Math Digest# Mathematical Digest

### Short Summaries of Articles about Mathematics

in the Popular Press

"Location Neurons Do Advanced Math," by Laura Helmuth.

*Science,*13 April 2001.

Barn owls, who hunt in the dark, have a precise way of locating preyby sound. This article---the cover story for this issue---reports on research that confirms that barn owls' auditory neurons, instead ofperforming like OR-gates (using addition), actually perform like AND-gates,that is, they "multiply." This "multiplication" makes such a neuron "morelike a little processor; computationally it's much more powerful [thana neuron that adds]," according to Christof Koch of Caltech. The full articlereferred to by Helmuth, written by José Luis Peña and MasakazuKonishi, is on page 249 of the same issue.

*--- Mike Breen*