Shared relations, specific choices: conditional sensitivity and competing pathways in language models
Organizations: Independent Researcher
Abstract
How does a relational representation shared across queries drive a query-specific choice? Controlled entity-binding experiments with GPT-2 Small, Qwen2.5-1.5B and Llama-3.2-1B reveal a low-dimensional relational background that is predominantly shared across query roles and transfers to new names. Same-domain interactions persist when another attribute domain is queried. After removing this component, restoring independently trained relation directions brings output contrasts closer to their original values than sign-reversed or equal-norm random controls in all three models. Yet a transferable relational representation need not have a transferable functional sign. In Qwen2.5, fixing model weights, the training-mean relation vector and edit dose yields opposite selection effects across binary and lexical-mapping prompts with different answer vocabularies. A factorial contrast of downstream sensitivities across attribute-query combinations determines the shared direction's local signed selection gain. In a separate eight-condition protocol, mean local gain is positive in Qwen2.5 and negative in Llama3.2. Late-component clamps resolve opposing pathway contributions: in Llama3.2, negative transmission through selected attention-only paths is partially offset by positive transmission through paths traversing both selected attention and MLP sets. Source-coordinate analyses establish distributed factor coverage, hidden-receiver readouts reveal layout-dependent combination, and instance-geometry interventions separate response direction from amplitude. These findings show how conditional sensitivity and competing pathways give shared relational structure its effect on specific choices.
Figures & tables
| GPT-2 | Qwen2.5 | Llama3.2 | |
| Blocks / channels | 12 / 768 | 28 / 1,536 | 16 / 2,048 |
| Query / KV heads | 12 / 12 | 12 / 2 | 32 / 8 |
| Normalization | LayerNorm | RMSNorm | RMSNorm |
| Position encoding | Absolute | RoPE | RoPE |
| Layer anchors | 2 / 6 / 10 | 5 / 14 / 23 | 3 / 8 / 13 |
| Material and intervention contrasts | |||
| Measurement | GPT-2 | Qwen2.5 | Llama3.2 |
|---|---|---|---|
| Pure-main-effect sharing in binding | |||
| Basis overlap (%) | 58.06 | 59.22 | 32.53 |
| Natural-pair overlap (%) | 11.01 | 15.28 | 10.43 |
| -on- excess (pp) | 37.04 [33.97, 40.02] | 20.74 [16.88, 24.71] | 19.75 [17.54, 22.03] |
| -on- excess (pp) | 36.08 [31.64, 40.59] | 21.70 [18.04, 25.58] | 16.37 [13.66, 19.09] |
| Role-decoupled background and new-name coverage | |||
| Quantity and protocol | GPT-2 | Qwen2.5 | Llama3.2 |
|---|---|---|---|
| Independent training-donor restoration, | |||
| Donor reversed | |||
| Donor random | |||
| Group-specific projection: derivatives and finite edits | |||
| , analytic, | |||
| , dose , | |||
| Measurement | Model or view | Estimate [95% interval] |
| Future-component deletion at the middle layer | ||
| NMSE | GPT-2 | |
| Qwen2.5 | ||
| Llama3.2 | ||
| Direct minus attribute-composed relation accuracy (pp) | ||
| GPT-2 binding | Hidden receivers | |
| Observed difference | Comparison and evidence scope | Mechanistic interpretation |
|---|---|---|
| Relation gain: native is in Qwen2.5 and in Llama3.2 ( ). | Native edits and fixed final denominators; clean clamps of selected late components in 64 eight-condition groups. | Conditional sensitivities and the measured balance of selected tangent paths determine signed transfer. |
| Candidate removal, pooled : , , . The GPT-2 interval spans zero. | Post-softmax removal, paired within 64 groups: late-minus-early is , , , with negative intervals. | Candidate contributions support later facts relative to earlier ones across models, despite different pooled signs. |
| Binding value-minus-routing NMSE: , , . | Synthetic derivative endpoints at natural amplitude in 32 binding groups per model; direction/amplitude decomposition and 16 distinct groups per layout. | Llama3.2’s value advantage is predominantly directional and concentrated in P0; layout strata vary position, spacing and context together. |
| Syntax local-minus-global NMSE: , , . | Held-out prediction with model-specific fits; norm/projection decomposition and five-fold scalar fitting at fixed prediction directions. | Llama3.2 combines better direction with excess amplitude. Calibrated local-minus-global error is [ ], leaving the difference unresolved. |
Appendix figures & tables45 assets
Supplementary material from the paper’s appendix.
Appendix
| A. Model configuration | |||
|---|---|---|---|
| Attribute | GPT-2 | Qwen2.5 | Llama3.2 |
| Blocks / channels | 12 / 768 | 28 / 1,536 | 16 / 2,048 |
| Query / KV heads | 12 / 12 | 12 / 2 | 32 / 8 |
| Head dimension | 64 | 128 | 64 |
| Unique parameters | 124,439,808 | 1,543,714,304 | 1,235,814,400 |
| Normalization | LayerNorm | RMSNorm | RMSNorm |
| Symbol | Definition |
|---|---|
| Parent state and activation-weighted reverse signal. | |
| Local derivative from parent state to retained child state. | |
| Orthonormal transform along token position. | |
| on calibration windows. | |
| , an independent full-channel map for each bin. | |
| . |
| GPT-2 | Qwen2.5 | Llama3.2 | |
|---|---|---|---|
| Target depth / edges | 2/6/10 | 5/14/23 | 3/8/13 |
| Windows per depth | 65,536 | 131,072 | 131,072 |
| Additional budget | L6: 131,072 | — | — |
| Map seeds | 123/321/567 | 123/321/567 | 123/321/567 |
| Window length / bins | 16 / 9 | 16 / 9 | 16 / 9 |
| Relative ridge, | 0.01 / 0.01 | 0.01 / 0.01 | 0.01 / 0.01 |
| Comparison | Reference | Full adjacent-edge result |
|---|---|---|
| Frequency constraint (configuration) | Earlier GPT-2: shared full-channel maps across frequency bins; 4,096 calibration windows | Independent full-channel maps at each of the nine stored calibration frequencies |
| GPT-2 L6, 65,536 windows | Three retained edges: 0.5863 | Six adjacent edges: 0.4718 |
| GPT-2 L10, 65,536 windows | Historical sparse boundaries: 0.6874 | Ten adjacent edges: 0.4563 |
| Qwen2.5 L14, 131,072 | Historical sparse boundaries: 0.8961 | Fourteen adjacent edges: 0.8498 |
| Llama3.2 L3, 131,072 | Historical sparse boundaries: 0.8038 | Three adjacent edges: 0.8592 |
| Llama3.2 L8, 131,072 | Historical sparse boundaries: 0.9013 | Eight adjacent edges: 0.8522 |
| Comparison | Effect | 95% interval | Holm | ||
|---|---|---|---|---|---|
| GPT-2: source comparisons | |||||
| Source-response NMSE: random minus estimated direction | 256 | ||||
| Syntax nested readout: single minus combined CE | 512 | ||||
| Syntax principal-direction selectivity minus random | 128 | ||||
| Syntax response prediction: global minus local NMSE | 512 | ||||
| Syntax shared minus split receiver RMS | 128 | ||||
| Model / task | Layer | Cosine | Cosine | (%) | |
|---|---|---|---|---|---|
| GPT-2 / Syntax | 2 | 0.985 [0.983, 0.987] | 0.986 [0.981, 0.989] | 0.38 [0.31, 0.46] | 0.167 [0.154, 0.180] |
| GPT-2 / Syntax | 6 | 0.976 [0.972, 0.980] | 0.964 [0.960, 0.968] | 0.71 [0.64, 0.78] | 0.235 [0.223, 0.247] |
| GPT-2 / Syntax | 10 | 0.852 [0.821, 0.878] | 0.860 [0.839, 0.879] | 3.49 [3.03, 4.02] | 0.509 [0.479, 0.542] |
| GPT-2 / Binding | 2 | 0.628 [0.589, 0.665] | 0.634 [0.589, 0.676] | 9.49 [8.68, 10.31] | 0.829 [0.794, 0.862] |
| GPT-2 / Binding | 6 | -0.379 [-0.416, -0.339] | -0.260 [-0.315, -0.200] | 48.91 [46.51, 51.27] | 1.617 [1.587, 1.643] |
| GPT-2 / Binding | 10 | -0.615 [-0.677, -0.547] | -0.464 [-0.565, -0.362] | 59.39 [55.40, 63.27] | 1.731 [1.692, 1.772] |
| Model | Task / factor | Task / opposite | Natural | Rank 256 / excess | Basis overlap |
|---|---|---|---|---|---|
| A. Conditional- energy: task rank 16; natural ranks 16, 64, 256; task–natural rank-16 overlap | |||||
| Model | Task r16 | Natural r16 | Natural r64 | Natural r256 | Overlap |
| GPT-2 | 69.90 | 15.51 | 36.23 | 77.03 | 16.31 |
| Qwen2.5 | 66.80 | 14.56 | 25.84 | 62.36 | 8.76 |
| Llama3.2 | 63.47 | 6.14 | 21.44 | 53.98 | 7.02 |
| B. Centered pure-main-effect and independent natural-pair overlaps | |||||
| Model | Layer / role | |||||||
|---|---|---|---|---|---|---|---|---|
| A. Seven-factor energy shares (%) | ||||||||
| GPT-2 | L2 / query | 3.71 | 3.39 | 91.12 | 0.50 | 0.63 | 0.59 | 0.05 |
| GPT-2 | L2 / pred | 26.46 | 26.50 | 44.14 | 2.72 | 0.10 | 0.08 | 0.00 |
| GPT-2 | L6 / query | 0.27 | 0.28 | 98.79 | 0.40 | 0.11 | 0.12 | 0.03 |
| GPT-2 | L6 / pred | 16.68 | 15.92 | 19.83 | 40.15 | 2.06 | 2.19 | 3.17 |
| GPT-2 | L10 / query | 4.70 | 4.99 | 68.97 | 18.99 | 0.57 | 0.57 | 1.21 |
| Condition / measurement | GPT-2 | Qwen2.5 | Llama3.2 |
|---|---|---|---|
| Direct attribute answers | |||
| Queried same-domain | 40.82 [39.49, 42.24] | 59.48 [58.57, 60.35] | 57.64 [57.05, 58.22] |
| Unqueried same-domain | 42.30 [41.08, 43.51] | 58.92 [57.92, 59.86] | 58.37 [57.61, 59.10] |
| Cross-domain | 0.090 [0.085, 0.095] | 1.076 [1.050, 1.104] | 0.449 [0.433, 0.468] |
| Domain-specific answer codes | |||
| Queried same-domain | 5.97 [5.68, 6.26] | 53.60 [52.41, 54.80] | 56.10 [54.56, 57.60] |
| Model / receiver | Predictor / comparison | NMSE / paired difference | Dev. gain |
|---|---|---|---|
| GPT-2 / query | Additive | 1.00546 [0.99923, 1.01170] | – |
| GPT-2 / query | Conditional linear | 1.00318 [0.99718, 1.00919] | – |
| GPT-2 / query | Local RBF | 0.99999 [0.99998, 0.99999] | – |
| GPT-2 / query | Scaled conditional | 1.00000 [1.00000, 1.00000] | 0.0000 |
| GPT-2 / query | Zero response | 1.00000 [1.00000, 1.00000] | – |
| GPT-2 / query | Scaled RBF | 0.00001 [0.00001, 0.00002] | – |
| Model | Receiver | versus | versus | versus |
|---|---|---|---|---|
| GPT-2 | L2/pred | — | ||
| GPT-2 | L6/pred | — | ||
| GPT-2 | L10/pred | |||
| Qwen2.5 | L5/pred | — | ||
| Qwen2.5 | L14/pred | — | ||
| Qwen2.5 | L23/pred |
| Model/task | Own other | Own rotated | |
|---|---|---|---|
| Context contrast at dose 0.25: estimates [95% CI] | |||
| GPT-2/syntax | 64 | ||
| GPT-2/binding | 64 | ||
| Qwen2.5/syntax | 64 | ||
| Qwen2.5/binding | 64 | ||
| Llama3.2/syntax | 64 | ||
| Model | , analytic ( ) | , dose ( ) | , dose ( ) |
|---|---|---|---|
| GPT-2 | |||
| Qwen2.5 | |||
| Llama3.2 |
| Model | Protocol | Donor reversed | Donor random |
|---|---|---|---|
| Donor recovery advantage; | |||
| GPT-2 | recovery | ||
| Qwen2.5 | recovery | ||
| Llama3.2 | recovery | ||
| Fixed mean-axis edit, dose : trained-axis and random-direction | |||
| Model | Material | Trained axis | Equal-norm random |
| Model | Contribution clamped | Residual | Residual |
|---|---|---|---|
| GPT-2 | Query | ||
| GPT-2 | Candidate | ||
| GPT-2 | Both | ||
| Qwen2.5 | Query | ||
| Qwen2.5 | Candidate | ||
| Qwen2.5 | Both |
| Clamped operation | ||||
|---|---|---|---|---|
| Qwen2.5: local derivatives at the common clean state | ||||
| none | — | |||
| attn5 | — | |||
| attn13 | — | |||
| attn21 | 0.00024 | |||
| attn23 | 0.92256 | |||
| Graph / path class | Qwen2.5 | Llama3.2 |
|---|---|---|
| Forward-graph gains | ||
| Native | ||
| Attention clamp | ||
| MLP clamp | ||
| Joint clamp | ||
| Additive tangent-path totals | ||
| Component | Static write | Net transmission |
|---|---|---|
| Static write (raw margin) and net dynamic transmission ( ) | ||
| Qwen2.5 mlp28 | ||
| Llama3.2 attn13 | ||
| Qwen2.5 Attention 23 net transmission ( ) | ||
| Stratum | Net transmission | |
| early | ||
| Quantity | Qwen2.5 | Llama3.2 |
|---|---|---|
| Derivative estimates and intervals ( ) | ||
| Native | ||
| Frozen-denominator | ||
| Native | ||
| Maximum absolute numerical differences (unscaled original units) | ||
| Clean-clamp margin | ||
| Model | Layer | Task | Shared RMS | Separate RMS | Difference [95% CI] |
|---|---|---|---|---|---|
| GPT-2 | 2 | syntax | 14.6733 | 1.0790 | |
| GPT-2 | 2 | binding | 4.2288 | 0.9165 | |
| GPT-2 | 6 | syntax | 2.1464 | 0.2265 | |
| GPT-2 | 6 | binding | 0.3662 | 0.0885 | |
| GPT-2 | 10 | syntax | 0.5386 | 0.0256 | |
| GPT-2 | 10 | binding | 0.2307 | 0.0122 |
| Model / contrast | First quantity | Second quantity | Paired contrast |
|---|---|---|---|
| Source removal: edited minus clean output (raw margin units) | |||
| Model / operation | |||
| GPT-2 / candidate_zero | |||
| GPT-2 / query_zero | |||
| Qwen2.5 / candidate_zero | |||
| Qwen2.5 / query_zero | |||
| Model / depth or task | Measurement | Estimate [95% interval] |
|---|---|---|
| GPT-2 L2 | Future deletion | |
| GPT-2 L6 | Future deletion | |
| GPT-2 L10 | Future deletion | |
| Qwen2.5 L5 | Future deletion | |
| Qwen2.5 L14 | Future deletion | |
| Qwen2.5 L23 | Future deletion |
| Model / depth | Query / node | Raw cosine | Centered cosine |
|---|---|---|---|
| GPT-2 L6 | all, node 0 | ||
| GPT-2 L6 | all, node 1 | ||
| GPT-2 L6 | all, node 2 | ||
| GPT-2 L6 | all, node 3 | ||
| GPT-2 L6 | all, node 4 | ||
| GPT-2 L6 | all, node 5 |
| Measurement | Two conditions or value | Contrast / interpretation |
|---|---|---|
| Relation, hidden receiver | 84.62 / 78.61 | |
| Relation, recipient source spans | 87.06 / 100.00 | |
| Relation, future source spans | 68.21 / 80.81 | |
| GPT-2 suffix cosine | 0.4900 / 0.8812 | Before / after alignment |
| Qwen2.5 permutation cosine gain | 0.5478 / 0.7102 | |
| Llama3.2 permutation cosine gain | 0.8624 / 0.9366 |
| Model / depth | Task / view | Adapted increment | Correction adaptation | All controls |
|---|---|---|---|---|
| GPT-2 L2 | SA / P0 | No | ||
| GPT-2 L6 | SA / P0 | Yes | ||
| GPT-2 L10 | SA / P0 | Yes | ||
| GPT-2 L2 | SB / P0 | No | ||
| GPT-2 L6 | SB / P0 | Yes | ||
| GPT-2 L10 | SB / P0 | Yes |
| Model / task / budget | Update / comparison | Source cosine or metric | Response cosine / effect |
|---|---|---|---|
| GPT-2 | Both tasks / natural | Fixed minus joint NMSE | |
| Qwen2.5 | Both tasks / natural | Fixed minus joint NMSE | |
| Llama3.2 | Both tasks / natural | Fixed minus joint NMSE | |
| GPT-2 B input-fixed | Fixed J | Not separately reported | |
| GPT-2 B nat. | Fixed J | Not separately reported | |
| GPT-2 B input-fixed | Joint H/J | Not separately reported |
| Model / task | Budget / update | Response NMSE | Source cosine | Response cosine |
|---|---|---|---|---|
| GPT-2 B | equal / Attention | |||
| GPT-2 B | equal / Fixed J | |||
| GPT-2 B | equal / Joint H/J | |||
| GPT-2 B | equal / Norm/MLP | |||
| GPT-2 B | equal / Routing | |||
| GPT-2 B | equal / Routing + Norm |
| Model / task / predictor | Local global | Global NMSE | Local NMSE | Random neighbors |
|---|---|---|---|---|
| GPT-2 Syntax H | ||||
| GPT-2 Syntax J | ||||
| GPT-2 Syntax H+J | ||||
| GPT-2 Binding H | ||||
| GPT-2 Binding J | ||||
| GPT-2 Binding H+J |
| Descriptor / measurement | GPT-2 | Qwen2.5 | Llama3.2 |
|---|---|---|---|
| Architecture | |||
| Normalization | LayerNorm | RMSNorm | RMSNorm |
| Feed-forward module | GELU MLP | SwiGLU | SwiGLU |
| Position encoding | Learned absolute | RoPE | RoPE |
| Attention grouping | Multi-head | Grouped-query | Grouped-query |
| Explicit Q/K/V bias | Present | Present | Absent |
LLM Interpretability
Large language model (LLM) interpretability studies how internal representations and computations produce outputs, and how they can be explained or controlled.
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