Homeostatic Override / Imminent-Death Drive Amplification Literature Pull

Paste this into a new Claude Code session as your opening message. Created: 2026-04-22 Origin: V3-EXQ-471 fishtank visualization showed a catatonic-locked agent whose energy depleted to zero with no homeostatic override. SD-036 (GABAergic decay) resolves the harm-stream lock but does not address the missing override authority that should let hunger override threat under survival demand.

Prompt

/lit-pull Homeostatic-need brain circuits and how they amplify or override other drive systems under imminent-death conditions – specifically the question of how hunger / energy depletion / dehydration acquires authority to override threat-driven avoidance behaviour. The architectural question: in V3 we have separate streams for threat (z_harm), goal (z_goal), drive (energy/homeostatic), and an arbitration mechanism (mode selection via SD-032a SalienceCoordinator). When a hazard event locks the agent into avoid mode and energy then runs to zero, no mechanism currently reverses the lock – avoid still wins arbitration even when starvation is imminent. Subjectively, hunger does not just compete with threat; it sharpens or amplifies multiple drives simultaneously (the dread stream may itself intensify, the fast-interrupt becomes more sensitive, goal pursuit becomes more compulsive). This suggests a broadcast neuromodulator that gain-modulates several streams from one homeostatic source, rather than a competing scalar.

Target claims to inform / extend:

  • SD-012 (drive-modulated goal seeding – currently has no override authority over z_harm-driven avoid mode)
  • SD-036 (GABAergic cross-stream decay regulator, registered 2026-04-22 – the decay layer is one half of the catatonia rescue; this lit-pull addresses the other half: what reverses the mode lock when survival demands it)
  • MECH-279 (PAG GABAergic freeze-gate – freeze exit may be normal-route via decay or override-route via homeostatic emergency)
  • SD-032a (SalienceCoordinator – target for whatever mechanism provides override authority)
  • Possible new SD/MECH for the override mechanism itself

Specific neurobiological systems to cover:

  1. Lateral hypothalamus (LH) – the canonical hunger/feeding circuit. Specifically:
    • LH GABAergic and glutamatergic projections to VTA, PAG, and PFC
    • How LH activity overrides defensive behaviour in foraging-under-threat paradigms
    • Burnett et al 2019 (LH circuits and feeding); Sternson lab work on AgRP/POMC
  2. Orexin / hypocretin (LHA) – broadcast arousal/motivation neuromodulator strongly implicated in the kind of multi-stream gain modulation the architectural question requires:
    • Orexin projections to VTA, LC, raphe, BLA, PFC, PAG
    • Berthoud, Saper, Sakurai work on orexin as a homeostasis-arousal coupler
    • How orexin loss (narcolepsy) produces specific failures in motivated behaviour under metabolic challenge – the human knockout
  3. Lateral parabrachial nucleus (LPB) and the brainstem sensory-aversive coupling:
    • How interoceptive distress signals (hunger, thirst, hypoxia, hypoglycaemia) are routed through LPB to higher centres
    • LPB CGRP neurons and threat-vs-need integration (Palmiter lab)
  4. Ventromedial hypothalamus (VMH) and defensive-vs-feeding switching:
    • VMH SF1 neurons in defensive behaviour and how they interact with LH feeding circuits
    • Lin et al, Anderson lab work on VMH switching
  5. Insula and interoceptive amplification under metabolic stress:
    • How insular processing of interoceptive signals scales with deprivation level
    • Craig 2009 + extensions; whether this maps onto SD-032c (AIC-analog) gain modulation under drive
  6. The clinical and ethological literature on starvation overriding fear:
    • Foraging-under-predation models (Lima & Dill 1990 and successors)
    • Clinical: anorexia nervosa as a failure of this override (drive does not acquire override authority – explanatory question for the architecture)
    • Clinical: hyperphagic conditions (Prader-Willi, hypothalamic damage) as pathological excess of override
    • The phenomenology of severe hypoglycaemia / hypoxia: which streams intensify vs which suppress

Architectural questions the lit-pull should help answer

  1. Single broadcast vs multi-target competition. Does a single homeostatic neuromodulator (orexin is the leading candidate) gain-modulate multiple streams simultaneously, or is the override mediated by point-to-point projections that each carry their own copy of the homeostatic signal? The former predicts a regulator-layer architecture (parallel to SD-036’s GABA layer); the latter predicts per-target wiring without a regulator.

  2. Threshold vs continuous. Does override authority appear gradually as drive accumulates, or does it cross a threshold and snap on? The latter would be architecturally cleaner and matches the clinical phenomenology of “I just couldn’t keep refusing food / stop drinking water.” The former matches the neuroeconomics literature on graded value.

  3. Symmetry across drives. Is the override mechanism the same for hunger, thirst, hypoxia, sleep deprivation, etc., or does each homeostatic system have its own override pathway? Architectural parsimony favours shared; neurobiological evidence may favour partly distinct (e.g. CO2-sensing for hypoxia is anatomically separable from glucose-sensing for hunger).

  4. Does the override AMPLIFY z_harm or REPLACE its arbitration weight? The user observation suggests amplification – hunger sharpens dread, not replaces it. This would predict that under starvation the agent becomes more threat-sensitive, not less, but also more willing to act despite threat (because both signals are amplified and the action threshold is the difference). This is a substantively different architecture from “drive overrides threat” and the lit-pull should be alert to which model the biology supports.

  5. What is the bridge to z_goal seeding (SD-012)? Currently SD-012 requires benefit_exposure > 0 to seed z_goal. Under override, does drive directly seed z_goal (skipping benefit_exposure), or does override force the agent into exploratory action that creates benefit_exposure, which then seeds z_goal via the normal pathway?

Output structure

Standard targeted_review_*/ format. Suggested directory: evidence/literature/targeted_review_homeostatic_override/

Per-paper records as usual. After the pull, write a short synthesis note flagging:

  • Which architectural question(s) each paper addresses
  • Which of the five questions above remain underdetermined and need additional pulls
  • Whether the evidence supports registering a new SD/MECH cluster for the override mechanism (and if so, draft proposed claim text)

Estimated scope: ~10-15 papers, single session.

Notes for the agent doing the pull

  • The user is a consultant psychiatrist who deals clinically with both ends of the override-failure spectrum (anorexia nervosa = override-deficient; hyperphagia = override-excessive). Use precise clinical terminology.
  • The architectural reading explicitly expects the override to be a broadcast neuromodulator – be alert to evidence that contradicts this expectation, not just evidence that supports it.
  • Connect to existing REE memory entries on homeostasis and drive: SD-012 (drive seeding), MECH-186/187/188 (serotonergic regulatory layer for the goal pipeline), SD-036 (GABAergic decay regulator). The hypothesised override layer is candidate third regulatory layer alongside 5-HT and GABA, plausibly orexin-mediated.
  • The exemplar that motivated this pull is V3-EXQ-471 (fishtank visualization, 2026-04-21 to 2026-04-22). Worth re-reading the trace summary in psychiatric_failure_modes.md “Catatonia, Subtype II” before starting.

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