Cerebral specialization and interhemispheric communication: Does the corpus callosum enable the human condition?

Michael S. Gazzaniga wrote this at the Center for Cognitive Neuroscience at Dartmouth College, by which point he was one of the founders of the field he had named, with four decades of split-brain work behind him. It is his own synthesising review of that programme, the place where the interpreter is defined at length for a research audience.

The paper appeared in 2000 as an invited review in Brain, one of the senior peer-reviewed neurology journals, running to more than thirty pages. Its argument has two moves: that the split-brain evidence shows the cortex to be a patchwork of specialised, lateralised modules, and that the corpus callosum is what let those specialisations evolve, by freeing one hemisphere to develop new functions while the other kept the old capacity. The unity a person feels over that modular machinery, he argues, is produced by the left hemisphere's interpreter, which keeps a running narrative that makes the self feel coherent.

This sits as a secondary, synthesising review, drawing decades of primary experiments — including the 1978 interpreter work — into one framework. It crosses into the black-box topic: the device Gazzaniga describes, which constructs theories to explain events it has no direct access to, is confabulation given a neuroanatomy.

Gazzaniga's stake is the framework itself. This is an advocacy piece for his own theory — the modular brain unified by a left-hemisphere narrator — written by its author rather than an outside assessor, so the confidence of the synthesis is part of what a reader weighs against it.