LSTM stands for Long Short-Term Memory. When we use this term most of the time we refer to a recurrent neural network or a block (part) of a bigger network.
LSTM (Long Short-Term Memory)
LSTM is a specialized type of Recurrent Neural Network (RNN) architecture designed to address the vanishing gradient problem that affects standard RNNs. Introduced by Hochreiter and Schmidhuber in 1997, LSTMs can learn long-term dependencies in sequential data.
Key Characteristics
- Memory Cell: Contains a cell state that acts as a conveyor belt of information flowing through the network
- Gating Mechanism: Uses three gates (input, forget, and output) to regulate information flow
- Long-term Dependencies: Effectively captures relationships between elements separated by many time steps
- Gradient Control: Special architecture prevents vanishing/exploding gradients common in vanilla RNNs
Applications
- Natural Language Processing (text generation, machine translation)
- Time Series Analysis and Prediction
- Speech Recognition
- Music Generation
- Video Analysis
- Anomaly Detection in sequential data
Technical Details
LSTMs process sequences through a chain of repeating modules. Each module contains:
- Forget Gate: Decides what information to discard from cell state
- Input Gate: Controls what new information enters the cell state
- Output Gate: Determines what parts of the cell state are output
Their ability to selectively remember or forget information makes LSTMs particularly effective for sequential data with long-range dependencies.
Learning Resources
Foundational Papers
- Long Short-Term Memory (Original Paper) by Hochreiter & Schmidhuber
- LSTM: A Search Space Odyssey by Greff et al.
Online Tutorials
- Understanding LSTM Networks by Christopher Olah
- The Unreasonable Effectiveness of Recurrent Neural Networks by Andrej Karpathy
Courses
- Deep Learning Specialization (Course 5) on Coursera by Andrew Ng
- Natural Language Processing with Deep Learning by Stanford University
Books
- "Deep Learning" by Goodfellow, Bengio, and Courville (Chapter on Sequence Modeling)
- "Hands-On Machine Learning with Scikit-Learn, Keras, and TensorFlow" by Aurélien Géron