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Multimodal sensorimotor grounding

concept/20-sensorimotor-grounding.md

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Scope

Grounding means that a model’s state is constrained by temporally ordered observation, action, and consequence—not that every concept must be reducible to pixels or motor commands. This chapter defines the trajectory record from which such state can be learned, how language attaches to it, and the tests that separate action-conditioned structure from passive multimodal correlation.

The central unit is a versioned episode containing asynchronous sensor events, commanded and realized interventions, exogenous events, and language with provenance. The model must predict and act under missing modalities, timing error, partial observability, and finite sensing energy. A representation is treated as grounded only to the extent that it supports held-out prediction, intervention, control, and reference at a declared uncertainty.

Biological observation

Biological perception is embedded in a closed loop. During active whisker exploration, measured contact mechanics predicted primary sensory-neuron firing better than whisker angle alone in the scoped mouse experiment (C-022). The result establishes that self-generated sensing mechanics can matter to the sensory code; it does not make embodiment necessary for every capability.

Other evidence constrains parts of the translation:

  • sparse coding can learn localized structure from natural images in the model studied under C-002;
  • latent target prediction can learn semantic image representations without pixel reconstruction under C-006;
  • children in a controlled toy study targeted actions toward unresolved causal structure under C-062;
  • pedagogical demonstration narrowed subsequent exploration in the scoped toy experiments under C-063; and
  • causal transparency changed copying of irrelevant demonstrated actions in a comparative puzzle-box experiment under C-064.

Together these findings motivate aligned experience, active evidence collection, and separation of imitation from outcome learning. They do not yet establish the project-level hypothesis that embodied multimodal training yields more general physical concepts than comparable text-centric training. That claim remains speculative under C-007.

Proposed AI translation

Canonical trajectory record

One episode is

τ=(ν,O,A,X,Y),\tau=(\nu,\mathcal{O},\mathcal{A},\mathcal{X},\mathcal{Y}),

where τ\tau is an episode record and all five components are immutable after publication; corrections create a new version.

SymbolMeaningUnit or type
ν\nuepisode metadataidentifiers and versioned configuration
O\mathcal{O}asynchronous observation-event settimestamped records
A\mathcal{A}commanded and realized action-event settimestamped records
X\mathcal{X}exogenous event settimestamped records
Y\mathcal{Y}language-event settimestamped text or token records

Metadata ν\nu contains episode and environment identifiers; train, development, or test split; actor or policy version; simulator or device version; clock domains; calibration versions; random seed when applicable; and parent episode for a counterfactual branch. Frames from one episode never cross data splits independently.

An observation event from modality rr is

or,k=(r,tr,kcap,tr,krecv,vr,k,mr,k,qr,k,pr,k),o_{r,k}= (r,t^{\mathrm{cap}}_{r,k},t^{\mathrm{recv}}_{r,k},v_{r,k},m_{r,k}, q_{r,k},p_{r,k}),

where:

  • rr is a modality identifier such as vision, audio, touch, proprioception, force, temperature, or depth;
  • kk is an event index;
  • tr,kcapt^{\mathrm{cap}}_{r,k} is physical capture time in seconds;
  • tr,krecvt^{\mathrm{recv}}_{r,k} is the time in seconds at which the learner could first access the event;
  • vr,kv_{r,k} is the sensor value with the sensor’s declared unit, shape, encoding, and quantization;
  • mr,km_{r,k} is a dimensionless missingness/status code;
  • qr,kq_{r,k} is a quality record with named quantities and units, such as exposure time in seconds or signal-to-noise ratio in decibels; and
  • pr,kp_{r,k} is a provenance pointer to source, calibration, transformation, and checksum records.

Capture and receipt time are both required. Offline alignment uses capture time; a deployable causal policy may use an event at time tt only when tr,krecvtt^{\mathrm{recv}}_{r,k}\le t. This prevents a delayed sensor packet from becoming accidental future information.

An action event is

αj=(tjcmd,tjon,tjoff,aj,a~j,πj,pj),\alpha_j=(t_j^{\mathrm{cmd}},t_j^{\mathrm{on}},t_j^{\mathrm{off}}, a_j,\widetilde{a}_j,\pi_j,p_j),

where tjcmdt_j^{\mathrm{cmd}}, tjont_j^{\mathrm{on}}, and tjofft_j^{\mathrm{off}} are command, realized onset, and realized offset times in seconds; aja_j is the commanded action; a~j\widetilde{a}_j is the measured realized action; πj\pi_j is the behavior-policy probability for a discrete action (dimensionless) or probability density for a continuous action (in reciprocal action-volume units) when it is known; and pjp_j is its provenance pointer. Each action component declares its physical unit—for example newtons, newton-metres, metres/second, radians, or a discrete tool identifier. Command and realization are never silently substituted for one another.

An exogenous event xlXx_l\in\mathcal{X} records event and receipt timestamps tleventt_l^{\mathrm{event}} and tlrecvt_l^{\mathrm{recv}} in seconds, event type, measured magnitude and unit, and provenance. Examples include another agent’s action, an uncommanded collision, lighting change, or simulator reset. Known simulator state sts_t^* may be stored for evaluation in its declared physical units, but it is oracle information and is withheld from learned systems unless a baseline explicitly receives it.

A language event is

yn=(tnstart,tnend,wn,cn,rn,pn),y_n=(t_n^{\mathrm{start}},t_n^{\mathrm{end}},w_n,c_n,r_n,p_n),

where the two timestamps are seconds, wnw_n is text or a token sequence, cnc_n identifies speaker and communicative role, rnr_n is a set of referent pointers to objects, events, trajectory intervals, or external records, and pnp_n is source provenance. A retrospective caption, an instruction available before action, a question, a report from another agent, and model-generated text have different roles even when their words match.

Observation is a versioned contract

A sensor record is not the latent state. Propagation, foreground, exposure, instrument response, background, calibration, reconstruction, threshold, and selection intervene before a downstream model sees it (C-218C-221). For latent target θ\theta, nuisance state η\eta, measurement yy, and response version HvH_v,

y=Hv(θ,η)+ϵ,y=H_v(\theta,\eta)+\epsilon,

where yy and HvH_v have matching declared units and ϵ\epsilon follows a declared noise and background model. If the analyzed record was selected by event S=1S=1, inference is conditional on that event:

p(θ,ηy,S=1,v)p(y,S=1θ,η,v)p(θ,ηv).p(\theta,\eta\mid y,S=1,v) \propto p(y,S=1\mid\theta,\eta,v)p(\theta,\eta\mid v).

The trajectory record therefore carries response and calibration version, exposure, selection state, detection power for non-detections, reconstruction choice, and data vintage. Cross-modal fusion also retains association uncertainty and shared dependencies; a different sensor type is not evidence of conditional independence (C-224).

Candidate 014 tests whether propagating this contract with each claim adds value beyond a complete typed, calibrated, lineage-aware, selection-aware, and simulation-checked evidence stack. The candidate must abstain on response null spaces and exact degeneracies rather than buy more observations that cannot identify the missing direction (C-229).

Derived observations inherit an interface and a support

A ratio, difference, derivative, normalized innovation, or latent coordinate is an observation operator, not a neutral rewrite of the raw signal. The operator record must name its input interface, reference state, causal window, positive-domain and saturation support, units, timestamp, calibration and any absolute information it removes. The statistic can legitimately change across the external-input, internal-state, downstream-readout and action interfaces: the Wnt/β-catenin result is an internal fold readout (C-1543), while the two NF-κB studies address different upstream and downstream arrows (C-1544, C-1545).

An invariant observation can make a transformed scale unidentifiable from that interface without proving that the information is universally destroyed. Adding a calibrated absolute observation or changing the output map can change recoverability (C-1549). The trajectory record therefore retains both the derived value and the smallest raw or calibrated side channel required by registered downstream targets.

Missingness is observed state, not a zero tensor

For modality rr and decision time tt, define Mt(r){0,1,2,3,4}M_t^{(r)}\in\{0,1,2,3,4\} as a dimensionless status:

CodeMeaning
0present and inside calibration range
1absent by experimental design
2unavailable because of sensor or transport failure
3present but occluded, saturated, clipped, or outside calibration
4status unknown

The raw value is not imputed before status is retained. If an imputed value is needed, the model receives both the imputation and Mt(r)M_t^{(r)}. Training dropout is labeled as synthetic missingness and is sampled in contiguous outages as well as isolated frames. Confirmatory tests include natural missingness, failure, corruption, and combinations not seen during training.

Missingness may itself be informative—for example a tactile sensor becomes available only after contact. Evaluation therefore distinguishes performance gained from legitimate availability structure from shortcut prediction of a label or environment identifier.

Temporal alignment contract

Each modality has a calibrated clock offset δr\delta_r in seconds and residual jitter scale σr\sigma_r in seconds. The corrected capture time is

tˉr,kcap=tr,kcapδr.\bar t^{\mathrm{cap}}_{r,k}=t^{\mathrm{cap}}_{r,k}-\delta_r.

Alignment does not mean forcing all modalities onto one frame rate. Encoders consume timestamped events or aggregate them inside declared causal windows. For a decision at time tt, the available history is

Ht={or,k:tr,krecvt}{αjt:tjcmdt}{xl:tlrecvt}{yn:tnendt},\mathcal{H}_t= \{o_{r,k}:t^{\mathrm{recv}}_{r,k}\le t\} \cup \{\alpha_j^{\le t}:t_j^{\mathrm{cmd}}\le t\} \cup \{x_l:t_l^{\mathrm{recv}}\le t\} \cup \{y_n:t_n^{\mathrm{end}}\le t\},

where Ht\mathcal{H}_t is a set of records, not a unit-bearing scalar, and αjt\alpha_j^{\le t} contains only action fields measured by time tt; a future realized offset or actuator trace is not revealed with the earlier command. The equation admits a language event after its end time; a streaming system may instead add explicitly timestamped token prefixes. Outcome targets may use later events, but the state used to choose an action may not.

Alignment robustness is tested by adding known per-modality offsets and jitter, dropping clock-synchronization messages, and withholding one calibration version. A mechanism that works only at exact simulator step boundaries has not learned a robust temporal relation.

Observation, intervention, and consequence

An action token is useful only when its consequence can be distinguished from background change. Training retains four separable cases:

  1. passive observation with no controlled action;
  2. policy-chosen action with known or estimated behavior probability πj\pi_j;
  3. randomized or scripted intervention with known assignment; and
  4. paired simulator branch from the same saved initial state with one changed action.

Only the third and fourth directly support an interventional comparison. Policy-chosen logs are confounded by the policy’s state and require a declared system-identification, propensity, or model-based assumption. Exogenous events remain separate from realized action so the model cannot credit itself for an outside cause.

For a horizon Δ>0\Delta>0 seconds, an action-conditioned predictor estimates

pθ ⁣(zt+Δzt,a~[t,t+Δ),Mt),p_\theta\!\left(z_{t+\Delta}\mid z_t, \widetilde{a}_{[t,t+\Delta)},M_{\le t}\right),

where ztRdz_t\in\mathbb{R}^d is a dimensionless latent state of width dd, θ\theta is the parameter vector, a~[t,t+Δ)\widetilde{a}_{[t,t+\Delta)} is the realized action sequence over the interval with per-component physical units, and MtM_{\le t} is missingness history. The predictor is not called causal merely because action is an input. Causal interpretation depends on the data case and evaluation intervention.

This realized-action form is used for training and retrospective scoring. A prospective rollout conditions on a candidate command aa and integrates over the calibrated distribution of actuator delay and realized action; it does not assume that a command is executed exactly.

Predictive state and action loop

The observation encoder forms

zt=Eϕ(Ht),z_t=E_\phi(\mathcal{H}_t),

where EϕE_\phi is an encoder with dimensionless parameters ϕ\phi and ztz_t is dimensionless. Separate heads predict future latent state, selected sensor targets, task outcomes, and calibrated uncertainty. Pixel or waveform reconstruction is used only when the task requires that detail; normalized latent prediction follows the narrower evidence in C-006.

For target-event set G\mathcal{G}, a probabilistic prediction loss is

Lpred=1GgGlogpθ(vgHtg,a~[tg,tg+Δg)),\mathcal{L}_{\mathrm{pred}} =-\frac{1}{|\mathcal{G}|} \sum_{g\in\mathcal{G}} \log p_\theta(v_g\mid\mathcal{H}_{t_g}, \widetilde{a}_{[t_g,t_g+\Delta_g)}),

where G|\mathcal{G}| is a target count, vgv_g is a declared target under a declared quantization or likelihood on dimensionless normalized coordinates, tgt_g is target context time in seconds, Δg\Delta_g is its prediction horizon in seconds, and Lpred\mathcal{L}_{\mathrm{pred}} is nats/target. A normalized latent-distance loss may be reported in dimensionless units, but it is not added to negative log likelihood without a declared conversion weight.

At a decision, the system may act on the world, request a modality, ask a question, consult sourced memory, or wait. Let bBtb\in\mathcal{B}_t denote one such acquisition or intervention choice. A conventional one-step value-of-information policy chooses

bt=argmaxbBt[V(bHt)λEE(b)λTT(b)],b_t^*=\arg\max_{b\in\mathcal{B}_t} \left[V(b\mid\mathcal{H}_t) -\lambda_E E(b)-\lambda_T T(b)\right],

where VV is expected task-utility improvement in declared utility units, E(b)E(b) is full sensor, communication, and compute energy in joules, T(b)T(b) is added latency in seconds, λE\lambda_E has units utility/joule, and λT\lambda_T has units utility/second. wait is an explicit zero-acquisition option. This is the strongest conventional null for claims that prediction error should route sensing or compute, as described under P-007 and in the engineering analogue audit.

Controlled observability and plant binding

The observation operator is partly controlled. Sensor pose, locomotor microstructure, emission timing, sampling density, and contact can change which state directions are observable (C-589C-592). At the same time, body, tool, attachment, payload, compliance, and contact change how commands become motion and sensory consequences (C-599, C-603C-605).

Separate the immediate task controller from the sensing controller:

ut=πtask(bt,Πv),atsense=πsense(bt,Ov,Πv),u_t=\pi_{\mathrm{task}}(b_t,\Pi_v), \qquad a_t^{\mathrm{sense}}=\pi_{\mathrm{sense}}(b_t,\mathcal O_v,\Pi_v),

where btb_t is a dimensionless belief state, task action utu_t retains its physical units, sensing action atsensea_t^{\mathrm{sense}} retains pose, emission, sampling, or motion units, Ov\mathcal O_v is observation-contract version vv, and Πv\Pi_v is the controller–plant binding

Πv=(B,T,A,C,S,J,Z,D,E),\Pi_v=(B,T,A,C,S,J,Z,D,E),

with body/tool identity BB, task TT, attachment/payload AA, contact model CC, sensor/actuator calibration SS, task Jacobian JJ, impedance/passivity envelope ZZ, delay model DD, and safety/authority envelope EE. Each field is typed, versioned, and linked to the controller, estimator, data, and tests that depend on it.

flowchart LR
    G["Task goal + risk envelope"] --> TC["Task controller"]
    B["Belief + uncertainty"] --> TC
    B --> SC["Sensing controller"]
    TC --> U["Motor command + reflex settings"]
    SC --> A["Pose · emission · sampling action"]
    U --> P["Versioned body · tool · actuator · contact plant"]
    A --> P
    P --> W["World + medium"]
    W --> O["Propagation + sensor physics"]
    P --> O
    O --> Y["Versioned observations"]
    U --> E["Action record / efference copy"]
    Y --> X["State + consequence estimator"]
    E --> X
    X --> B
    V["Plant · attachment · calibration · delay · impedance · safety version"] -.-> P
    V -.-> X
    V -.-> TC
    H["Health · passivity · wear · energy · contact"] -.-> TC
    H -.-> SC
    Z["Counterfactual swap + selective invalidation"] -.-> V

Editable source: controlled-observability-plant-binding.mmd.

Two held tests share this record:

  1. Controlled observability. Keep the task policy fixed while a sensing policy maintains information through pose, emission, or sampling. It must beat fixed excitation, random acquisition, one-step expected value of information, active SLAM, observability MPC, and dual control at equal action, time, risk, compute, and energy (C-596).
  2. Counterfactual plant binding. Swap one body, tool, attachment, payload, sensor, delay, contact, or impedance field at a time. Dependencies should predict which estimator/controller state is safe to reuse and which must be invalidated. It must beat reset/retraining, unversioned adaptation, model banks, gain scheduling, operational-space impedance control, and adaptive MPC (C-606).

This composition avoids two attribution errors. Passive mechanics and compliance are credited before a controller (C-597); an action-correlated internal signal is not assumed to be a complete accurate forward model (C-601).

Opportunity- and history-qualified adaptive action

Comparative cognition adds a sharper condition to the observation contract: the same apparatus does not create the same task when bodies, sensors, prior training, rewards, demonstrators, handlers, or feasible actions differ. The evidence in C-804C-841 spans tool manufacture, causal transfer, future preparation, event memory, uncertainty control, imitation, teaching, exploration, negative transfer, and central-versus-peripheral control. Its durable contribution is not a species ranking. It is a requirement to record the opportunity that made an outcome possible.

Extend each episode with

Ω=(X,S,A,H,R,C,τ,U),\Omega=(X,S,A,H,R,C,\tau,U),

where XX is task and apparatus state, SS is the sensory information actually available, AA is the feasible realized-action set, HH is prior training and social exposure, RR is reward and stopping state, CC is the intervention and control set, τ\tau is elapsed time in seconds, and UU is the sampling unit. The detailed definitions and units are maintained in the opportunity/history mathematics.

This record prevents several category errors:

  1. Terminal success is not transfer. First-trial response after a material, geometry, cue, relation, body, or history change is retained separately from later test-time learning.
  2. One copied outcome is not one copied process. Demonstrations are decomposed into action form, trajectory, end state, location, demonstrator, and functional relation. Ghost and result-only controls identify which component changed the learner.
  3. A future-directed action is not a unique memory mechanism. Value tables, successor representations, planning, and retrieval remain nulls for delayed selection and resource reservation.
  4. Adaptive checking is not a unique uncertainty mechanism. Public difficulty cues, response strength, calibrated confidence, selective prediction, and ordinary value of information must be beaten.
  5. Local control is not independent control. Body mechanics, local sensing, peripheral feedback, central goal selection, override latency, and message traffic are measured separately.
  6. Repeated trials are not independent agents. Episode, learner, dyad, group, site, rearing or training cohort, and population remain distinct sampling levels.
flowchart LR
    task["Task · apparatus · hidden regime"] --> channel["Actual sensory channel + receipt time"]
    body["Body · tool · feasible action set"] --> channel
    history["Training · reward · social exposure · handler cues"] --> state["Opportunity/history-qualified state"]
    channel --> state
    controls["Intervention · ghost · cue reversal · history swap"] --> task
    state --> policy["Act · inspect · abstain · retrieve · communicate"]
    policy --> plant["Realized action through compliant plant"]
    plant --> outcome["Outcome + first-trial transfer + safety + cost"]
    outcome --> diagnosis{"Which relation transferred?"}
    diagnosis --> affordance["Affordance · causal model · search"]
    diagnosis --> memory["Event · semantic · prospective memory"]
    diagnosis --> social["Action form · result · location · convention"]
    diagnosis --> control["Central · local · mechanical contribution"]
    nulls["RL · POMDP/MPC · retrieval · VOI · imitation · hierarchical control"] --> diagnosis
    diagnosis --> revision["Retain · narrow · reject · revise"]
    revision --> history

Editable source: opportunity-history-qualified-action.mmd.

Fixture F-003 turns the contract into eight separable tracks: manufacture transfer, causal inversion, future resource reservation, event memory, costed uncertainty, copy-target decomposition, social acquisition, and local/central/mechanical control. It compares the full composition with learned affordances and search, model-free and model-based RL, POMDP/MPC, semantic and episodic retrieval, selective prediction and value of information, imitation learning, central replay, and hierarchical control under one lifecycle boundary.

The fixture earns architectural credit only when opportunity qualification changes a conclusion, exposes a reproducible confound missed by the existing stack, or produces robust transfer beyond the complete nulls. Otherwise the episode contract remains useful instrumentation and the additional mechanism is retired.

Grounded learning loop

flowchart LR
    world["World and body"] --> events["Aligned multimodal<br/>events"]
    events --> model["Grounded predictive<br/>state"]
    language["Language and<br/>sourced knowledge"] <--> model
    model --> assurance["Uncertainty and<br/>provenance"]
    assurance --> decision{"Act, query,<br/>or wait?"}
    decision --> action["Bounded action or<br/>sensor request"]
    action --> world

Editable source: ../assets/diagrams/grounded-learning-loop.mmd.

Language attaches to grounded state

Language serves at least four different functions:

  1. reference: name an object, relation, action, event, or trajectory span;
  2. instruction and query: change the agent’s task or request information;
  3. compression and communication: summarize learned regularity for another time, module, or agent; and
  4. testimony: introduce facts and abstractions not available through direct sensorimotor experience.

Reference is trained from the rnr_n links in language events, including negative and ambiguous referents. Instructions are available only from their receipt time and are treated as interventions that may change action. Testimony retains source, version, trust policy, and retrieval trace; it is not forced into a fictional physical observation. A concept can therefore combine direct experience, action–outcome evidence, and sourced symbolic knowledge without erasing which support came from where.

The staged design learns predictive physical state before or alongside a small language adapter, then compares late attachment, joint training, and language-first training under equal data and capacity budgets. Physical probes use paraphrases and unseen names; language probes include relations with no direct sensory referent. Demonstrated action and demonstrated outcome are separate targets, following the distinction motivated by C-064.

Uncertainty and provenance contract

Each prediction exposes a distribution or calibrated interval at the level at which action is chosen. Report negative log likelihood in nats/target, Brier score for declared categorical events, interval coverage in percent, and calibration error with binning fixed before evaluation. Calibration is broken out by modality status, prediction horizon, intervention type, environment, and linguistic versus direct evidence.

A single confidence scalar does not replace modality-specific uncertainty. The system records whether uncertainty arose from noisy observation, missing modality, disagreement among plausible dynamics, unseen composition, ambiguous language, or untrusted testimony when the estimator supports that distinction. If it does not, the output remains an undifferentiated predictive uncertainty.

Every training and evaluation event resolves through pr,kp_{r,k}, pjp_j, or pnp_n to:

  • raw or generated source identifier and checksum;
  • simulator, device, actor, and policy version;
  • capture and receipt clock domains;
  • calibration and transformation chain;
  • missingness and corruption operations;
  • split assignment and counterfactual parent; and
  • license or access policy where applicable.

Answers and plans can then cite direct observation, intervened outcome, retrieved testimony, or model rollout separately. Provenance does not make a prediction correct; it makes its evidential path inspectable and reversible.

Strongest conventional baselines and nulls

IDBaselineQuestion it answers
B0Text-only model with matched language tokens and capacityDoes language alone explain the reported transfer?
B1Passive multimodal encoder on the same recorded sensor eventsDoes temporal multimodality help without action conditioning?
B2Synchronized masked/contrastive multimodal predictorDoes ordinary cross-modal prediction explain the gain?
B3Standard action-conditioned latent state-space/world modelDoes the proposed data and uncertainty contract add value beyond a conventional world model?
B4Behavioral cloning and action-prediction modelIs copying the logged policy enough without predicting consequences?
B5Calibrated linear/nonlinear system-identification model on tasks where its assumptions applyIs learned grounding better than an established dynamics estimator?
B6Random, entropy-seeking, and one-step EVSI acquisition policiesDoes active sensing beat ordinary exploration and information purchasing?
B7Oracle-state predictor/controllerHow much error comes from partial observation rather than dynamics or control?
B8Intact architecture with time, action, modality, or language links shuffledDoes performance depend on the claimed alignment and causal structure?

B7 is an upper bound, not a superiority baseline. Comparisons match trajectory seeds, raw sensor exposure where logically possible, model capacity, optimizer updates, action count, sensor acquisitions, context bytes, latency ceiling, and lifecycle energy. The active-data question and the action-conditioning question are evaluated separately: hiding action tokens in the same log is not the same experiment as allowing an agent to collect a different log.

Staged experiment

Stage 0 — Data and clock qualification

Build a deterministic replay harness before training a world model. It must reproduce event order, verify checksums and split isolation, expose capture and receipt time, reconstruct commanded versus realized actions, and audit every missingness code. Inject known offsets, jitter, packet delay, dropped intervals, and actuator lag. Reject a dataset version when these perturbations cannot be recovered or bounded from its metadata.

Stage 1 — Passive action-conditioned prediction

Use a controlled compositional environment with vision, audio, proprioception, touch/force, and optional depth. Objects vary independently in shape, color, mass, surface friction, and containment. Actions include look, approach, push, lift, rotate, drop, occlude, and tool contact. The held-out split contains:

  • unseen combinations of known object properties;
  • new visual textures and camera placement;
  • changed mass or friction under familiar appearance;
  • action delays and partial actuator failure; and
  • one-modality and multi-modality outages.

Training, development, and test split by episode seed, object combination, and environment configuration—not by frames. Simulator state sts_t^* is stored for evaluation and B7 only.

Train B1–B5 and the candidate predictive state on the same logged trajectories. Compare intact realized actions with actions masked, time-shifted, and permuted within episode. Primary outcomes are future-state and sensor NLL in nats/target, physical-property probe error in declared units, held-out intervention error, control success percent with a frozen small controller, calibration, bytes, and joules/qualified episode.

Stage 2 — Paired interventions and active acquisition

From a saved initial state, run paired branches differing in one action or sensor request while holding the environment seed fixed. Separately allow each active policy the same maximum world actions, sensor acquisitions, wall time, and energy. Compare random exploration, entropy seeking, one-step EVSI, and the candidate policy.

Measure prediction change in the correct physical direction, intervention effect error, successful disambiguations/action, downstream task utility, unsafe interventions, sensor byte, action energy, total joules, and latency. This stage tests the open issue in C-022 and the targeted-exploration translation from C-062.

Stage 3 — Language attachment

Attach language using trajectory-span and referent links. Compare late attachment to a frozen physical core, joint training from initialization, and language-first pretraining followed by grounded data. Equalize language tokens, grounded episodes, trainable parameter count, optimizer updates, and tuning budget.

Evaluate new names for known referents, paraphrased instructions, ambiguous reference, imitation versus outcome emulation, physical questions about unseen compositions, testimony-only facts with changed source versions, and removal of language at control time. Report whether language improves sample efficiency without becoming the only route to physical success.

Stage 4 — Asynchronous physical transfer

Move the frozen comparison to one named real sensorimotor platform. Preserve native clocks, packet delay, actuator mismatch, calibration changes, occlusion, and sensor failure. Recalibrate energy at device and node boundaries using the energy evaluation contract. Simulation-to-real transfer, recovery, and negative results are reported by intervention and missingness stratum rather than one average.

The real platform adds two contracts that simulation accuracy cannot supply. First, estimation is qualified by integrity. An illustrative position protection level is

PL=Kintσpos,usable only when PLAL,PL=K_{\mathrm{int}}\sigma_{\mathrm{pos}}, \qquad \text{usable only when }PL\le AL,

where PLPL, position standard uncertainty σpos\sigma_{\mathrm{pos}}, and alert limit ALAL are in metres, while KintK_{\mathrm{int}} is dimensionless and tied to a declared fault and risk allocation. A learned confidence score does not become integrity without bias bounds, dependence, coverage, and time-to-alert (C-446).

Second, a controller handoff must preserve exclusive effective authority while the world keeps moving. The transfer binds the controlled effect, epoch, outgoing and incoming controller, actual and pending mode, observation basis, headroom, time-to-boundary, faults, outstanding commands, fallback reachable set, expiry, acknowledgement, atomic activation, and observed postcondition.

stateDiagram-v2
    [*] --> StableOwner
    StableOwner --> TransferProposed: effect + epoch + observation
    TransferProposed --> TransferRejected: stale / unsupported / not ready
    TransferProposed --> Armed: receiver ready + fallback reachable
    Armed --> NewOwner: atomic activation + old authority revoked
    Armed --> Fallback: timeout / fault / margin exhausted
    NewOwner --> StableOwner: postcondition verified
    NewOwner --> Fallback: postcondition fails
    TransferRejected --> StableOwner
    Fallback --> StableOwner: recovery + explicit reassignment

Editable source: asynchronous-authority-transfer.mmd.

This is a refinement of Candidate 012, not a new autonomy layer. It must beat mode annunciation, interlocks, epoch leases, runtime assurance, explicit arbitration, Candidate 014, and the recoverable-initiative contract under split-brain, stale-command, no-owner, delayed-link, common-mode, and failed- postcondition injections (C-447C-461).

Efficiency mechanism

Grounding adds sensors and interaction, so its efficiency claim is conditional: the learned state must avoid more future sensing, compute, data movement, or failed action than it costs to acquire and maintain.

The candidate levers are:

  • event-driven encoding: update modality state on timestamped change rather than resampling every channel at the highest rate;
  • latent prediction: predict task-relevant state without reconstructing every high-bandwidth detail;
  • local preprocessing: reduce raw sensor traffic near the source while retaining calibration and uncertainty metadata;
  • conditional acquisition: power, transmit, or process another modality only when its expected utility exceeds energy and latency cost;
  • temporal reuse: carry forward stable state with an uncertainty increase instead of re-encoding unchanged observations; and
  • language compression: communicate grounded referents and relations when sending the underlying sensor history is unnecessary.

Every experiment reports sensor-on time in seconds, sensor energy in joules, raw and processed bytes by boundary, acquisitions/episode, world actions/episode, encoder and world-model operations, latency in seconds, controller energy, maintenance/calibration energy, and total lifecycle joules/qualified episode. A lower model FLOP count is not a grounding-efficiency result when sensor collection or interaction dominates.

The relevant efficiency comparison is a frontier over task utility, risk, latency, energy, and physical interaction. One-step EVSI is the minimum null for conditional acquisition. A passive model trained on a larger recorded dataset is an additional null when interaction energy, not online autonomy, is the proposed benefit.

Evidence status

  • Sparse natural-image representation under C-002: established for the cited model and images.
  • Joint-embedding image prediction under C-006: established for the cited image experiments.
  • Active sensor mechanics under C-022: established for the measured whisker task.
  • Targeted exploration under C-062, pedagogical narrowing under C-063, and imitation/emulation difference under C-064: established for the scoped behavioral tasks.
  • A generally useful predictive-coding abstraction under C-005: plausible, not a complete grounding theory.
  • Robust general physical concepts from the integrated multimodal curriculum under C-007: speculative.
  • Navigation integrity, protection-envelope scope, fault-stage separation, degraded/fallback distinctions, and assurance boundaries under C-445C-460: established or plausible within the audited vehicle domains.
  • Validated asynchronous authority transfer under C-461: speculative.
  • Opportunity, history, causal-transfer, event-memory, social-learning, and distributed-control observations under C-804C-840: established, plausible, or disputed only within their declared tasks; the integrated action contract under C-841 is speculative.

Speculative extensions

Controllability curriculum

Order early tasks by what an agent can reliably change and observe: persistence and contact, motion and occlusion, material response, tools and other agents, then linguistic abstraction. Curriculum order becomes an ablation rather than an assumed developmental law.

Learned morphology and sensor placement

Jointly adapt sensor placement, body parameters, and control only after the fixed-body grounding loop is understood. The simulation evidence under C-029 motivates the question, while lifecycle energy and reality-gap robustness remain required outcomes.

Socially supplied interventions

Treat demonstration, correction, question answering, and pedagogy as actions that change the learner’s evidence policy. The system can preserve uncertainty after a demonstration and deliberately test affordances not shown, rather than assuming instruction is exhaustive.

Counterfactual branch memory

Store compact paired branches from matched initial states as high-value causal records. Promotion into long-term memory depends on reuse and provenance, not on intervention novelty alone.

Failure modes

SignatureInterpretation and required response
Action shuffling leaves held-out intervention error unchangedthe representation uses passive correlation; remove the action-grounding claim
Timestamp shuffling or large clock offsets cause no degradationstatic identifiers or leakage dominate; audit split and alignment
Exact simulator timing wins but calibrated jitter collapses performancetemporal relation is brittle; retain time uncertainty or revise the encoder
Missingness code alone predicts task labelsacquisition policy or dataset artifacts leak the answer; rebalance and report the shortcut
One modality receives nearly all gradient or attention and its removal collapses all tasksshared state has become single-modality state; enforce and test modality-specific competence
Commanded action predicts outcomes but realized action does notactuator or logging shortcut; train and evaluate on realized intervention
B3 or B5 matches the candidateconventional world modeling or system identification explains the result; use the simpler baseline
One-step EVSI matches active acquisitionno new sensing principle is supported; retain EVSI as the controller
Language removal destroys physical control learned before languagelinguistic shortcut or catastrophic overwriting; separate adapters and replay physical probes
Fluent reports disagree with action-conditioned predictionslanguage head is not constrained by world state; expose uncertainty and provenance by source
Counterfactual performance is high only when oracle state leaks into inputthe partial-observation problem remains unsolved; remove oracle fields and rerun
Active training wins only because it observed more frames or spent more action energydata or resource exposure explains the result; compare at matched events, actions, and joules
Sensor and interaction energy erase compute savingsnarrow the result to representation quality; do not claim system efficiency
Calibration fails specifically under missing modalities or novel interventionsuncertainty is not deployment-valid; block autonomous escalation in those strata
Low state-estimation error coexists with integrity alerts that are late or absentaverage accuracy is not safe-to-use evidence; bind fault hypotheses, alert limit, and deadline
Handoff produces overlapping owners, a control gap, or stale queued effectstransfer is not atomic or command expiry is incomplete; revoke, fall back, and preserve the trace
Raw task success changes after body, cue, training, reward, handler, or site changesthe opportunity record is incomplete; stratify and rerun before attributing a mechanism
A socially exposed policy reaches the same end state but changes no novel action formresult, affordance, or location learning explains the effect; remove the imitation claim
A local controller wins until passive mechanics, local hardware, or communication are chargedthe control-locus claim is misattributed; keep the cheaper complete baseline

Measurable predictions

H-G1 — Action-conditioned consequence

With identical logged sensor events, intact realized actions will improve held-out intervention NLL and physical-effect error over masked, shifted, and permuted actions. If only reconstruction or in-distribution probe accuracy improves, the result does not support action grounding.

H-G2 — Temporal alignment

Models trained with explicit capture/receipt time and calibrated clock uncertainty will degrade more gradually under held-out offset, jitter, and packet delay than fixed-step concatenation. The comparison reports error as a function of injected milliseconds and identifies the offset at which the quality envelope is crossed.

H-G3 — Missing modalities

Typed missingness plus modality-specific predictive heads will preserve a better quality–calibration frontier under contiguous sensor outages than zero imputation or independent encoders fused only at the output. Performance is reported separately for absence, failure, occlusion/corruption, and unknown status.

H-G4 — Active evidence collection

At the same action, acquisition, latency, and joule budgets, a learned active policy will require fewer interventions to identify held-out mass, friction, containment, or causal relations than random and entropy-seeking exploration. It supports a new mechanism only if it also improves beyond calibrated one-step EVSI; otherwise EVSI becomes the accepted implementation of P-007.

H-G5 — Compositional physical transfer

Action-conditioned predictive state will yield lower sample count to a fixed control-success threshold on unseen property combinations and dynamics than text-only, passive multimodal, and behavioral-cloning baselines of matched capacity. The threshold, maximum episodes, and unsuccessful runs are fixed before evaluation.

H-G6 — Language attachment

Late or joint language attachment with explicit referent and provenance links will improve new-name, paraphrase, and testimony-version tests without reducing pre-language physical probes beyond a preregistered equivalence margin. If language-first training alone matches intervention transfer at equal grounded episodes, the additional grounding curriculum has not earned its cost.

H-G7 — Calibrated abstention

Prediction uncertainty will increase under unseen interventions, multi-sensor failure, and ambiguous reference, and calibrated abstention or acquisition will reduce high-cost physical errors at a declared false-abstention rate. Average confidence without stratum calibration does not satisfy this prediction.

H-G8 — Lifecycle efficiency

Conditional sensing, event-driven updates, and latent prediction will reduce sensor byte, processed byte, and node joules/qualified episode at matched task utility, risk, and latency relative to always-on sensing and fixed-rate encoding. The claim is rejected if the confidence interval for lifecycle energy includes the preregistered equivalence margin after collection, calibration, language, maintenance, and failed-action costs are included.

H-G9 — Integrity-qualified authority transfer

Under delayed links, boundary misclassification, degraded sensors, outstanding commands, common-mode faults, and failed postconditions, a validated transfer record will reduce double-owner, no-owner, stale-command, and unsafe-boundary time beyond mode annunciation, interlocks, epoch leases, runtime assurance, ordinary arbitration, and the HCI/observation contracts at equal sensing, reserve, communication, training, review, latency, and joule budgets. A tie merges its useful fields into those conventional mechanisms.

H-G10 — Opportunity-qualified transfer

At equal episodes, interventions, action feasibility, search, storage, communication, human effort, and lifecycle joules, explicit opportunity and history state will improve first-trial functional transfer and calibration under held material, causal-relation, body/tool, acquisition-history, and social-channel changes relative to an otherwise identical learner. The claim is rejected if the gain disappears after actual sensor cues, feasible actions, prior training, reward schedule, handler/site, or later test-time learning are modeled, or if the complete affordance/search, planning, retrieval, VOI, imitation, replay, and hierarchical-control stack matches the result.

Promotion requires H-G1 plus at least one transfer result from H-G3–H-G6, valid uncertainty under H-G7, and no lifecycle contradiction under H-G8. Stage-4 authority-transfer claims additionally require H-G9. A comparative-cognition-derived transfer claim additionally requires H-G10. A positive result remains scoped to its trajectory schema, intervention family, environment shift, hardware boundary, and evaluated language role.