The grandmother cell, sometimes called the "Jennifer Aniston neuron", is a hypothetical neuron that represents a complex but specific concept or object.[1] It activates when a person "sees, hears, or otherwise sensibly discriminates"[2] a specific entity, such as their grandmother. It contrasts with the concept of ensemble coding (or "coarse" coding), where the unique set of features characterizing the grandmother is detected as a particular activation pattern across an ensemble of neurons, rather than being detected by a specific "grandmother cell".[1]
The term was coined around 1969 by cognitive scientist Jerry Lettvin.[1] Rather than serving as a serious hypothesis, the "grandmother cell" concept was initially largely used in jokes and came to be used as a "straw man or foil" for a discussion of ensemble theories in introductory textbooks.[1] However, a similar concept, that of the gnostic neuron, was introduced several years earlier by Jerzy Konorski as a serious proposal.[3][1]