Wearable electronic devices and brain-computer interface (BCI) systems featuring biocompatible nanoparticles for the stimulation and recording of neural activity, signal capture and transmission, thought-controlled digital device interaction, enhanced human-machine integration, real-time brain activity monitoring, cognitive function enhancement, cognitive rehabilitation therapies, and improved accessibility for individuals with physical limitations; Downloadable and recorded software for use with brain-computer interface (BCI) devices and systems, enabling non-invasive neural activity stimulation and recording, signal capture and transmission, thought-controlled digital device interaction, enhanced human-machine integration, real-time brain activity monitoring, cognitive function enhancement, cognitive rehabilitation therapies, and improved accessibility for individuals with physical limitations; Downloadable mobile applications for use with brain-computer interface (BCI) devices and systems, facilitating non-invasive neural activity stimulation and recording, signal capture and transmission, thought-controlled digital device interaction, enhanced human-machine integration, real-time brain activity monitoring, cognitive function enhancement, cognitive rehabilitation therapies, and improved accessibility for individuals with physical limitations; Downloadable software development kits (SDKs) for creating applications that utilize brain-computer interface (BCI) technology for neurological treatment and human-machine interaction