self-gating
**Self-Gating** is a **mechanism where a neural network layer gates its own activations using a function of the same input** — the input multiplied by a sigmoid (or similar gate) of itself, allowing the network to selectively amplify or suppress its features.
**How Does Self-Gating Work?**
- **Formula**: $y = x cdot sigma(Wx + b)$ where $sigma$ is a gate function (sigmoid, tanh).
- **Swish**: The simplest self-gating: $x cdot sigma(x)$ (no learned gate parameters).
- **SE-Net**: Self-gating via channel attention: learn per-channel gates from global statistics.
- **GLU**: Gated Linear Unit splits input into two halves — one gates the other.
**Why It Matters**
- **Expressiveness**: Self-gating allows multiplicative interactions, which are more expressive than additive transformations.
- **Feature Selection**: The gate learns to suppress irrelevant features and amplify important ones.
- **Foundation**: Self-gating is the core principle behind Swish, GLU, SwiGLU, and SE-Net.
**Self-Gating** is **the input controlling its own flow** — a powerful mechanism where features decide their own importance.