Overfitting in large neural networks occurs when the model becomes too specialized in the training data, developing complex dependencies that do not generalize well to unseen data. This can happen when the model has too many parameters or is trained for too long, leading it to learn noise and irrelevant information in the dataset.
The dropout technique mitigates overfitting by randomly deactivating a portion of the neural network's neurons during training. This prevents neurons from relying too heavily on specific features or other neurons, forcing them to learn more generalized representations. As a result, the model becomes more robust and less prone to overfitting the training data.
The probability of deactivating neurons in dropout is typically set between 0.2 and 0.5. This means that during each training iteration, a fraction of the input units (neurons) is set to zero with the specified probability3. This helps to prevent overfitting by encouraging the network to learn robust representations and feature generalization.