Jerome Ysroael Lettvin (February 23, 1920 – April 23, 2011), often known as Jerry Lettvin, was an American cognitive scientist, and Professor of Electrical and Bioengineering and Communications Physiology at the Massachusetts Institute of Technology (MIT). He is best known as the lead author of the paper, "What the Frog's Eye Tells the Frog's Brain" (1959), one of the most cited papers in the Science Citation Index. He wrote it along with Humberto Maturana, Warren McCulloch and Walter Pitts, and in the paper they gave special thanks and mention to Oliver Selfridge at MIT. Lettvin carried out neurophysiological studies in the spinal cord, made the first demonstration of "feature detectors" in the visual system, and studied information processing in the terminal branches of single axons. Around 1969, he originated the term "grandmother cell" to illustrate the logical inconsistency of the concept.