Is the brain the largest unexplored territory in longevity?

Two companies thought so and announced a sensor on your head this month:

-> Atlas Mankind:
> US$499 plus US$30 monthly subscription to track a signal (EEG) the field already accepts.
> Benchmarks against a US$30k lab rig, then ship. 500k+ brain recordings and counting.

-> Temple:
> US$900 (rumoured), no subscriptions to track a signal they've created: "Entropy".
> First validation study released yesterday - the first public evidence that a consumer device can watch the brain's blood flow instead of guessing from the pulse.

So far, consumer wearables have been (mostly) measuring the heart to infer everything. Meanwhile healthspan is decided in the brain: Cognitive decline builds silently for 15 to 20 years, and almost nobody is measuring it.

The brain is getting studied now because it's the last major organ without a continuous vital sign. The heart got ECG and PPG on the wrist, glucose got CGMs etc, and those proxies alone built the wearables industry to what it is today.

But, dont get too excited, as both products are early.

-> Temple must prove the number is real:
> Peer review, then independent replication in older, sicker bodies, not 23 healthy ones
> Published evidence for 'Entropy', the metric on the box. Today: none

-> Atlas must prove the habit is real:
> still worn at month 12. EEG is accepted; retention is not
> a US$30 monthly interpretation people don't cancel

Finally, I know there's many more out there.. So please share: What projects and studies in this space have genuinely excited you?

I'm Jean-Baptiste Roy, building Seveno Capital . I write about where the next biomarker gets validated, and who gets paid for it.