Fly connectome demos aren't what they seem: Beat Saber video is overfit replay, real RL not done yet
dotey · x · 2026-09-10
dotey debunks the viral "fly brain playing Beat Saber" video: the motion output is a model overfit to pre-recorded sequences and replayed—no real vision or RL yet, and the connectome is a static wiring diagram.
Key facts:
- On Sep 3, HHMI Janelia, Google Research, and Cambridge published the complete male fly CNS connectome in Cell: 166,700 neurons and 125M synapses, the largest full brain map, covering brain plus ventral nerve cord, CC-BY open-sourced.
- Two days after release, Georgia Tech grad student Evan Smith fit all neurons into Minecraft using GPT-6 Astra; Beat Saber, Mario 64, and Doom demos followed.
- Real finding: comparing male vs female connectomes at synapse precision, only 4.8% of neurons show sex differences, concentrated in decision-making regions—sensory/motor areas are nearly identical.
- Next: Google and Harvard mapping the zebrafish whole-brain connectome; mouse regions in progress.
More from Fun
- PIP, a Clippy-style helper that pops out to sharpen your AI prompts — cong_ml · 2026-09-10
- Creator behind GPT-made GTA 6 rejected from X's original content creator program — kimmonismus · 2026-09-10
- Grammar joke: AI turns 'the report was late' into corporate word-salad — paulnovosad · 2026-09-10
- X user offers free Astra subs to demoralized mathematicians — on one condition — ctjlewis · 2026-09-10
- Users joke Claude is pushing them toward femboy personas — shakoistsLog · 2026-09-10
- Dev's GPT-6 Astra bot beats Balatro's hardest Black Deck on Gold Stake twice — Attol8 · 2026-09-10