Inside one decision

How the model reaches its answer

MedGemma is a vision-language model that reads a chest X-ray and outputs findings. Pick a case on the left; this map shows the frozen-attention attribution for that one finding: the features that contributed most, flowing left to right into the answer.

What am I looking at?
  • Each dot is a feature: a specific, sparse pattern we isolated from inside the model (see the Features tab for named examples). The dot on the far right is the answer (the finding, e.g. cardiomegaly).
  • Warm dots come from the X-ray image; cool dots come from the question it was asked.
  • Lines are each feature's effect on the answer. The model is really deciding yes-or-no on the finding: orange makes it lean yes (the finding is present), blue makes it lean no. Thicker lines mean a stronger effect.
  • Columns run left to right, from the earliest to the latest stage of the model's processing. Hover a dot to light up its connections; click it for details and the other cases it shows up in.
click a dot for details · scroll to zoom · drag to pan