# Oral-B-v2 cold-start recovery: dense innovation plus target psychometrics This branch begins only after the complete, frozen `oral_b_v2_development_v1` grid failed. That failure is retained at `results/bci_v2_dev_gate.json`: none of 24 records was eligible, no candidate exceeded 0.78% full-horizon evaluation success, and confirmation task seeds `30--35` were not touched. The recovery does not edit that protocol, result, or gate. ## Development-only diagnosis The failure localized cleanly. Learned-role cosine was about `0.995`, the neutral residual remained decorrelated from soma, and the surrounding-state and velocity-over-error diagnostics passed, but even the exact-role oracle could not learn. Before the first success, the critic can observe only the dense performance-change term. Frozen v2 scaled that term by `0.25`, so the largest actor rate was effectively one quarter of the already validated temporal-difference rule and the terminal reward was unreachable. On already used development task seed 20, a causal postmortem changed only the dense velocity scale from `0.25` to `1.0`: final success changed from about 1% to 100%. With critic enabled, success rose sharply on days 7--8; without critic it did not rise until days 13--14. At scale 1, the diagnostic also recovered learned-role cosine `0.983`, residual--soma correlation `0.058`, surrounding decoder `54.4%`, velocity advantage `0.643`, and an acute-outcome-lesion loss of `0.386` in role-aligned terminal separation. These are exploratory postmortem values and are not R1 or R2 evidence. That postmortem exposed a second structural issue: the learned fixed-target policy reaches target `0.8` within four steps on every trial, so no horizon-only assay can produce an unrewarded class. A development-only uncensored probe placed the maximum cursor transition between targets 1.55 and 1.80. The recovery therefore replaces the failed horizon ladder with a fixed target psychometric ladder. This is disclosed development tuning, not claimed as preregistration against task seed 20. ## Frozen recovery The mechanism, local updates, six paired conditions, neutral warmup, cost accounting, full-horizon performance assay, and all other parameters remain as in `ORAL_B_V2.md`, except: ```text velocity_reward_scale = 1.0 forward_eta = 0.1 gamma = 0.8 critic_eta = 0.03 ``` There is no recovery hyperparameter grid. Endpoint-free tests establish that the nonterminal TD and actor update are exactly four times the failed v2 cold-start drive when critic and terminal reward are absent. They also bind the ordered target ladder. The signature assay uses six targets `{1.55, 1.60, 1.65, 1.70, 1.75, 1.80}`, 128 independent full-28-step episodes per target, and no target selection or reweighting. All targets are pooled. The same trained intact model is replayed under intact, acute critic lesion, and acute terminal-outcome lesion. This is a psychometric generalization assay: ordinary performance remains measured at the trained target `0.8`. The target ladder is intended to create rewarded and censored timeout trials without defining outcome directly from a balanced random label. ## R1 independent development validation R1 uses previously untouched development-validation task seeds `23--25` and model seed 0. Full performance seed is `460000 + task_seed`; target-ladder seed for zero-based target index `k` is `470000 + 1000 task_seed + k`. There is one fixed candidate and exactly three records. Every seed must pass every check: - intact final success at least 70%, early-to-late gain at least 10 points, fixed-role gap at least 20 points, oracle deficit at most 10 points, plasticity lesion at most half the intact gain, and role cosine at least `0.80`; - pooled target-ladder success fraction in `[0.15, 0.85]`; - terminal residual outcome balanced accuracy at least 75%, role-aligned outcome separation at least `0.20`, acute outcome lesion separation drop at least `0.20`, critic expectedness contribution at least `0.05`, and paired critic contribution/value correlation at least `0.95`; - residual--soma correlation at most `0.10`, raw-minus-residual correlation gap at least `0.20`, surrounding-event accuracy at least 52%, and decoder-distance correlation at least `0.02`; and - sign inversion at least `0.01` and velocity-over-error advantage at least `0.05`. R1 cannot change the score. Any failure closes this recovery and leaves confirmation untouched. ## R2 untouched confirmation Only a complete R1 pass permits the fixed candidate on task seeds `30--35` and model seeds `0--4`, exactly 30 records with no replacement or further selection. Full performance seed is `520000 + task_seed`; target-ladder seed is `530000 + 1000 task_seed + k`. The task seed is the uncertainty unit: the five models are averaged within each task, then one-sided 95% Student-t bounds use five degrees of freedom. Learning/plasticity requirements are unchanged from the prior frozen R2: mean final at least 70%, every task mean and lower bound at least 60%; mean gain at least 10 points and lower bound 5; mean fixed-role gap at least 20 points and lower bound 10; mean oracle deficit at most 10 points and upper bound 20; nonnegative lower bound for `0.5 intact_gain - lesion_gain`; mean role cosine at least `0.80` and every record at least `0.70`. Innovation requirements are: mean residual--soma correlation at most `0.10` with upper bound `0.12`; raw-minus-residual gap at least `0.20` with lower bound `0.15`; surrounding accuracy at least 52% with lower bound 50%; decoder-distance correlation at least `0.05` with nonnegative lower bound; positive sign in at least 25/30 records and every task mean; velocity advantage at least `0.05` with nonnegative lower bound. Outcome-surprise requirements are: every pooled success fraction in `[0.10, 0.90]`; terminal accuracy mean at least 80% and lower bound 75%; role-aligned separation mean at least `0.20` and lower bound `0.15`; acute outcome-lesion drop mean at least `0.20` and lower bound `0.15`; critic expectedness mean at least `0.05` and lower bound `0.02`; every paired critic/value correlation at least `0.95`. All records require a clean tracked tree, exact filenames, and SHA-256 binding to both preserved failure gates, the D4 gate, protocol, dynamics, metrics, runners, analyzers, and R1 gate where applicable. A complete R2 pass raises the formal repository milestone from 7 to 8 and permits a separately frozen oral-A-v2 protocol. It does not erase either failure, open the old oral-A gate, or establish online apical control.