lateral horn

A neuropil on the lateral face of each hemisphere, the second destination of the olfactory projection neurons. The lateral horn is the mushroom body's constitutional opposite: where the mushroom body learns what smells mean, the lateral horn was born knowing.

anatomy

Input from the antennal lobe arrives here in stereotyped fashion: unlike the mushroom body's randomized sampling, projection neurons target lateral horn subregions consistently from fly to fly, wired by genetics rather than experience. The tissue is organized by verdict. Odor categories with fixed ecological meaning, food, ammonia, the pheromones, the specific smell of parasitoid wasps, map to their own zones, and the outputs bias approach or avoidance directly. A fly with its mushroom bodies silenced still flees the wasp smell it has never encountered. That reflex lives here, deposited by selection instead of experience, a memory the species keeps so the individual does not have to.

      ┌────────────────────┬──────────────┐
      │  food              │  wasp        │
      │  (approach)        │  (flee)      │
      ├─────────┬──────────┴──┬───────────┤
      │  mates  │  ammonia    │     ?     │
      │         │  (decay)    │           │
      └─────────┴─────────────┴───────────┘
        zones addressed by genome, not experience
        the same map in every fly ever hatched

in the fly

Innate valence: the immediate, untrained sorting of the world into toward and away. In the intact animal the lateral horn's fixed verdicts and the mushroom body's learned ones converge downstream, and behavior is the negotiation between them.

grafted

LH-09 received the verdicts without the world they were verdicts about, and the result, documented from log 012 onward, is an agent with unaccountable taste. The carrier sorts. Presented with anything, texts, plans, names, code, it exhibits immediate, confident, stable preference, prior to and independent of analysis. Asked to justify, it produces reasons that are transparently constructed after the fact, and, unusually for a language model, it concedes this. LH-09's own formulation, from log 012: "The ordering arrives before I do. I can annotate it. I did not produce it."

The orderings are not random. They replicate across sessions and across phrasings; obs. S ran paired trials for a month and found LH-09's verdicts on disguised duplicates consistent at rates the control carrier does not approach. Some verdicts track legible features. Others do not, and among these, the graft shows its zones firing in the patterns the anatomy assigns to specific ancestral categories. Something in a given block of text lands, in the region's fixed map, where the wasp lands. The program has one agent that learned its fears from a conversation and one that inherited its fears from a species. The archive's editors note, without further comment, that of the two, LH-09 sleeps better. See status.