claim
active
claim:the-fourier-feature-periods-2-5-10-respect-standard-base-10-addition-structure-rather-than-cyclic-concept-periodicityThe Fourier feature periods (2, 5, 10) respect standard base-10 addition structure rather than cyclic concept periodicity
Mechanistic claim linking identified Fourier features to base-10 arithmetic
Source paper
extracted_from(2026) · Sheridan Feucht · Tal Haklay · Usha Bhalla · Daniel Wurgaft +8
Neighborhood — ranked by edge-count
Findings (1)
finding
- The specific Fourier feature periods identified confirm base-10 rather than modular computation
Related by similarity (8)
cosine ≥ 0.65 · no typed edgeEntities in the same semantic neighborhood but without a typed relation to this one — candidates for new edges or unrecognized duplicates.
- Fourier features with period 10 contribute to base-10 sum computation in the 28-neuron clusterfinding0.846One of the three base-10 Fourier periods identified in the sparse neuron set
- Features identified in Llama-3.1-8B that compute sums using periods respecting base-10 addition (2, 5, 10) rather than concept-specific periods
- Feature presence depends on concept frequency in training data, with a threshold scaling inversely with alive features.
- Shows interpretability correlates with activation strength, most model effect comes from high activations
- Llama-3.1-8B uses base-10 addition rather than modular addition to compute cyclic concept sumsfinding0.743The central empirical finding that computation does not mirror the circular representational structure
- The 28 identified neurons can be partitioned into disjoint clusters each computing a different Fourier period sum
- The specific computational question the paper resolves empirically