Axonal delay dispersion decides whether a neuron detects an event or a sequence, and predicts cortical column diameter
How wire spacing in the brain decides what neurons recognize
A neuron's ability to detect a single synchronized burst versus a specific sequence of inputs depends on one physical property: how spread out the conduction delays are on its receiving branches. The researchers show that this single measurement—which maps onto the anatomical difference between myelinated and unmyelinated connections in the brain—acts as a computational switch, and that this same property predicts the actual diameter of cortical columns, one of the brain's fundamental structural units.
This work reveals that anatomy directly determines what computations neurons can perform. Because the brain's wiring can now be understood as encoding specific detection capabilities, neuroscientists can predict what kinds of signals a region of cortex can process just by measuring its physical structure. It also suggests that the brain's choice between myelinated and unmyelinated connections isn't simply about speed—it's about switching neurons between fundamentally different modes of information processing.