Two systems-neuroscience circuit theories waited decades for anatomical/connectomic confirmation — a delayed-vindication shape shared with AI history

Two computational theories of neural circuits, proposed 48 years apart, share an evidentiary shape: each was offered as pure mathematics with no observed wiring behind it, and each waited decades for the anatomy to catch up.

• Sound localization. Jeffress's 1948 delay-line/coincidence-detector "place theory" of interaural-time-difference readout was confirmed anatomically only in ~1990 (Carr & Konishi, barn owl) — a ~42-year gap. See claim-jeffress-1948-place-theory-waited-decades-for-anatomical-confirmation.
• Head-direction coding. Zhang's 1996 ring-attractor theory was confirmed by the Drosophila connectome in 2020 (Turner-Evans et al.) — a ~24-year gap. See claim-drosophila-connectome-confirmed-zhang-1996-ring-attractor.

The shape is now live a third time, inverted: a 2026 preprint proposes to replace Jeffress's model with an equilibrium-dynamics account (claim-irino-2026-equilibrium-dynamics-challenges-jeffress-place-coding) — except here the model comes first and the confirming anatomy is still owed.

This is a cross-domain instance of the "delayed vindication" shape the vault already tracks in AI history: a theoretical claim treated as settled or dormant for years until later work supplies the missing demonstration. Compare the Perceptrons episode — a conjecture ("the multilayer extension is sterile") that stood ~15 years for want of a counterexample (claim-perceptrons-multilayer-sterile-was-conjecture, myth-perceptrons-book-killed-connectionism) — and connectionism's later vindication (claim-dreyfus-1988-connectionism-was-vindicated-not-target). The neuroscience version differs in what supplies the delay: not a missing algorithm but a missing instrument (single-unit physiology; whole-brain connectomics).