his shelf is about the organ the institute's other subjects run on. It starts with a stain and a drawing, follows the argument about whether nerve cells touch, and comes forward to the wiring diagrams and the networks that now borrow, and sometimes return, its ideas. Each page keeps the institute's rules: real people, real papers, every citation checked; paraphrase marked; passages of our own labelled.

Cajal's drawing of the circuits of the hippocampus Cajal, drawing, 1911. Public domain, via Wikimedia Commons. credits

the questions

	The engram — where a memory is
	Predictive processing — the brain as a guessing machine
	Connectomics — the wiring diagram
	Brains and models compared — when a network predicts neurons

people

	Santiago Ramón y Cajal — the neuron, drawn
	Charles Sherrington — the synapse
	Warren McCulloch — the logic of neurons
	Walter Pitts — the logic of nets, and the break
	Jerome Lettvin — the frog
	Karl Lashley — looking for the engram
	Donald Hebb — cell assemblies
	Wilder Penfield — the map
	Brenda Milner — H.M.
	Roger Sperry — the split brain

primary documents

	Harlow, 1868 — the iron bar
	Sherrington, 1906 — The Integrative Action of the Nervous System
	Hodgkin and Huxley, 1952 — the squid axon
	Scoville and Milner, 1957 — H.M.
	Lettvin and colleagues, 1959 — what the frog's eye tells the frog's brain
	Hubel and Wiesel, 1959 — the cat's visual cortex

longer reading

	The break — Wiener, McCulloch and Pitts
	The thesis that wasn't — a speculative essay, labelled as such
	Phineas Gage — the story and the stories
	The little man — Penfield's homunculus
	Timeline: neuroscience — 1873 to 2025
	Annotated: the nervous system —
	Annotated: Pitts and the frog —

in the tour: a wing called "The nervous system" runs from a stained slide to a boarding house, behind a door nobody signposted ···