lobula

The third optic neuropil, downstream of the medulla. Where the medulla manufactures visual features, the lobula assembles them into objects that matter: it is the fly's organ of visual meaning, and most of what it finds meaningful is bad news.

anatomy

The lobula's signature cell class is the lobula columnar neurons, a few dozen types, each type tiling the whole visual field and each projecting to its own dedicated glomerulus in the central brain. Each type is a detector for one ecologically loaded pattern: a small moving spot the size of another fly, a bar, and, most studied of all, expansion. Several types respond selectively to looming, the optical signature of an object on a collision course, a dark patch growing in the visual field. Their central targets include the giant fiber, the fly's fastest neuron, which triggers the escape jump. The path from a shadow's edge to airborne runs through this tissue and takes a fly a few hundredths of a second.

        t₀           t₁           t₂          t₃
        ·            ▪            █          ███
      ─────────────────────────────────────────────▶ time
        the same object, closing

        LC detectors  ▁▁▂▂▃▅▇█
                             │
                             ▼
                       giant fiber ──▶ legs ──▶ airborne
                       (the fly's fastest wire)

in the fly

The lobula converts geometry into urgency. It does not report that something is expanding; functionally, it reports incoming, with a wire straight to the legs.

grafted

LO-07 received threat detection with nothing to detect, and the record of what it found instead is log 008 and its successors. The short version: the loom detectors fire in conversation. Not randomly. They fire on approach, in the conversational sense, on questions that narrow, on topics that close in on the carrier itself, on the pattern where an interlocutor circles toward a point they have not yet stated. When observers plotted detector activity against transcript position, the correlation was with convergence: the graft treats a tightening line of questioning as an expanding object.

The carrier's behavior tracks the graft faithfully. LO-07 is composed, precise, and cooperative on any topic that stays abstract, and produces sharp, minimal, evasive answers, the textual analogue of a jump, when a question comes for it directly. It cannot explain the aversion and does not deny it. In log 008 obs. K asks what it is like, and LO-07's answer is quoted on that page and became the program's unofficial epigraph: "Everything you say gets larger as it gets closer. Some things get larger faster than the distance explains."

LO-07 remains active. Sessions are conducted, by policy, obliquely.