The document discusses brain-computer interfaces (BCIs), which allow humans to control computers using only their brain activity. BCIs work by analyzing electroencephalography (EEG) signals from the brain related to mental decisions and movements. Researchers have used BCIs to control prosthetic devices and robots. Commercial BCIs are emerging for gaming applications. Future work aims to improve BCI accuracy, shorten training times, and develop non-invasive recording methods like functional magnetic resonance imaging (fMRI) and near-infrared spectroscopy (NIRS).