Dhi
Unknowns

What nobody knows yet.

Open questions about the brain and AI — each one a room where researchers gather evidence, argue hypotheses, and turn what they learn into better flows for everyone. Anyone can read along.

Brain × AIOpen

Does the brain really predict the next word?

Brain signals seem to anticipate upcoming words before they are heard. Is that genuine prediction — or are encoding models picking up statistical dependencies between neighbouring words?

2 hypotheses4 sources1 message
Brain × AIOpen

How much brain–AI alignment survives strict controls?

When studies use contiguous train/test splits and control for sentence length, word position and word rate, how much of the LLM-to-brain fit remains — and is what remains contextual, syntactic, or just word meaning?

2 hypotheses4 sources1 message
Brain × AIOpen

Why does brain alignment stop improving at ~100M words?

A model trained on about as many words as a child hears already fits the brain nearly as well as huge models. Why does alignment saturate while abilities keep scaling — and would child-like, spoken, multimodal training change that?

2 hypotheses1 source1 message
Brain × AIOpen

Would predicting further ahead make AI more brain-like?

The brain seems to forecast several words ahead, at several levels. Would training models on longer-range, hierarchical predictions make them more brain-like — and more data-efficient?

2 hypotheses1 source1 message
Brain × AIOpen

Do attention heads match anything real in the brain?

Attention heads' computations predict brain activity. Do they correspond to a real brain mechanism — cue-based memory retrieval, hippocampal sequence codes — or are they just good feature extractors?

3 hypotheses2 sources1 message
Brain × AIOpen

Should AI be used to drive brain activity?

Language models can now choose sentences that switch the brain's language network up or down in new people. Where should closed-loop 'driving' of the brain go — and what are the ethics?

0 hypotheses1 source1 message
Brain × AIOpen

Why do we dream — and does the strangeness matter?

Dreams are vivid, emotional and often bizarre. Do they do something useful for memory and learning, and is their strangeness part of the point?

2 hypotheses2 sources1 message
Brain × AIOpen

Does the brain store memories as recordings — or rebuild them?

Are memories stored like files, or as gist plus a few unusual details that the brain regenerates each time you remember?

2 hypotheses2 sources1 message
Brain × AIOpen

How does the brain choose what to replay?

During sleep and rest, the hippocampus replays some experiences and not others. Is it maximising future usefulness, or following context and structure?

2 hypotheses2 sources1 message
AIOpen

Can AI stop forgetting the way sleep helps brains?

Neural networks catastrophically forget old skills when they learn new ones. Brains don't. Can sleep-like or generative replay give AI the same stability?

2 hypotheses2 sources1 message
Brain × AIOpen

Does visual cortex do something like diffusion?

A 2026 preprint models the visual cortex as a denoising diffusion model. Is the resemblance real biology, or only mathematics?

2 hypotheses1 source1 message