Why does a neural network need an activation function?

?the activation function breathes non-linearity into networks.
Geoffrey Hinton

How It Works:

Activation functions transform a neuron?s weighted sum into a nonlinear output, enabling networks to approximate complex patterns instead of just linear relationships.

Key Benefits:

  • Expressivity: Learns intricate mappings from inputs to outputs.
  • Feature hierarchy: Builds richer representations layer by layer.
  • Versatility: Different functions suit different tasks.

Real-World Use Cases:

  • Image classification: ReLU in convolutional nets for object detection.
  • Binary classification: Sigmoid at output layers for probability scores.

FAQs

What if I omit activation?
Can I mix functions?