I'm Ali, a principal AI engineer in Vienna. I work on the evaluation, alignment, security and interpretability of AI systems.

Most of my research asks whether a claim about a model holds up under a harder test. The questions get more interesting as models get more capable.

Reading multilingual transformers against the listening brain

94 people heard Le Petit Prince in English, French or Chinese while fMRI recorded them. Two papers read the same story through XLM-R-base and the NLLB-200 encoder and use each sentence's representation to predict brain activity, region by region.

  1. 1Which part of a sentence representation predicts the brain better?

    The part the three languages share. Each sentence representation is split into a component the three languages have in common and a language-specific residual. In the middle-late layers the shared component predicts the brain's semantic regions better, in all six model-by-language tests and after correction for multiple comparisons.

    Language-Neutral or Language-Specific? Disentangling Multilingual LLM Subspaces with Naturalistic fMRI

  2. 2Which computations inside the transformer carry that shared signal?

    The attention side. Each of the 12 blocks is tapped at four points, and in every encoder and cohort the states around attention align with the semantic regions better than the feed-forward states, the opposite of what the pre-specified hypothesis predicted. Nine of the 12 best taps sit on the attention side.

    Attention-Side Transformer Computations Organize Shared Multilingual Brain Alignment during Naturalistic Story Listening

AU-5
Etched cells: ROI-projected held-out Fisher z of the selected component, at layer 7 (XLM-R) or 8 (NLLB)Ten axial plates, z −38 to 70 mm, 12 mm apart with the lever downEtched borders: semantic regions solid, auditory dotted, control dim; outer line: MNI152 brain at that height, for orientationSlide windows: round XLM-R-base, square NLLB-200 encoderRecorder: semantic regions by layer depth, shared solid, specific dashed; meters: middle-late shared − specific in semantic, auditory and control regionsThe paper splits each sentence representation from XLM-R-base and the NLLB-200 encoder into a shared component built from the other two languages' translations and an orthogonal residual specific to the heard language, then fits both to fMRI from 94 people hearing Le Petit Prince in English, French or Chinese. Over the middle-late layers the shared component predicts the semantic regions better in all six model-by-language tests, by 0.019 to 0.061 in held-out Fisher z, and every test survives Holm correction. The shared advantage holds in every one of the 48 semantic ROI rows, also appears in auditory and superior temporal regions, and is smaller in control regions.

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