Communication is a fundamental human right that enables the transmission and reception of information, essential for social and educational inclusion. However, children and young people with additional support needs, due to neurological or motor diseases, face severe communication barriers. Technologies such as Augmentative and Alternative Communication (AAC) and Brain-Computer Interfaces (BCI) offer solutions to overcome these barriers, providing alternative means of expression and interaction. This chapter presents the concept of BCI and explores how spontaneous brain activity in response to stimuli can be used to develop effective communication methods for individuals facing severe communication difficulties due to neurological conditions such as cerebral palsy and multiple sclerosis. The study adopts an action-research approach, using the Unicorn Hybrid Black Speller system. The results indicate that, although there are technical challenges in calibrating and using the systems, there is significant potential for their application in educational and social contexts, improving the autonomy and quality of life of users.