Hebbian Memory

Neurons that fire together, wire together.

Hebbian learning is one of the oldest and most fundamental concepts in neuroscience. Donald Hebb proposed in 1949 that when two neurons are activated simultaneously, the connection between them strengthens.

The Core Principle

The basic Hebbian learning rule can be expressed as:

Where is the learning rate, and , are the activations of neurons and .

Connections

This idea connects to Spaced Repetition — reviewing material at increasing intervals leverages the strengthening of neural pathways over time.

It also relates to how Associative Memory works in both biological and artificial systems.

Decay

Without reinforcement, connections weaken. This is the forgetting curve in action — a form of anti-Hebbian decay that prunes unused pathways.