Grandmother cell

The grandmother cell, sometimes called the "Jennifer Aniston neuron", is a hypothetical neuron that represents a complex but specific concept or object. It activates when a person "sees, hears, or otherwise sensibly discriminates" 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".

The term was coined around 1969 by cognitive scientist Jerry Lettvin. 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. However, a similar concept, that of the gnostic neuron, was introduced several years earlier by Jerzy Konorski as a serious proposal.