Digital Selection and Analogue Amplification Coexist in a Cortex-Inspired Silicon Circuit

Nature 405, 947 — 951 (2000). There were two errors in the reference list of this paper. Reference 22 should have been: Sharpeshkar, R. Analog versus digital: extrapolating from electronics to neurobiology. Neural Comput. 10, 1601–1638 (1998). Also, the following reference was omitted but should have been cited along with refs 5–9 at the top of page 948.