory: alignment happens early in the disease only to later decline

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We found that age and AD systematically alter FC across the entire cortex

These changes aligned w axes of brain organization which reflect core principles of cortical function:

🔹 Age → executive–nonexecutive axis (Gradient 3)
🔹 AD → sensory–association axis (Gradient 1)

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Prior studies of FC in age and AD have reported both hyper- and hypo-connectivity across different regions and networks, sometimes in discrepancy with one another

We took a broader view and examined these changes from the lens of large scale functional organization (gradients)

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How does the brain reorganize in the context of age and AD?

Are functional changes in age and AD similar?

Are these changes dynamic across the age/AD spectrum?

We unpack these questions in a sample of N=973 with AD biomarkers

Preprint: tinyurl.com/ymv8s7h8

⬇️🧵

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