Brain signals reflect the handled activities and controlling behavior of the brain or the influence of the received information from other body parts either sensing or internal organs. Brain Computer Interfacing provides a channeling facility between brain and external equipment.
BCI applications have attracted the research community. Several studies have been presented in this paper regarding the growing interest in BCI application fields such as medical, organizational, transportation, games and entertainment, and security and authentication fields. It also demonstrates the various devices used for capturing brain signals.
These recording devices are divided into two main categories: invasive and non-invasive. Invasive category, which requires implanting surgery, is usually needed for critical paralyzed situations because of their higher accuracy rates achieved either spatially or temporally. On the other hand, the non-invasive category, as mentioned previously, has been widely spread in other application fields due to its advantages over the invasive one. Other challenges and issues posed as a result of utilizing brain signals have also been discussed along with some solutions offered by different algorithms at various BCI processing components.